Three-Dimensional Odontometric Mapping of Maxillary Anterior Teeth Using CBCT in an Indian Cohort for Precision Endodontic Access cavity preparation: A primary investigation

Three-Dimensional Odontometric Mapping of Maxillary Anterior Teeth Using CBCT in an Indian Cohort for Precision Endodontic Access cavity preparation: A primary investigation | 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 Article Three-Dimensional Odontometric Mapping of Maxillary Anterior Teeth Using CBCT in an Indian Cohort for Precision Endodontic Access cavity preparation: A primary investigation Monal Ajay Kohok, Ashish Mandwe, Anuj Bhardwaj, Dian Agustin Wahjuningrum, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6988842/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 05 Nov, 2025 Read the published version in Scientific Reports → Version 1 posted 18 You are reading this latest preprint version Abstract Access cavity preparation is an important part of endodontic therapy, affecting the effectiveness of canal instrumentation and the durability of the tooth over time. Currently, most access preparation protocols are based on information from a Western population and do not address the anatomical differences of different ethnic groups. This retrospective CBCT study assessed specific odontometric measurements in maxillary anterior teeth—central incisors, lateral incisors and canines—using an Indian population to help identify a clinically relevant and conservative access cavity preparation. A total of six hundred cone-beam computed tomography (CBCT) images of maxillary central incisors, lateral incisors, and canines (n = 200 per tooth) were evaluated. These images were obtained from Indian individuals aged 18 to 25 years. Three measurements were made in sagittal view: the distance from the central fossa to the pulp chamber roof (CF–PC), the incisal edge to pulp chamber (IE–PC), and the central fossa to cingulum (CF–C). Differences attributable to gender, and between teeth, were statistically significant (p < 0.05). The lateral incisors had the largest amount of anatomical variability, while the canines had the steepest trajectory of access. These findings provide the first population-based CBCT reference values for maxillary anterior teeth in India, and a practical guide to help achieve safe access design that is mindful of tooth anatomy and minimizes the invasiveness of the access. Health sciences/Anatomy Health sciences/Diseases Health sciences/Health care Health sciences/Medical research Cone-Beam Computed Tomography Odontometry Access Cavity Preparation Three-Dimensional Imaging Tooth Morphology Figures Figure 1 Figure 2 Figure 3 Introduction The precision of endodontic treatment essentially begins with proper design and execution of the access cavity. This is a critical part of the endodontic treatment that dictates the success of the remainder of the procedures of debridement, shaping of the canals, and obturation. It also has considerable influence over the long-term success of treatment. These include missing canals, over-preparation, perforation, inadequate seal, and ultimately failure 1 . While there are common principles established in endodontic access cavity design and execution, advances in technology, materials, treatment philosophies (e.g., minimally invasive endodontics) call for an updated, evidence-based approach to access protocols using imaging and anatomical evidence from today's fields of endodontics and dental/restorative practices 2 . The maxillary anterior teeth; central incisors, lateral incisors, and canines may differ when it comes to access cavity preparation. While maxillary anterior teeth are less complex than posterior teeth in terms of the canal architecture, they can present unique, anatomical difficulties in root angulation, enamel-dentin thickness, and location of pulp chamber for different ethnic groups 3 . The risk for potential iatrogenic damage is increased when clinicians apply a generalized anatomic understanding based on mostly Caucasian morphometric datasets. Given that dentistry is currently transitioning towards the era of precision and personalization, there is increased risk when the same generic based assumptions outlined in universal guidelines are applied to clinicians practice which can risk both the outcome of the care recipient and the structure of the teeth that are meant to be protected 4 . Current literature indicates the Indian population displays specific dental morphologies that necessitate separate clinical management 5,6 . For example, while Western maxillary lateral incisors have variable pulp chamber depths and variability in canal morphology, Indian maxillary lateral incisors were more variable than the standard Western incisor 7 . Additionally, reported variations in maxillary canines despite being a fairly straight forward tooth may have increased curvature, increased depth of pulp chamber and increased enamel thickness can potentially require changes in conventional access 8 . Finally, in addition to the existing anatomic morphometric variations in teeth, there are additional sex differentials that contribute additional complexity to the morphometric and operative access 9,10 . Traditional access approaches are heavily reliant on visual external indicators such as the incisal edge, central fossa or the cementoenamel junction (CEJ) to approximate the location and angle of the internal pulp chamber. These previously described anatomical features are not always reliable, as there may be calcification, trauma, excessive restorations or congenital issues 11 . This is further complicated by the use of 2D periapical radiographs, which can be affected by image distortion, superimposed anatomical variances and, ultimately, imaging is a sole representation of the internal tooth structures without true spatial relationships in the sagittal and axial dimensions 12 . Cone-beam computed tomography (CBCT) has dramatically changed dental diagnosis due to three-dimensional, high resolution and multiplanar imaging allowing the clinician to visualize the tooth and surrounding structure and permitting them to do so without overlapping images. CBCT is an excellent tool for endodontic practice as it allows the clinician to see pulp chamber morphology, canal orientation, pericervical dentin thickness, and any anatomical variations that will inform the development of safe and conservative access designs 13,14 . The use of CBCT is well-supported in the literature in regards to planning and executing both primary and retreatment endodontic cases, especially when anatomical variations will be suspected 15 . Modern endodontic practice has seen a change in philosophy, of late, rationalizing a more minimally invasive access cavity (MIAC) preparation to preserve tooth structure without compromising the ideal visual and mechanical access to the canal system and subsequent central access instrumentation and debridement. The MIAC paradigm emphasizes preserving the pericervical dentin (PCD), which is the most critical variable for fracture resistance following treatment, as well as longevity of the tooth 16 . However, it may lead to a challenge trying to conserve part of the access cavity while properly preparing and imaging the canal, as overly conservative or inaccurate designs could leave an incomplete canal anatomy resulting in insufficient debridement. Therefore, success in MIAC procedures is heavily dependent upon accurate anatomical knowledge and preoperative imaging, which CBCT has the potential to provide 17 . Yet, the absence of population-specific odontometric data available for comparing analyzing CBCT images is still substantial, particularly within a South Asian context. The majority of studies available are aimed at European, North American, or East Asian cohorts and while they can be informative, generalizing for clinical applicability to India is limited with this data. Given India's vast population and population structure, which is highly heterogeneous and includes distinctive differences in craniofacial morphology based on both region and ethnic group, international data may lead to poor access strategies and a greater occurrence of procedural errors 18 . Furthermore, no CBCT-based studies on access cavity design come with a standardized, reproducible measurement protocol nor evaluate the clinical significance within minimal intervention practice. The translational gap between morphometric data and clinical protocols also needs to be addressed. The other gap in the literature is the role of anatomical sex differences in access cavity designs. Previous studies indicate that males tend to have larger pulp chambers and dentin thicknesses while females presented narrower root canals and more curvature in specific tooth types when assessing dentin thickness 19–21 . While these differences may be small in nature, they can contribute to depth and angulation of access cavities more so in the higher risk teeth (eg, lateral incisors, curved canines). As such, accounting for anatomical sex differences may further enhance planning to more explicitly match treatment strategies. This study aims to fulfil these unmet needs by performing a complete CBCT-driven odontometric study of maxillary anterior teeth of an Indian population. This study measures three clinically relevant measurements: The distance from the central fossa to the pulp chamber (CF-PC), The distance from the incisal edge to the pulp chamber (IE-PC), and The distance from the central fossa to the cingulum (CF-C). These measurements are critical in determining the entry point, angulation, and depth when preparing access cavities. These anatomical landmarks are chosen because they are clinically visible, reproducible between patients, and clinically relevant to where the endodontic files are placed. Beyond measuring population averages, this study also focuses on sex-specific differences and inter-tooth differences (central incisor, lateral incisor, canine) to produce relevant clinical data for clinical applications. Methodology Study Design and Ethical Compliance This research was conducted as a retrospective, cross-sectional imaging analysis using cone beam computed tomography (CBCT), and assessed some odontometric parameters in relation to access cavity preparation in maxillary anterior teeth. The study protocol was reviewed and approved by the institutional ethics committee of the College of Dental Sciences and Hospital (Ref. No. CDSH/Admin/2024; dated 15-10-2024), and was conducted with the full understanding and consent of the ethical principles of the Declaration of Helsinki. In view of the study's retrospective design and the use of existing anonymised radiographic information, informed consent was not required. Sample size estimation Sample size for this study was determined based on the primary outcome, which is the distance from the cusp tip to the furcation; we used an effect size from a previous study. In a previous study 22 , it reported an effect size of 0.215 for the distance from the cusp tip to the furcation. Therefore, in order to have a statistical power of 0.80 and a significance level of 0.10 our minimum estimated sample size was 534 with GPower (Version 3.1.9.3). In our case, the pilot study used 10% of sample size or 53 samples. In GPower we performed the analysis with a one-tailed test, an effect size (d) 0.2156878, a α error probability of 0.05, a power (1 − β) of 0.80, and an allocation ratio (N2/N1) of 1. The analysis output included a noncentrality parameter (δ) of 2.4921043, a critical t of 1.6477229, 533 degrees of freedom, 534 total sample size, and actual power of 0.8006877. In order to allow a more thorough examination on all the tooth types being studied, the sample was increased to 600 teeth. Each tooth type (the maxillary central incisor, the maxillary lateral incisor, and the maxillary canine) was then represented with a subsample of 200. Sample Selection and Imaging Protocol The institutional imaging database was accessed to identify eligible CBCT scans retrospectively. The scans had been originally taken for diagnostic purposes unrelated to the current study velocity during the period January 2022 to December 2023. Eligibility criteria Indian adults aged 18–25 years. Permanent maxillary central incisors, lateral incisors, and canines with both good dental morphology, and fully erupted. CBCT scans from radiology departments with sufficient resolution and/or diagnostic quality. Exclusion criteria: Presence of crown or root fractures, extensive restorative treatment, caries, prostheses, or previous endodontics. Evidence of periapical pathology, root resorption, calcified canals and/or severe malalignment. CBCT scans with artefacts, insufficient resolution, or data loss Imaging Parameters To ensure coherence between diagnostic protocols and measurement accuracy, all CBCT scans contributed to the outcome of this investigation were acquired using a standardized imaging protocol. Imaging was completed utilizing a Planmeca ProMax® 3D (Planmeca Group Planmeca Oy, Helsinki, Finland) system with the following imaging parameters; tube voltage of 90 kV; tube current of 10 mA; and an approximate field of exposure of 13.8 seconds. Depending on the required anatomical coverage, the field of view (FOV) ranged from 12×15 cm to 16×16 cm, with a voxel size of 0.40 mm, which provided acceptable spatial resolution to evaluate the small anatomical details relevant to access cavity planning. The estimated averaged radiation dose was in the range of 2.0 and 2.2 milligrays (mGy), which is within acceptable diagnostic ranges for dental CBCT protocols. This protocol provided a balance between minimizing the patients radiation exposure and developing sufficient image clarity to make accurate three-dimensional odontometric measurements. All images were reconstructed in DICOM format and evaluated using proprietary CBCT viewing software Romexis® 3D (Planmeca Group Planmeca Oy, Helsinki, Finland) in sagittal cross-sectional view. Odontometric Parameters and Measurement Protocol Three clinically significant odontometric parameters were measured for each tooth in the sagittal plane, following anatomical standardization: CF–PC (Central Fossa to Pulp Chamber Roof): Indicates the vertical penetration depth required to reach the pulp chamber while minimizing over-extension. Aids in controlling bur advancement to avoid floor perforation. IE–PC (Incisal Edge to Pulp Chamber Roof): A spatial reference indicating the pulpal entry point of the bur. Also indicates the incisal-pulpal vertical relationship which is critical when choosing the initial angulation for cutting in access preparation of anterior teeth. CF–C (Central Fossa to Cingulum): Serves as a spatial reference for modifying bur trajectory in a labio-palatal direction, but also reliably orients bur trajectory to improve any sort of minimally invasive access orientation. Measuring method Identification of the incisal edge, pulp chamber roof, central fossa, and cingulum anatomical landmarks was performed manually, using the sagittal cross-section. The software's digital caliper tool allowed for direct linear measurements in millimeters (mm) along a linear vector reflecting the long axis of the tooth. All values were recorded to two decimal points (Figure 1). Each parameter was measured independently by two calibrated observers. To reduce operator bias, measurements were repeated after a two-week interval for 10% of the sample, and the mean value was used for final analysis. Observer Calibration and Reliability Measurement Two trained endodontists (MK and AMP) went through a structured calibration process, which included: Training on how to navigate the CBCT software and identify anatomical landmarks. Practice measuring on a subset of 30 scans that were randomly selected and excluded from the final analysis. Inter-observer reliability was determined using Cohen’s kappa statistics (κ). Reliability values of >0.85 indicates excellent measure agreement. Intra-observer reliability was calculated using the intraclass correlation coefficient (ICC), and all ICC values exceeded 0.90 confirming a substantial reliability of subjective measurements. To improve the accuracy of measurements, where applicable, the automated edge-detection features of the CBCT software were used to reduce user error when identifying landmark locations retrospectively. Statistical Analysis Data were compiled and examined with the IBM SPSS Statistics (v25.0; IBM Corp., Armonk, NY). Descriptive means, standard deviation (SD), range and 95% confidence intervals were calculated for all odontometric parameters. For comparison Independent samples t-tests were performed to investigate gender-based differences in measurements for each tooth type. Where appropriate, ANOVA or Kruskal-Wallis tests took place to compare values for tooth types (central incisor, lateral incisor, canine). A p-value < 0.05 stated statistical significance. All statistical approaches accounted for all assumptions of normality and homoscedasticity. For datasets that violated normality, or followed non-parametric distributions, non-parametric alternatives were selected instead. Graphical representations of the data, including box plots, were also created to visualise trends in anatomy and potential outliers. Results Sample Characteristics In total, 600 maxillary anterior teeth (central incisors, lateral incisors, and canines) scanned from Indian patients aged 18-25 were included in the final analysis. 243 teeth were collected from male patients while 357 were from female patients. All selected scans met the inclusion criteria, and none of the data were omitted as a result of image artifacts or incomplete anatomical view. Odontometric Measurements Three principal odontometric measurements from this study are illustrated in Figure 1: CF–PC, IE–PC, and CF–C, were Product examples from the three-dimensional CBCT. While they can be used in application in any clinical access cavity plan, they given their direct measuring of landmark points relevant to clinical purpose of access cavity planning on a maxillary anterior tooth. The CF–PC (Central Fossa to Pulp Chamber Roof) measurement gives the clinician a relevant estimate of vertical depth by demonstrating the distance to achieve penetration to the pulp chamber without compromising the pulpal floor. The IE–PC (Incisal Edge to Pulp Chamber Roof) measurement provides vertical spatial reference and demonstrates the distance from the incisal point of reference to the pulp chamber to guide incisal angulation and entry point during access preparation. The CF-C (Central Fossa to Cingulum) measurement establishes the labio-palatal orientation and therefore guides an ideal axial trajectory of the bur in an indirect manner. The odontometric data collected using sagittal CBCT images of maxillary anterior teeth is displayed in Figure 2. This figure should be used to provide a visual guide to ensure three main measurements could be repeatedly and consistently identified and recorded: CF – PC (Central Fossa to Pulp Chamber Roof); IE – PC (Incisal Edge to Pulp Chamber Roof); CF – C (Central Fossa to Cingulum). The images (a – i) illustrate the stepwise identification of the anatomical landmarks to take reproducible, standardized measurements. Table 1 provides mean, standard deviation (SD), and range for the three odontometric parameters and all tooth types. As seen in the three tooth types, there are considerable anatomical differences between the central incisor, lateral incisor, and canine. Central incisors had the least mean CF–PC distance (2.21 ± 0.37 mm) and the canines had the most CF–PC (3.42 ± 0.85 mm). Central incisors had the largest IE–PC (5.02 ± 0.77 mm) distance compared to the other two tooth types which would equate to deeper penetration of the chamber relative to the incisal edge. The mean CF-C dimension, which indicates the axial buccopalatal angulation difference was most in the central incisor (4.41 ± 0.68) and least in the canine (2.62 ± 0.79 mm) and consistent with their directional difference in morphology. Lateral incisors had the largest standard deviation for all measurements, and this is representative of their variability anatomically in comparison to the central incisor and canine. Table 1. Descriptive Statistics of Odontometric Parameters by Tooth Type. Tooth CF–PC (Mean ± SD) IE–PC (Mean ± SD) CF–C (Mean ± SD) Central Incisor 2.21 ± 0.368 5.02 ± 0.774 4.41 ± 0.675 Lateral Incisor 2.86 ± 0.597 4.52 ± 1.399 3.41 ± 0.807 Canine 3.42 ± 0.848 4.90 ± 1.107 2.62 ± 0.793 CF–PC: Central Fossa to Pulp Chamber Roof; IE–PC: Incisal Edge to Pulp Chamber Roof; CF–C: Central Fossa to Cingulum. Gender Differences Gender comparisons were examined with independent samples t-tests (Table 2). Statistically significant differences were observed in: CF–PC and IE–PC values for both central and lateral incisors were significantly greater for males (p < 0.001 and p < 0.05, respectively). CF–C for any tooth type did not have significant differences between genders. In contrast, canines did not have statistically significant differences based on gender in any of the three dimensions (p > 0.05) indicating anatomical symmetry between sexes in these types. Table 2. Gender-Based Comparison of Odontometric Parameters (Male vs Female, in mm). Tooth CF–PC (M vs F) CF–PC (p) IE–PC (M vs F) IE–PC (p) CF–C (M vs F) CF–C (p) Central Incisor 2.31 vs 2.05 < 0.001* 5.22 vs 4.73 < 0.001* 4.45 vs 4.38 0.304 Lateral Incisor 2.94 vs 2.74 0.022* 4.52 vs 4.52 0.996 3.45 vs 3.37 0.690 Canine 3.49 vs 3.32 0.172 5.00 vs 4.80 0.281 2.67 vs 2.57 0.287 Values represent mean distances in millimeters (mm) for each odontometric parameter. CF–PC: Central Fossa to Pulp Chamber Roof; IE–PC: Incisal Edge to Pulp Chamber Roof; CF–C: Central Fossa to Cingulum. M: Male; F: Female. * indicates a statistically significant difference after independent samples t-tests. Tooth Type Comparison A one-way ANOVA indicated significant differences in all odontometric parameters across tooth types (p < 0.001). Post-hoc Tukey testing revealed that (Table 3): Canines significantly differed from central and lateral incisors in CF–PC and CF–C distances. Lateral incisors differed significantly from central incisors in all three parameters, highlighting their clinical complexity. Table 3. Inter-Tooth Comparison of Odontometric Parameters (ANOVA Summary) Parameter F-statistic p-value Post-hoc Summary CF–PC 15.47 Lateral > Central IE–PC 8.92 Canine ≈ Lateral CF–C 22.63 Lateral > Canine Box plots (Figure 3) show how all measurements were anatomically distributed and included representation of each measurement within tooth types, with clear outliers found predominantly in lateral incisors. Discussion Access cavity preparation is the first step in endodontic treatment stages. It shapes the pathway to all subsequent interventions, including canal negotiation, debridement and shaping, and obturation. Various definitions of access preparation describe it as a type of surgical entry which makes, with proper design, for a potentially successful procedure and conservation of the tooth. Access cavity preparation is of clinical importance, yet it appears little interest has been paid to reporting access cavity design relative to variations in human anatomy 23 . The use of presumptive access cavity design or general forms having derived from Western populations, implicates inter-ethnic and intra-ethnic differences in the treatment, or lack thereof, of instrumentation in endodontics. This discrepancy has implications for clinical accuracy more so than academic. This current CBCT-based study aims to address the gap in evidence regarding access cavity preparation components by providing high-resolution, 3-dimensional, and population based odontometric characteristics regarding access cavity preparation for anterior maxillary teeth. Our research shows that although anterior maxillary teeth are often regarded as morphologically uncomplicated, they exhibit considerable internal variation. The three odontometric parameters CF–PC (central fossa to pulp chamber), IE–PC (incisal edge to pulp chamber), and CF–C (central fossa to cingulum) exhibited statistically significant differences between teeth and between sexes. Central incisors had the shallowest CF–PC measurement but exhibited the highest IE–PC values. Canines had the deepest CF–PC measurement due to their only slight incisal edge, but their apex and internal anatomy reflects its unique prominence of that tooth with a sagittal curvature. It is noteworthy that lateral incisors were the most variable in all three dimensions. Using the previous studies put forth in the literature, the lateral incisor represents the most morphologically unpredictable tooth 24 . This clinical characterization of what appears to be a visually simple tooth has a significant clinical implication; while the lateral incisor may appear visually uncomplicated, it may still be more likely to be over or under-prepared if adhering to standard principles of access. While we did not provide anatomical angles, IE–PC and CF–C values gave us some indirect information regarding the ideal access orientation and together provide evidence that the ideal access trajectory is more incisal or slightly labial in relation to the canal's long axis (especially given a canine or central incisor). Our findings agree with the qualitative findings reported by LaTurno and Zillich 25 , who demonstrated using radiographs that if access is directed more Incisal, it allows for straighter access passageways into the pulp canal system. LaTurno and Zillich 25 did not provide direct quantitative angular values for the access angles, but it still represents a great starting point. Our results support the direction their, using providing direct numerical value: Elevated IE–PC and CF–C values indicate that incisal access allows for an access preparation that is both biomechanically advantageous and also anatomical. Even though we did not have direct angle measures, there is data that indirectly suggests, when performing access preparations, the need to follow the incisal access angle. A particularly interesting comparison arises when comparing our study with the only known attempt to quantify anterior tooth access depth: the study by Lee et al., 26 . In that study, the authors performed an in vitro study of 600 extracted anterior teeth (maxillary and mandibular) by using 2D digital radiography to measure the distance from the lingual surface of the tooth to the pulp chamber. The authors reported access depths of 5.0 mm (lateral incisors) to 5.5 mm (canines) and had low coefficients of variation for all tooth classes. While their data may fit superficially with our IE–PC values, the study design limitations diminish its clinical applicability. Our research provides several methodological enhancements. First, as in vivo imaging is focused via CBCT, we visualised spatial relationships in each plane, including sagittal, axial, and coronal views, with no distortions or overlaps like 2D radiography. Second, while Lee et al, used teeth undergoing caries, restorations, or with uncertain demographic origin, opening the door for measurement variances, we neglected teeth that were not intact and specified individuals with known age and ethnicity, mitigating biases regarding data accuracies and reproducibility. Third, and arguably the most important, Lee et al., 26 ignored anatomical differences related to population-based and sex-based anatomy, including the statistically significant and clinically important findings we documented. The gender-based odontometric differences documented in this study are similar to results in the previous literature and are clinically relevant. Males exhibited significantly larger CF–PC and IE–PC in central and lateral incisors, suggesting a deeper pulp chamber position, along with incisor size differences overall. These differences are in line with prior CBCT-based studies indicating that males tend to have larger pulp volumes, wider canals, and thicker dentin across multiple tooth types due to greater overall crown-root dimensions and dentoalveolar development during adolescence and early adulthood 6 , 19 , 20 . Chaleefong et al., 20 found variability in dentin thickness and pulp-to-tooth ratios to be sex restricted noting that the female mandibular molar canals were narrower and the pulp space constricted which is consistent with data seen in anterior teeth in the previous study. Likewise, Olivieri et al., 19 reported male root dentine thickness was consistently thicker in a variety of tooth types; this is relevant because it informs clinical problematic tooth access both during endodontic planning and iatrogenic error risk. Lee et al., 26 did not evaluate access angulation, nor did they try to quantify access path trajectory directional considerations. Our measure of CF-C adds a new component to the anatomical evaluation of anterior teeth by indirectly measuring the labio-palatal orientation of the pulp chamber. Specifically in relation to central incisors, CF-C is greatest for the central incisors; when considering access to the pulp chamber in this situation, they require angulation caution to minimize gouging or excessive dentin removal on the facial wall. These findings are not purely morphometric in nature; they represent direct considerations of operative decisions with access in relation to direction of bur, point of entry, and penetration depth. Conserving pericervical dentin (PCD) is also of paramount importance in current endodontic practice 27 . The PCD serves as the biomechanical “belt” of tooth, important in sustaining functional stresses and averting vertical root fractures (VRFs) 28 . Indeed, VRFs were reported as prevalent in 10.9% of treated anterior teeth with notably higher risks affecting those with aggressive access or where the dentin was compromised resulting in sacrifice of the dentin 29 , 30 . Our study will contribute to the minimally invasive access cavity (MIAC) model by providing the quantitative landmarks, in particular CF–PC and CF–C to help guide the clinician access the pulp chamber while preserving the dentin that contour it. Our study not only informs on fracture resistance of the tooth but may influence noteworthy aspects of treatment as well, including the restoration of the coronal portion of tooth and eventual refitting of the tooth. The change to MIAC from "straight-line" access is not just theoretical; it is evidence-based 31 . Research has demonstrated that wide generalized access openings do not necessarily improve clinical outcomes and do risk preserving tooth structure 31 , 32 . CBCT-guided access, which relies upon identification of anatomical landmarks, is a compromise between visibility and efficacious conservation 33 . Our data reveals access planning based upon CF–PC and IE–PC distances can be conservatively effective, especially with directional certainty by CF–C measurement. Clinicians may also look forward to including our data in their digital workflows. This study provides values that can be utilized as standardized values in their CAD/CAM software to create individualized access templates. This aspect of the study is particularly useful for challenging cases involving calcified canals, previous trauma, and/or esthetics. In addition to the example above, this research created a body of data for an exciting opportunity to develop machine learning algorithms that delineate the optimal access entry points and angulations based on ethnicities’ specific CBCT datasets. The integration of artificial intelligence could reduce operator variability and time efficiency in practice, especially in general dental practice, where the anatomical subtleties required for optimal access may not be emphasized. This study additionally contributes to the global movement towards personalizing dental care. Currently, the accepted standard of access cavity design relies heavily on Caucasian morphometric studies 34 , and while the Indian population has variations in craniofacial morphology, the dentition exhibits diverse attributes 35 . If we do not account for these differences, the consequence of procedural inaccuracy could subsequently increase the chances of over-preparation, gouging or missing canals. This study offers a dataset based on Indian anatomy to begin developing protocols that account for ethnicity, and thus contribute to equitable and effective dental care. The clinical relevance of our work has numerous implications when considering real-world situations. In cases where anterior esthetics are a priority, such as in young adults or individuals with public-facing employment, effective access that supports minimally invasive approaches is important. Similarly, in endodontic retreatment cases where prior overextension occurred, canal trajectory can be reestablished through physical access procedures in conjunction with CBCT and odontometric references. In addition, these measures can, for less experienced clinicians, help provide evidence-based feasibility toward safe decision-making on bur angulation, depth of access, and canal entry—particularly when external landmarks are altered by trauma, attrition, or restoration. Beyond access trajectory planning, the observed gender-based morphometry also influences downstream clinical and restorative decisions. The lack of significant gender differences in CF–C across all tooth types indicates that the labio-palatal orientation of the access trajectory may be relatively constant, while depth and vertical angulation (as reflected by CF–PC and IE–PC) require sex-specific considerations. These differences may be clinically important when determining access cavity depth, especially in minimally invasive access cavity (MIAC) designs, where even small misjudgements in vertical trajectory may result in under-preparation, missed canals, or pulp chamber perforation. Implementing custom access cavity protocols with sex-based measurements of anatomy may have positive outcomes and potentially decrease errors in procedures, particularly in challenging teeth like lateral incisors that revealed differences in anatomical variability but also in sex differences. The results of this study provide an important basis to establish personalized access cavity protocols with CBCT by assuming relevant contextual endodontic planning tailored to individualized anatomy. Nonetheless, our study has limitations. The design is retrospective and cross-sectional design places limitations on our ability to correlate morphometric data with clinical outcomes, such as treatment success, fracture rate, or postoperative sensitivity. The sample is taken from a single institutional center and could restrict our representation of India's vast inter-regional anatomical variation. Additional limitations include that, while CBCT presents excellent resolution, even high-quality imaging can present variation as a result of factors such as voxel size, software calibration, and operator judgement. We limited these effects via tight observer calibration (ICC > 0.90) and measurement method, but there will always be a certain level of error associated with manual measurement. Some of the possible future work may help alleviate some of these limitations. Future clinical trials could evaluate the effectiveness of access cavity preparations using CBCT and population-specific measurements to see if: 1. relevant clinical consequences for success were found; 2. the preparation process improved iatrogenic positivity; and, 3. tooth survival after endodontics could be confirmed as a consequent improvement. Future work involving dozens of respective clinical trials, and larger multicenter studies to generate sampling from different regions of India may strengthen the odontometric norms and provide reference points of regional variance. Future work that includes artificial intelligence (AI) based tools already being developed to automatically segment and measure access-related parameters in the CBCT may also improve our working definition of circumstances surrounding "endodontic planning". Another avenue of future work - the development of printable access templates using patient-specific views in CBCT - would be an interesting adjunct for teaching and clinician's use with anterior teeth. Conclusion This CBCT-based study is the first to publish accurate population-specific odontometric data reflecting anterior maxillary teeth in a young Indian cohort. There was considerable anatomical diversity—most markedly in lateral incisors—and canines had the deepest CF-PC trajectories to emphasize tooth-specific considerations for access planning. Additionally, we found statistically significant male versus female differences in several parameters that demonstrated that males regularly have greater CF-PC and IE-PC values in central and lateral incisors. Our findings indicated that universal access designs are inadequate and promote access planning that is anatomically driven, gender-sensitive, and ethnicity-informed. We contributed to the literature by providing new measurements (e.g., CF-C) disconnected from previous measurements to guide inferred access trajectories. Our study connected morphometric data with operative relevance in a relationship-building manner. Our work supports a change in the way we approach the science of endodontics towards precision, conservation, and personalized to the clinician. Declarations Competing interests The authors declare no competing interests. Funding This study was supported by the Deanship of Scientific Research and Graduate Studies at King Khalid University in Abha, Saudi Arabia under the Large research group program grant number (RGP.2/469/45). The supporting organization did not participate in the design of the study and collection, analysis, or interpretation of data, in the writing of the report or the decision to submit the report for publication. Author Contribution MAK and AMP conceived and designed the study. MAK and AMP collected the data and performed the primary data analysis. AB provided statistical expertise and contributed to the data interpretation. DAW and DD assisted with the literature review and contextualization of the findings. AMP contributed to the study design and data validation. TPDP, AM, and SA provided guidance on the methodology. MAK and AMP drafted the manuscript and DAW and DD provided critical revisions. All authors reviewed and approved the final manuscript. Data Availability Data is provided within the supplementary information files References Elmatary, A., Moawad, E., Heidarifar, O. & Stone, S. Endodontic access cavity preparation: challenges and recent advancements. Br. Dent. J. 238 , 469–475 (2025). Chan, M. Y. C., Cheung, V., Lee, A. H. C. & Zhang, C. A Literature Review of Minimally Invasive Endodontic Access Cavities - Past, Present and Future. Eur. Endod. J. 7 , 1–10 (2022). Ahmed, H. M. A., Wolf, T. G., Rossi-Fedele, G. & Dummer, P. M. H. The Study and Relevance of Pulp Chamber Anatomy in Endodontics - A Comprehensive Review. Eur. Endod. J. 9 , 18–34 (2024). Darling-Hammond, L., Flook, L., Cook-Harvey, C., Barron, B. & Osher, D. Implications for educational practice of the science of learning and development. Appl. Dev. Sci. 24 , 97–140 (2020). Kataria, S. et al. From teeth to ethnicity: A neural network approach to predicting population of origin through dental traits and anomalies. J. Oral Maxillofac. Pathol. 28 , 515–525 (2024). Pawar, A. M. & Singh, S. The morphology of the pulp chamber floor of permanent mandibular first and second molars in an Indian subpopulation-a descriptive cross-sectional study employing Pawar and Singh classification. PeerJ 10 , e14392 (2022). Srivastav, A., Aggarwal, D. & Jain, A. Variations in morphology of permanent maxillary lateral incisors and its impact on oral hygiene and diseases. J. Glob. Oral Health 6 , 118–122 (2023). Soukup, J. W., Jeffery, J., Hetzel, S. J., Ploeg, H.-L. & Henak, C. R. Morphological quantification of the maxillary canine tooth in the domestic dog (Canis lupus familiaris). Ann. Anat. Anat. Anz. Off. Organ Anat. Ges. 246 , 152041 (2023). Ghavate, V. R. et al. Retrospective evaluation of the morphometric properties of intact maxillary sinus using cone-beam computed tomography for sex estimation in an Indian population. PeerJ 12 , e16991 (2024). Ghorbanyjavadpour, F., Jamali, K., Roayaei Ardakani, M. & Rakhshan, V. Morphometric variations and nonmetric anatomical traits or anomalies of the primary molar teeth, plus the molars’ size thresholds for sex identification. BMC Oral Health 24 , 200 (2024). Hildebrand, H. et al. Guided endodontics versus conventional access cavity preparation: an ex vivo comparative study of substance loss. BMC Oral Health 23 , 713 (2023). Antony, D. P., Thomas, T. & Nivedhitha, M. S. Two-dimensional Periapical, Panoramic Radiography Versus Three-dimensional Cone-beam Computed Tomography in the Detection of Periapical Lesion After Endodontic Treatment: A Systematic Review. Cureus 12 , e7736 (2020). Silva, E. J. N. L. et al. Present status and future directions – Minimal endodontic access cavities. Int. Endod. J. 55 , 531–587 (2022). Kolarkodi, S. H. The importance of cone-beam computed tomography in endodontic therapy: A review. Saudi Dent. J. 35 , 780–784 (2023). Chan, F., Brown, L. & Parashos, P. CBCT in contemporary endodontics. Aust. Dent. J. 68 , s39–s55 (2023). Sevin, M., Orio, E. & Collignon, A.-M. Minimally Invasive Access Cavities: A Benefit/Risk Analysis. J. Clin. Med. 14 , 2476 (2025). McGuigan, M. B. et al. The impact of cone beam CT on outcomes associated with endodontic access cavity preparation: a controlled human analogue study using 3D-printed first maxillary molars. Dentomaxillofacial Radiol. 54 , 43–55 (2025). Uppada, U. K., Tauro, D. P. & Senthilnathan, K. P. Anthropometric Analysis of Indian Faces: A Systematic Review. J. Maxillofac. Oral Surg. 23 , 451–461 (2024). Olivieri, J. G. & Duran-Sindreu, F. Root Dentine Thickness and Concavity Depth in Mandibular Molars: A Cone Beam Computed Tomography Population Study. Eur. Endod. J. 3 , 160–166 (2018). Chaleefong, M., Prapayasatok, S., Nalampang, S. & Louwakul, P. Comparing the pulp/tooth area ratio and dentin thickness of mandibular first molars in different age groups: A cone-beam computed tomography study. J. Conserv. Dent. JCD 24 , 158–162 (2021). Kfir, A. et al. Root canal configuration and root wall thickness of first maxillary premolars in an Israeli population. A Cone-beam computed tomography study. Sci. Rep. 10 , 434 (2020). Joshi Amatya, N., Prajapati, K., Shrestha, S. & Wagle, S. Determination & comparison of maxillary first premolar pulp chamber landmarks using intraoral periapical radiograph and cone-beam computed tomography. J. Chitwan Med. Coll. 9 , 2–5 (2019). Abdellatif, D. et al. Access cavity in endodontics: Balancing precision, preservation, and clinical needs. J. Conserv. Dent. Endod. 28 , 573–587 (2025). Fekonja, A. Morphological Diversity of Permanent Maxillary Lateral Incisors and Their Impact on Aesthetics and Function in Orthodontically Treated Patients. Diagnostics 12 , 2759 (2022). LaTurno, S. A. & Zillich, R. M. Straight-line endodontic access to anterior teeth. Oral Surg. Oral Med. Oral Pathol. 59 , 418–419 (1985). Lee, M. et al. Morphological Measurements of Anatomic Landmarks in Pulp Chambers of Human Anterior Teeth. J. Endod. 33 , 129–131 (2007). Haridoss, S. et al. Impact of Pericervical Dentin on Fracture Resistance of Endodontically Treated Posterior Permanent Teeth: A Systematic Review and Meta-analysis. J. Contemp. Dent. Pract. 25 , 372–385 (2024). García-Guerrero, C., Mendoza-Beltrán, W., Roldan-Roldan, M., Villa-Machado, P. & Restrepo-Restrepo, F. Vertical root fractures: A time-dependent clinical condition. A case-control study in two colombian populations. J. Clin. Exp. Dent. 13 , e1104–e1111 (2021). Hsiao, L.-T., Ho, J.-C., Huang, C.-F., Hung, W.-C. & Chang, C.-W. Analysis of clinical associated factors of vertical root fracture cases found in endodontic surgery. J. Dent. Sci. 15 , 200–206 (2020). Liao, W.-C., Chen, C.-H., Pan, Y.-H., Chang, M.-C. & Jeng, J.-H. Vertical Root Fracture in Non-Endodontically and Endodontically Treated Teeth: Current Understanding and Future Challenge. J. Pers. Med. 11 , 1375 (2021). Santosh, S. S., Ballal, S. & Natanasabapathy, V. Influence of Minimally Invasive Access Cavity Designs on the Fracture Resistance of Endodontically Treated Mandibular Molars Subjected to Thermocycling and Dynamic Loading. J. Endod. 47 , 1496–1500 (2021). Gavriil, D., Kakka, A., Myers, P. & O´Connor, C. J. Pre-endodontic restoration of structurally compromised teeth: current concepts. Br. Dent. J. 231 , 343–349 (2021). Jakovljevic, I. et al. Importance of CBCT Analysis in the Preoperative Planning of TAD Placement in the Anterior Maxillary Region. Appl. Sci. 15 , 6866 (2025). Popowics, T. & Mulimani, P. Mammalian dental diversity: an evolutionary template for regenerative dentistry. Front. Dent. Med. 4 , 1158482 (2023). Srikant, N. et al. Tooth shade variation in Indian population: An objective guide to age estimation. Heliyon 7 , e06164 (2021). Additional Declarations No competing interests reported. Supplementary Files RawDataMonal.xlsx Cite Share Download PDF Status: Published Journal Publication published 05 Nov, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 11 Aug, 2025 Reviews received at journal 10 Aug, 2025 Reviews received at journal 07 Aug, 2025 Reviewers agreed at journal 07 Aug, 2025 Reviews received at journal 05 Aug, 2025 Reviewers agreed at journal 03 Aug, 2025 Reviewers agreed at journal 03 Aug, 2025 Reviewers agreed at journal 02 Aug, 2025 Reviewers agreed at journal 01 Aug, 2025 Reviewers agreed at journal 01 Aug, 2025 Reviewers agreed at journal 01 Aug, 2025 Reviewers agreed at journal 01 Aug, 2025 Reviewers agreed at journal 01 Aug, 2025 Reviewers invited by journal 01 Aug, 2025 Editor invited by journal 21 Jul, 2025 Editor assigned by journal 07 Jul, 2025 Submission checks completed at journal 04 Jul, 2025 First submitted to journal 27 Jun, 2025 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. 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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-6988842","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":498706347,"identity":"7aaba0e5-e687-4422-838a-4a040844e15e","order_by":0,"name":"Monal Ajay Kohok","email":"","orcid":"","institution":"Nair Hospital Dental College","correspondingAuthor":false,"prefix":"","firstName":"Monal","middleName":"Ajay","lastName":"Kohok","suffix":""},{"id":498706348,"identity":"d89e7105-bc74-4b31-b655-5da127c6e7f8","order_by":1,"name":"Ashish Mandwe","email":"","orcid":"","institution":"Nair Hospital Dental College","correspondingAuthor":false,"prefix":"","firstName":"Ashish","middleName":"","lastName":"Mandwe","suffix":""},{"id":498706349,"identity":"52131f6b-4c01-4eb5-9a60-ab6bf8fa20e8","order_by":2,"name":"Anuj Bhardwaj","email":"","orcid":"","institution":"College of Dental Sciences and Hospital","correspondingAuthor":false,"prefix":"","firstName":"Anuj","middleName":"","lastName":"Bhardwaj","suffix":""},{"id":498706350,"identity":"28f032f6-24de-49ca-8434-69341963c16c","order_by":3,"name":"Dian Agustin Wahjuningrum","email":"data:image/png;base64,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","orcid":"","institution":"Universitas Airlangga","correspondingAuthor":true,"prefix":"","firstName":"Dian","middleName":"Agustin","lastName":"Wahjuningrum","suffix":""},{"id":498706351,"identity":"8048dd04-5ec2-4c2f-881f-5cd15a03c6b9","order_by":4,"name":"Suraj Arora","email":"","orcid":"","institution":"King Khalid University","correspondingAuthor":false,"prefix":"","firstName":"Suraj","middleName":"","lastName":"Arora","suffix":""},{"id":498706352,"identity":"085415ad-8063-40a2-8ce6-8d75484105b7","order_by":5,"name":"Diah Diah","email":"","orcid":"","institution":"Universitas Brawijaya","correspondingAuthor":false,"prefix":"","firstName":"Diah","middleName":"","lastName":"Diah","suffix":""},{"id":498706353,"identity":"af77f6c1-f16d-4337-8503-594fcce4b5f3","order_by":6,"name":"Tegar Permadi Dimas Prakoso","email":"","orcid":"","institution":"Universitas Airlangga","correspondingAuthor":false,"prefix":"","firstName":"Tegar","middleName":"Permadi Dimas","lastName":"Prakoso","suffix":""},{"id":498706354,"identity":"ca573410-ecce-4e29-b7d5-2fb8a6ed5b3e","order_by":7,"name":"Ajinkya M. Pawar","email":"","orcid":"","institution":"Nair Hospital Dental College","correspondingAuthor":false,"prefix":"","firstName":"Ajinkya","middleName":"M.","lastName":"Pawar","suffix":""}],"badges":[],"createdAt":"2025-06-27 07:08:41","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6988842/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6988842/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-21978-4","type":"published","date":"2025-11-05T15:57:19+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":88948271,"identity":"768abc6a-a782-4d72-bd1b-a4df49326d26","added_by":"auto","created_at":"2025-08-13 05:33:24","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":279754,"visible":true,"origin":"","legend":"\u003cp\u003eA schematic representation of the 3 different measurements that were considered for the study.\u003c/p\u003e","description":"","filename":"floatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-6988842/v1/ebddc6ed148df34da0b286b3.png"},{"id":88948273,"identity":"09c01c65-dffe-4311-8cd6-bba5a697ed67","added_by":"auto","created_at":"2025-08-13 05:33:24","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":347604,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative sagittal CBCT images, illustrating three principal odontometric variables for maxillary anterior teeth. (a – c) measured in maxillary central incisors, (d – f) in lateral incisors, and (g – i) in canines. \u003cem\u003e(a, d, g): Distance from central fossa to the roof of the pulp chamber (CF–PC); (b, e, h): Distance from incisal edge to the roof of the pulp chamber (IE–PC); and (c, f, i): Distance from central fossa to the cingulum (CF–C).\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6988842/v1/fce44faf0908e67c83129688.jpeg"},{"id":88948277,"identity":"910b17a2-ac6a-4b25-89a1-734343d513af","added_by":"auto","created_at":"2025-08-13 05:33:24","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":191698,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of Odontometric Parameters by Tooth Type presented by box plots.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eEach box illustrates the interquartile range (IQR), with the median line inside the box and whiskers extending to 1.5× IQR. Outliers are displayed as individual points. Notably, lateral incisors exhibited the greatest anatomical variability, while canines showed the steepest CF–PC values.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-6988842/v1/d6fe8448614bd383e227a6d3.png"},{"id":95564220,"identity":"a0e87dd9-d074-4505-8b13-23629dcab811","added_by":"auto","created_at":"2025-11-10 16:09:02","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1567141,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6988842/v1/5fe4db51-a11c-47c2-8c9c-254eba7b7210.pdf"},{"id":88948272,"identity":"37c2d435-42c8-4145-aa26-3e7e25468f26","added_by":"auto","created_at":"2025-08-13 05:33:24","extension":"xlsx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":21677,"visible":true,"origin":"","legend":"","description":"","filename":"RawDataMonal.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-6988842/v1/1cc3ba25b4c1a4962334458b.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Three-Dimensional Odontometric Mapping of Maxillary Anterior Teeth Using CBCT in an Indian Cohort for Precision Endodontic Access cavity preparation: A primary investigation","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe precision of endodontic treatment essentially begins with proper design and execution of the access cavity. This is a critical part of the endodontic treatment that dictates the success of the remainder of the procedures of debridement, shaping of the canals, and obturation. It also has considerable influence over the long-term success of treatment. These include missing canals, over-preparation, perforation, inadequate seal, and ultimately failure\u0026nbsp;\u003csup\u003e1\u003c/sup\u003e. While there are common principles established in endodontic access cavity design and execution, advances in technology, materials, treatment philosophies (e.g., minimally invasive endodontics) call for an updated, evidence-based approach to access protocols using imaging and anatomical evidence from today\u0026apos;s fields of endodontics and dental/restorative practices\u0026nbsp;\u003csup\u003e2\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThe maxillary anterior teeth; central incisors, lateral incisors, and canines may differ when it comes to access cavity preparation. While maxillary anterior teeth are less complex than posterior teeth in terms of the canal architecture, they can present unique, anatomical difficulties in root angulation, enamel-dentin thickness, and location of pulp chamber for different ethnic groups\u0026nbsp;\u003csup\u003e3\u003c/sup\u003e. The risk for potential iatrogenic damage is increased when clinicians apply a generalized anatomic understanding based on mostly Caucasian morphometric datasets. Given that dentistry is currently transitioning towards the era of precision and personalization, there is increased risk when the same generic based assumptions outlined in universal guidelines are applied to clinicians practice which can risk both the outcome of the care recipient and the structure of the teeth that are meant to be protected\u0026nbsp;\u003csup\u003e4\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eCurrent literature indicates the Indian population displays specific dental morphologies that necessitate separate clinical management\u0026nbsp;\u003csup\u003e5,6\u003c/sup\u003e. For example, while Western maxillary lateral incisors have variable pulp chamber depths and variability in canal morphology, Indian maxillary lateral incisors were more variable than the standard Western incisor\u0026nbsp;\u003csup\u003e7\u003c/sup\u003e. Additionally, reported variations in maxillary canines despite being a fairly straight forward tooth may have increased curvature, increased depth of pulp chamber and increased enamel thickness can potentially require changes in conventional access\u0026nbsp;\u003csup\u003e8\u003c/sup\u003e. Finally, in addition to the existing anatomic morphometric variations in teeth, there are additional sex differentials that contribute additional complexity to the morphometric and operative access\u0026nbsp;\u003csup\u003e9,10\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eTraditional access approaches are heavily reliant on visual external indicators such as the incisal edge, central fossa or the cementoenamel junction (CEJ) to approximate the location and angle of the internal pulp chamber. These previously described anatomical features are not always reliable, as there may be calcification, trauma, excessive restorations or congenital issues\u0026nbsp;\u003csup\u003e11\u003c/sup\u003e. \u0026nbsp; This is further complicated by the use of 2D periapical radiographs, which can be affected by image distortion, superimposed anatomical variances and, ultimately, imaging is a sole representation of the internal tooth structures without true spatial relationships in the sagittal and axial dimensions\u0026nbsp;\u003csup\u003e12\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eCone-beam computed tomography (CBCT) has dramatically changed dental diagnosis due to three-dimensional, high resolution and multiplanar imaging allowing the clinician to visualize the tooth and surrounding structure and permitting them to do so without overlapping images. CBCT is an excellent tool for endodontic practice as it allows the clinician to see pulp chamber morphology, canal orientation, pericervical dentin thickness, and any anatomical variations that will inform the development of safe and conservative access designs\u0026nbsp;\u003csup\u003e13,14\u003c/sup\u003e. The use of CBCT is well-supported in the literature in regards to planning and executing both primary and retreatment endodontic cases, especially when anatomical variations will be suspected\u0026nbsp;\u003csup\u003e15\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eModern endodontic practice has seen a change in philosophy, of late, rationalizing a more minimally invasive access cavity (MIAC) preparation to preserve tooth structure without compromising the ideal visual and mechanical access to the canal system and subsequent central access instrumentation and debridement. The MIAC paradigm emphasizes preserving the pericervical dentin (PCD), which is the most critical variable for fracture resistance following treatment, as well as longevity of the tooth\u0026nbsp;\u003csup\u003e16\u003c/sup\u003e. However, it may lead to a challenge trying to conserve part of the access cavity while properly preparing and imaging the canal, as overly conservative or inaccurate designs could leave an incomplete canal anatomy resulting in insufficient debridement. Therefore, success in MIAC procedures is heavily dependent upon accurate anatomical knowledge and preoperative imaging, which CBCT has the potential to provide\u0026nbsp;\u003csup\u003e17\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eYet, the absence of population-specific odontometric data available for comparing analyzing CBCT images is still substantial, particularly within a South Asian context. The majority of studies available are aimed at European, North American, or East Asian cohorts and while they can be informative, generalizing for clinical applicability to India is limited with this data. Given India\u0026apos;s vast population and population structure, which is highly heterogeneous and includes distinctive differences in craniofacial morphology based on both region and ethnic group, international data may lead to poor access strategies and a greater occurrence of procedural errors\u0026nbsp;\u003csup\u003e18\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eFurthermore, no CBCT-based studies on access cavity design come with a standardized, reproducible measurement protocol nor evaluate the clinical significance within minimal intervention practice. The translational gap between morphometric data and clinical protocols also needs to be addressed. The other gap in the literature is the role of anatomical sex differences in access cavity designs. Previous studies indicate that males tend to have larger pulp chambers and dentin thicknesses while females presented narrower root canals and more curvature in specific tooth types when assessing dentin thickness\u0026nbsp;\u003csup\u003e19\u0026ndash;21\u003c/sup\u003e. While these differences may be small in nature, they can contribute to depth and angulation of access cavities more so in the higher risk teeth (eg, lateral incisors, curved canines). As such, accounting for anatomical sex differences may further enhance planning to more explicitly match treatment strategies.\u003c/p\u003e\n\u003cp\u003eThis study aims to fulfil these unmet needs by performing a complete CBCT-driven odontometric study of maxillary anterior teeth of an Indian population. This study measures three clinically relevant measurements:\u0026nbsp;\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eThe distance from the central fossa to the pulp chamber (CF-PC),\u003c/li\u003e\n \u003cli\u003eThe distance from the incisal edge to the pulp chamber (IE-PC), and\u003c/li\u003e\n \u003cli\u003eThe distance from the central fossa to the cingulum (CF-C).\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThese measurements are critical in determining the entry point, angulation, and depth when preparing access cavities. These anatomical landmarks are chosen because they are clinically visible, reproducible between patients, and clinically relevant to where the endodontic files are placed. Beyond measuring population averages, this study also focuses on sex-specific differences and inter-tooth differences (central incisor, lateral incisor, canine) to produce relevant clinical data for clinical applications.\u0026nbsp;\u003c/p\u003e"},{"header":"Methodology","content":"\u003cp\u003e\u003cstrong\u003eStudy Design and Ethical Compliance\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was conducted as a retrospective, cross-sectional imaging analysis using cone beam computed tomography (CBCT), and assessed some odontometric parameters in relation to access cavity preparation in maxillary anterior teeth. The study protocol was reviewed and approved by the institutional ethics committee of the College of Dental Sciences and Hospital (Ref. No. CDSH/Admin/2024; dated 15-10-2024), and was conducted with the full understanding and consent of the ethical principles of the Declaration of Helsinki. In view of the study\u0026apos;s retrospective design and the use of existing anonymised radiographic information, informed consent was not required.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSample size estimation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSample size for this study was determined based on the primary outcome, which is the distance from the cusp tip to the furcation; we used an effect size from a previous study. In a previous study \u003csup\u003e22\u003c/sup\u003e, it reported an effect size of 0.215 for the distance from the cusp tip to the furcation. Therefore, in order to have a statistical power of 0.80 and a significance level of 0.10 our minimum estimated sample size was 534 with GPower (Version 3.1.9.3). In our case, the pilot study used 10% of sample size or 53 samples. In GPower we performed the analysis with a one-tailed test, an effect size (d) 0.2156878, a \u0026alpha; error probability of 0.05, a power (1 \u0026minus; \u0026beta;) of 0.80, and an allocation ratio (N2/N1) of 1. The analysis output included a noncentrality parameter (\u0026delta;) of 2.4921043, a critical t of 1.6477229, 533 degrees of freedom, 534 total sample size, and actual power of 0.8006877. In order to allow a more thorough examination on all the tooth types being studied, the sample was increased to 600 teeth. Each tooth type (the maxillary central incisor, the maxillary lateral incisor, and the maxillary canine) was then represented with a subsample of 200.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSample Selection and Imaging Protocol\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe institutional imaging database was accessed to identify eligible CBCT scans retrospectively. The scans had been originally taken for diagnostic purposes unrelated to the current study velocity during the period January 2022 to December 2023.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEligibility criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eIndian adults aged 18\u0026ndash;25 years.\u003c/li\u003e\n \u003cli\u003ePermanent maxillary central incisors, lateral incisors, and canines with both good dental morphology, and fully erupted.\u003c/li\u003e\n \u003cli\u003eCBCT scans from radiology departments with sufficient resolution and/or diagnostic quality.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion criteria:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003ePresence of crown or root fractures, extensive restorative treatment, caries, prostheses, or previous endodontics.\u003c/li\u003e\n \u003cli\u003eEvidence of periapical pathology, root resorption, calcified canals and/or severe malalignment.\u003c/li\u003e\n \u003cli\u003eCBCT scans with artefacts, insufficient resolution, or data loss\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eImaging Parameters\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo ensure coherence between diagnostic protocols and measurement accuracy, all CBCT scans contributed to the outcome of this investigation were acquired using a standardized imaging protocol. Imaging was completed utilizing a Planmeca ProMax\u0026reg; 3D (Planmeca Group Planmeca Oy, Helsinki, Finland) system with the following imaging parameters; tube voltage of 90 kV; tube current of 10 mA; and an approximate field of exposure of 13.8 seconds. Depending on the required anatomical coverage, the field of view (FOV) ranged from 12\u0026times;15 cm to 16\u0026times;16 cm, with a voxel size of 0.40 mm, which provided acceptable spatial resolution to evaluate the small anatomical details relevant to access cavity planning. The estimated averaged radiation dose was in the range of 2.0 and 2.2 milligrays (mGy), which is within acceptable diagnostic ranges for dental CBCT protocols. This protocol provided a balance between minimizing the patients radiation exposure and developing sufficient image clarity to make accurate three-dimensional odontometric measurements. All images were reconstructed in DICOM format and evaluated using proprietary CBCT viewing software Romexis\u0026reg; 3D (Planmeca Group Planmeca Oy, Helsinki, Finland) \u0026nbsp;in sagittal cross-sectional view.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOdontometric Parameters and Measurement Protocol\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThree clinically significant odontometric parameters were measured for each tooth in the sagittal plane, following anatomical standardization:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eCF\u0026ndash;PC (Central Fossa to Pulp Chamber Roof): Indicates the vertical penetration depth required to reach the pulp chamber while minimizing over-extension. Aids in controlling bur advancement to avoid floor perforation.\u003c/li\u003e\n \u003cli\u003eIE\u0026ndash;PC (Incisal Edge to Pulp Chamber Roof): A spatial reference indicating the pulpal entry point of the bur. Also indicates the incisal-pulpal vertical relationship which is critical when choosing the initial angulation for cutting in access preparation of anterior teeth.\u003c/li\u003e\n \u003cli\u003eCF\u0026ndash;C (Central Fossa to Cingulum): Serves as a spatial reference for modifying bur trajectory in a labio-palatal direction, but also reliably orients bur trajectory to improve any sort of minimally invasive access orientation.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eMeasuring method\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eIdentification of the incisal edge, pulp chamber roof, central fossa, and cingulum anatomical landmarks was performed manually, using the sagittal cross-section.\u003c/li\u003e\n \u003cli\u003eThe software\u0026apos;s digital caliper tool allowed for direct linear measurements in millimeters (mm) along a linear vector reflecting the long axis of the tooth.\u003c/li\u003e\n \u003cli\u003eAll values were recorded to two decimal points (Figure 1).\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eEach parameter was measured independently by two calibrated observers. To reduce operator bias, measurements were repeated after a two-week interval for 10% of the sample, and the mean value was used for final analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObserver Calibration and Reliability Measurement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwo trained endodontists (MK and AMP) went through a structured calibration process, which included:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eTraining on how to navigate the CBCT software and identify anatomical landmarks.\u003c/li\u003e\n \u003cli\u003ePractice measuring on a subset of 30 scans that were randomly selected and excluded from the final analysis.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eInter-observer reliability was determined using Cohen\u0026rsquo;s kappa statistics (\u0026kappa;). Reliability values of \u0026gt;0.85 indicates excellent measure agreement. Intra-observer reliability was calculated using the intraclass correlation coefficient (ICC), and all ICC values exceeded 0.90 confirming a substantial reliability of subjective measurements. To improve the accuracy of measurements, where applicable, the automated edge-detection features of the CBCT software were used to reduce user error when identifying landmark locations retrospectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData were compiled and examined with the IBM SPSS Statistics (v25.0; IBM Corp., Armonk, NY). Descriptive means, standard deviation (SD), range and 95% confidence intervals were calculated for all odontometric parameters.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor comparison\u003c/strong\u003e\u003c/p\u003e\n\u003cul class=\"decimal_type\"\u003e\n \u003cli\u003eIndependent samples t-tests were performed to investigate gender-based differences in measurements for each tooth type.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eWhere appropriate, ANOVA or Kruskal-Wallis tests took place to compare values for tooth types (central incisor, lateral incisor, canine).\u003c/li\u003e\n \u003cli\u003eA p-value \u0026lt; 0.05 stated statistical significance.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eAll statistical approaches accounted for all assumptions of normality and homoscedasticity. For datasets that violated normality, or followed non-parametric distributions, non-parametric alternatives were selected instead. Graphical representations of the data, including box plots, were also created to visualise trends in anatomy and potential outliers.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eSample Characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn total, 600 maxillary anterior teeth (central incisors, lateral incisors, and canines) scanned from Indian patients aged 18-25 were included in the final analysis. 243 teeth were collected from male patients while 357 were from female patients. All selected scans met the inclusion criteria, and none of the data were omitted as a result of image artifacts or incomplete anatomical view.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOdontometric Measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThree principal odontometric measurements from this study are illustrated in Figure 1: CF\u0026ndash;PC, IE\u0026ndash;PC, and CF\u0026ndash;C, were Product examples from the three-dimensional CBCT. While they can be used in application in any clinical access cavity plan, they given their direct measuring of landmark points relevant to clinical purpose of access cavity planning on a maxillary anterior tooth. The CF\u0026ndash;PC (Central Fossa to Pulp Chamber Roof) measurement gives the clinician a relevant estimate of vertical depth by demonstrating the distance to achieve penetration to the pulp chamber without compromising the pulpal floor. The IE\u0026ndash;PC (Incisal Edge to Pulp Chamber Roof) measurement provides vertical spatial reference and demonstrates the distance from the incisal point of reference to the pulp chamber to guide incisal angulation and entry point during access preparation. The CF-C (Central Fossa to Cingulum) measurement establishes the labio-palatal orientation and therefore guides an ideal axial trajectory of the bur in an indirect manner.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe odontometric data collected using sagittal CBCT images of maxillary anterior teeth is displayed in Figure 2. This figure should be used to provide a visual guide to ensure three main measurements could be repeatedly and consistently identified and recorded: CF \u0026ndash; PC (Central Fossa to Pulp Chamber Roof); IE \u0026ndash; PC (Incisal Edge to Pulp Chamber Roof); CF \u0026ndash; C (Central Fossa to Cingulum). The images (a \u0026ndash; i) illustrate the stepwise identification of the anatomical landmarks to take reproducible, standardized measurements.\u003c/p\u003e\n\u003cp\u003eTable 1 provides mean, standard deviation (SD), and range for the three odontometric parameters and all tooth types. As seen in the three tooth types, there are considerable anatomical differences between the central incisor, lateral incisor, and canine.\u003c/p\u003e\n\u003cp\u003eCentral incisors had the least mean CF\u0026ndash;PC distance (2.21 \u0026plusmn; 0.37 mm) and the canines had the most CF\u0026ndash;PC (3.42 \u0026plusmn; 0.85 mm). Central incisors had the largest IE\u0026ndash;PC (5.02 \u0026plusmn; 0.77 mm) distance compared to the other two tooth types which would equate to deeper penetration of the chamber relative to the incisal edge. The mean CF-C dimension, which indicates the axial buccopalatal angulation difference was most in the central incisor (4.41 \u0026plusmn; 0.68) and least in the canine (2.62 \u0026plusmn; 0.79 mm) and consistent with their directional difference in morphology. Lateral incisors had the largest standard deviation for all measurements, and this is representative of their variability anatomically in comparison to the central incisor and canine.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e Descriptive Statistics of Odontometric Parameters by Tooth Type.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"629\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eTooth\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eCF\u0026ndash;PC (Mean \u0026plusmn; SD)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eIE\u0026ndash;PC (Mean \u0026plusmn; SD)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eCF\u0026ndash;C (Mean \u0026plusmn; SD)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCentral Incisor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.21 \u0026plusmn; 0.368\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5.02 \u0026plusmn; 0.774\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4.41 \u0026plusmn; 0.675\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLateral Incisor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.86 \u0026plusmn; 0.597\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4.52 \u0026plusmn; 1.399\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.41 \u0026plusmn; 0.807\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCanine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.42 \u0026plusmn; 0.848\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4.90 \u0026plusmn; 1.107\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.62 \u0026plusmn; 0.793\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cem\u003eCF\u0026ndash;PC: Central Fossa to Pulp Chamber Roof; IE\u0026ndash;PC: Incisal Edge to Pulp Chamber Roof; CF\u0026ndash;C: Central Fossa to Cingulum.\u003c/em\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGender Differences\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGender comparisons were examined with independent samples t-tests (Table 2). Statistically significant differences were observed in:\u003c/p\u003e\n\u003cul class=\"decimal_type\"\u003e\n \u003cli\u003eCF\u0026ndash;PC and IE\u0026ndash;PC values for both central and lateral incisors were significantly greater for males (p \u0026lt; 0.001 and p \u0026lt; 0.05, respectively).\u003c/li\u003e\n \u003cli\u003eCF\u0026ndash;C for any tooth type did not have significant differences between genders.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn contrast, canines did not have statistically significant differences based on gender in any of the three dimensions (p \u0026gt; 0.05) indicating anatomical symmetry between sexes in these types.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2.\u003c/strong\u003e Gender-Based Comparison of Odontometric Parameters (Male vs Female, in mm).\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"756\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTooth\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCF\u0026ndash;PC (M vs F)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCF\u0026ndash;PC (p)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eIE\u0026ndash;PC (M vs F)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eIE\u0026ndash;PC (p)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCF\u0026ndash;C (M vs F)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCF\u0026ndash;C (p)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003eCentral Incisor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e2.31 vs 2.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e\u0026lt; 0.001*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e5.22 vs 4.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026lt; 0.001*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e4.45 vs 4.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.304\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003eLateral Incisor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e2.94 vs 2.74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e0.022*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e4.52 vs 4.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.996\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e3.45 vs 3.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.690\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003eCanine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e3.49 vs 3.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e0.172\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e5.00 vs 4.80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.281\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e2.67 vs 2.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.287\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eValues represent mean distances in millimeters (mm) for each odontometric parameter. \u003cem\u003eCF\u0026ndash;PC: Central Fossa to Pulp Chamber Roof; IE\u0026ndash;PC: Incisal Edge to Pulp Chamber Roof; CF\u0026ndash;C: Central Fossa to Cingulum. M: Male; F: Female. * indicates a statistically significant difference after\u0026nbsp;\u003c/em\u003e\u003cem\u003eindependent samples t-tests.\u003c/em\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTooth Type Comparison\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA one-way ANOVA indicated significant differences in all odontometric parameters across tooth types (p \u0026lt; 0.001). Post-hoc Tukey testing revealed that (Table 3):\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eCanines significantly differed from central and lateral incisors in CF\u0026ndash;PC and CF\u0026ndash;C distances.\u003c/li\u003e\n \u003cli\u003eLateral incisors differed significantly from central incisors in all three parameters, highlighting their clinical complexity.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3.\u003c/strong\u003e Inter-Tooth Comparison of Odontometric Parameters (ANOVA Summary)\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"544\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eF-statistic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ePost-hoc Summary\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCF\u0026ndash;PC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e15.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCanine \u0026gt; Lateral \u0026gt; Central\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eIE\u0026ndash;PC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCentral \u0026gt; Canine \u0026asymp; Lateral\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCF\u0026ndash;C\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e22.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCentral \u0026gt; Lateral \u0026gt; Canine\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eBox plots (Figure 3) show how all measurements were anatomically distributed and included representation of each measurement within tooth types, with clear outliers found predominantly in lateral incisors.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAccess cavity preparation is the first step in endodontic treatment stages. It shapes the pathway to all subsequent interventions, including canal negotiation, debridement and shaping, and obturation. Various definitions of access preparation describe it as a type of surgical entry which makes, with proper design, for a potentially successful procedure and conservation of the tooth. Access cavity preparation is of clinical importance, yet it appears little interest has been paid to reporting access cavity design relative to variations in human anatomy \u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. The use of presumptive access cavity design or general forms having derived from Western populations, implicates inter-ethnic and intra-ethnic differences in the treatment, or lack thereof, of instrumentation in endodontics. This discrepancy has implications for clinical accuracy more so than academic. This current CBCT-based study aims to address the gap in evidence regarding access cavity preparation components by providing high-resolution, 3-dimensional, and population based odontometric characteristics regarding access cavity preparation for anterior maxillary teeth.\u003c/p\u003e\u003cp\u003eOur research shows that although anterior maxillary teeth are often regarded as morphologically uncomplicated, they exhibit considerable internal variation. The three odontometric parameters CF\u0026ndash;PC (central fossa to pulp chamber), IE\u0026ndash;PC (incisal edge to pulp chamber), and CF\u0026ndash;C (central fossa to cingulum) exhibited statistically significant differences between teeth and between sexes. Central incisors had the shallowest CF\u0026ndash;PC measurement but exhibited the highest IE\u0026ndash;PC values. Canines had the deepest CF\u0026ndash;PC measurement due to their only slight incisal edge, but their apex and internal anatomy reflects its unique prominence of that tooth with a sagittal curvature. It is noteworthy that lateral incisors were the most variable in all three dimensions. Using the previous studies put forth in the literature, the lateral incisor represents the most morphologically unpredictable tooth \u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. This clinical characterization of what appears to be a visually simple tooth has a significant clinical implication; while the lateral incisor may appear visually uncomplicated, it may still be more likely to be over or under-prepared if adhering to standard principles of access.\u003c/p\u003e\u003cp\u003eWhile we did not provide anatomical angles, IE\u0026ndash;PC and CF\u0026ndash;C values gave us some indirect information regarding the ideal access orientation and together provide evidence that the ideal access trajectory is more incisal or slightly labial in relation to the canal's long axis (especially given a canine or central incisor). Our findings agree with the qualitative findings reported by LaTurno and Zillich \u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e, who demonstrated using radiographs that if access is directed more Incisal, it allows for straighter access passageways into the pulp canal system. LaTurno and Zillich \u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e did not provide direct quantitative angular values for the access angles, but it still represents a great starting point. Our results support the direction their, using providing direct numerical value: Elevated IE\u0026ndash;PC and CF\u0026ndash;C values indicate that incisal access allows for an access preparation that is both biomechanically advantageous and also anatomical. Even though we did not have direct angle measures, there is data that indirectly suggests, when performing access preparations, the need to follow the incisal access angle.\u003c/p\u003e\u003cp\u003eA particularly interesting comparison arises when comparing our study with the only known attempt to quantify anterior tooth access depth: the study by Lee et al., \u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e. In that study, the authors performed an in vitro study of 600 extracted anterior teeth (maxillary and mandibular) by using 2D digital radiography to measure the distance from the lingual surface of the tooth to the pulp chamber. The authors reported access depths of 5.0 mm (lateral incisors) to 5.5 mm (canines) and had low coefficients of variation for all tooth classes. While their data may fit superficially with our IE\u0026ndash;PC values, the study design limitations diminish its clinical applicability.\u003c/p\u003e\u003cp\u003eOur research provides several methodological enhancements. First, as in vivo imaging is focused via CBCT, we visualised spatial relationships in each plane, including sagittal, axial, and coronal views, with no distortions or overlaps like 2D radiography. Second, while Lee et al, used teeth undergoing caries, restorations, or with uncertain demographic origin, opening the door for measurement variances, we neglected teeth that were not intact and specified individuals with known age and ethnicity, mitigating biases regarding data accuracies and reproducibility. Third, and arguably the most important, Lee et al., \u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e ignored anatomical differences related to population-based and sex-based anatomy, including the statistically significant and clinically important findings we documented.\u003c/p\u003e\u003cp\u003eThe gender-based odontometric differences documented in this study are similar to results in the previous literature and are clinically relevant. Males exhibited significantly larger CF\u0026ndash;PC and IE\u0026ndash;PC in central and lateral incisors, suggesting a deeper pulp chamber position, along with incisor size differences overall. These differences are in line with prior CBCT-based studies indicating that males tend to have larger pulp volumes, wider canals, and thicker dentin across multiple tooth types due to greater overall crown-root dimensions and dentoalveolar development during adolescence and early adulthood \u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e,\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. Chaleefong et al., \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e found variability in dentin thickness and pulp-to-tooth ratios to be sex restricted noting that the female mandibular molar canals were narrower and the pulp space constricted which is consistent with data seen in anterior teeth in the previous study. Likewise, Olivieri et al., \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e reported male root dentine thickness was consistently thicker in a variety of tooth types; this is relevant because it informs clinical problematic tooth access both during endodontic planning and iatrogenic error risk.\u003c/p\u003e\u003cp\u003eLee et al., \u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e did not evaluate access angulation, nor did they try to quantify access path trajectory directional considerations. Our measure of CF-C adds a new component to the anatomical evaluation of anterior teeth by indirectly measuring the labio-palatal orientation of the pulp chamber. Specifically in relation to central incisors, CF-C is greatest for the central incisors; when considering access to the pulp chamber in this situation, they require angulation caution to minimize gouging or excessive dentin removal on the facial wall. These findings are not purely morphometric in nature; they represent direct considerations of operative decisions with access in relation to direction of bur, point of entry, and penetration depth.\u003c/p\u003e\u003cp\u003eConserving pericervical dentin (PCD) is also of paramount importance in current endodontic practice \u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. The PCD serves as the biomechanical \u0026ldquo;belt\u0026rdquo; of tooth, important in sustaining functional stresses and averting vertical root fractures (VRFs) \u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. Indeed, VRFs were reported as prevalent in 10.9% of treated anterior teeth with notably higher risks affecting those with aggressive access or where the dentin was compromised resulting in sacrifice of the dentin \u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e,\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e. Our study will contribute to the minimally invasive access cavity (MIAC) model by providing the quantitative landmarks, in particular CF\u0026ndash;PC and CF\u0026ndash;C to help guide the clinician access the pulp chamber while preserving the dentin that contour it. Our study not only informs on fracture resistance of the tooth but may influence noteworthy aspects of treatment as well, including the restoration of the coronal portion of tooth and eventual refitting of the tooth.\u003c/p\u003e\u003cp\u003eThe change to MIAC from \"straight-line\" access is not just theoretical; it is evidence-based \u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e. Research has demonstrated that wide generalized access openings do not necessarily improve clinical outcomes and do risk preserving tooth structure \u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e,\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. CBCT-guided access, which relies upon identification of anatomical landmarks, is a compromise between visibility and efficacious conservation \u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e. Our data reveals access planning based upon CF\u0026ndash;PC and IE\u0026ndash;PC distances can be conservatively effective, especially with directional certainty by CF\u0026ndash;C measurement.\u003c/p\u003e\u003cp\u003eClinicians may also look forward to including our data in their digital workflows. This study provides values that can be utilized as standardized values in their CAD/CAM software to create individualized access templates. This aspect of the study is particularly useful for challenging cases involving calcified canals, previous trauma, and/or esthetics. In addition to the example above, this research created a body of data for an exciting opportunity to develop machine learning algorithms that delineate the optimal access entry points and angulations based on ethnicities\u0026rsquo; specific CBCT datasets. The integration of artificial intelligence could reduce operator variability and time efficiency in practice, especially in general dental practice, where the anatomical subtleties required for optimal access may not be emphasized.\u003c/p\u003e\u003cp\u003eThis study additionally contributes to the global movement towards personalizing dental care. Currently, the accepted standard of access cavity design relies heavily on Caucasian morphometric studies \u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e, and while the Indian population has variations in craniofacial morphology, the dentition exhibits diverse attributes \u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. If we do not account for these differences, the consequence of procedural inaccuracy could subsequently increase the chances of over-preparation, gouging or missing canals. This study offers a dataset based on Indian anatomy to begin developing protocols that account for ethnicity, and thus contribute to equitable and effective dental care.\u003c/p\u003e\u003cp\u003eThe clinical relevance of our work has numerous implications when considering real-world situations. In cases where anterior esthetics are a priority, such as in young adults or individuals with public-facing employment, effective access that supports minimally invasive approaches is important. Similarly, in endodontic retreatment cases where prior overextension occurred, canal trajectory can be reestablished through physical access procedures in conjunction with CBCT and odontometric references. In addition, these measures can, for less experienced clinicians, help provide evidence-based feasibility toward safe decision-making on bur angulation, depth of access, and canal entry\u0026mdash;particularly when external landmarks are altered by trauma, attrition, or restoration.\u003c/p\u003e\u003cp\u003eBeyond access trajectory planning, the observed gender-based morphometry also influences downstream clinical and restorative decisions. The lack of significant gender differences in CF\u0026ndash;C across all tooth types indicates that the labio-palatal orientation of the access trajectory may be relatively constant, while depth and vertical angulation (as reflected by CF\u0026ndash;PC and IE\u0026ndash;PC) require sex-specific considerations. These differences may be clinically important when determining access cavity depth, especially in minimally invasive access cavity (MIAC) designs, where even small misjudgements in vertical trajectory may result in under-preparation, missed canals, or pulp chamber perforation. Implementing custom access cavity protocols with sex-based measurements of anatomy may have positive outcomes and potentially decrease errors in procedures, particularly in challenging teeth like lateral incisors that revealed differences in anatomical variability but also in sex differences. The results of this study provide an important basis to establish personalized access cavity protocols with CBCT by assuming relevant contextual endodontic planning tailored to individualized anatomy.\u003c/p\u003e\u003cp\u003eNonetheless, our study has limitations. The design is retrospective and cross-sectional design places limitations on our ability to correlate morphometric data with clinical outcomes, such as treatment success, fracture rate, or postoperative sensitivity. The sample is taken from a single institutional center and could restrict our representation of India's vast inter-regional anatomical variation. Additional limitations include that, while CBCT presents excellent resolution, even high-quality imaging can present variation as a result of factors such as voxel size, software calibration, and operator judgement. We limited these effects via tight observer calibration (ICC\u0026thinsp;\u0026gt;\u0026thinsp;0.90) and measurement method, but there will always be a certain level of error associated with manual measurement.\u003c/p\u003e\u003cp\u003eSome of the possible future work may help alleviate some of these limitations. Future clinical trials could evaluate the effectiveness of access cavity preparations using CBCT and population-specific measurements to see if: 1. relevant clinical consequences for success were found; 2. the preparation process improved iatrogenic positivity; and, 3. tooth survival after endodontics could be confirmed as a consequent improvement. Future work involving dozens of respective clinical trials, and larger multicenter studies to generate sampling from different regions of India may strengthen the odontometric norms and provide reference points of regional variance. Future work that includes artificial intelligence (AI) based tools already being developed to automatically segment and measure access-related parameters in the CBCT may also improve our working definition of circumstances surrounding \"endodontic planning\". Another avenue of future work - the development of printable access templates using patient-specific views in CBCT - would be an interesting adjunct for teaching and clinician's use with anterior teeth.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis CBCT-based study is the first to publish accurate population-specific odontometric data reflecting anterior maxillary teeth in a young Indian cohort. There was considerable anatomical diversity\u0026mdash;most markedly in lateral incisors\u0026mdash;and canines had the deepest CF-PC trajectories to emphasize tooth-specific considerations for access planning. Additionally, we found statistically significant male versus female differences in several parameters that demonstrated that males regularly have greater CF-PC and IE-PC values in central and lateral incisors. Our findings indicated that universal access designs are inadequate and promote access planning that is anatomically driven, gender-sensitive, and ethnicity-informed. We contributed to the literature by providing new measurements (e.g., CF-C) disconnected from previous measurements to guide inferred access trajectories. Our study connected morphometric data with operative relevance in a relationship-building manner. Our work supports a change in the way we approach the science of endodontics towards precision, conservation, and personalized to the clinician.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003ch2\u003eCompeting interests\u003c/h2\u003e\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e\u003cp\u003eThis study was supported by the Deanship of Scientific Research and Graduate Studies at King Khalid University in Abha, Saudi Arabia under the Large research group program grant number (RGP.2/469/45). The supporting organization did not participate in the design of the study and collection, analysis, or interpretation of data, in the writing of the report or the decision to submit the report for publication.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eMAK and AMP conceived and designed the study. MAK and AMP collected the data and performed the primary data analysis. AB provided statistical expertise and contributed to the data interpretation. DAW and DD assisted with the literature review and contextualization of the findings. AMP contributed to the study design and data validation. TPDP, AM, and SA provided guidance on the methodology. MAK and AMP drafted the manuscript and DAW and DD provided critical revisions. All authors reviewed and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData is provided within the supplementary information files\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eElmatary, A., Moawad, E., Heidarifar, O. \u0026amp; Stone, S. Endodontic access cavity preparation: challenges and recent advancements. \u003cem\u003eBr. Dent. J.\u003c/em\u003e \u003cstrong\u003e238\u003c/strong\u003e, 469\u0026ndash;475 (2025).\u003c/li\u003e\n\u003cli\u003eChan, M. Y. C., Cheung, V., Lee, A. H. C. \u0026amp; Zhang, C. 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Mammalian dental diversity: an evolutionary template for regenerative dentistry. \u003cem\u003eFront. Dent. Med.\u003c/em\u003e \u003cstrong\u003e4\u003c/strong\u003e, 1158482 (2023).\u003c/li\u003e\n\u003cli\u003eSrikant, N. \u003cem\u003eet al.\u003c/em\u003e Tooth shade variation in Indian population: An objective guide to age estimation. \u003cem\u003eHeliyon\u003c/em\u003e \u003cstrong\u003e7\u003c/strong\u003e, e06164 (2021).\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Cone-Beam Computed Tomography, Odontometry, Access Cavity Preparation, Three-Dimensional Imaging, Tooth Morphology","lastPublishedDoi":"10.21203/rs.3.rs-6988842/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6988842/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAccess cavity preparation is an important part of endodontic therapy, affecting the effectiveness of canal instrumentation and the durability of the tooth over time. Currently, most access preparation protocols are based on information from a Western population and do not address the anatomical differences of different ethnic groups. This retrospective CBCT study assessed specific odontometric measurements in maxillary anterior teeth\u0026mdash;central incisors, lateral incisors and canines\u0026mdash;using an Indian population to help identify a clinically relevant and conservative access cavity preparation. A total of six hundred cone-beam computed tomography (CBCT) images of maxillary central incisors, lateral incisors, and canines (n\u0026thinsp;=\u0026thinsp;200 per tooth) were evaluated. These images were obtained from Indian individuals aged 18 to 25 years. Three measurements were made in sagittal view: the distance from the central fossa to the pulp chamber roof (CF\u0026ndash;PC), the incisal edge to pulp chamber (IE\u0026ndash;PC), and the central fossa to cingulum (CF\u0026ndash;C). Differences attributable to gender, and between teeth, were statistically significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The lateral incisors had the largest amount of anatomical variability, while the canines had the steepest trajectory of access. These findings provide the first population-based CBCT reference values for maxillary anterior teeth in India, and a practical guide to help achieve safe access design that is mindful of tooth anatomy and minimizes the invasiveness of the access.\u003c/p\u003e","manuscriptTitle":"Three-Dimensional Odontometric Mapping of Maxillary Anterior Teeth Using CBCT in an Indian Cohort for Precision Endodontic Access cavity preparation: A primary investigation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-13 05:33:20","doi":"10.21203/rs.3.rs-6988842/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-11T10:25:38+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-10T09:13:02+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-07T10:41:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"55681036419651111685396816106694785946","date":"2025-08-07T10:27:07+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-05T21:30:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"266499498654594904647872293240208566487","date":"2025-08-04T00:03:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"173250933426069448676559922631123983477","date":"2025-08-03T17:21:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"274970558380612702273474442166324469667","date":"2025-08-02T06:17:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"315181248354899802635769218792521145197","date":"2025-08-02T01:42:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"658011059258504057489134636537607516","date":"2025-08-01T23:25:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"49857009768841865392266889524787884020","date":"2025-08-01T17:08:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"50131298704797504526166296691479616670","date":"2025-08-01T17:03:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"174106154730530084564882279264465255190","date":"2025-08-01T16:06:01+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-01T15:46:53+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-07-21T17:06:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-07T10:01:50+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-04T08:52:48+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-06-27T07:06:09+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"71fd3d32-420e-461e-9422-dd3726034141","owner":[],"postedDate":"August 13th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":52965483,"name":"Health sciences/Anatomy"},{"id":52965484,"name":"Health sciences/Diseases"},{"id":52965485,"name":"Health sciences/Health care"},{"id":52965486,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2025-11-10T16:05:50+00:00","versionOfRecord":{"articleIdentity":"rs-6988842","link":"https://doi.org/10.1038/s41598-025-21978-4","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-11-05 15:57:19","publishedOnDateReadable":"November 5th, 2025"},"versionCreatedAt":"2025-08-13 05:33:20","video":"","vorDoi":"10.1038/s41598-025-21978-4","vorDoiUrl":"https://doi.org/10.1038/s41598-025-21978-4","workflowStages":[]},"version":"v1","identity":"rs-6988842","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6988842","identity":"rs-6988842","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}