Morphological and Morphometric Characteristics of the Nasopalatine Canal in Dentate and Edentulous Patients: A Cone-Beam Computed Tomography Cross-Sectional Study

Morphological and Morphometric Characteristics of the Nasopalatine Canal in Dentate and Edentulous Patients: A Cone-Beam Computed Tomography Cross-Sectional Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Morphological and Morphometric Characteristics of the Nasopalatine Canal in Dentate and Edentulous Patients: A Cone-Beam Computed Tomography Cross-Sectional Study Cam Hong, Nhung Nguyen, Quynh Ngo, Tram Nguyen, Ngoc Nguyen, Tu Doan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9187671/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Anatomical changes associated with tooth loss may alter the morphology and dimensions of the nasopalatine canal, potentially affecting implant planning. However, comparative evidence between dentate and completely edentulous maxillae remains limited. This study aimed to evaluate and compare the morphological and morphometric characteristics of the nasopalatine canal and the anterior bone region in dentate and completely edentulous patients via cone-beam computed tomography (CBCT). Methods Cross-sectional CBCT analysis was performed on 108 patients (54 dentate maxillae and 54 completely edentulous maxillae). Morphometric parameters of the nasopalatine canal and the bone anterior to the canal were measured in the axial, sagittal, and coronal planes. Interobserver reliability was assessed via intraclass correlation coefficients (ICCs) and Cohen’s kappa. Intergroup comparisons were conducted via regression models adjusted for age and sex. Results Compared with the edentulous group, the dentate group presented a significantly greater nasopalatine canal length (mean difference: 1.66 mm; 95% CI: 0.42–2.90; p = 0.009), whereas canal angulation was smaller (− 6.47°; 95% CI: −9.93 to − 3.00; p < 0.001). On sagittal images, the middle and inferior canal widths were significantly smaller in the dentate group (ratios of means: 0.79 and 0.80; p < 0.001), whereas the superior width was not different. Similarly, on axial views, the middle and inferior horizontal canal widths were reduced in the dentate group. The bone region anterior to the nasopalatine canal in the dentate individuals presented greater buccal crestal length (4.66 mm; p < 0.001) and greater bone width at 1 mm and 6 mm apical to the crest (ratios: 1.65 and 1.24; p < 0.001). Morphologically, the Y-shaped canal configuration predominated in dentate patients (51.9%), whereas the single-canal configuration was more common in the edentulous group (64.8%). On the sagittal plane, cylindrical morphology was significantly more common in dentate individuals (odds ratio (OR) = 3.68; 95% CI: 1.56–9.00). Conclusions Edentulous patients exhibit wider and more angulated canals but reduced canal length and anterior bone volume. These findings highlight the importance of individualized CBCT evaluation to optimize implant planning and minimize surgical complications in the anterior maxilla. Trial registration: Not applicable nasopalatine canal incisive canal cone-beam computed tomography edentulous maxilla dental implants Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Background Dental implant therapy has become a well-established and highly reliable method for replacing missing teeth, especially in areas with strict functional and aesthetic requirements, such as the anterior maxilla [ 1 , 2 ]. However, the anterior maxilla presents significant anatomical challenges. It is often affected by progressive alveolar bone loss following tooth extraction and contains several critical neurovascular structures. One important anatomical feature to consider during preoperative implant planning is the nasopalatine canal, which must be carefully assessed [ 3 ]. The nasopalatine canal is a midline anatomical structure of the maxilla that contains the nasopalatine nerve and accompanying vascular branches responsible for sensory innervation of the anterior palate. Clinically, the morphology, dimensions, trajectory, and spatial relationship of the nasopalatine canal with the surrounding anterior maxillary bone exhibit substantial interindividual variability. Such anatomical variations may directly influence the position and angulation of implant placement and may increase the risk of complications, including sensory disturbances, intraoperative hemorrhage, impaired osseointegration, or the development of nasopalatine duct cysts [ 4 ]. Moreover, in cases of severe alveolar ridge resorption following complete edentulism of the maxilla, the nasopalatine canal and its surrounding structures have increasingly been utilized as anchorage sites for implant placement [ 5 , 6 ]. Comprehensive assessment of the nasopalatine canal via cone-beam computed tomography (CBCT) is therefore essential for accurate planning of implant treatment, enabling clinicians to determine the most appropriate therapeutic approach while minimizing the risk of complications associated with implant placement in this region [ 7 ]. Numerous CBCT-based studies have investigated the anatomical characteristics and morphometric parameters of the nasopalatine canal [ 8 – 13 ]. However, the majority of these studies have focused primarily on canal morphology in dentate populations [ 8 , 9 ] or in edentulous patients alone [ 11 ]. Other investigations have compared partially edentulous individuals with dentate subjects [ 8 , 12 , 13 ]. In contrast, research specifically examining the nasopalatine canal in completely edentulous patients remains relatively scarce, and the few available studies are generally based on limited sample sizes [ 12 ]. Despite the increasing clinical importance of this anatomical region, the available literature remains limited regarding comprehensive evaluations of the nasopalatine canal in completely edentulous patients, particularly studies that directly compare these characteristics with those observed in dentate individuals. Therefore, the present study aimed to investigate and compare the anatomical features of the nasopalatine canal via CBCT in two distinct patient populations: individuals with a completely edentulous maxilla and those with preserved dentition. Methods A descriptive cross-sectional study was performed using CBCT datasets obtained from 108 patients who underwent imaging at a private hospital between April 2024 and December 2025. The CBCT records were categorized into two groups according to dental status. The edentulous group consisted of 54 CBCT scans from patients with complete maxillary edentulism, whereas the dentate group included 54 CBCT scans from patients retaining natural dentition in the anterior maxillary region. Ethical approval for this study was obtained from the Institutional Ethics Committee in Biomedical Research at the University of Health Sciences, Vietnam National University, Ho Chi Minh City, under approval number 02/QD-HDDD. Maxillae demonstrating the presence of natural teeth or residual root fragments within the anterior maxillary region were classified into the dentate group. Conversely, maxillae presenting with complete edentulism, or those retaining only a limited number of teeth but lacking anterior maxillary teeth, were assigned to the edentulous group. Sample selection CBCT scans, including cases affected by artifacts, scattering, or incomplete visualization of the region of interest, were excluded if the image quality was insufficient for accurate evaluation. Images showing previously placed dental implants in the nasopalatine canal region or in the maxillary central incisor area were also excluded. In addition, scans demonstrating prior bone grafting procedures in the anterior maxilla were not considered. Patients presenting with radiographic evidence of pathological conditions, such as tumors or cystic lesions involving the nasopalatine canal or the maxillary incisor region, were excluded. Furthermore, CBCT images indicating bone defects in the nasopalatine canal region attributable to pathology, trauma, or previous surgical interventions within the area of interest were not included in the study. CBCT scans were retrieved from the institutional database. After applying predefined inclusion and exclusion criteria, eligible scans were selected for analysis (Fig. 1 ). Sample size calculation Sample size estimation was performed to detect a clinically meaningful difference in the morphometric parameters of the nasopalatine canal between the dentate and edentulous groups. The calculation was based on data from a previous study [ 7 ] reporting mean values of 2.73 mm and 2.77 mm with standard deviations of 1.37 mm and 1.40 mm, respectively. The pooled standard deviation was therefore estimated at 1.385 mm. Assuming a minimum detectable difference of 0.75 mm, a two-sided significance level of 0.05, and a statistical power of 80%, the required sample size was calculated via the following formula for comparing two independent means: Z α/2 = 1.96; Z β = 0.84, SD p = 1.385 and δ = 0.75. On the basis of these parameters, the required sample size was 54 participants per group (108 total). The corresponding standardized effect size (Cohen’s d) was 0.54, indicating a moderate effect. This sample size provides adequate statistical power to detect clinically relevant differences in the morphometric characteristics of the nasopalatine canal between the two study groups. Radiographic imaging acquisition CBCT examinations were performed via a dedicated cone-beam computed tomography unit (NewTom GiANO HR; Cefla, Imola, Italy). All scans were acquired via standardized imaging parameters in accordance with the manufacturer’s recommendations. The acquisition protocol included a voxel size of 0.16 mm, a tube voltage of 90 kVp, and a tube current of 15 mA. The exposure time was set at 16.8 seconds, and a field of view (FOV) of 10 × 10 cm was selected to ensure complete visualization of the anterior maxillary region, including the nasopalatine canal and surrounding anatomical structures. During CBCT scanning, patients were positioned in an upright posture with the chin resting on the chin support and the head stabilized to minimize motion artifacts. The radiology technician ensured proper alignment by orienting the patient according to the Frankfort horizontal plane and adjusting the reference beams to pass through the canine region. After image acquisition, the datasets were reviewed to confirm image quality and completeness. In cases where image acquisition errors or data storage failure occurred, the scan was repeated. All the CBCT datasets were exported and archived in Digital Imaging and Communications in Medicine (DICOM) format for subsequent analysis. Image orientation and standardization Prior to measurement, all the CBCT datasets were standardized to ensure consistent anatomical orientation. The images were reoriented using the Frankfort horizontal plane as the reference plane. The sagittal plane was adjusted to pass through the anterior nasal spine, whereas the coronal plane was aligned perpendicularly to the sagittal plane. This standardized orientation minimized measurement bias and ensured consistency across all evaluated scans. Morphometric measurements and anatomical assessments of the nasopalatine canal and the bone region anterior to the canal were performed on axial, sagittal (sections passing through the anterior nasal spine), and coronal planes. All morphometric measurements were subsequently performed via the built-in digital measurement tools of the analysis software (Blue Sky Bio version 4.13, Blue Sky Bio, Libertyville, IL, USA), and values were recorded in millimeters (mm). CBCT morphometric measurements Morphological and morphometric characteristics of the nasopalatine canal On the sagittal section passing through the anterior nasal spine (ANS), the sagittal canal width was measured at three levels—inferior, middle, and superior—parallel to the reference plane. The canal width measured at the nasal opening and palatal opening corresponded to the sagittal canal superior width and the sagittal canal inferior width, respectively. On the same sagittal section, the canal length was defined as the linear distance extending from the superior plane to the inferior plane along the longitudinal axis of the canal. The nasopalatine canal angle was determined as the angle formed between the canal axis and the reference plane. Figure 2 a provides a schematic representation of the measurement procedures for the evaluated variables. The horizontal canal width was defined as the maximum canal width measured on axial sections at the superior, middle, and inferior levels (Fig. 3 ). CSW, horizontal superior canal width; CMW, horizontal middle canal width; CIW, horizontal inferior canal width. The morphology of the nasopalatine canal was classified according to its appearance on the sagittal plane into four categories: cylindrical, funnel-shaped, hourglass-shaped, and banana-shaped (Fig. 4 ). On the coronal plane, canal morphology was categorized into three configurations: single and broad, two parallel canals, and Y-shaped canals (Fig. 5 ). (A) Cylindrical; (B) funnel shaped; (C) hourglass shaped; (D) banana shaped. (A) Single and broad canal; (B) two parallel canals; (C) Y-shaped canal. Buccal bone region of the nasopalatine canal For the same sagittal section passing through the ANS, the buccal bone height was measured as the vertical distance from the alveolar crest to the nasal floor, perpendicular to the reference plane. The width of the buccal bone was measured at 1 mm and 6 mm apical to the alveolar crest toward the nasal floor (Fig. 2 b). The mean cancellous bone density in this region was measured at three locations along the vertical axis, corresponding to the superior, middle, and inferior thirds of the bone. Bone density values were recorded in grayscale density values (GSVs). Observer calibration and measurement reliability All morphometric measurements were independently performed by two calibrated examiners with experience in CBCT image analysis. Prior to the formal evaluation, both examiners underwent a calibration session to standardize the identification of anatomical landmarks and the measurement protocol within the analysis software. To assess intra- and interobserver reliability, 30 CBCT scans were randomly selected from the total dataset, including 15 scans from the dentate group and 15 scans from the edentulous group. These cases were re-evaluated independently by both examiners following the same measurement protocol. To assess the measurement reliability of the quantitative variables, the ICC was calculated via representative parameters, including the sagittal canal middle width, horizontal canal middle width, anterior bone height, and buccal bone width at 6 mm apical to the alveolar crest. For the qualitative variable of sagittal canal shape, interobserver agreement was evaluated via Cohen’s kappa coefficient. The reliability coefficients were interpreted according to commonly accepted thresholds, where higher ICC and kappa values indicate stronger agreement between measurements. Statistical analysis All the statistical analyses were performed via R statistical software (R Foundation for Statistical Computing, Vienna, Austria). Continuous variables were assessed for normality via the Shapiro–Wilk test and graphical inspection (histograms and Q–Q plots). Intergroup comparisons of morphometric parameters of the nasopalatine canal between the dentate and edentulous groups were conducted while adjusting for age and sex. Variables with approximately normal distributions were analyzed via analysis of covariance (ANCOVA) with linear models to estimate adjusted mean differences. Positively skewed variables were analyzed via generalized linear models (GLMs) with a gamma distribution and log link, and the results are reported as ratios of adjusted means. The magnitude of the intergroup differences was quantified via standardized effect sizes (Cohen’s d with Hedges’ correction) and partial eta squared (partial η²). The morphological characteristics of the nasopalatine canal on the coronal and sagittal planes were summarized as frequencies and percentages. Differences in distribution between groups were assessed via the chi-square test or Fisher’s exact test, followed by post hoc logistic regression to estimate ORs with 95% CIs for each configuration. Bonferroni correction was applied to account for multiple comparisons. A two-sided p value < 0.05 was considered statistically significant. Results ICC and Kappa The ICC values ranged from 0.791 to 0.905, demonstrating good to excellent interobserver reliability for all the CBCT measurements. Cohen’s kappa analysis demonstrated substantial interobserver agreement for the assessment of nasopalatine canal morphology in both imaging planes (coronal plane: κ = 0.789; sagittal plane: κ = 0.775; both p < 0.001). Participant characteristics A total of 108 CBCT scans from 108 patients (48 females and 60 males) were included in the analysis. The mean age of the participants in the edentulous group was 62.72 ± 10.23 years, whereas those in the dentate group had a mean age of 59.22 ± 10.20 years. Morphometric characteristics of the nasopalatine canal The length of the nasopalatine canal was significantly greater in the dentate group than in the edentulous group, with an adjusted mean difference of 1.66 mm (95% CI: 0.42–2.90; p = 0.009). In contrast, the angulation of the nasopalatine canal was significantly smaller in the dentate group, with an adjusted mean difference of − 6.47° (95% CI: − 9.93 to − 3.00; p < 0.001). On the sagittal plane, no significant difference was observed in the superior sagittal canal width between the two groups (ratio of means = 0.95, 95% CI: 0.80–1.12; p = 0.522). However, the middle sagittal canal width and inferior sagittal canal width were significantly smaller in the dentate group than in the edentulous group, with adjusted ratios of 0.79 (95% CI: 0.69–0.91; p = 0.001) and 0.80 (95% CI: 0.73–0.87; p < 0.001), corresponding to approximately 21% and 20% lower values, respectively. On the axial plane, the superior horizontal canal width did not differ significantly between the two groups (mean ratio = 1.10, 95% CI: 0.98–1.25; p = 0.122). In contrast, both the middle and the inferior horizontal canal widths were significantly smaller in the dentate group. The adjusted ratio of the means for the middle horizontal canal width was 0.85 (95% CI: 0.75–0.97; p = 0.017), whereas the inferior horizontal canal width showed an adjusted mean difference of − 1.04 mm (95% CI: − 1.46 to − 0.63; p < 0.001). The detailed results of the morphometric characteristics of the nasopalatine canal are presented in Table 1 . Table 1 Morphometric characteristics of the nasopalatine canal. Superior horizontal canal width Edentulous group (mean ± SD) (mm) Dentate group (mean ± SD) (mm) Estimate 95% CI P value Model 4.51 ± 1.34 4.92 ± 1.69 1.10 0.98 to 1.25 0.122 GLM Middle horizontal canal width 4.31 ± 1.15 3.70 ± 1.45 0.85 0.75 to 0.97 0.017 GLM Inferior horizontal canal width 4.83 ± 1.24 3.85 ± 0.87 -1.04 -1.46 to -0.63 < 0.001 LM Superior sagittal canal width 3.73 ± 1.51 3.49 ± 1.58 0.95 0.80 to 1.12 0.522 GLM Middle sagittal canal width 3.42 ± 1.15 2.74 ± 1.01 0.79 0.69 to 0.91 0.001 GLM Inferior sagittal canal width 4.72 ± 1.17 3.80 ± 0.85 0.80 0.73 to 0.87 < 0.001 GLM Length of the canal 9.63 ± 3.54 11.45 ± 2.88 1.66 0.42 to 2.90 0.009 LM Nasopalatine canal angle 120.39 ± 10.57 113.82 ± 7.43 -6.47 -9.93 to -3.00 < 0.001 LM GLM: generalized linear models, estimate: adjusted ratio of means. LM: linear models, estimate: adjusted mean difference. Morphometric characteristics of the bone anterior to the nasopalatine canal With respect to the bone anterior to the nasopalatine canal, the length of the buccal crestal bone was significantly greater in the dentate group than in the edentulous group, with an adjusted mean difference of 4.66 mm (95% CI: 3.23–6.09; p < 0.001). In contrast, bone density did not differ significantly between the two groups (mean ratio = 1.12, 95% CI: 0.98–1.27; p = 0.097). Similarly, the bone width measured 1 mm apical to the alveolar crest was significantly greater in the dentate group, with an adjusted ratio of means of 1.65 (95% CI: 1.35–2.02; p < 0.001), indicating an approximately 65% greater bone width than that in the edentulous group. The bone width measured 6 mm apical to the alveolar crest was also significantly greater in the dentate group (mean ratio = 1.24, 95% CI: 1.10–1.39; p < 0.001), corresponding to an approximately 24% increase relative to the edentulous group. The detailed results of the morphometric characteristics of the bone anterior to the nasopalatine canal are presented in Table 2 . Table 2 Morphometric characteristics of the bone anterior to the nasopalatine canal. Length of crestal buccal bone Edentulous group Dentate group Estimate 95% CI P value Model 13.91 ± 4.12 18.50 ± 3.12 4.66 3.23 to 6.09 < 0.001 LM The bone width measured 1 mm apical to the alveolar crest 2.12 ± 0.94 3.46 ± 2.13 1.65 1.35 to 2.02 < 0.001 GLM The bone width measured 6 mm apical to the alveolar crest 5.76 ± 2.03 7.06 ± 1.69 1.24 1.10 to 1.39 < 0.001 GLM Bone Density 915.76 ± 325.46 1039.02 ± 337.20 1.12 0.98 to 1.27 0.097 GLM LM: linear model; Estimate: adjusted mean difference. GLM: generalized linear model; estimate: adjusted ratio of means Effect size interpretation For the morphometric characteristics of the nasopalatine canal, canal length had a moderate effect (d = 0.52; partial η² = 0.08), whereas canal angulation had a moderate-to-large effect (d = − 0.73; partial η² = 0.12). Among the sagittal canal dimensions, the superior sagittal width had a trivial effect (d = − 0.13; partial η² = 0.01), whereas the middle and inferior sagittal widths had moderate-to-large (d = − 0.66; partial η² = 0.09) and large effects (d = − 0.92; partial η² = 0.16), respectively. For the horizontal canal measurements, the superior horizontal width had a small effect (d = 0.24; partial η² = 0.01), whereas the middle and inferior horizontal widths had moderate (d = − 0.55; partial η² = 0.07) and large effects (d = − 0.98; partial η² = 0.18). With respect to the bone anterior to the nasopalatine canal, the length of the buccal crestal bone had the greatest effect among all the variables (d = 1.27; partial η² = 0.29). The bone widths measured 1 mm and 6 mm apical to the alveolar crest also demonstrated large effects (d = 0.88; partial η² = 0.15 and d = 0.80; partial η² = 0.13, respectively). In contrast, bone density showed only a small effect (d = 0.31; partial η² = 0.04). Overall, the greatest anatomical differences between dentate and edentulous individuals were observed in terms of the buccal crestal bone length and inferior canal dimensions, whereas superior canal measurements and bone density had minimal effects. Morphological characteristics of the nasopalatine canal Table 3 presents the distributions of the morphological configurations of the nasopalatine canal. Coronal Plane Morphology On the coronal plane, the single canal configuration and the Y-shaped configuration were the two most frequently observed morphologies in both groups. In the dentate group, the Y-shaped configuration was the most prevalent pattern, accounting for 51.9% of the cases. In contrast, the edentulous group predominantly presented a single canal configuration (64.8%). The parallel double canal configuration was rarely observed and was identified only in the edentulous group (5.6%). The Y-shaped configuration was significantly more common in the dentate group than in the edentulous group (OR = 2.53; 95% CI: 1.08–6.11), indicating that dentate individuals were approximately 2.5 times more likely to exhibit this configuration. In contrast, the single canal configuration was not significantly different between the groups (p = 0.120). The parallel double-canal configuration, although detected only in the edentulous group, did not significantly differ (p = 0.243). Overall, these findings suggest that the greater prevalence of the Y-shaped configuration in dentate individuals contributed the most to the observed morphological differences between the two groups on the coronal plane. Sagittal plane morphology On the sagittal plane, the cylindrical configuration was the most common nasopalatine canal morphology observed in the overall sample. In the dentate group, the cylindrical shape accounted for 61.1% of the cases, followed by the funnel-shaped configuration (20.4%), the banana-shaped configuration (11.1%), and the hourglass-shaped configuration (7.4%). In contrast, the edentulous group demonstrated a more even distribution of canal morphologies, with relatively higher proportions of banana-shaped canals (24.1%) and hourglass-shaped canals (22.2%), although the cylindrical configuration remained the most frequent morphology (29.6%). Among the evaluated configurations, only the cylindrical shape demonstrated a statistically significant difference between the groups. Dentate individuals were approximately 3.7 times more likely to exhibit a cylindrical nasopalatine canal than edentulous patients were (OR = 3.68; 95% CI: 1.56–9.00). This association remained statistically significant after Bonferroni correction for multiple comparisons (adjusted p = 0.007). Conversely, the banana-shaped, hourglass-shaped, and funnel-shaped configurations did not significantly differ between the two groups. Among these, the hourglass-shaped configuration tended to have a lower prevalence in the dentate group (OR = 0.28; 95% CI: 0.06–1.02; p = 0.055), although this difference did not reach statistical significance after correction for multiple testing. Table 3 Morphological characteristics of the nasopalatine canal. Edentulous group (%) Dentate group (%) p value On the coronal plane 0.019* Single and broad cannal 35 (64.8%) 26 (48.1%) Y- shaped canals 16 (29.6%) 28 (51.9%) Two parallel canals 3 (5.6%) 0 (0.0%) On the sagittal plane 0.005* Banana-shaped 13 (24.1%) 6 (11.1%) Hourglass 12 (22.2%) 4 (7.4%) Cylindrical 16 (29.6%) 33 (61.1%) Funnel 13 (24.1%) 11 (20.4%) (*) Fisher’s exact test Discussion With the advancement of CBCT, detailed three-dimensional evaluation of craniofacial anatomical structures has become possible, particularly for the nasopalatine canal, which exhibits considerable morphological variability and represents an important anatomical structure to consider during dental procedures in the anterior maxilla [ 2 , 14 ]. The present study was conducted to investigate potential differences in the anatomical characteristics of the nasopalatine canal and the bone region anterior to the canal between completely edentulous and dentate maxillae. To the best of our knowledge, this study represents the first investigation evaluating these anatomical structures in a Southeast Asian population while directly comparing dentate individuals with completely edentulous patients. In the present study, the results indicated that the nasopalatine canal width tended to increase in edentulous patients, both in the buccolingual and mesiodistal dimensions. Notably, in this study, the buccolingual width was measured using the Frankfort horizontal plane as the reference plane. This measurement approach may result in slightly smaller canal diameter values than the actual anatomical diameter, which may partially explain the differences observed when the present findings are compared with those reported in previous studies [ 13 , 15 ]. Nevertheless, the overall trend observed in this study is consistent with several previous investigations that reported a significant association between tooth loss and changes in nasopalatine canal dimensions [ 16 – 18 ]. These anatomical alterations are generally attributed to alveolar bone remodeling following tooth extraction, which may lead to relative enlargement of the canal [ 12 , 13 ]. Conversely, some investigations have suggested that the diameter of the nasopalatine canal may remain relatively stable in edentulous individuals [ 17 ]. Such discrepancies across studies may be related to differences in measurement protocols, reference planes, imaging parameters, or population characteristics. With respect to the length of the nasopalatine canal, the present study revealed mean values of 11.45 ± 2.88 mm in the dentate group and 9.63 ± 3.54 mm in the edentulous group, indicating a tendency toward reduced canal length in edentulous patients. This finding is consistent with the observations reported by Tözüm et al. [ 7 ], who similarly noted a decrease in canal height following tooth loss. Several other CBCT-based studies have also reported that dentate individuals tend to present greater nasopalatine canal lengths than edentulous subjects do, although the absolute measurements vary across studies [ 6 , 12 ]. The variability in reported values may be explained in part by differences in measurement protocols and landmark identification. In the present study, canal length was determined via reference points primarily derived from width-related anatomical landmarks, which may influence the final measurement. Consequently, the measured canal length may slightly underestimate the true anatomical length in certain morphological configurations. This effect is particularly evident in banana-shaped canals, where the curved trajectory of the canal may lead to smaller linear measurements when a straight reference axis is used. In contrast, for other canal morphologies, the discrepancy between the measured and actual canal lengths is expected to be minimal. With respect to the nasopalatine canal morphology observed on the coronal plane, the single canal and Y-shaped configurations were the two most frequently encountered patterns in both study groups. In the dentate group, the Y-shaped configuration was the most prevalent morphology, accounting for 51.9% of the cases, which is consistent with the findings reported by Fukuda et al. [ 19 ]. In contrast, the edentulous group demonstrated a predominance of the single canal configuration (64.8%), a distribution similar to that described by Özarslantürk et al. [ 11 ] in partially edentulous patients. The observed differences in canal morphology between dentate and edentulous individuals on the coronal plane may be related to post-extraction anatomical remodeling. Following tooth loss, alveolar bone resorption and expansion of the nasopalatine canal may occur, potentially altering the internal branching pattern of the canal. These structural changes may contribute to the increased prevalence of simplified canal configurations, such as the single canal type, in edentulous patients. The classification of nasopalatine canal morphology on the sagittal plane in the present study followed a four-type system—cylindrical, funnel-shaped, hourglass-shaped, and banana-shaped—similar to the classification proposed by Fukuda et al. [ 19 ]. Overall, the cylindrical configuration was the most frequently observed morphology in the entire sample, which is consistent with the findings reported in several previous CBCT studies [ 20 , 21 ]. In the dentate group, the cylindrical type accounted for 61.1% of the cases, followed by the funnel-shaped configuration (20.4%), the banana-shaped configuration (11.1%), and the hourglass-shaped configuration (7.4%). In contrast, the edentulous group demonstrated a more evenly distributed pattern of canal morphologies, with relatively higher proportions of banana-shaped (24.1%) and hourglass-shaped (22.2%) canals, although the cylindrical type remained the most common configuration (29.6%). However, the distribution observed in the present study differs from that reported by Fukuda et al. [ 19 ], who reported the funnel-shaped canal to be the most prevalent morphology in maxillary specimens, followed by the cylindrical type. Similar findings were also reported by Mardinger et al. [ 22 ]. These discrepancies may suggest that factors such as ethnic background, environmental influences, and dental status may significantly affect the morphological characteristics of the nasopalatine canal. With respect to the bone region anterior to the nasopalatine canal, the present study demonstrated that the dentate group presented significantly greater buccal bone dimensions than did the edentulous group did, particularly in terms of bone width measured at 1 mm and 6 mm apical to the alveolar crest. A similar trend was reported by Gil-Marques et al. [ 12 ], although the measurement protocol differed. In their study, the width of the buccal bone was evaluated at three reference levels, namely, at the horizontal level of the anterior nasal spine, at the most anterior-inferior point of the buccal cortex of the maxilla, and at the midpoint between these two levels. Despite differences in measurement landmarks and methodological approaches, both studies consistently demonstrated that the buccal bone plate is thicker in dentate individuals than in edentulous patients. The values reported in the present study differ considerably from those described by Mehrotra et al. [ 23 ], who reported mean bone heights of 7.99 ± 1.40 mm in dentate individuals and 5.18 ± 1.10 mm in edentulous patients. Nevertheless, both studies consistently reported that the buccal bone height anterior to the nasopalatine canal is greater in dentate individuals than in edentulous individuals, suggesting that tooth loss is associated with significant vertical and horizontal bone resorption in the anterior maxilla. The findings of the present study indicate that edentulous patients tend to exhibit increased nasopalatine canal width, greater canal angulation, and a reduction in the surrounding anterior maxillary bone volume. In addition, the results demonstrated an increase in the nasopalatine canal angle and a decrease in the buccal bone height anterior to the canal in edentulous individuals, which is consistent with the observations reported by Jia et al. [ 24 ]. These anatomical alterations may be largely attributed to alveolar bone resorption associated with aging and, more prominently, following tooth extraction [ 21 , 25 ]. Progressive bone remodeling in the anterior maxilla may lead to relative enlargement of the nasopalatine canal and a reduction in the surrounding bone volume over time. Furthermore, the observed variations may also be influenced by several factors, including demographic characteristics, ethnic background, environmental influences, and the patient’s dental status. In the present study, the investigated population consisted of completely edentulous patients, whereas most previously published studies have primarily examined dentate or partially edentulous populations. Studies specifically focusing on completely edentulous individuals remain relatively limited worldwide. In addition, differences in measurement protocols, reference landmarks, and methods used to determine canal orientation and angulation may contribute to the variability in findings reported across different studies. In recent years, implant placement involving the nasopalatine canal region has become increasingly utilized in full-arch rehabilitation for patients with severe maxillary bone resorption. This anatomical site has been proposed as a feasible implant anchorage area, with studies suggesting that it does not pose a substantial surgical risk and may contribute to improved load distribution in full-arch prosthetic restorations [ 5 , 6 ]. Currently, two principal surgical approaches have been described for implant placement in the nasopalatine canal region. The first technique involves removal of the nasopalatine neurovascular bundle followed by direct implant placement within the canal. In this approach, the implant engages the bony walls of the nasopalatine canal; therefore, the implant diameter is largely determined by the canal dimensions [ 26 ]. In the present study, the largest mean canal diameter measured 4.72 ± 1.17 mm in the buccolingual direction and 4.83 ± 1.24 mm in the mesiodistal direction, which falls within the commonly available range of implant diameters of approximately 3–6 mm. The second technique involves implant placement in the bone anterior to the nasopalatine canal while preserving the neurovascular bundle within the canal [ 27 ]. In this approach, successful implant placement depends largely on the available bone volume and density in the anterior bone region. Consequently, careful selection of the implant dimension is needed to ensure adequate primary stability while avoiding injury to the neurovascular structures of the nasopalatine. In the present study, the mean canal length and anterior bone height in edentulous patients were 9.63 mm and 13.91 mm, respectively, which are generally compatible with the implant lengths commonly used in clinical practice. Overall, these findings suggest that the nasopalatine canal region represents a potentially viable anatomical site for implant placement, particularly in cases of severe anterior maxillary bone resorption. However, owing to the considerable interindividual variability in both canal morphology and dimensions, careful preoperative CBCT evaluation and individualized implant planning are essential to ensure safe and predictable treatment outcomes. Several limitations of this study should be acknowledged. First, the study was conducted with a relatively limited sample size, and the data were obtained from a single center, which may limit the representativeness of the study population and reduce the generalizability of the findings. Second, clinical information regarding the patients, including their oral health status and the duration of tooth loss, was not comprehensively available in the dataset. These factors may play a role in the extent of alveolar bone remodeling and nasopalatine canal morphology and therefore could have influenced the results. Future studies with larger multicenter samples, balanced demographic characteristics, and comprehensive clinical data are needed to further validate and expand upon the findings of the present study. Conclusion The present CBCT-based study demonstrated that tooth loss is associated with significant anatomical alterations in the nasopalatine canal and the surrounding anterior maxillary bone. Specifically, edentulous patients exhibited increased canal width and angulation, whereas the canal length and the bone volume anterior to the canal were reduced compared with those of dentate individuals. In addition, the nasopalatine canal showed substantial morphological variability. In the coronal plane, the Y-shaped configuration predominated in dentate individuals, whereas the single canal configuration was more common in completely edentulous patients. On the sagittal plane, the cylindrical morphology represented the most frequent configuration across the entire sample. These findings underscore the dynamic anatomical changes occurring in the anterior maxilla following tooth loss and highlight the importance of comprehensive CBCT evaluation for individualized planning of implant treatment in this region. Given the considerable interindividual variability in canal morphology and surrounding bone dimensions, patient-specific anatomical assessment should be considered essential for optimizing implant placement and minimizing surgical complications in the anterior maxilla. Abbreviations CBCT cone-beam computed tomography ICC intraclass correlation coefficient ANS anterior nasal spine GSV grayscale density values CI confidence interval OR odds ratio ANCOVA analysis of covariance GLM generalized linear model Declarations Ethics approval and consent to participate: Ethical approval for this study was obtained from the Institutional Ethics Committee in Biomedical Research at the University of Health Sciences, Ho Chi Minh City, under approval number 02/QD-HDDD. Written informed consent was obtained from all participants, and they were made aware of the potential risks associated with CBCT. Consent for publication - Not applicable Competing interests - The authors declare that they have no competing interests. Funding – This study did not receive any specific grants from any funding agencies or commercials. Author Contribution C.L.N.H. contributed to the study conceptualization and design, data analysis, and review and editing the manuscript. Q.T.N.N. and T.N.P.P. collected the data regarding the morphometric and morphological characteristics of the canal. N.T.T.N. and N.H.N. contributed to the study conceptualization and design and prepared the original draft. L.T.D. contributed to the study conceptualization and design, data analysis, review and editing of the manuscript, and approved the final version of the manuscript. Acknowledgments – None Data Availability The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request. References Bodereau EF, Flores VY, Naldini P, Torassa D, Tortolini P. Clinical Evaluation of the Nasopalatine Canal in Implant-Prosthetic Treatment: A Pilot Study. Dent J (Basel). 2020;8(2). Bains SK, Bhatia A, Sodhi SS, Sharma A. Assessment of the Nasopalatine Canal in Patients Requiring Dental Implants in the Maxillary Anterior Region Using Cone Beam Computed Tomography. Cureus. 2023;15(12):e50643. Singhal MK, Dandriyal R, Aggarwal A, Agarwal A, Yadav S, Baranwal P. Implant Placement into the Nasopalatine Foramen: Considerations from Anatomical and Surgical Point of View. Annals maxillofacial Surg. 2018;8(2):347–51. de Mello JS, Faot F, Correa G, Chagas Júnior OL. Success rate and complications associated with dental implants in the incisive canal region: a systematic review. Int J Oral Maxillofac Surg. 2017;46(12):1584–91. Leighton Y, de Souza RF, Borie E. Using the Nasopalatine Canal for Enhanced Distribution in Severely Atrophic Maxilla With Immediate Loading of Zygomatic Implants: An 8-Year Retrospective Cohort Study. J Craniofac Surg. 2025;36(4):e374–6. Vasiljevic M, Selakovic D, Rosic G, Stevanovic M, Milanovic J, Arnaut A et al. Anatomical Factors of the Anterior and Posterior Maxilla Affecting Immediate Implant Placement Based on Cone Beam Computed Tomography Analysis: A Narrative Review. Diagnostics (Basel Switzerland). 2024;14(15). Tözüm TF, Güncü GN, Yıldırım YD, Yılmaz HG, Galindo-Moreno P, Velasco-Torres M, et al. Evaluation of maxillary incisive canal characteristics related to dental implant treatment with computerized tomography: a clinical multicenter study. J Periodontol. 2012;83(3):337–43. Firincioglulari M, Orhan K. Morphological Variations of the Nasopalatine Canal in the North Cyprus Population: A Cone Beam Computed Tomography Study. Med Sci monitor: Int Med J experimental Clin Res. 2024;30:e944868. Khan M, Habib S, Ghafoor R. Evaluation of the Nasopalatine Canal (NPC) in a subset of Pakistani population, using Cone Beam Computed Tomography (CBCT). JPMA J Pakistan Med Association. 2023;73(1):49–53. Sarna K, Estreed MA, Sonigra KJ, Amuti T, Opondo F, Kamau M, et al. Anatomical Patterns of the Nasopalatine Canal and Incisive Foramen in an African Setting: A Cross-Sectional Study. Craniomaxillofacial trauma reconstruction. 2023;16(3):222–33. Özarslantürk S, Ceylan Şen S, Saraç Atagün Ö. Retrospective Evaluation of Nasopalatine Canal Anatomy, Dimensions, and Variations with Alveolar Bone in Patients Scheduled for Maxillary Anterior Dental Implant Surgery Using Cone Beam Computed Tomography. Tomography (Ann Arbor, Mich). 2025;11(10). Gil-Marques B, Sanchis-Gimeno JA, Brizuela-Velasco A, Perez-Bermejo M, Larrazábal-Morón C. Differences in the shape and direction-course of the nasopalatine canal among dentate, partially edentulous and completely edentulous subjects. Anat Sci Int. 2020;95(1):76–84. Demiralp K, Kurşun-Çakmak E, Bayrak S, Sahin O, Atakan C, Orhan K. Evaluation of Anatomical and Volumetric Characteristics of the Nasopalatine Canal in Anterior Dentate and Edentulous Individuals: A CBCT Study. Implant Dent. 2018;27(4):474–9. Alhumaidi AM, Al Moaleem MM, Gadah TS, Alahmari NM, Al Makramani BMA, Mattoo K, et al. Variations in nasopalatine canal morphology across populations: a cone-beam computed tomography systematic review and proposed nomenclature system. Folia Morphol. 2025;84(3):521–33. Kim YT, Lee JH, Jeong SN. Three-dimensional observations of the incisive foramen on cone-beam computed tomography image analysis. J periodontal implant Sci. 2020;50(1):48–55. Bornstein MM, Balsiger R, Sendi P, von Arx T. Morphology of the nasopalatine canal and dental implant surgery: a radiographic analysis of 100 consecutive patients using limited cone-beam computed tomography. Clin Oral Implants Res. 2011;22(3):295–301. Güncü GN, Yıldırım YD, Yılmaz HG, Galindo-Moreno P, Velasco-Torres M, Al-Hezaimi K, et al. Is there a gender difference in anatomic features of incisive canal and maxillary environmental bone? Clin Oral Implants Res. 2013;24(9):1023–6. Peñarrocha D, Candel E, Guirado JL, Canullo L, Peñarrocha M. Implants placed in the nasopalatine canal to rehabilitate severely atrophic maxillae: a retrospective study with long follow-up. J Oral Implantol. 2014;40(6):699–706. Fukuda M, Matsunaga S, Odaka K, Oomine Y, Kasahara M, Yamamoto M, et al. Three-dimensional analysis of incisive canals in human dentulous and edentulous maxillary bones. Int J implant dentistry. 2015;1(1):12. Safi Y, Moshfeghi M, Rahimian S, Kheirkhahi M, Eslami Manouchehri MJIJR. Assessment of nasopalatine canal anatomic variations using cone beam computed tomography in a group of Iranian population. 2017;14(1):e37028. Khojastepour L, Haghnegahdar A, Keshtkar M. Morphology and Dimensions of Nasopalatine Canal: a Radiographic Analysis Using Cone Beam Computed Tomography. J dentistry (Shiraz Iran). 2017;18(4):244–50. Mardinger O, Namani-Sadan N, Chaushu G, Schwartz-Arad D. Morphologic changes of the nasopalatine canal related to dental implantation: a radiologic study in different degrees of absorbed maxillae. J Periodontol. 2008;79(9):1659–62. Mehrotra G, Bhoosreddy A, Bhoosreddy S, Bhadage C, Sharma K, Shah KJJICDRO. Three-Dimensional Analysis of the Nasopalatine Canal in Dentulous and Edentulous Maxilla–A Cone-Beam Computed Tomography Study. 2020;12(2):148–53. Jia X, Hu W, Meng H. Relationship of central incisor implant placement to the ridge configuration anterior to the nasopalatine canal in dentate and partially edentulous individuals: a comparative study. PeerJ. 2015;3:e1315. Mishra R, Thimmarasa V, Jaju PP, Mishra R, Shrivastava AJJDI. Influence of gender and age on nasopalatine canal: A cone-beam computed tomography study. 2017;7(1):15–9. Scher EL. Use of the incisive canal as a recipient site for root form implants: preliminary clinical reports. Implant Dent. 1994;3(1):38–41. Artzi Z, Nemcovsky CE, Bitlitum I, Segal P. Displacement of the incisive foramen in conjunction with implant placement in the anterior maxilla without jeopardizing vitality of nasopalatine nerve and vessels: a novel surgical approach. Clin Oral Implants Res. 2000;11(5):505–10. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9187671","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":626960521,"identity":"484d885b-6cfc-4f01-9be0-0beabcfe2946","order_by":0,"name":"Cam Hong","email":"","orcid":"","institution":"University of Health Sciences, Vietnam National University","correspondingAuthor":false,"prefix":"","firstName":"Cam","middleName":"","lastName":"Hong","suffix":""},{"id":626960522,"identity":"d57b3098-667d-44d8-8209-1fbf06fbfbc2","order_by":1,"name":"Nhung Nguyen","email":"","orcid":"","institution":"University of Health Sciences, Vietnam National University","correspondingAuthor":false,"prefix":"","firstName":"Nhung","middleName":"","lastName":"Nguyen","suffix":""},{"id":626960523,"identity":"e6b2fded-cc1b-461b-954c-931f7ac588e7","order_by":2,"name":"Quynh Ngo","email":"","orcid":"","institution":"University of Health Sciences, Vietnam National University","correspondingAuthor":false,"prefix":"","firstName":"Quynh","middleName":"","lastName":"Ngo","suffix":""},{"id":626960524,"identity":"f1d5f11d-9d6b-4061-9a9e-d90864a81d82","order_by":3,"name":"Tram Nguyen","email":"","orcid":"","institution":"University of Health Sciences, Vietnam National University","correspondingAuthor":false,"prefix":"","firstName":"Tram","middleName":"","lastName":"Nguyen","suffix":""},{"id":626960525,"identity":"89bd7fa2-e1f1-46b7-9c2a-e3486d5c6dfa","order_by":4,"name":"Ngoc Nguyen","email":"","orcid":"","institution":"University of Health Sciences, Vietnam National University","correspondingAuthor":false,"prefix":"","firstName":"Ngoc","middleName":"","lastName":"Nguyen","suffix":""},{"id":626960526,"identity":"5759236b-556e-4e7a-8177-c87f59e022c2","order_by":5,"name":"Tu Doan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxklEQVRIiWNgGAWjYDCCA0DMA8T8IE5CAVFamCFaJBtAWgxI0WIAso6BGC18t88fk3hTYZdnfH514ocHBgzy/GIH8GuRPJfMJjnnTHKx2Y23myWADjOcOTsBvxaDM8xs0rxtzInbbpzdANKSYHCbOC31iZtnnN38gxQthxM38PduI84WyTPMxpZzzhxPnHGDd5tFgoEEYb/wnWF8eONNRXVif//ZzTd/VNjI80sT0IIAEmCVEsQqBwH+A6SoHgWjYBSMgpEEANt2RFpWuUYVAAAAAElFTkSuQmCC","orcid":"","institution":"University of Health Sciences, Vietnam National University","correspondingAuthor":true,"prefix":"","firstName":"Tu","middleName":"","lastName":"Doan","suffix":""}],"badges":[],"createdAt":"2026-03-21 19:08:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9187671/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9187671/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107615704,"identity":"746dc15b-f7b4-4728-89e7-90332b34073c","added_by":"auto","created_at":"2026-04-23 09:12:12","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":65065,"visible":true,"origin":"","legend":"\u003cp\u003eFlow diagram of CBCT scan selection and inclusion. Of 202 retrieved scans, 94 were excluded based on predefined criteria, resulting in 108 eligible scans included in the final analysis. The sample was equally divided into dentate (n = 54) and edentulous (n = 54) groups, with all cases subjected to morphological and morphometric assessment.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-9187671/v1/68d75074a5fb1a6961e9f9c7.png"},{"id":107615693,"identity":"7567ad88-bab7-4e44-878d-8be4763b6529","added_by":"auto","created_at":"2026-04-23 09:12:10","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":199826,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurements were obtained from sagittal sections passing through the anterior nasal spine.\u003c/p\u003e\n\u003cp\u003e(A) Morphometric characteristics of the nasopalatine canal.\u003c/p\u003e\n\u003cp\u003e(B) Morphometric characteristics of the bone anterior to the nasopalatine canal.\u003c/p\u003e\n\u003cp\u003eSSW, sagittal superior canal width; SMW, sagittal middle canal width; SIW, sagittal inferior canal width; CL, canal length; CA, canal angulation; BW1, buccal bone width measured 1 mm apical to the alveolar crest; BW6, buccal bone width measured 6 mm apical to the alveolar crest; BL, buccal bone height.\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9187671/v1/6be0751b32fc3b2a297746fe.jpeg"},{"id":107615695,"identity":"bd91b98f-fc55-4965-a1c8-49a7591b6d1e","added_by":"auto","created_at":"2026-04-23 09:12:10","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":90812,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurements of horizontal canal width at different axial levels.\u003c/p\u003e\n\u003cp\u003eCSW, horizontal superior canal width; CMW, horizontal middle canal width; CIW, horizontal inferior canal width.\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9187671/v1/d38c653048b11c47c7145a0f.jpeg"},{"id":107615635,"identity":"5d97796d-0797-497b-bc00-195893fc980e","added_by":"auto","created_at":"2026-04-23 09:12:06","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":301471,"visible":true,"origin":"","legend":"\u003cp\u003eMorphological configurations of the nasopalatine canal in the sagittal plane:\u003c/p\u003e\n\u003cp\u003e(A) Cylindrical; (B) funnel shaped; (C) hourglass shaped; (D) banana shaped.\u003c/p\u003e","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9187671/v1/117bfa2c3bc7ffbd35bf7132.jpeg"},{"id":107615602,"identity":"a8c89f5f-d4f7-46b2-8bf5-d06d4f12b36b","added_by":"auto","created_at":"2026-04-23 09:11:55","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":93445,"visible":true,"origin":"","legend":"\u003cp\u003eMorphological configurations of the nasopalatine canal in the coronal plane:\u003c/p\u003e\n\u003cp\u003e(A) Singleand broad canal; (B) two parallel canals; (C) Y-shaped canal.\u003c/p\u003e","description":"","filename":"floatimage6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9187671/v1/168b318cfd2a93fdb919a0cc.jpeg"},{"id":109153273,"identity":"28babc78-514d-4ad0-b42b-e829bae71941","added_by":"auto","created_at":"2026-05-13 06:14:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1054587,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9187671/v1/dc852886-d1e3-452b-bd9c-ad35008a4ca4.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Morphological and Morphometric Characteristics of the Nasopalatine Canal in Dentate and Edentulous Patients: A Cone-Beam Computed Tomography Cross-Sectional Study","fulltext":[{"header":"Background","content":"\u003cp\u003eDental implant therapy has become a well-established and highly reliable method for replacing missing teeth, especially in areas with strict functional and aesthetic requirements, such as the anterior maxilla [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. However, the anterior maxilla presents significant anatomical challenges. It is often affected by progressive alveolar bone loss following tooth extraction and contains several critical neurovascular structures. One important anatomical feature to consider during preoperative implant planning is the nasopalatine canal, which must be carefully assessed [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe nasopalatine canal is a midline anatomical structure of the maxilla that contains the nasopalatine nerve and accompanying vascular branches responsible for sensory innervation of the anterior palate. Clinically, the morphology, dimensions, trajectory, and spatial relationship of the nasopalatine canal with the surrounding anterior maxillary bone exhibit substantial interindividual variability. Such anatomical variations may directly influence the position and angulation of implant placement and may increase the risk of complications, including sensory disturbances, intraoperative hemorrhage, impaired osseointegration, or the development of nasopalatine duct cysts [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Moreover, in cases of severe alveolar ridge resorption following complete edentulism of the maxilla, the nasopalatine canal and its surrounding structures have increasingly been utilized as anchorage sites for implant placement [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eComprehensive assessment of the nasopalatine canal via cone-beam computed tomography (CBCT) is therefore essential for accurate planning of implant treatment, enabling clinicians to determine the most appropriate therapeutic approach while minimizing the risk of complications associated with implant placement in this region [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Numerous CBCT-based studies have investigated the anatomical characteristics and morphometric parameters of the nasopalatine canal [\u003cspan additionalcitationids=\"CR9 CR10 CR11 CR12\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. However, the majority of these studies have focused primarily on canal morphology in dentate populations [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] or in edentulous patients alone [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Other investigations have compared partially edentulous individuals with dentate subjects [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In contrast, research specifically examining the nasopalatine canal in completely edentulous patients remains relatively scarce, and the few available studies are generally based on limited sample sizes [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite the increasing clinical importance of this anatomical region, the available literature remains limited regarding comprehensive evaluations of the nasopalatine canal in completely edentulous patients, particularly studies that directly compare these characteristics with those observed in dentate individuals. Therefore, the present study aimed to investigate and compare the anatomical features of the nasopalatine canal via CBCT in two distinct patient populations: individuals with a completely edentulous maxilla and those with preserved dentition.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e A descriptive cross-sectional study was performed using CBCT datasets obtained from 108 patients who underwent imaging at a private hospital between April 2024 and December 2025. The CBCT records were categorized into two groups according to dental status. The edentulous group consisted of 54 CBCT scans from patients with complete maxillary edentulism, whereas the dentate group included 54 CBCT scans from patients retaining natural dentition in the anterior maxillary region. Ethical approval for this study was obtained from the Institutional Ethics Committee in Biomedical Research at the University of Health Sciences, Vietnam National University, Ho Chi Minh City, under approval number 02/QD-HDDD.\u003c/p\u003e \u003cp\u003eMaxillae demonstrating the presence of natural teeth or residual root fragments within the anterior maxillary region were classified into the dentate group. Conversely, maxillae presenting with complete edentulism, or those retaining only a limited number of teeth but lacking anterior maxillary teeth, were assigned to the edentulous group.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSample selection\u003c/h2\u003e \u003cp\u003eCBCT scans, including cases affected by artifacts, scattering, or incomplete visualization of the region of interest, were excluded if the image quality was insufficient for accurate evaluation. Images showing previously placed dental implants in the nasopalatine canal region or in the maxillary central incisor area were also excluded. In addition, scans demonstrating prior bone grafting procedures in the anterior maxilla were not considered. Patients presenting with radiographic evidence of pathological conditions, such as tumors or cystic lesions involving the nasopalatine canal or the maxillary incisor region, were excluded. Furthermore, CBCT images indicating bone defects in the nasopalatine canal region attributable to pathology, trauma, or previous surgical interventions within the area of interest were not included in the study. CBCT scans were retrieved from the institutional database. After applying predefined inclusion and exclusion criteria, eligible scans were selected for analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSample size calculation\u003c/h3\u003e\n\u003cp\u003eSample size estimation was performed to detect a clinically meaningful difference in the morphometric parameters of the nasopalatine canal between the dentate and edentulous groups. The calculation was based on data from a previous study [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] reporting mean values of 2.73 mm and 2.77 mm with standard deviations of 1.37 mm and 1.40 mm, respectively. The pooled standard deviation was therefore estimated at 1.385 mm. Assuming a minimum detectable difference of 0.75 mm, a two-sided significance level of 0.05, and a statistical power of 80%, the required sample size was calculated via the following formula for comparing two independent means:\u003c/p\u003e \u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"292\" height=\"82\"\u003e\u003c/p\u003e\u003cp\u003eZ\u003csub\u003eα/2\u003c/sub\u003e = 1.96; Z\u003csub\u003eβ\u003c/sub\u003e = 0.84, SD\u003csub\u003ep\u003c/sub\u003e = 1.385 and δ\u0026thinsp;=\u0026thinsp;0.75. On the basis of these parameters, the required sample size was 54 participants per group (108 total).\u003c/p\u003e \u003cp\u003eThe corresponding standardized effect size (Cohen\u0026rsquo;s d) was 0.54, indicating a moderate effect. This sample size provides adequate statistical power to detect clinically relevant differences in the morphometric characteristics of the nasopalatine canal between the two study groups.\u003c/p\u003e\n\u003ch3\u003eRadiographic imaging acquisition\u003c/h3\u003e\n\u003cp\u003eCBCT examinations were performed via a dedicated cone-beam computed tomography unit (NewTom GiANO HR; Cefla, Imola, Italy). All scans were acquired via standardized imaging parameters in accordance with the manufacturer\u0026rsquo;s recommendations. The acquisition protocol included a voxel size of 0.16 mm, a tube voltage of 90 kVp, and a tube current of 15 mA. The exposure time was set at 16.8 seconds, and a field of view (FOV) of 10 \u0026times; 10 cm was selected to ensure complete visualization of the anterior maxillary region, including the nasopalatine canal and surrounding anatomical structures.\u003c/p\u003e \u003cp\u003eDuring CBCT scanning, patients were positioned in an upright posture with the chin resting on the chin support and the head stabilized to minimize motion artifacts. The radiology technician ensured proper alignment by orienting the patient according to the Frankfort horizontal plane and adjusting the reference beams to pass through the canine region. After image acquisition, the datasets were reviewed to confirm image quality and completeness. In cases where image acquisition errors or data storage failure occurred, the scan was repeated. All the CBCT datasets were exported and archived in Digital Imaging and Communications in Medicine (DICOM) format for subsequent analysis.\u003c/p\u003e\n\u003ch3\u003eImage orientation and standardization\u003c/h3\u003e\n\u003cp\u003ePrior to measurement, all the CBCT datasets were standardized to ensure consistent anatomical orientation. The images were reoriented using the Frankfort horizontal plane as the reference plane. The sagittal plane was adjusted to pass through the anterior nasal spine, whereas the coronal plane was aligned perpendicularly to the sagittal plane. This standardized orientation minimized measurement bias and ensured consistency across all evaluated scans.\u003c/p\u003e \u003cp\u003eMorphometric measurements and anatomical assessments of the nasopalatine canal and the bone region anterior to the canal were performed on axial, sagittal (sections passing through the anterior nasal spine), and coronal planes. All morphometric measurements were subsequently performed via the built-in digital measurement tools of the analysis software (Blue Sky Bio version 4.13, Blue Sky Bio, Libertyville, IL, USA), and values were recorded in millimeters (mm).\u003c/p\u003e\n\u003ch3\u003eCBCT morphometric measurements\u003c/h3\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eMorphological and morphometric characteristics of the nasopalatine canal\u003c/h2\u003e \u003cp\u003eOn the sagittal section passing through the anterior nasal spine (ANS), the sagittal canal width was measured at three levels\u0026mdash;inferior, middle, and superior\u0026mdash;parallel to the reference plane. The canal width measured at the nasal opening and palatal opening corresponded to the sagittal canal superior width and the sagittal canal inferior width, respectively. On the same sagittal section, the canal length was defined as the linear distance extending from the superior plane to the inferior plane along the longitudinal axis of the canal. The nasopalatine canal angle was determined as the angle formed between the canal axis and the reference plane. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea provides a schematic representation of the measurement procedures for the evaluated variables.\u003c/p\u003e \u003cp\u003eThe horizontal canal width was defined as the maximum canal width measured on axial sections at the superior, middle, and inferior levels (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eCSW, horizontal superior canal width; CMW, horizontal middle canal width; CIW, horizontal inferior canal width.\u003c/p\u003e \u003cp\u003eThe morphology of the nasopalatine canal was classified according to its appearance on the sagittal plane into four categories: cylindrical, funnel-shaped, hourglass-shaped, and banana-shaped (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). On the coronal plane, canal morphology was categorized into three configurations: single and broad, two parallel canals, and Y-shaped canals (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e(A) Cylindrical; (B) funnel shaped; (C) hourglass shaped; (D) banana shaped.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e(A) Single and broad canal; (B) two parallel canals; (C) Y-shaped canal.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eBuccal bone region of the nasopalatine canal\u003c/h3\u003e\n\u003cp\u003eFor the same sagittal section passing through the ANS, the buccal bone height was measured as the vertical distance from the alveolar crest to the nasal floor, perpendicular to the reference plane. The width of the buccal bone was measured at 1 mm and 6 mm apical to the alveolar crest toward the nasal floor (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). The mean cancellous bone density in this region was measured at three locations along the vertical axis, corresponding to the superior, middle, and inferior thirds of the bone. Bone density values were recorded in grayscale density values (GSVs).\u003c/p\u003e\n\u003ch3\u003eObserver calibration and measurement reliability\u003c/h3\u003e\n\u003cp\u003eAll morphometric measurements were independently performed by two calibrated examiners with experience in CBCT image analysis. Prior to the formal evaluation, both examiners underwent a calibration session to standardize the identification of anatomical landmarks and the measurement protocol within the analysis software. To assess intra- and interobserver reliability, 30 CBCT scans were randomly selected from the total dataset, including 15 scans from the dentate group and 15 scans from the edentulous group. These cases were re-evaluated independently by both examiners following the same measurement protocol. To assess the measurement reliability of the quantitative variables, the ICC was calculated via representative parameters, including the sagittal canal middle width, horizontal canal middle width, anterior bone height, and buccal bone width at 6 mm apical to the alveolar crest. For the qualitative variable of sagittal canal shape, interobserver agreement was evaluated via Cohen\u0026rsquo;s kappa coefficient. The reliability coefficients were interpreted according to commonly accepted thresholds, where higher ICC and kappa values indicate stronger agreement between measurements.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eAll the statistical analyses were performed via R statistical software (R Foundation for Statistical Computing, Vienna, Austria). Continuous variables were assessed for normality via the Shapiro\u0026ndash;Wilk test and graphical inspection (histograms and Q\u0026ndash;Q plots). Intergroup comparisons of morphometric parameters of the nasopalatine canal between the dentate and edentulous groups were conducted while adjusting for age and sex. Variables with approximately normal distributions were analyzed via analysis of covariance (ANCOVA) with linear models to estimate adjusted mean differences. Positively skewed variables were analyzed via generalized linear models (GLMs) with a gamma distribution and log link, and the results are reported as ratios of adjusted means. The magnitude of the intergroup differences was quantified via standardized effect sizes (Cohen\u0026rsquo;s d with Hedges\u0026rsquo; correction) and partial eta squared (partial η\u0026sup2;). The morphological characteristics of the nasopalatine canal on the coronal and sagittal planes were summarized as frequencies and percentages. Differences in distribution between groups were assessed via the chi-square test or Fisher\u0026rsquo;s exact test, followed by post hoc logistic regression to estimate ORs with 95% CIs for each configuration. Bonferroni correction was applied to account for multiple comparisons. A two-sided p value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eICC and Kappa\u003c/h2\u003e \u003cp\u003eThe ICC values ranged from 0.791 to 0.905, demonstrating good to excellent interobserver reliability for all the CBCT measurements. Cohen\u0026rsquo;s kappa analysis demonstrated substantial interobserver agreement for the assessment of nasopalatine canal morphology in both imaging planes (coronal plane: κ\u0026thinsp;=\u0026thinsp;0.789; sagittal plane: κ\u0026thinsp;=\u0026thinsp;0.775; both p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eParticipant characteristics\u003c/h2\u003e \u003cp\u003eA total of 108 CBCT scans from 108 patients (48 females and 60 males) were included in the analysis. The mean age of the participants in the edentulous group was 62.72\u0026thinsp;\u0026plusmn;\u0026thinsp;10.23 years, whereas those in the dentate group had a mean age of 59.22\u0026thinsp;\u0026plusmn;\u0026thinsp;10.20 years.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eMorphometric characteristics of the nasopalatine canal\u003c/h2\u003e \u003cp\u003eThe length of the nasopalatine canal was significantly greater in the dentate group than in the edentulous group, with an adjusted mean difference of 1.66 mm (95% CI: 0.42\u0026ndash;2.90; p\u0026thinsp;=\u0026thinsp;0.009). In contrast, the angulation of the nasopalatine canal was significantly smaller in the dentate group, with an adjusted mean difference of \u003cspan fontcategory=\"NonProportional\" class=\"\" name=\"Emphasis\"\u003e\u0026minus;\u003c/span\u003e \u0026thinsp; 6.47\u0026deg; (95% CI: \u003cspan fontcategory=\"NonProportional\" class=\"\" name=\"Emphasis\"\u003e\u0026minus;\u003c/span\u003e 9.93 to \u003cspan fontcategory=\"NonProportional\" class=\"\" name=\"Emphasis\"\u003e\u0026minus;\u003c/span\u003e \u0026thinsp; 3.00; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003eOn the sagittal plane, no significant difference was observed in the superior sagittal canal width between the two groups (ratio of means\u0026thinsp;=\u0026thinsp;0.95, 95% CI: 0.80\u0026ndash;1.12; p\u0026thinsp;=\u0026thinsp;0.522). However, the middle sagittal canal width and inferior sagittal canal width were significantly smaller in the dentate group than in the edentulous group, with adjusted ratios of 0.79 (95% CI: 0.69\u0026ndash;0.91; p\u0026thinsp;=\u0026thinsp;0.001) and 0.80 (95% CI: 0.73\u0026ndash;0.87; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), corresponding to approximately 21% and 20% lower values, respectively.\u003c/p\u003e \u003cp\u003eOn the axial plane, the superior horizontal canal width did not differ significantly between the two groups (mean ratio\u0026thinsp;=\u0026thinsp;1.10, 95% CI: 0.98\u0026ndash;1.25; p\u0026thinsp;=\u0026thinsp;0.122). In contrast, both the middle and the inferior horizontal canal widths were significantly smaller in the dentate group. The adjusted ratio of the means for the middle horizontal canal width was 0.85 (95% CI: 0.75\u0026ndash;0.97; p\u0026thinsp;=\u0026thinsp;0.017), whereas the inferior horizontal canal width showed an adjusted mean difference of \u003cspan fontcategory=\"NonProportional\" class=\"\" name=\"Emphasis\"\u003e\u0026minus;\u003c/span\u003e \u0026thinsp; 1.04 mm (95% CI: \u003cspan fontcategory=\"NonProportional\" class=\"\" name=\"Emphasis\"\u003e\u0026minus;\u003c/span\u003e 1.46 to \u003cspan fontcategory=\"NonProportional\" class=\"\" name=\"Emphasis\"\u003e\u0026minus;\u003c/span\u003e \u0026thinsp; 0.63; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003eThe detailed results of the morphometric characteristics of the nasopalatine canal are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMorphometric characteristics of the nasopalatine canal.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSuperior horizontal canal width\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEdentulous group\u003c/p\u003e \u003cp\u003e(mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003cp\u003e(mm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDentate\u0026nbsp;group\u003c/p\u003e \u003cp\u003e(mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003cp\u003e(mm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEstimate\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e95% CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eModel\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.51\u0026thinsp;\u0026plusmn;\u0026thinsp;1.34\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.92\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.10\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.98 to 1.25\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.122\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eGLM\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiddle horizontal canal width\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e4.31\u0026thinsp;\u0026plusmn;\u0026thinsp;1.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e3.70\u0026thinsp;\u0026plusmn;\u0026thinsp;1.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.75 to 0.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eGLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInferior horizontal canal width\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e4.83\u0026thinsp;\u0026plusmn;\u0026thinsp;1.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e3.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-1.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-1.46 to -0.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSuperior sagittal canal width\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e3.73\u0026thinsp;\u0026plusmn;\u0026thinsp;1.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e3.49\u0026thinsp;\u0026plusmn;\u0026thinsp;1.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.80 to 1.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.522\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eGLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiddle sagittal canal width\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e3.42\u0026thinsp;\u0026plusmn;\u0026thinsp;1.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.74\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.69 to 0.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eGLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInferior sagittal canal width\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e4.72\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e3.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.73 to 0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eGLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLength of the canal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e9.63\u0026thinsp;\u0026plusmn;\u0026thinsp;3.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e11.45\u0026thinsp;\u0026plusmn;\u0026thinsp;2.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.42 to 2.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.009\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNasopalatine canal angle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e120.39\u0026thinsp;\u0026plusmn;\u0026thinsp;10.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e113.82\u0026thinsp;\u0026plusmn;\u0026thinsp;7.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-6.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-9.93 to -3.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eGLM: generalized linear models, estimate: adjusted ratio of means.\u003c/p\u003e \u003cp\u003eLM: linear models, estimate: adjusted mean difference.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eMorphometric characteristics of the bone anterior to the nasopalatine canal\u003c/h2\u003e \u003cp\u003eWith respect to the bone anterior to the nasopalatine canal, the length of the buccal crestal bone was significantly greater in the dentate group than in the edentulous group, with an adjusted mean difference of 4.66 mm (95% CI: 3.23\u0026ndash;6.09; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). In contrast, bone density did not differ significantly between the two groups (mean ratio\u0026thinsp;=\u0026thinsp;1.12, 95% CI: 0.98\u0026ndash;1.27; p\u0026thinsp;=\u0026thinsp;0.097).\u003c/p\u003e \u003cp\u003eSimilarly, the bone width measured 1 mm apical to the alveolar crest was significantly greater in the dentate group, with an adjusted ratio of means of 1.65 (95% CI: 1.35\u0026ndash;2.02; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), indicating an approximately 65% greater bone width than that in the edentulous group. The bone width measured 6 mm apical to the alveolar crest was also significantly greater in the dentate group (mean ratio\u0026thinsp;=\u0026thinsp;1.24, 95% CI: 1.10\u0026ndash;1.39; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), corresponding to an approximately 24% increase relative to the edentulous group. The detailed results of the morphometric characteristics of the bone anterior to the nasopalatine canal are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMorphometric characteristics of the bone anterior to the nasopalatine canal.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cb\u003eLength of crestal\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003ebuccal bone\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEdentulous group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDentate\u0026nbsp;group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEstimate\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e95% CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eModel\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.91\u0026thinsp;\u0026plusmn;\u0026thinsp;4.12\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18.50\u0026thinsp;\u0026plusmn;\u0026thinsp;3.12\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.66\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.23 to 6.09\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLM\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eThe bone width measured 1 mm apical to the alveolar crest\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e3.46\u0026thinsp;\u0026plusmn;\u0026thinsp;2.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.35 to 2.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eGLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eThe bone width measured 6 mm apical to the alveolar crest\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e5.76\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e7.06\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.10 to 1.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eGLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBone Density\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e915.76\u0026thinsp;\u0026plusmn;\u0026thinsp;325.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1039.02\u0026thinsp;\u0026plusmn;\u0026thinsp;337.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.98 to 1.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.097\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eGLM\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eLM: linear model; Estimate: adjusted mean difference.\u003c/p\u003e \u003cp\u003eGLM: generalized linear model; estimate: adjusted ratio of means\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eEffect size interpretation\u003c/h2\u003e \u003cp\u003eFor the morphometric characteristics of the nasopalatine canal, canal length had a moderate effect (d\u0026thinsp;=\u0026thinsp;0.52; partial η\u0026sup2; = 0.08), whereas canal angulation had a moderate-to-large effect (d\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.73; partial η\u0026sup2; = 0.12). Among the sagittal canal dimensions, the superior sagittal width had a trivial effect (d\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.13; partial η\u0026sup2; = 0.01), whereas the middle and inferior sagittal widths had moderate-to-large (d\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.66; partial η\u0026sup2; = 0.09) and large effects (d\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.92; partial η\u0026sup2; = 0.16), respectively. For the horizontal canal measurements, the superior horizontal width had a small effect (d\u0026thinsp;=\u0026thinsp;0.24; partial η\u0026sup2; = 0.01), whereas the middle and inferior horizontal widths had moderate (d\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.55; partial η\u0026sup2; = 0.07) and large effects (d\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.98; partial η\u0026sup2; = 0.18).\u003c/p\u003e \u003cp\u003eWith respect to the bone anterior to the nasopalatine canal, the length of the buccal crestal bone had the greatest effect among all the variables (d\u0026thinsp;=\u0026thinsp;1.27; partial η\u0026sup2; = 0.29). The bone widths measured 1 mm and 6 mm apical to the alveolar crest also demonstrated large effects (d\u0026thinsp;=\u0026thinsp;0.88; partial η\u0026sup2; = 0.15 and d\u0026thinsp;=\u0026thinsp;0.80; partial η\u0026sup2; = 0.13, respectively). In contrast, bone density showed only a small effect (d\u0026thinsp;=\u0026thinsp;0.31; partial η\u0026sup2; = 0.04).\u003c/p\u003e \u003cp\u003eOverall, the greatest anatomical differences between dentate and edentulous individuals were observed in terms of the buccal crestal bone length and inferior canal dimensions, whereas superior canal measurements and bone density had minimal effects.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003eMorphological characteristics of the nasopalatine canal\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e presents the distributions of the morphological configurations of the nasopalatine canal.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eCoronal Plane Morphology\u003c/h2\u003e \u003cp\u003eOn the coronal plane, the single canal configuration and the Y-shaped configuration were the two most frequently observed morphologies in both groups. In the dentate group, the Y-shaped configuration was the most prevalent pattern, accounting for 51.9% of the cases. In contrast, the edentulous group predominantly presented a single canal configuration (64.8%). The parallel double canal configuration was rarely observed and was identified only in the edentulous group (5.6%).\u003c/p\u003e \u003cp\u003eThe Y-shaped configuration was significantly more common in the dentate group than in the edentulous group (OR\u0026thinsp;=\u0026thinsp;2.53; 95% CI: 1.08\u0026ndash;6.11), indicating that dentate individuals were approximately 2.5 times more likely to exhibit this configuration. In contrast, the single canal configuration was not significantly different between the groups (p\u0026thinsp;=\u0026thinsp;0.120). The parallel double-canal configuration, although detected only in the edentulous group, did not significantly differ (p\u0026thinsp;=\u0026thinsp;0.243). Overall, these findings suggest that the greater prevalence of the Y-shaped configuration in dentate individuals contributed the most to the observed morphological differences between the two groups on the coronal plane.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003eSagittal plane morphology\u003c/h2\u003e \u003cp\u003eOn the sagittal plane, the cylindrical configuration was the most common nasopalatine canal morphology observed in the overall sample. In the dentate group, the cylindrical shape accounted for 61.1% of the cases, followed by the funnel-shaped configuration (20.4%), the banana-shaped configuration (11.1%), and the hourglass-shaped configuration (7.4%). In contrast, the edentulous group demonstrated a more even distribution of canal morphologies, with relatively higher proportions of banana-shaped canals (24.1%) and hourglass-shaped canals (22.2%), although the cylindrical configuration remained the most frequent morphology (29.6%).\u003c/p\u003e \u003cp\u003eAmong the evaluated configurations, only the cylindrical shape demonstrated a statistically significant difference between the groups. Dentate individuals were approximately 3.7 times more likely to exhibit a cylindrical nasopalatine canal than edentulous patients were (OR\u0026thinsp;=\u0026thinsp;3.68; 95% CI: 1.56\u0026ndash;9.00). This association remained statistically significant after Bonferroni correction for multiple comparisons (adjusted p\u0026thinsp;=\u0026thinsp;0.007). Conversely, the banana-shaped, hourglass-shaped, and funnel-shaped configurations did not significantly differ between the two groups. Among these, the hourglass-shaped configuration tended to have a lower prevalence in the dentate group (OR\u0026thinsp;=\u0026thinsp;0.28; 95% CI: 0.06\u0026ndash;1.02; p\u0026thinsp;=\u0026thinsp;0.055), although this difference did not reach statistical significance after correction for multiple testing.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMorphological characteristics of the nasopalatine canal.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEdentulous group\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDentate\u0026nbsp;group\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eOn the coronal plane\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e0.019*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSingle and broad cannal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35 (64.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26 (48.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eY- shaped canals\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16 (29.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28 (51.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTwo parallel canals\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (5.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eOn the sagittal plane\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e0.005*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBanana-shaped\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13 (24.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (11.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHourglass\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (22.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (7.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCylindrical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16 (29.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33 (61.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFunnel\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13 (24.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11 (20.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e(*) Fisher\u0026rsquo;s exact test\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eWith the advancement of CBCT, detailed three-dimensional evaluation of craniofacial anatomical structures has become possible, particularly for the nasopalatine canal, which exhibits considerable morphological variability and represents an important anatomical structure to consider during dental procedures in the anterior maxilla [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The present study was conducted to investigate potential differences in the anatomical characteristics of the nasopalatine canal and the bone region anterior to the canal between completely edentulous and dentate maxillae. To the best of our knowledge, this study represents the first investigation evaluating these anatomical structures in a Southeast Asian population while directly comparing dentate individuals with completely edentulous patients.\u003c/p\u003e \u003cp\u003eIn the present study, the results indicated that the nasopalatine canal width tended to increase in edentulous patients, both in the buccolingual and mesiodistal dimensions. Notably, in this study, the buccolingual width was measured using the Frankfort horizontal plane as the reference plane. This measurement approach may result in slightly smaller canal diameter values than the actual anatomical diameter, which may partially explain the differences observed when the present findings are compared with those reported in previous studies [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Nevertheless, the overall trend observed in this study is consistent with several previous investigations that reported a significant association between tooth loss and changes in nasopalatine canal dimensions [\u003cspan additionalcitationids=\"CR17\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. These anatomical alterations are generally attributed to alveolar bone remodeling following tooth extraction, which may lead to relative enlargement of the canal [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Conversely, some investigations have suggested that the diameter of the nasopalatine canal may remain relatively stable in edentulous individuals [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Such discrepancies across studies may be related to differences in measurement protocols, reference planes, imaging parameters, or population characteristics.\u003c/p\u003e \u003cp\u003eWith respect to the length of the nasopalatine canal, the present study revealed mean values of 11.45\u0026thinsp;\u0026plusmn;\u0026thinsp;2.88 mm in the dentate group and 9.63\u0026thinsp;\u0026plusmn;\u0026thinsp;3.54 mm in the edentulous group, indicating a tendency toward reduced canal length in edentulous patients. This finding is consistent with the observations reported by T\u0026ouml;z\u0026uuml;m et al. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], who similarly noted a decrease in canal height following tooth loss. Several other CBCT-based studies have also reported that dentate individuals tend to present greater nasopalatine canal lengths than edentulous subjects do, although the absolute measurements vary across studies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The variability in reported values may be explained in part by differences in measurement protocols and landmark identification. In the present study, canal length was determined via reference points primarily derived from width-related anatomical landmarks, which may influence the final measurement. Consequently, the measured canal length may slightly underestimate the true anatomical length in certain morphological configurations. This effect is particularly evident in banana-shaped canals, where the curved trajectory of the canal may lead to smaller linear measurements when a straight reference axis is used. In contrast, for other canal morphologies, the discrepancy between the measured and actual canal lengths is expected to be minimal.\u003c/p\u003e \u003cp\u003eWith respect to the nasopalatine canal morphology observed on the coronal plane, the single canal and Y-shaped configurations were the two most frequently encountered patterns in both study groups. In the dentate group, the Y-shaped configuration was the most prevalent morphology, accounting for 51.9% of the cases, which is consistent with the findings reported by Fukuda et al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. In contrast, the edentulous group demonstrated a predominance of the single canal configuration (64.8%), a distribution similar to that described by \u0026Ouml;zarslant\u0026uuml;rk et al. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] in partially edentulous patients. The observed differences in canal morphology between dentate and edentulous individuals on the coronal plane may be related to post-extraction anatomical remodeling. Following tooth loss, alveolar bone resorption and expansion of the nasopalatine canal may occur, potentially altering the internal branching pattern of the canal. These structural changes may contribute to the increased prevalence of simplified canal configurations, such as the single canal type, in edentulous patients.\u003c/p\u003e \u003cp\u003eThe classification of nasopalatine canal morphology on the sagittal plane in the present study followed a four-type system\u0026mdash;cylindrical, funnel-shaped, hourglass-shaped, and banana-shaped\u0026mdash;similar to the classification proposed by Fukuda et al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Overall, the cylindrical configuration was the most frequently observed morphology in the entire sample, which is consistent with the findings reported in several previous CBCT studies [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. In the dentate group, the cylindrical type accounted for 61.1% of the cases, followed by the funnel-shaped configuration (20.4%), the banana-shaped configuration (11.1%), and the hourglass-shaped configuration (7.4%). In contrast, the edentulous group demonstrated a more evenly distributed pattern of canal morphologies, with relatively higher proportions of banana-shaped (24.1%) and hourglass-shaped (22.2%) canals, although the cylindrical type remained the most common configuration (29.6%). However, the distribution observed in the present study differs from that reported by Fukuda et al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], who reported the funnel-shaped canal to be the most prevalent morphology in maxillary specimens, followed by the cylindrical type. Similar findings were also reported by Mardinger et al. [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. These discrepancies may suggest that factors such as ethnic background, environmental influences, and dental status may significantly affect the morphological characteristics of the nasopalatine canal.\u003c/p\u003e \u003cp\u003eWith respect to the bone region anterior to the nasopalatine canal, the present study demonstrated that the dentate group presented significantly greater buccal bone dimensions than did the edentulous group did, particularly in terms of bone width measured at 1 mm and 6 mm apical to the alveolar crest. A similar trend was reported by Gil-Marques et al. [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], although the measurement protocol differed. In their study, the width of the buccal bone was evaluated at three reference levels, namely, at the horizontal level of the anterior nasal spine, at the most anterior-inferior point of the buccal cortex of the maxilla, and at the midpoint between these two levels. Despite differences in measurement landmarks and methodological approaches, both studies consistently demonstrated that the buccal bone plate is thicker in dentate individuals than in edentulous patients. The values reported in the present study differ considerably from those described by Mehrotra et al. [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], who reported mean bone heights of 7.99\u0026thinsp;\u0026plusmn;\u0026thinsp;1.40 mm in dentate individuals and 5.18\u0026thinsp;\u0026plusmn;\u0026thinsp;1.10 mm in edentulous patients. Nevertheless, both studies consistently reported that the buccal bone height anterior to the nasopalatine canal is greater in dentate individuals than in edentulous individuals, suggesting that tooth loss is associated with significant vertical and horizontal bone resorption in the anterior maxilla.\u003c/p\u003e \u003cp\u003eThe findings of the present study indicate that edentulous patients tend to exhibit increased nasopalatine canal width, greater canal angulation, and a reduction in the surrounding anterior maxillary bone volume. In addition, the results demonstrated an increase in the nasopalatine canal angle and a decrease in the buccal bone height anterior to the canal in edentulous individuals, which is consistent with the observations reported by Jia et al. [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. These anatomical alterations may be largely attributed to alveolar bone resorption associated with aging and, more prominently, following tooth extraction [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Progressive bone remodeling in the anterior maxilla may lead to relative enlargement of the nasopalatine canal and a reduction in the surrounding bone volume over time. Furthermore, the observed variations may also be influenced by several factors, including demographic characteristics, ethnic background, environmental influences, and the patient\u0026rsquo;s dental status. In the present study, the investigated population consisted of completely edentulous patients, whereas most previously published studies have primarily examined dentate or partially edentulous populations. Studies specifically focusing on completely edentulous individuals remain relatively limited worldwide. In addition, differences in measurement protocols, reference landmarks, and methods used to determine canal orientation and angulation may contribute to the variability in findings reported across different studies.\u003c/p\u003e \u003cp\u003eIn recent years, implant placement involving the nasopalatine canal region has become increasingly utilized in full-arch rehabilitation for patients with severe maxillary bone resorption. This anatomical site has been proposed as a feasible implant anchorage area, with studies suggesting that it does not pose a substantial surgical risk and may contribute to improved load distribution in full-arch prosthetic restorations [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Currently, two principal surgical approaches have been described for implant placement in the nasopalatine canal region. The first technique involves removal of the nasopalatine neurovascular bundle followed by direct implant placement within the canal. In this approach, the implant engages the bony walls of the nasopalatine canal; therefore, the implant diameter is largely determined by the canal dimensions [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. In the present study, the largest mean canal diameter measured 4.72\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17 mm in the buccolingual direction and 4.83\u0026thinsp;\u0026plusmn;\u0026thinsp;1.24 mm in the mesiodistal direction, which falls within the commonly available range of implant diameters of approximately 3\u0026ndash;6 mm. The second technique involves implant placement in the bone anterior to the nasopalatine canal while preserving the neurovascular bundle within the canal [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. In this approach, successful implant placement depends largely on the available bone volume and density in the anterior bone region. Consequently, careful selection of the implant dimension is needed to ensure adequate primary stability while avoiding injury to the neurovascular structures of the nasopalatine. In the present study, the mean canal length and anterior bone height in edentulous patients were 9.63 mm and 13.91 mm, respectively, which are generally compatible with the implant lengths commonly used in clinical practice. Overall, these findings suggest that the nasopalatine canal region represents a potentially viable anatomical site for implant placement, particularly in cases of severe anterior maxillary bone resorption. However, owing to the considerable interindividual variability in both canal morphology and dimensions, careful preoperative CBCT evaluation and individualized implant planning are essential to ensure safe and predictable treatment outcomes.\u003c/p\u003e \u003cp\u003eSeveral limitations of this study should be acknowledged. First, the study was conducted with a relatively limited sample size, and the data were obtained from a single center, which may limit the representativeness of the study population and reduce the generalizability of the findings. Second, clinical information regarding the patients, including their oral health status and the duration of tooth loss, was not comprehensively available in the dataset. These factors may play a role in the extent of alveolar bone remodeling and nasopalatine canal morphology and therefore could have influenced the results. Future studies with larger multicenter samples, balanced demographic characteristics, and comprehensive clinical data are needed to further validate and expand upon the findings of the present study.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe present CBCT-based study demonstrated that tooth loss is associated with significant anatomical alterations in the nasopalatine canal and the surrounding anterior maxillary bone. Specifically, edentulous patients exhibited increased canal width and angulation, whereas the canal length and the bone volume anterior to the canal were reduced compared with those of dentate individuals. In addition, the nasopalatine canal showed substantial morphological variability. In the coronal plane, the Y-shaped configuration predominated in dentate individuals, whereas the single canal configuration was more common in completely edentulous patients. On the sagittal plane, the cylindrical morphology represented the most frequent configuration across the entire sample.\u003c/p\u003e \u003cp\u003eThese findings underscore the dynamic anatomical changes occurring in the anterior maxilla following tooth loss and highlight the importance of comprehensive CBCT evaluation for individualized planning of implant treatment in this region. Given the considerable interindividual variability in canal morphology and surrounding bone dimensions, patient-specific anatomical assessment should be considered essential for optimizing implant placement and minimizing surgical complications in the anterior maxilla.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCBCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econe-beam computed tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eICC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eintraclass correlation coefficient\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eANS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eanterior nasal spine\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGSV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003egrayscale density values\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econfidence interval\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eodds ratio\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eANCOVA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eanalysis of covariance\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGLM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003egeneralized linear model\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e \u003cp\u003e Ethical approval for this study was obtained from the Institutional Ethics Committee in Biomedical Research at the University of Health Sciences, Ho Chi Minh City, under approval number 02/QD-HDDD. Written informed consent was obtained from all participants, and they were made aware of the potential risks associated with CBCT.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003e \u003cb\u003eConsent for publication\u003c/b\u003e -\u003c/strong\u003e \u003cp\u003eNot applicable\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003e \u003cb\u003eCompeting interests\u003c/b\u003e -\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding \u0026ndash;\u003c/h2\u003e \u003cp\u003eThis study did not receive any specific grants from any funding agencies or commercials.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eC.L.N.H. contributed to the study conceptualization and design, data analysis, and review and editing the manuscript. Q.T.N.N. and T.N.P.P. collected the data regarding the morphometric and morphological characteristics of the canal. N.T.T.N. and N.H.N. contributed to the study conceptualization and design and prepared the original draft. L.T.D. contributed to the study conceptualization and design, data analysis, review and editing of the manuscript, and approved the final version of the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgments \u0026ndash;\u003c/h2\u003e \u003cp\u003eNone\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBodereau EF, Flores VY, Naldini P, Torassa D, Tortolini P. Clinical Evaluation of the Nasopalatine Canal in Implant-Prosthetic Treatment: A Pilot Study. Dent J (Basel). 2020;8(2).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBains SK, Bhatia A, Sodhi SS, Sharma A. Assessment of the Nasopalatine Canal in Patients Requiring Dental Implants in the Maxillary Anterior Region Using Cone Beam Computed Tomography. Cureus. 2023;15(12):e50643.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSinghal MK, Dandriyal R, Aggarwal A, Agarwal A, Yadav S, Baranwal P. Implant Placement into the Nasopalatine Foramen: Considerations from Anatomical and Surgical Point of View. Annals maxillofacial Surg. 2018;8(2):347\u0026ndash;51.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ede Mello JS, Faot F, Correa G, Chagas J\u0026uacute;nior OL. Success rate and complications associated with dental implants in the incisive canal region: a systematic review. Int J Oral Maxillofac Surg. 2017;46(12):1584\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeighton Y, de Souza RF, Borie E. Using the Nasopalatine Canal for Enhanced Distribution in Severely Atrophic Maxilla With Immediate Loading of Zygomatic Implants: An 8-Year Retrospective Cohort Study. J Craniofac Surg. 2025;36(4):e374\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVasiljevic M, Selakovic D, Rosic G, Stevanovic M, Milanovic J, Arnaut A et al. Anatomical Factors of the Anterior and Posterior Maxilla Affecting Immediate Implant Placement Based on Cone Beam Computed Tomography Analysis: A Narrative Review. Diagnostics (Basel Switzerland). 2024;14(15).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eT\u0026ouml;z\u0026uuml;m TF, G\u0026uuml;nc\u0026uuml; GN, Yıldırım YD, Yılmaz HG, Galindo-Moreno P, Velasco-Torres M, et al. Evaluation of maxillary incisive canal characteristics related to dental implant treatment with computerized tomography: a clinical multicenter study. J Periodontol. 2012;83(3):337\u0026ndash;43.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFirincioglulari M, Orhan K. Morphological Variations of the Nasopalatine Canal in the North Cyprus Population: A Cone Beam Computed Tomography Study. Med Sci monitor: Int Med J experimental Clin Res. 2024;30:e944868.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKhan M, Habib S, Ghafoor R. Evaluation of the Nasopalatine Canal (NPC) in a subset of Pakistani population, using Cone Beam Computed Tomography (CBCT). JPMA J Pakistan Med Association. 2023;73(1):49\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSarna K, Estreed MA, Sonigra KJ, Amuti T, Opondo F, Kamau M, et al. Anatomical Patterns of the Nasopalatine Canal and Incisive Foramen in an African Setting: A Cross-Sectional Study. Craniomaxillofacial trauma reconstruction. 2023;16(3):222\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e\u0026Ouml;zarslant\u0026uuml;rk S, Ceylan Şen S, Sara\u0026ccedil; Atag\u0026uuml;n \u0026Ouml;. Retrospective Evaluation of Nasopalatine Canal Anatomy, Dimensions, and Variations with Alveolar Bone in Patients Scheduled for Maxillary Anterior Dental Implant Surgery Using Cone Beam Computed Tomography. Tomography (Ann Arbor, Mich). 2025;11(10).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGil-Marques B, Sanchis-Gimeno JA, Brizuela-Velasco A, Perez-Bermejo M, Larraz\u0026aacute;bal-Mor\u0026oacute;n C. Differences in the shape and direction-course of the nasopalatine canal among dentate, partially edentulous and completely edentulous subjects. Anat Sci Int. 2020;95(1):76\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDemiralp K, Kurşun-\u0026Ccedil;akmak E, Bayrak S, Sahin O, Atakan C, Orhan K. Evaluation of Anatomical and Volumetric Characteristics of the Nasopalatine Canal in Anterior Dentate and Edentulous Individuals: A CBCT Study. Implant Dent. 2018;27(4):474\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlhumaidi AM, Al Moaleem MM, Gadah TS, Alahmari NM, Al Makramani BMA, Mattoo K, et al. Variations in nasopalatine canal morphology across populations: a cone-beam computed tomography systematic review and proposed nomenclature system. Folia Morphol. 2025;84(3):521\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim YT, Lee JH, Jeong SN. Three-dimensional observations of the incisive foramen on cone-beam computed tomography image analysis. J periodontal implant Sci. 2020;50(1):48\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBornstein MM, Balsiger R, Sendi P, von Arx T. Morphology of the nasopalatine canal and dental implant surgery: a radiographic analysis of 100 consecutive patients using limited cone-beam computed tomography. Clin Oral Implants Res. 2011;22(3):295\u0026ndash;301.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG\u0026uuml;nc\u0026uuml; GN, Yıldırım YD, Yılmaz HG, Galindo-Moreno P, Velasco-Torres M, Al-Hezaimi K, et al. Is there a gender difference in anatomic features of incisive canal and maxillary environmental bone? Clin Oral Implants Res. 2013;24(9):1023\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePe\u0026ntilde;arrocha D, Candel E, Guirado JL, Canullo L, Pe\u0026ntilde;arrocha M. Implants placed in the nasopalatine canal to rehabilitate severely atrophic maxillae: a retrospective study with long follow-up. J Oral Implantol. 2014;40(6):699\u0026ndash;706.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFukuda M, Matsunaga S, Odaka K, Oomine Y, Kasahara M, Yamamoto M, et al. Three-dimensional analysis of incisive canals in human dentulous and edentulous maxillary bones. Int J implant dentistry. 2015;1(1):12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSafi Y, Moshfeghi M, Rahimian S, Kheirkhahi M, Eslami Manouchehri MJIJR. Assessment of nasopalatine canal anatomic variations using cone beam computed tomography in a group of Iranian population. 2017;14(1):e37028.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKhojastepour L, Haghnegahdar A, Keshtkar M. Morphology and Dimensions of Nasopalatine Canal: a Radiographic Analysis Using Cone Beam Computed Tomography. J dentistry (Shiraz Iran). 2017;18(4):244\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMardinger O, Namani-Sadan N, Chaushu G, Schwartz-Arad D. Morphologic changes of the nasopalatine canal related to dental implantation: a radiologic study in different degrees of absorbed maxillae. J Periodontol. 2008;79(9):1659\u0026ndash;62.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMehrotra G, Bhoosreddy A, Bhoosreddy S, Bhadage C, Sharma K, Shah KJJICDRO. Three-Dimensional Analysis of the Nasopalatine Canal in Dentulous and Edentulous Maxilla\u0026ndash;A Cone-Beam Computed Tomography Study. 2020;12(2):148\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJia X, Hu W, Meng H. Relationship of central incisor implant placement to the ridge configuration anterior to the nasopalatine canal in dentate and partially edentulous individuals: a comparative study. PeerJ. 2015;3:e1315.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMishra R, Thimmarasa V, Jaju PP, Mishra R, Shrivastava AJJDI. Influence of gender and age on nasopalatine canal: A cone-beam computed tomography study. 2017;7(1):15\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eScher EL. Use of the incisive canal as a recipient site for root form implants: preliminary clinical reports. Implant Dent. 1994;3(1):38\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArtzi Z, Nemcovsky CE, Bitlitum I, Segal P. Displacement of the incisive foramen in conjunction with implant placement in the anterior maxilla without jeopardizing vitality of nasopalatine nerve and vessels: a novel surgical approach. Clin Oral Implants Res. 2000;11(5):505\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"nasopalatine canal, incisive canal, cone-beam computed tomography, edentulous maxilla, dental implants","lastPublishedDoi":"10.21203/rs.3.rs-9187671/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9187671/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eAnatomical changes associated with tooth loss may alter the morphology and dimensions of the nasopalatine canal, potentially affecting implant planning. However, comparative evidence between dentate and completely edentulous maxillae remains limited. This study aimed to evaluate and compare the morphological and morphometric characteristics of the nasopalatine canal and the anterior bone region in dentate and completely edentulous patients via cone-beam computed tomography (CBCT).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eCross-sectional CBCT analysis was performed on 108 patients (54 dentate maxillae and 54 completely edentulous maxillae). Morphometric parameters of the nasopalatine canal and the bone anterior to the canal were measured in the axial, sagittal, and coronal planes. Interobserver reliability was assessed via intraclass correlation coefficients (ICCs) and Cohen\u0026rsquo;s kappa. Intergroup comparisons were conducted via regression models adjusted for age and sex.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eCompared with the edentulous group, the dentate group presented a significantly greater nasopalatine canal length (mean difference: 1.66 mm; 95% CI: 0.42\u0026ndash;2.90; p\u0026thinsp;=\u0026thinsp;0.009), whereas canal angulation was smaller (\u0026minus;\u0026thinsp;6.47\u0026deg;; 95% CI: \u0026minus;9.93 to \u0026minus;\u0026thinsp;3.00; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). On sagittal images, the middle and inferior canal widths were significantly smaller in the dentate group (ratios of means: 0.79 and 0.80; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), whereas the superior width was not different. Similarly, on axial views, the middle and inferior horizontal canal widths were reduced in the dentate group. The bone region anterior to the nasopalatine canal in the dentate individuals presented greater buccal crestal length (4.66 mm; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and greater bone width at 1 mm and 6 mm apical to the crest (ratios: 1.65 and 1.24; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Morphologically, the Y-shaped canal configuration predominated in dentate patients (51.9%), whereas the single-canal configuration was more common in the edentulous group (64.8%). On the sagittal plane, cylindrical morphology was significantly more common in dentate individuals (odds ratio (OR)\u0026thinsp;=\u0026thinsp;3.68; 95% CI: 1.56\u0026ndash;9.00).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eEdentulous patients exhibit wider and more angulated canals but reduced canal length and anterior bone volume. These findings highlight the importance of individualized CBCT evaluation to optimize implant planning and minimize surgical complications in the anterior maxilla.\u003c/p\u003e\u003ch2\u003eTrial registration:\u003c/h2\u003e \u003cp\u003eNot applicable\u003c/p\u003e","manuscriptTitle":"Morphological and Morphometric Characteristics of the Nasopalatine Canal in Dentate and Edentulous Patients: A Cone-Beam Computed Tomography Cross-Sectional Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-23 09:09:38","doi":"10.21203/rs.3.rs-9187671/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d037a36a-0b15-4282-89a3-6032a0a0bfa8","owner":[],"postedDate":"April 23rd, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Rejected","date":"2026-05-13T05:54:41+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-13T06:13:20+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-23 09:09:38","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9187671","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9187671","identity":"rs-9187671","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}