Comparing short- and long-term effects of mandibular advancement with versus without maxillary setback on the oropharyngeal airway in skeletal Class II individuals: An extensive 2-year follow-up study

Comparing short- and long-term effects of mandibular advancement with versus without maxillary setback on the oropharyngeal airway in skeletal Class II individuals: An extensive 2-year follow-up study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Comparing short- and long-term effects of mandibular advancement with versus without maxillary setback on the oropharyngeal airway in skeletal Class II individuals: An extensive 2-year follow-up study Hong-Yi Tang, Zi-Rui Zhou, Jiang-Feng Fu, Qian-Wen Li, Li Gao, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6932425/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 12 Dec, 2025 Read the published version in BMC Oral Health → Version 1 posted 16 You are reading this latest preprint version Abstract Objective This study assessed 2-year oropharyngeal airway changes in skeletal Class II patients after mandibular advancement without maxillary posterior displacement (MAWMP) versus mandibular advancement with maxillary setback (MAWMS). Materials and methods A total of 25 MAWMP and 57 MAWMS patients underwent CBCT preoperatively (T0) and at 3 months (T1) and 2 years postoperatively (T2). The total upper airway volume (V), minimum cross-sectional area (CSA min ), and volumes of the nasopharynx (V NA ), velopharynx (V VE ), and glossopharynx (V GL ) were measured via Dolphin Imaging. Results MAWMP significantly increased V, CSA min , V NA , V VE , and V GL by 38.86%, 69.49%, 22.31%, 46.05%, and 46.94%, respectively, at T1 ( P <0.01) and 21.85%, 43.11%, 13.85%, 19.73%, and 25.38%, respectively, at T2 ( P <0.05). From T1 to T2, V, CSA min , V VE , and V GL decreased by 12.24%, 15.56%, 18.02%, and 14.67%, respectively ( P <0.05). Multivariate regression revealed that each 1 mm advancement of the PNS and B points increased V by 1038.18 mm³ and V VE by 519.11 mm³; PNS advancement increased V NA by 708.30 mm³ ( P <0.05). Compared with MAWMS, MAWMP yielded greater short-term improvements (V: +11175.00 vs. +3638.00 mm³; P <0.001) and superior long-term stability in V and V NA ( P <0.05). Intriguingly, the combined advancement of PNS and B point may be a robust predictor for postoperative changes of the upper airway volume. Conclusion MAWMP induces sustained upper airway expansion for 2 years, which is driven primarily by hard-tissue advancements. Compared with MAWMS, this technique has superior short- and long-term efficacy, providing guidance for the optimized management of skeletal Class II patients. Skeletal Class II MAWMP MAWMS Oropharyngeal airway Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Obstructive sleep apnea (OSA), a respiratory disorder characterized by recurrent upper airway obstruction during sleep, can lead to snoring, intermittent waking, and systemic diseases such as hypertension, cardiovascular diseases, and sedentary behaviors [ 1 – 5 ] . Notably, skeletal Class II patients, who often present with retrusive mandibles and narrowed oropharyngeal airways, are more susceptible to OSA than the general population is [ 4 , 6 ] . This poses a significant threat to their quality of life and overall health, highlighting the urgent need for effective treatment strategies [ 6 , 7 ] . Current studies have confirmed the significant effects of maxillomandibular advancement (MMA) on improving the upper airway morphology and apnea‒hypopnea index (AHI) of skeletal Class II patients [ 8 – 11 ] . However, due to relatively mild maxillary retrusion in Asian patients, MMA is less commonly applied domestically. Instead, the mainstream method is mandibular advancement without maxillary posterior displacement (MAWMP), which avoids the adverse effects of maxillary setback on upper airway morphology while preserving patients' facial aesthetics [ 12 ] . Despite its clinical application, few studies have comprehensively analyzed long-term changes in the upper airway and related influencing factors 2 years after MAWMPs. This study aims to fill this research gap by evaluating upper airway changes at 3 months and 2 years post-MAWMP surgery, analyzing the quantitative relationship between long-term postoperative upper airway changes and intraoperative hard and soft tissue movements, and further comparing the long-term upper airway impacts of the MAWMP and MAWMS. The findings of this study will provide valuable insights for clinicians in selecting optimal surgical approaches for skeletal Class II patients, ultimately improving treatment outcomes and patients' quality of life. Materials and methods Study Design and Participants This retrospective study was conducted at Peking University Stomatological Hospital from January 2017 to October 2023. A total of 86 skeletal Class II patients who had undergone MAWMP or MAWMS were recruited. The inclusion criteria were as follows: (1) age > 18 years with skeletal Class II malocclusion (ANB > 5°); and (2) availability of cone-beam computed tomography (CBCT) scans at three specific time points: preoperatively (T0), 3 months postoperatively (T1), and 2 years postoperatively (T2). The exclusion criteria were as follows: (1) severe facial asymmetry; (2) previous orthognathic surgery; (3) history of facial trauma; (4) severe obesity (BMI > 35 kg/m²); (5) severe craniofacial syndrome; (6) history of significant cardiovascular or pulmonary diseases; and (7) history of diabetes or severe lipid metabolism disorders. The study was approved by the Ethics Committee of Peking University Stomatological Hospital (Approval No. PKUSSIRB-202167121). Data Acquisition CBCT imaging examinations were performed on all patients at T0, T1, and T2 via a NewTom VG Aperio Services CBCT scanner (Imola, Italy) with the following parameters: 110 kV, 2.05 mA, field of view 15 cm × 12 cm, voxel size 0.3 mm, and scan time 3.6 seconds. Patients were instructed to maintain an upright position with their head in the natural position, teeth in centric occlusion, and the tongue against the palate and to avoid swallowing during the scan. All the CBCT data were saved in Digital Imaging and Communications in Medicine (DICOM) format. Measurement methods Dolphin Imaging software (version 19.5; Dolphin Imaging and Management Solutions, Chatsworth, Calif.) was used for all the measurements. The CBCT images were reoriented along the midpalatal suture, tangent to the nasal base, and parallel to the Frankfort horizontal plane (FHP). A three-dimensional coordinate system was established with the FH plane as the x-coordinate and the y-coordinate (VFH) perpendicular to both the FH plane and the midsagittal plane, passing through the baseline point. The following anatomical landmarks were selected for evaluation: A point (the deepest point on the concavity of the maxilla between the ANS and the maxillary alveolus), PNS point (posterior nasal spine), B point (the innermost point on the contour of the mandible between the mandibular incisor and chin), Me point (Menton, the most interior point on the chin), and H point (Hyoidale, the most superior and anterior point on the body of the hyoid bone) (Fig. 1 ). The parameters NF-10 (maxillary width parallel to and 10 mm above the lowest line of the nasal base) and MP-FH (the angle between the Go-Gn plane and the FH plane) were used to determine the maxillary width and vertical skeletal evaluation, respectively (Fig. 2 ). Mandibular length, width, and depth were also measured to assess the three-dimensional size of the mandible (Fig. 3 ). The upper airway was divided into three segments: the nasopharynx, velopharynx, and glossopharynx. The minimum cross-sectional area (CSA min ) was also evaluated. The volume, cross-sectional area, and transverse and sagittal diameters of each segment were measured. For soft-tissue measurements, the length, angle, and area of the soft palate were measured in the midsagittal plane (Fig. 4 ). The detailed definitions of the terms are summarized in Table 1 . Sample Size Estimation Sample size estimation was performed via PASS 21.0 software (Power Analysis and Sample Size Software 21.0, NCSS, USA). The reference value for the sample size calculation was the measurement result of the upper airway representative indicator CSA min . Single-factor repeated measures analysis of variance was used for the calculation, with a significance level (α) of 0.05 and a statistical power (1-β) of 80%. The maximum sample size obtained from the calculation was used as the required sample size for this study. Statistical analysis The data were analyzed via SPSS (v23.0). The normality of upper airway parameters ( V , CSA min , V NA , V VE , V GL ) was tested via the Kolmogorov‒Smirnov test. Longitudinal changes (T0-T1-T2) were evaluated with paired t tests or Wilcoxon signed-rank tests. Correlations between skeletal advancements (e.g., PNS and B point movements) and airway changes were analyzed via Pearson/Spearman tests. Baseline characteristics (age, BMI, sex) were compared between the MAWMP and MAWMS groups via independent t tests and chi-square tests. Postoperative differences in airway parameters ( V , CSA min , segment volumes) between procedures were assessed with the Wilcoxon rank-sum test. Multiple linear regression analyses were performed to investigate the quantitative relationships between changes in upper airway volume and contributing factors. The total sample (N = 82) met statistical guidelines requiring 15 observations per predictor, ensuring model robustness. Variables with significant correlations in univariate analyses (e.g., PNS and B point advancements) were incorporated into multivariate models to identify independent predictors of airway expansion. Table 1 Definitions of Parameters Parameters Definitions Hard tissue A The deepest point on the concavity of the maxilla between ANS and the maxillary alveolus B The innermost point on the contour of mandible between mandibular incisor and chin PNS Posterior nasal spine Me Menton, the most interior point on the chin H Hyoidale, the most superior and anterior point on the body of the hyoid bone Ba Basion, median point of anterior margin of foramen magnum Go The most anterior and inferior point of the mandible Gn The most posterior and inferior points of the mandible NF-10 Maxillary width parallel to and 10 mm above the lowest line of the nasal base FH Frankfort horizontal plane VFH A plane perpendicular to the FHP, midsagittal plane and passing through Basion point MP/FH The angle between the Go-Gn plane and the FH plane Mandibular body length The distance from Gn to the left or right Go Mandibular width The distance between the left and right Go Mandibular depth The 2-dimensional distance from Gn to Go PNS + B The sum of the sagittal position distance of PNS and that of B Soft tissue Soft-palatal angle The angle between the tip of uvula, PNS, and ANS Soft-palatal length The distance from the posterior and inferior point of soft palatal to PNS Soft-palatal area The area of the soft palate Upper airway V The anterior border is the line passing through PNS and S; the inferior border is the line parallel to the FHP passing through the root of epiglottis, and the posterior border is the pharyngeal posterior wall CSA min Minimum cross-sectional area of the upper airway Nasopharynx The anterior border is the line passing through PNS and S, the inferior border is the line parallel to the FHP passing through PNS, and the posterior border is the pharyngeal posterior wall Velopharynx The superior border is the line parallel to the FHP passing through PNS, the inferior border is the line parallel to the FHP passing through the tip of uvula, and the posterior border is the pharyngeal posterior wall Glossopharynx The superior border is the line parallel to the FHP passing through the tip of uvula, the inferior border is the line parallel to the FHP passing through the root of epiglottis, and the posterior border is the pharyngeal posterior wall Results Hard and Soft Tissue Changes This study included 25 skeletal Class II patients who underwent MAWMPs (11 males, 14 females; age 29.08 ± 4.10 years; BMI 22.35 ± 2.42 kg/m²). Preoperative cephalometric analysis confirmed skeletal Class II characteristics, with mean SNA, SNB, and ANB angles of 79.56 ± 1.35°, 72.50 ± 2.42°, and 7.06 ± 2.42°, respectively (Table 2 ). Comparisons of hard and soft tissue parameters were made preoperatively (T0) and 3 months (T1) and 2 years (T2) after surgery. At T1, points A, PNS, B, Me, and H moved anteriorly, while points PNS, B, and Me moved downward, and point H moved vertically. The maxillary width and mandibular contour increased significantly. The soft palate angle and median sagittal area decreased significantly at T1. Similar changes were observed at T2, except that the upward movement of point H was no longer significant. Notably, hard tissue changes remained consistent from T1 to T2, whereas a decreased soft palate angle and median sagittal area were not observed at T2 (Table S1 ). Table 2 Hard and Soft Tissue Changes in Different Periods Parameters (N = 25) T0 T1 T2 P Hard tissue A-FH (mm) 33.83 ± 2.61 33.06 ± 2.58 33.23 ± 2.63 0.061 A-VFH (mm) 85.43 ± 5.67 87.98 ± 5.32 87.64 ± 5.40 < 0.001 PNS-FH (mm) 25.34 ± 2.55 26.60 ± 2.88 26.25 ± 3.07 0.002 PNS-VFH (mm) 40.58 ± 3.65 43.57 ± 3.69 43.04 ± 3.37 < 0.001 B-FH (mm) 74.56 ± 5.26 76.51 ± 4.19 76.32 ± 4.51 0.002 B-VFH (mm) 71.04 ± 7.59 77.24 ± 7.50 76.70 ± 7.19 < 0.001 Me-FH (mm) 92.14 ± 6.12 94.52 ± 4.93 94.69 ± 5.10 < 0.001 Me-VFH (mm) 63.15 ± 9.65 71.98 ± 8.97 72.28 ± 7.73 < 0.001 NF-10 (mm) 103.41 ± 8.41 105.40 ± 8.45 105.11 ± 8.20 < 0.001 Mandibular Body Length (mm) 84.78 ± 5.45 93.60 ± 4.62 93.28 ± 4.79 < 0.001 Mandibular Width (mm) 98.44 ± 6.26 101.26 ± 6.20 101.15 ± 6.29 < 0.001 Mandibular Body Depth (mm) 69.42 ± 5.64 78.73 ± 4.76 78.67 ± 4.58 < 0.001 MP-FH (°) 32.34 ± 7.24 31.51 ± 4.86 32.59 ± 5.41 0.334 H-FH (mm) 85.53 ± 8.09 83.06 ± 7.27 84.24 ± 8.58 < 0.001 H-VFH (mm) 30.02 ± 6.96 33.74 ± 6.68 32.80 ± 5.89 0.001 Soft tissue Soft Palate Angle (°) 134.11 ± 27.86 131.87 ± 27.97 133.97 ± 27.58 0.056 Soft Palate Length (mm) 34.94 ± 4.12 33.58 ± 4.45 34.50 ± 4.61 0.045 Midline Area (mm²) 263.38 ± 60.59 238.52 ± 52.88 252.36 ± 51.69 0.002 Changes in Upper Airway Morphology Significant increases in upper airway volume (V), minimum cross-sectional area (CSA min ), and segment volume were observed at T1 and T2 compared with those at T0 (Fig. 5 & Table 3 ). The rates of increase from T0 to T1 for V, CSA min , V NA , V VE , and V GL were 38.86%, 69.49%, 22.31%, 46.05%, and 46.94% (P < 0.01), respectively. From T0 to T2, these rates were 21.85%, 43.11%, 13.85%, 19.73%, and 25.38%, respectively (P < 0.05). Conversely, from T1 to T2, V, CSA min , V VE , and V GL decreased by 12.24%, 15.56%, 18.02%, and 14.67% (P < 0.05), respectively, with no significant change in V NA (Tables S2&3). Table 3 Parameters of Upper Airway Segments Over time Parameters (N = 25) T0 T1 T2 P A NA (mm²) 644.74 ± 148.28 728.55 ± 164.57 692.56 ± 155.93 < 0.001 TD NA (mm) 37.86 ± 5.85 40.73 ± 6.85 39.98 ± 7.02 0.004 SD NA (mm) 28.69 ± 4.63 31.16 ± 5.02 30.12 ± 5.16 0.017 A VE (mm²) 243.97 ± 107.41 451.77 ± 149.44 361.12 ± 128.52 < 0.001 TD VE (mm) 27.31 ± 6.17 35.90 ± 5.17 32.95 ± 5.86 < 0.001 SD VE (mm) 13.09 ± 4.53 20.85 ± 5.25 17.36 ± 4.65 < 0.001 A GL (mm²) 324.99 ± 118.74 426.27 ± 100.83 380.04 ± 81.64 < 0.001 TD GL (mm) 34.86 ± 4.45 39.48 ± 3.72 37.58 ± 3.99 < 0.001 SD GL (mm) 13.96 ± 3.20 19.84 ± 2.54 17.46 ± 2.08 < 0.001 Correlation and Regression Analysis At T1, increases in B point advancement (B-VFH), hyoid bone elevation (H-FH), reduction in the soft palate angle, and the sum of PNS and B point advancement (PNS + B) were positively correlated with increases in V (P < 0.05) (Tables S4&6). For each airway segment, PNS point advancement was significantly positively correlated with an increase in VNA (P < 0.05), whereas B point advancement, a reduction in the soft palate angle, and an increase in the PNS + B were positively correlated with an increase in V VE at T1 (Table S5). At T2, B point advancement (B-VFH), Me point advancement (Me-VFH), and PNS + B were positively correlated with the increase in V at 2 years postoperatively (P < 0.05). The increase in V was negatively correlated with the preoperative CSA min . PNS and A-point advancement remained significantly correlated with V NA increase at T2 (P < 0.05). Similarly, B point advancement, a reduction in the soft palate angle, and an increase in the PNS + B were positively correlated with an increase in V VE at T2. The increase in PNS + B changed from a negative to a positive correlation with the increase in V GL at T2 (Table S7). Multivariate regression analysis at 2 years postsurgery revealed positive correlations between the sum of PNS and B point advancements and increases in V and V VE and between PNS advancement and V NA increase (P < 0.05). Quantitatively, each mm increase in PNS and B point advancements led to a 1038.18 mm³ increase in V and a 519.11 mm³ increase in V VE ; each mm PNS advancement led to a 708.30 mm³ increase in V NA at 2 years postoperatively (Table 4 ). Table 4 Results of Multiple Linear Regression Analysis Parameters (N = 25) Adjusted R² P Regression P VIF V 0.376 0.013* 1038.18 * PNS + B + 17110.65 0.003* 1.190 V NA 0.256 0.040* 708.3 * PNS-VFH + 5789.88 0.008* 1.125 V VE 0.343 0.021* 519.11 * PNS + B − 351.14 * Uvular angle + 5838.58 0.043* 1.168 0.008* 1.127 V GL 0.201 0.273 497.41 * PNS + B -1204.29 0.049* 1.157 Comparison of upper airway morphology after MAWMP and MAWMS To further compare the different effects on the upper airway between MAWMP and MAWMS, 57 patients with skeletal Class II malocclusion who underwent MAWMS were included, with detailed information from previous studies [ 7 ] (Table S8). There were no significant differences in the baseline data (age, sex, or BMI) between the two groups before treatment. Comparisons of upper airway changes revealed significant intergroup differences in the increase in all upper airway volumes and CSA min at 3 months postsurgery (P < 0.05), with the MAWMP group showing a significantly greater increase than the MAWMS group (Table 5 ). However, at 2 years postsurgery, only the increases in V and V NA showed significant intergroup differences (P < 0.05), whereas the other segments did not show significant differences in volume or CSA min (Table 6 ). Table 5 Postoperative Upper Airway Changes at 3 Months (MAWMP vs MAWMS) Parameters MAWMP (N = 25) MAWMS (N = 57) P value V 11175.00 (9749.00) 3638.00 (8101.50) < 0.001* CSA min 97.00 (135.00) 54.00 (94.50) 0.004* V NA 1811.00 (2203.00) 430.00 (2734.50) 0.001* V VE 4598.00 (4107.50) 112.00 (4647.00) < 0.001* V GL 4164.00 (3709.00) 1502.00 (3242.50) 0.003* Table 6 Long-term Upper Airway Changes at 2 Years (MAWMP vs MAWMS) Parameters MAWMP (N = 25) MAWMS (N = 57) P value V 8258.00 (9842.00) 3152.00 (6812.09) 0.015* CSA min 82.00 (87.00) 49.00 (118.87) 0.084 V NA 1026.00 (2149.50) 204.00 (2158.00) 0.040* V VE 2421.00 (5875.00) 459.00 (4256.50) 0.104 V GL 1475.00 (4114.50) 1571.00 (2963.00) 0.247 Discussion Growing evidence indicates that skeletal Class II patients face a greater risk of obstructive sleep apnea (OSA) due to narrowed upper airways, in addition to dental and facial discrepancies [ 1 , 2 , 6 ] . Given the significant impact of OSA on quality of life and systemic health, optimal orthodontic and orthognathic treatments for these patients should aim to increase upper airway volume and reduce OSA risk. While many studies have investigated how bimaxillary surgery affects upper airway morphology, long-term data on single-jaw surgery, particularly mandibular advancement without maxillary posterior displacement (MAWMP), are lacking [ 3 , 7 ] . In this study, we assessed both short-term and long-term upper airway changes following MAWMPs. Our data revealed a significant 37.0% increase in total upper airway volume at 3 months postsurgery, which is in line with previous research [ 13 ] . Despite some reduction in airway volume from 3 months to 2 years postoperatively, it remained significantly greater than it was preoperatively, indicating the long-term stability of the MAWMP in enhancing airway morphology [ 14 ] . Similarly, Parsi et al. and Yamashita et al. reported sustained airway improvements with mandibular advancement procedures [ 8 , 9 ] . Our study also underscores the critical role of mandibular advancement in upper airway reconstruction. Hernandez-Alfaro et al. reported that patients who underwent mandibular advancement (69.8%) or bimaxillary advancement (78.3%) exhibited significantly greater increases in upper airway volume than did those who underwent maxillary advancement alone (37.7%) [ 15 ] . Similarly, studies on mandibular advancement appliances, such as the Twin-Block, have demonstrated positive effects on airway volume and OSA symptom alleviation [ 16 , 17 ] . However, Pereira et al. reported no significant correlation between mandibular advancement and airway volume after a 4-year follow-up, underscoring the need for larger sample sizes and extended observation periods [ 18 ] . In the short term, the MAWMP resulted in significant anterior and upward displacement of the hyoid bone (H point) and a reduction in the soft-palate angle. These changes were positively correlated with increases in airway volume at 3 months postsurgery. However, these soft-tissue changes became nonsignificant by the 2-year follow-up, likely due to adaptive remodeling of the velopharyngeal musculature. The velopharyngeal region is a common site of collapse in OSA patients, and even surgical interventions such as umbilicalopharyngoplasty often fail to prevent soft-tissue relapse. In contrast, the mandibular position remained significantly advanced at both 3 months and 2 years postoperatively, which is consistent with findings from studies on maxillomandibular advancement (MMA) and MAWMS [ 19 , 20 ] . These findings suggest that long-term improvements in airway volume are driven primarily by hard-tissue changes, whereas the velopharyngeal region may be more susceptible to relapse. The increase in the volume of various parts of the upper airway caused by the MAWMP was significantly greater than that caused by the MAWMS, which is consistent with previous findings [ 8 , 9 ] . Brunetto et al. reported that changes in the upper airway were more unpredictable when the maxilla and mandible were moved in different directions than when they were moved in the same direction [ 21 ] . This study, which used MAWMS as a control, confirmed the unique advantages of MAWMP in improving the upper airway. Intriguingly, at 2 years postsurgery, no significant intergroup differences were observed in the volume changes in the upper airway, except for V and VNA. The postoperative changes in the upper airway may exhibit a compensatory effect; that is, the greater the volume of the upper airway in the short term after surgery (T1), the greater the degree of relapse over time (T1–T2) [ 22 ] . The long-term relapse rate of the MAWMP was greater than that of the MAWMS, which may be related to the disappearance of the intergroup differences in the increase in VVE and VGL at 2 years postsurgery. A novel finding of this study is the robust predictive value of combined PNS and B point advancements for long-term airway changes. While previous research has focused primarily on the individual movements of landmarks such as the PNS, A, or B, this study is the first to explore the correlation between the sum of the PNS and B point advancements and upper airway volume [ 8 , 23 ] . Our results indicate that even at 2 years postsurgery, this combined measurement remained significantly correlated with increases in multiple airway segments. This finding provides valuable guidance for orthodontists and orthognathic surgeons in designing jaw movements to optimize airway outcomes. This study has several limitations. First, the relatively small sample size of the MAWMP group (n = 25) may limit the statistical power and generalizability of the findings. Second, the retrospective design introduces potential selection bias and residual confounding factors. Third, the exclusion of obese patients (BMI > 35 kg/m²) restricts their applicability to high-risk OSA populations. Additionally, although standardized, CBCT-based measurements could be influenced by subtle variations in head posture or tongue positioning during scans. Finally, soft-tissue adaptations have transient effects, necessitating longer-term monitoring to elucidate relapse mechanisms. Future prospective studies with larger cohorts, broader BMI inclusion, and multimodal imaging protocols could address these limitations and refine surgical strategies for sustained airway improvements. Conclusion This study demonstrated that mandibular advancement without maxillary posterior displacement (MAWMP) significantly improved oropharyngeal airway morphology in skeletal Class II patients, with sustained benefits observed over a 2-year follow-up period. V, CSA min , and segmental volumes (V NA , V VE , V GL ) exhibited substantial increases at both 3 months and 2 years postoperatively compared with baseline, despite a partial relapse in velopharyngeal and glossopharyngeal volumes over time. Multivariate regression analysis highlighted the critical role of combined PNS and B-point advancements in driving long-term airway expansion, with each millimeter of advancement correlating with quantifiable increases in airway volume. Notably, the MAWMP outperformed the MAWMS in both short-term and long-term upper airway improvements, particularly in total volume and nasopharyngeal stability. These findings underscore the clinical value of prioritizing mandibular advancement and coordinated maxillomandibular repositioning in skeletal Class II patients, especially those at risk of OSA. Future studies should explore the mechanisms of soft-tissue adaptation and relapse to optimize surgical protocols for sustained airway patency. Declarations Data availability The data of this study are available from the corresponding author upon reasonable request. Clinical trial number Not applicable. Funding This work was supported by the National Nature Science Fond(China, fond number 81000440). Ethical approval and consent to participate All procedures performed in the study were approved by the Ethics Committee of Peking University Stomatological Hospital (Approval No. PKUSSIRB-202167121), conducted in accordance with the 1975 Declaration of Helsinki as revised in 2013. Informed consent was obtained from all participants included in the study or from a parent and/or legal guardian for study participation. Consent for publication Not applicable. Competing interests The authors declare no competing interests. Author Contribution Hong-Yi Tang and Zi-Rui Zhou contribute equally to this work.All authors contributed substantially to data interpretation, manuscript drafting, critical revision, final approval, and accountability for the work. Additionally, JHJ, LG, HYT and ZRZ conceived and designed the study; HYT and ZRZ collected data and developed methodology; JFF and QWL analyzed data; LG. coordinated the project with JHJ led the manuscript writing. Acknowledgements This work was supported by the National Nature Science Fond(China, fond number 81000440). References Jordan A S, Mcsharry D G, Malhotra A. Adult obstructive sleep apnoea[J]. Lancet, 2014, 383(9918): 736-47. Lévy P, Kohler M, Mcnicholas W T, et al. Obstructive sleep apnoea syndrome[J]. 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Exploring long-term changes and influencing factors of the upper airway in patients with a skeletal Class II relationship after mandibular advancement with maxillary setback surgery: A comprehensive 2-year follow-up investigation[J]. Am J Orthod Dentofacial Orthop, 2024, 165(5): 520-532.e3. Parsi G K, Alsulaiman A A, Kotak B, et al. Volumetric changes of the upper airway following maxillary and mandibular advancement using cone beam computed tomography[J]. Int J Oral Maxillofac Surg, 2019, 48(2): 203-210. Yamashita A L, Iwaki Filho L, Leite P C C, et al. Three-dimensional analysis of the pharyngeal airway space and hyoid bone position after orthognathic surgery[J]. J Craniomaxillofac Surg, 2017, 45(9): 1408-1414. Raffaini M, Pisani C. Clinical and cone-beam computed tomography evaluation of the three-dimensional increase in pharyngeal airway space following maxillo-mandibular rotation-advancement for Class II-correction in patients without sleep apnoea (OSA)[J]. 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Effect of mono- and bimaxillary advancement on pharyngeal airway volume: cone-beam computed tomography evaluation[J]. J Oral Maxillofac Surg, 2011, 69(11): e395-400. Shete C S, Bhad W A. Three-dimensional upper airway changes with mandibular advancement device in patients with obstructive sleep apnea[J]. Am J Orthod Dentofacial Orthop, 2017, 151(5): 941-948. Ryan C F, Love L L, Peat D, et al. Mandibular advancement oral appliance therapy for obstructive sleep apnoea: effect on awake calibre of the velopharynx[J]. Thorax, 1999, 54(11): 972-7. Pereira P K N, De Castro Rocha V, Degan V V, et al. Upper airways after mandibular advancement orthognathic surgery: A 4-year follow-up[J]. Am J Orthod Dentofacial Orthop, 2021, 159(6): 743-749. Fairburn S C, Waite P D, Vilos G, et al. Three-dimensional changes in upper airways of patients with obstructive sleep apnea following maxillomandibular advancement[J]. J Oral Maxillofac Surg, 2007, 65(1): 6-12. Abramson Z, Susarla S M, Lawler M, et al. Three-dimensional computed tomographic airway analysis of patients with obstructive sleep apnea treated by maxillomandibular advancement[J]. J Oral Maxillofac Surg, 2011, 69(3): 677-86. Brunetto D P, Velasco L, Koerich L, et al. Prediction of 3-dimensional pharyngeal airway changes after orthognathic surgery: a preliminary study[J]. Am J Orthod Dentofacial Orthop, 2014, 146(3): 299-309. Trevisiol L, Bersani M, Sanna G, et al. Posterior airways and orthognathic surgery: What really matters for successful long-term results?[J]. Am J Orthod Dentofacial Orthop, 2022, 161(5): e486-e497. Chang M K, Sears C, Huang J C, et al. Correlation of Airway Volume With Orthognathic Surgical Movement Using Cone-Beam Computed Tomography[J]. J Oral Maxillofac Surg, 2015, 73(12 Suppl): S67-76. Additional Declarations No competing interests reported. Supplementary Files Supplementaryinformation.docx Cite Share Download PDF Status: Published Journal Publication published 12 Dec, 2025 Read the published version in BMC Oral Health → Version 1 posted Editorial decision: Revision requested 01 Aug, 2025 Reviews received at journal 31 Jul, 2025 Reviewers agreed at journal 31 Jul, 2025 Reviewers agreed at journal 30 Jul, 2025 Reviewers agreed at journal 30 Jul, 2025 Reviewers agreed at journal 29 Jul, 2025 Reviews received at journal 29 Jul, 2025 Reviewers agreed at journal 29 Jul, 2025 Reviewers agreed at journal 28 Jul, 2025 Reviewers agreed at journal 28 Jul, 2025 Reviewers agreed at journal 28 Jul, 2025 Reviewers invited by journal 28 Jul, 2025 Editor invited by journal 28 Jul, 2025 Editor assigned by journal 02 Jul, 2025 Submission checks completed at journal 02 Jul, 2025 First submitted to journal 19 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-6932425","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":492237200,"identity":"d7e531c1-cb2a-4424-96f1-5fa4139e4081","order_by":0,"name":"Hong-Yi Tang","email":"","orcid":"","institution":"Peking University Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hong-Yi","middleName":"","lastName":"Tang","suffix":""},{"id":492237202,"identity":"dd9e2b31-bb4d-475d-b622-51c01448d669","order_by":1,"name":"Zi-Rui Zhou","email":"","orcid":"","institution":"Peking University Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zi-Rui","middleName":"","lastName":"Zhou","suffix":""},{"id":492237205,"identity":"0c276015-7fe3-4dca-bf5b-6938dfb2f73f","order_by":2,"name":"Jiang-Feng Fu","email":"","orcid":"","institution":"Peking University Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jiang-Feng","middleName":"","lastName":"Fu","suffix":""},{"id":492237206,"identity":"914591f5-74f2-4eff-aab3-2fe5cd6709f8","order_by":3,"name":"Qian-Wen Li","email":"","orcid":"","institution":"Peking University Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Qian-Wen","middleName":"","lastName":"Li","suffix":""},{"id":492237208,"identity":"20c39be1-5a35-4fec-8d96-3cccbeef3258","order_by":4,"name":"Li Gao","email":"","orcid":"","institution":"Peking University Stomatological Hospital","correspondingAuthor":false,"prefix":"","firstName":"Li","middleName":"","lastName":"Gao","suffix":""},{"id":492237210,"identity":"97ea81c8-5dcf-4606-a5a9-ae2961c74807","order_by":5,"name":"Jiu-Hui H. Jiang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAwklEQVRIiWNgGAWjYDCCAwwJB0A0PzPz4QekaZFsZ0szIFYLBBic51GQIEoH3+0DDw/83FGbuPkwD4MBQ41NNEEtkucSEg72njmeuO0w74EHDMfSchsIaTE4A/QLb9ux3G2H+RIMGBsOE6fl4F+gls3NPAYSRGs5zNtWk7uBmVgtkiAtsm0H6mccBgZyAjF+4TvDk/zxbVudMX//4cMPPtTYENbCwMCTACQOQ9gJhJWDAPsBIFFHnNpRMApGwSgYmQAAn9NILvQiJn0AAAAASUVORK5CYII=","orcid":"","institution":"Peking University Stomatological Hospital","correspondingAuthor":true,"prefix":"","firstName":"Jiu-Hui","middleName":"H.","lastName":"Jiang","suffix":""}],"badges":[],"createdAt":"2025-06-19 15:08:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6932425/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6932425/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12903-025-07462-5","type":"published","date":"2025-12-12T15:57:53+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":87885911,"identity":"1869cff5-8ea8-4edc-9012-adeb1314b39c","added_by":"auto","created_at":"2025-07-30 05:08:43","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":62697,"visible":true,"origin":"","legend":"\u003cp\u003eLandmark positions in the sagittal and vertical planes. 1, A-VFH; 2, A-FH; 3, PNS-VFH; 4, PNS-FH; 5, B-VFH; 6, B-FH; 7, Me-VFH; 8, Me-FH; 9, H-VFH; 10, H-FH.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6932425/v1/b026adafaa97738f023950a7.jpg"},{"id":87885917,"identity":"498c59cd-2886-4ff5-9cc8-28c64267b19e","added_by":"auto","created_at":"2025-07-30 05:08:44","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":48727,"visible":true,"origin":"","legend":"\u003cp\u003eMaxillary Width Measurement in the Coronal Plane. (A) Coronal plane alignment at the zygomatic bone’s lowest point. (B) NF-10: Maxillary width 10 mm above the nasal floor (NF line).\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6932425/v1/4a2195f5e178325a063d9351.jpg"},{"id":87885890,"identity":"0e45de74-d863-494a-91f3-6a88ffedaa1a","added_by":"auto","created_at":"2025-07-30 05:08:41","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":101055,"visible":true,"origin":"","legend":"\u003cp\u003eMandibular Contour Measurements (A) Mandibular body length ([A1 + A2]/2); (B) intergonial width; (C) mandibular depth; (D) MP/FH angle (between the Go-Gn plane and the FH plane).\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6932425/v1/3065eed4b5aa78a7c9f1e7d6.jpg"},{"id":87885889,"identity":"b1f7ebbd-e9d9-4323-85b1-b3ae4e39012e","added_by":"auto","created_at":"2025-07-30 05:08:41","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":81718,"visible":true,"origin":"","legend":"\u003cp\u003e(A) The volume of the upper airway and its 3 sections (purplish red). (B) Minimum cross-sectional area (purple‒red). (C) Soft‒palatal angle (between the tip of the uvula, PNS, and ANS) and length (from the posterior and inferior points of the soft palate to the PNS). (D) Soft-palatal area.\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6932425/v1/877f619015194a30e88fed7b.jpg"},{"id":87885899,"identity":"315c3522-34a8-43f2-b845-53591302eb1a","added_by":"auto","created_at":"2025-07-30 05:08:43","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":38232,"visible":true,"origin":"","legend":"\u003cp\u003eUpper Airway Volume Changes Over Time. Comparisons of total airway volume (V) at the preoperative (T0), 3-month (T1), and 2-year (T2) time points. The arrows indicate significant increases (T0→T1, T0→T2) and partial relapse (T1→T2). *, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05; **, \u003cem\u003eP\u003c/em\u003e\u0026lt; 0.01.\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6932425/v1/380fc173ee55f79fbca4b013.jpg"},{"id":98243746,"identity":"fd2ad27a-a52c-4d0e-a196-c2c807af6b57","added_by":"auto","created_at":"2025-12-15 16:10:19","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1269127,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6932425/v1/4486e3aa-0380-4d55-858b-b0b5e2bf6b05.pdf"},{"id":87885900,"identity":"3102b06e-5408-405e-bd69-fe9473a0331e","added_by":"auto","created_at":"2025-07-30 05:08:43","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":36081,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementaryinformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-6932425/v1/e72061ba40410e8eb7b82f7c.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparing short- and long-term effects of mandibular advancement with versus without maxillary setback on the oropharyngeal airway in skeletal Class II individuals: An extensive 2-year follow-up study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eObstructive sleep apnea (OSA), a respiratory disorder characterized by recurrent upper airway obstruction during sleep, can lead to snoring, intermittent waking, and systemic diseases such as hypertension, cardiovascular diseases, and sedentary behaviors\u003csup\u003e[\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. Notably, skeletal Class II patients, who often present with retrusive mandibles and narrowed oropharyngeal airways, are more susceptible to OSA than the general population is\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. This poses a significant threat to their quality of life and overall health, highlighting the urgent need for effective treatment strategies\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eCurrent studies have confirmed the significant effects of maxillomandibular advancement (MMA) on improving the upper airway morphology and apnea‒hypopnea index (AHI) of skeletal Class II patients \u003csup\u003e[\u003cspan additionalcitationids=\"CR9 CR10\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. However, due to relatively mild maxillary retrusion in Asian patients, MMA is less commonly applied domestically. Instead, the mainstream method is mandibular advancement without maxillary posterior displacement (MAWMP), which avoids the adverse effects of maxillary setback on upper airway morphology while preserving patients' facial aesthetics\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. Despite its clinical application, few studies have comprehensively analyzed long-term changes in the upper airway and related influencing factors 2 years after MAWMPs.\u003c/p\u003e\u003cp\u003eThis study aims to fill this research gap by evaluating upper airway changes at 3 months and 2 years post-MAWMP surgery, analyzing the quantitative relationship between long-term postoperative upper airway changes and intraoperative hard and soft tissue movements, and further comparing the long-term upper airway impacts of the MAWMP and MAWMS. The findings of this study will provide valuable insights for clinicians in selecting optimal surgical approaches for skeletal Class II patients, ultimately improving treatment outcomes and patients' quality of life.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003eStudy Design and Participants\u003c/h2\u003e\n \u003cp\u003eThis retrospective study was conducted at Peking University Stomatological Hospital from January 2017 to October 2023. A total of 86 skeletal Class II patients who had undergone MAWMP or MAWMS were recruited. The inclusion criteria were as follows: (1) age\u0026thinsp;\u0026gt;\u0026thinsp;18 years with skeletal Class II malocclusion (ANB\u0026thinsp;\u0026gt;\u0026thinsp;5\u0026deg;); and (2) availability of cone-beam computed tomography (CBCT) scans at three specific time points: preoperatively (T0), 3 months postoperatively (T1), and 2 years postoperatively (T2). The exclusion criteria were as follows: (1) severe facial asymmetry; (2) previous orthognathic surgery; (3) history of facial trauma; (4) severe obesity (BMI\u0026thinsp;\u0026gt;\u0026thinsp;35 kg/m\u0026sup2;); (5) severe craniofacial syndrome; (6) history of significant cardiovascular or pulmonary diseases; and (7) history of diabetes or severe lipid metabolism disorders. The study was approved by the Ethics Committee of Peking University Stomatological Hospital (Approval No. PKUSSIRB-202167121).\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003eData Acquisition\u003c/h3\u003e\n\u003cp\u003eCBCT imaging examinations were performed on all patients at T0, T1, and T2 via a NewTom VG Aperio Services CBCT scanner (Imola, Italy) with the following parameters: 110 kV, 2.05 mA, field of view 15 cm \u0026times; 12 cm, voxel size 0.3 mm, and scan time 3.6 seconds. Patients were instructed to maintain an upright position with their head in the natural position, teeth in centric occlusion, and the tongue against the palate and to avoid swallowing during the scan. All the CBCT data were saved in Digital Imaging and Communications in Medicine (DICOM) format.\u003c/p\u003e\n\u003ch3\u003eMeasurement methods\u003c/h3\u003e\n\u003cp\u003eDolphin Imaging software (version 19.5; Dolphin Imaging and Management Solutions, Chatsworth, Calif.) was used for all the measurements. The CBCT images were reoriented along the midpalatal suture, tangent to the nasal base, and parallel to the Frankfort horizontal plane (FHP). A three-dimensional coordinate system was established with the FH plane as the x-coordinate and the y-coordinate (VFH) perpendicular to both the FH plane and the midsagittal plane, passing through the baseline point. The following anatomical landmarks were selected for evaluation: A point (the deepest point on the concavity of the maxilla between the ANS and the maxillary alveolus), PNS point (posterior nasal spine), B point (the innermost point on the contour of the mandible between the mandibular incisor and chin), Me point (Menton, the most interior point on the chin), and H point (Hyoidale, the most superior and anterior point on the body of the hyoid bone) (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). The parameters NF-10 (maxillary width parallel to and 10 mm above the lowest line of the nasal base) and MP-FH (the angle between the Go-Gn plane and the FH plane) were used to determine the maxillary width and vertical skeletal evaluation, respectively (Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). Mandibular length, width, and depth were also measured to assess the three-dimensional size of the mandible (Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). The upper airway was divided into three segments: the nasopharynx, velopharynx, and glossopharynx. The minimum cross-sectional area (CSA\u003csub\u003emin\u003c/sub\u003e) was also evaluated. The volume, cross-sectional area, and transverse and sagittal diameters of each segment were measured. For soft-tissue measurements, the length, angle, and area of the soft palate were measured in the midsagittal plane (Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e). The detailed definitions of the terms are summarized in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n\u003ch3\u003eSample Size Estimation\u003c/h3\u003e\n\u003cp\u003eSample size estimation was performed via PASS 21.0 software (Power Analysis and Sample Size Software 21.0, NCSS, USA). The reference value for the sample size calculation was the measurement result of the upper airway representative indicator CSA\u003csub\u003emin\u003c/sub\u003e. Single-factor repeated measures analysis of variance was used for the calculation, with a significance level (\u0026alpha;) of 0.05 and a statistical power (1-\u0026beta;) of 80%. The maximum sample size obtained from the calculation was used as the required sample size for this study.\u003c/p\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n \u003ch2\u003eStatistical analysis\u003c/h2\u003e\n \u003cp\u003eThe data were analyzed via SPSS (v23.0). The normality of upper airway parameters (\u003cem\u003eV\u003c/em\u003e, \u003cem\u003eCSA\u003c/em\u003e\u003csub\u003e\u003cem\u003emin\u003c/em\u003e\u003c/sub\u003e, \u003cem\u003eV\u003c/em\u003e\u003csub\u003e\u003cem\u003eNA\u003c/em\u003e\u003c/sub\u003e, \u003cem\u003eV\u003c/em\u003e\u003csub\u003e\u003cem\u003eVE\u003c/em\u003e\u003c/sub\u003e, \u003cem\u003eV\u003c/em\u003e\u003csub\u003e\u003cem\u003eGL\u003c/em\u003e\u003c/sub\u003e) was tested via the Kolmogorov‒Smirnov test. Longitudinal changes (T0-T1-T2) were evaluated with paired \u003cem\u003et\u003c/em\u003e tests or Wilcoxon signed-rank tests. Correlations between skeletal advancements (e.g., \u003cem\u003ePNS\u003c/em\u003e and \u003cem\u003eB\u003c/em\u003e point movements) and airway changes were analyzed via Pearson/Spearman tests. Baseline characteristics (age, BMI, sex) were compared between the MAWMP and MAWMS groups via independent \u003cem\u003et\u003c/em\u003e tests and chi-square tests. Postoperative differences in airway parameters (\u003cem\u003eV\u003c/em\u003e, \u003cem\u003eCSA\u003c/em\u003e\u003csub\u003e\u003cem\u003emin\u003c/em\u003e\u003c/sub\u003e, segment volumes) between procedures were assessed with the Wilcoxon rank-sum test.\u003c/p\u003e\n \u003cp\u003eMultiple linear regression analyses were performed to investigate the quantitative relationships between changes in upper airway volume and contributing factors. The total sample (N\u0026thinsp;=\u0026thinsp;82) met statistical guidelines requiring 15 observations per predictor, ensuring model robustness. Variables with significant correlations in univariate analyses (e.g., PNS and B point advancements) were incorporated into multivariate models to identify independent predictors of airway expansion.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab1\" border=\"1\" class=\"fr-table-selection-hover\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eDefinitions of Parameters\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eParameters\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDefinitions\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHard tissue\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe deepest point on the concavity of the maxilla between ANS and the maxillary alveolus\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe innermost point on the contour of mandible between mandibular incisor and chin\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePosterior nasal spine\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMenton, the most interior point on the chin\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHyoidale, the most superior and anterior point on the body of the hyoid bone\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBasion, median point of anterior margin of foramen magnum\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe most anterior and inferior point of the mandible\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGn\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe most posterior and inferior points of the mandible\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNF-10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMaxillary width parallel to and 10 mm above the lowest line of the nasal base\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFrankfort horizontal plane\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eVFH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eA plane perpendicular to the FHP, midsagittal plane and passing through Basion point\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMP/FH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe angle between the Go-Gn plane and the FH plane\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMandibular body length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe distance from Gn to the left or right Go\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMandibular width\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe distance between the left and right Go\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMandibular depth\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe 2-dimensional distance from Gn to Go\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePNS\u0026thinsp;+\u0026thinsp;B\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe sum of the sagittal position distance of PNS and that of B\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSoft tissue\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSoft-palatal angle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe angle between the tip of uvula, PNS, and ANS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSoft-palatal length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe distance from the posterior and inferior point of soft palatal to PNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSoft-palatal area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe area of the soft palate\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUpper airway\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe anterior border is the line passing through PNS and S; the inferior border is the line parallel to the FHP passing through the root of epiglottis, and the posterior border is the pharyngeal posterior wall\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCSA\u003csub\u003emin\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMinimum cross-sectional area of the upper airway\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNasopharynx\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe anterior border is the line passing through PNS and S, the inferior border is the line parallel to the FHP passing through PNS, and the posterior border is the pharyngeal posterior wall\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eVelopharynx\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe superior border is the line parallel to the FHP passing through PNS, the inferior border is the line parallel to the FHP passing through the tip of uvula, and the posterior border is the pharyngeal posterior wall\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGlossopharynx\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe superior border is the line parallel to the FHP passing through the tip of uvula, the inferior border is the line parallel to the FHP passing through the root of epiglottis, and the posterior border is the pharyngeal posterior wall\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003eHard and Soft Tissue Changes\u003c/h2\u003e\u003cp\u003eThis study included 25 skeletal Class II patients who underwent MAWMPs (11 males, 14 females; age 29.08\u0026thinsp;\u0026plusmn;\u0026thinsp;4.10 years; BMI 22.35\u0026thinsp;\u0026plusmn;\u0026thinsp;2.42 kg/m\u0026sup2;). Preoperative cephalometric analysis confirmed skeletal Class II characteristics, with mean SNA, SNB, and ANB angles of 79.56\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35\u0026deg;, 72.50\u0026thinsp;\u0026plusmn;\u0026thinsp;2.42\u0026deg;, and 7.06\u0026thinsp;\u0026plusmn;\u0026thinsp;2.42\u0026deg;, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Comparisons of hard and soft tissue parameters were made preoperatively (T0) and 3 months (T1) and 2 years (T2) after surgery. At T1, points A, PNS, B, Me, and H moved anteriorly, while points PNS, B, and Me moved downward, and point H moved vertically. The maxillary width and mandibular contour increased significantly. The soft palate angle and median sagittal area decreased significantly at T1. Similar changes were observed at T2, except that the upward movement of point H was no longer significant. Notably, hard tissue changes remained consistent from T1 to T2, whereas a decreased soft palate angle and median sagittal area were not observed at T2 (Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eHard and Soft Tissue Changes in Different Periods\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters (N\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eT0\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eT1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eT2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHard tissue\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eA-FH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e33.83\u0026thinsp;\u0026plusmn;\u0026thinsp;2.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e33.06\u0026thinsp;\u0026plusmn;\u0026thinsp;2.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e33.23\u0026thinsp;\u0026plusmn;\u0026thinsp;2.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.061\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eA-VFH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e85.43\u0026thinsp;\u0026plusmn;\u0026thinsp;5.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e87.98\u0026thinsp;\u0026plusmn;\u0026thinsp;5.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e87.64\u0026thinsp;\u0026plusmn;\u0026thinsp;5.40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePNS-FH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e25.34\u0026thinsp;\u0026plusmn;\u0026thinsp;2.55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e26.60\u0026thinsp;\u0026plusmn;\u0026thinsp;2.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e26.25\u0026thinsp;\u0026plusmn;\u0026thinsp;3.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.002\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePNS-VFH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e40.58\u0026thinsp;\u0026plusmn;\u0026thinsp;3.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e43.57\u0026thinsp;\u0026plusmn;\u0026thinsp;3.69\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e43.04\u0026thinsp;\u0026plusmn;\u0026thinsp;3.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eB-FH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e74.56\u0026thinsp;\u0026plusmn;\u0026thinsp;5.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e76.51\u0026thinsp;\u0026plusmn;\u0026thinsp;4.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e76.32\u0026thinsp;\u0026plusmn;\u0026thinsp;4.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.002\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eB-VFH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e71.04\u0026thinsp;\u0026plusmn;\u0026thinsp;7.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e77.24\u0026thinsp;\u0026plusmn;\u0026thinsp;7.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e76.70\u0026thinsp;\u0026plusmn;\u0026thinsp;7.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMe-FH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e92.14\u0026thinsp;\u0026plusmn;\u0026thinsp;6.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e94.52\u0026thinsp;\u0026plusmn;\u0026thinsp;4.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e94.69\u0026thinsp;\u0026plusmn;\u0026thinsp;5.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMe-VFH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e63.15\u0026thinsp;\u0026plusmn;\u0026thinsp;9.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e71.98\u0026thinsp;\u0026plusmn;\u0026thinsp;8.97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e72.28\u0026thinsp;\u0026plusmn;\u0026thinsp;7.73\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNF-10 (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e103.41\u0026thinsp;\u0026plusmn;\u0026thinsp;8.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e105.40\u0026thinsp;\u0026plusmn;\u0026thinsp;8.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e105.11\u0026thinsp;\u0026plusmn;\u0026thinsp;8.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMandibular Body Length (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e84.78\u0026thinsp;\u0026plusmn;\u0026thinsp;5.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e93.60\u0026thinsp;\u0026plusmn;\u0026thinsp;4.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e93.28\u0026thinsp;\u0026plusmn;\u0026thinsp;4.79\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMandibular Width (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e98.44\u0026thinsp;\u0026plusmn;\u0026thinsp;6.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e101.26\u0026thinsp;\u0026plusmn;\u0026thinsp;6.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e101.15\u0026thinsp;\u0026plusmn;\u0026thinsp;6.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMandibular Body Depth (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e69.42\u0026thinsp;\u0026plusmn;\u0026thinsp;5.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e78.73\u0026thinsp;\u0026plusmn;\u0026thinsp;4.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e78.67\u0026thinsp;\u0026plusmn;\u0026thinsp;4.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMP-FH (\u0026deg;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e32.34\u0026thinsp;\u0026plusmn;\u0026thinsp;7.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e31.51\u0026thinsp;\u0026plusmn;\u0026thinsp;4.86\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e32.59\u0026thinsp;\u0026plusmn;\u0026thinsp;5.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.334\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eH-FH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e85.53\u0026thinsp;\u0026plusmn;\u0026thinsp;8.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e83.06\u0026thinsp;\u0026plusmn;\u0026thinsp;7.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e84.24\u0026thinsp;\u0026plusmn;\u0026thinsp;8.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eH-VFH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e30.02\u0026thinsp;\u0026plusmn;\u0026thinsp;6.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e33.74\u0026thinsp;\u0026plusmn;\u0026thinsp;6.68\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e32.80\u0026thinsp;\u0026plusmn;\u0026thinsp;5.89\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSoft tissue\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSoft Palate Angle (\u0026deg;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e134.11\u0026thinsp;\u0026plusmn;\u0026thinsp;27.86\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e131.87\u0026thinsp;\u0026plusmn;\u0026thinsp;27.97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e133.97\u0026thinsp;\u0026plusmn;\u0026thinsp;27.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.056\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSoft Palate Length (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e34.94\u0026thinsp;\u0026plusmn;\u0026thinsp;4.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e33.58\u0026thinsp;\u0026plusmn;\u0026thinsp;4.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e34.50\u0026thinsp;\u0026plusmn;\u0026thinsp;4.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.045\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMidline Area (mm\u0026sup2;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e263.38\u0026thinsp;\u0026plusmn;\u0026thinsp;60.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e238.52\u0026thinsp;\u0026plusmn;\u0026thinsp;52.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e252.36\u0026thinsp;\u0026plusmn;\u0026thinsp;51.69\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.002\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eChanges in Upper Airway Morphology\u003c/h3\u003e\n\u003cp\u003eSignificant increases in upper airway volume (V), minimum cross-sectional area (CSA\u003csub\u003emin\u003c/sub\u003e), and segment volume were observed at T1 and T2 compared with those at T0 (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e \u0026amp; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The rates of increase from T0 to T1 for V, CSA\u003csub\u003emin\u003c/sub\u003e, V\u003csub\u003eNA\u003c/sub\u003e, V\u003csub\u003eVE\u003c/sub\u003e, and V\u003csub\u003eGL\u003c/sub\u003e were 38.86%, 69.49%, 22.31%, 46.05%, and 46.94% (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01), respectively. From T0 to T2, these rates were 21.85%, 43.11%, 13.85%, 19.73%, and 25.38%, respectively (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Conversely, from T1 to T2, V, CSA\u003csub\u003emin\u003c/sub\u003e, V\u003csub\u003eVE\u003c/sub\u003e, and V\u003csub\u003eGL\u003c/sub\u003e decreased by 12.24%, 15.56%, 18.02%, and 14.67% (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), respectively, with no significant change in V\u003csub\u003eNA\u003c/sub\u003e (Tables S2\u0026amp;3).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eParameters of Upper Airway Segments Over time\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters (N\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eT0\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eT1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eT2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eA \u003csub\u003eNA\u003c/sub\u003e (mm\u0026sup2;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e644.74\u0026thinsp;\u0026plusmn;\u0026thinsp;148.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e728.55\u0026thinsp;\u0026plusmn;\u0026thinsp;164.57\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e692.56\u0026thinsp;\u0026plusmn;\u0026thinsp;155.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTD \u003csub\u003eNA\u003c/sub\u003e (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e37.86\u0026thinsp;\u0026plusmn;\u0026thinsp;5.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e40.73\u0026thinsp;\u0026plusmn;\u0026thinsp;6.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e39.98\u0026thinsp;\u0026plusmn;\u0026thinsp;7.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.004\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSD \u003csub\u003eNA\u003c/sub\u003e (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e28.69\u0026thinsp;\u0026plusmn;\u0026thinsp;4.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e31.16\u0026thinsp;\u0026plusmn;\u0026thinsp;5.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e30.12\u0026thinsp;\u0026plusmn;\u0026thinsp;5.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.017\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eA \u003csub\u003eVE\u003c/sub\u003e (mm\u0026sup2;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e243.97\u0026thinsp;\u0026plusmn;\u0026thinsp;107.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e451.77\u0026thinsp;\u0026plusmn;\u0026thinsp;149.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e361.12\u0026thinsp;\u0026plusmn;\u0026thinsp;128.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTD \u003csub\u003eVE\u003c/sub\u003e (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e27.31\u0026thinsp;\u0026plusmn;\u0026thinsp;6.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e35.90\u0026thinsp;\u0026plusmn;\u0026thinsp;5.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e32.95\u0026thinsp;\u0026plusmn;\u0026thinsp;5.86\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSD \u003csub\u003eVE\u003c/sub\u003e (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e13.09\u0026thinsp;\u0026plusmn;\u0026thinsp;4.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e20.85\u0026thinsp;\u0026plusmn;\u0026thinsp;5.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e17.36\u0026thinsp;\u0026plusmn;\u0026thinsp;4.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eA \u003csub\u003eGL\u003c/sub\u003e (mm\u0026sup2;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e324.99\u0026thinsp;\u0026plusmn;\u0026thinsp;118.74\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e426.27\u0026thinsp;\u0026plusmn;\u0026thinsp;100.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e380.04\u0026thinsp;\u0026plusmn;\u0026thinsp;81.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTD \u003csub\u003eGL\u003c/sub\u003e (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e34.86\u0026thinsp;\u0026plusmn;\u0026thinsp;4.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e39.48\u0026thinsp;\u0026plusmn;\u0026thinsp;3.72\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e37.58\u0026thinsp;\u0026plusmn;\u0026thinsp;3.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSD \u003csub\u003eGL\u003c/sub\u003e (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e13.96\u0026thinsp;\u0026plusmn;\u0026thinsp;3.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e19.84\u0026thinsp;\u0026plusmn;\u0026thinsp;2.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e17.46\u0026thinsp;\u0026plusmn;\u0026thinsp;2.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eCorrelation and Regression Analysis\u003c/h2\u003e\u003cp\u003eAt T1, increases in B point advancement (B-VFH), hyoid bone elevation (H-FH), reduction in the soft palate angle, and the sum of PNS and B point advancement (PNS\u0026thinsp;+\u0026thinsp;B) were positively correlated with increases in V (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (Tables S4\u0026amp;6). For each airway segment, PNS point advancement was significantly positively correlated with an increase in VNA (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), whereas B point advancement, a reduction in the soft palate angle, and an increase in the PNS\u0026thinsp;+\u0026thinsp;B were positively correlated with an increase in V\u003csub\u003eVE\u003c/sub\u003e at T1 (Table S5). At T2, B point advancement (B-VFH), Me point advancement (Me-VFH), and PNS\u0026thinsp;+\u0026thinsp;B were positively correlated with the increase in V at 2 years postoperatively (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The increase in V was negatively correlated with the preoperative CSA\u003csub\u003emin\u003c/sub\u003e. PNS and A-point advancement remained significantly correlated with V\u003csub\u003eNA\u003c/sub\u003e increase at T2 (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Similarly, B point advancement, a reduction in the soft palate angle, and an increase in the PNS\u0026thinsp;+\u0026thinsp;B were positively correlated with an increase in V\u003csub\u003eVE\u003c/sub\u003e at T2. The increase in PNS\u0026thinsp;+\u0026thinsp;B changed from a negative to a positive correlation with the increase in V \u003csub\u003eGL\u003c/sub\u003e at T2 (Table S7).\u003c/p\u003e\u003cp\u003eMultivariate regression analysis at 2 years postsurgery revealed positive correlations between the sum of PNS and B point advancements and increases in V and V\u003csub\u003eVE\u003c/sub\u003e and between PNS advancement and V\u003csub\u003eNA\u003c/sub\u003e increase (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Quantitatively, each mm increase in PNS and B point advancements led to a 1038.18 mm\u0026sup3; increase in V and a 519.11 mm\u0026sup3; increase in V\u003csub\u003eVE\u003c/sub\u003e; each mm PNS advancement led to a 708.30 mm\u0026sup3; increase in V\u003csub\u003eNA\u003c/sub\u003e at 2 years postoperatively (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eResults of Multiple Linear Regression Analysis\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003cp\u003e(N\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAdjusted R\u0026sup2;\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eP\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRegression\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eVIF\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.376\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.013*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1038.18 * \u003cem\u003ePNS\u0026thinsp;+\u0026thinsp;B\u003c/em\u003e\u0026thinsp;+\u0026thinsp;17110.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.003*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1.190\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV \u003csub\u003eNA\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.256\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.040*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e708.3 * \u003cem\u003ePNS-VFH\u003c/em\u003e\u0026thinsp;+\u0026thinsp;5789.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.008*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1.125\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eV \u003csub\u003eVE\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.343\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.021*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e519.11 * \u003cem\u003ePNS\u0026thinsp;+\u0026thinsp;B\u003c/em\u003e \u0026minus;\u0026thinsp;351.14 * \u003cem\u003eUvular angle\u003c/em\u003e\u0026thinsp;+\u0026thinsp;5838.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.043*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1.168\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.008*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1.127\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV \u003csub\u003eGL\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.201\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.273\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e497.41 * \u003cem\u003ePNS\u0026thinsp;+\u0026thinsp;B\u003c/em\u003e -1204.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.049*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1.157\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003eComparison of upper airway morphology after MAWMP and MAWMS\u003c/h2\u003e\u003cp\u003eTo further compare the different effects on the upper airway between MAWMP and MAWMS, 57 patients with skeletal Class II malocclusion who underwent MAWMS were included, with detailed information from previous studies\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e (Table S8). There were no significant differences in the baseline data (age, sex, or BMI) between the two groups before treatment. Comparisons of upper airway changes revealed significant intergroup differences in the increase in all upper airway volumes and CSA\u003csub\u003emin\u003c/sub\u003e at 3 months postsurgery (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), with the MAWMP group showing a significantly greater increase than the MAWMS group (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). However, at 2 years postsurgery, only the increases in V and V \u003csub\u003eNA\u003c/sub\u003e showed significant intergroup differences (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), whereas the other segments did not show significant differences in volume or CSA\u003csub\u003emin\u003c/sub\u003e (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePostoperative Upper Airway Changes at 3 Months (MAWMP vs MAWMS)\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMAWMP (N\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMAWMS (N\u0026thinsp;=\u0026thinsp;57)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e11175.00 (9749.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3638.00 (8101.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCSA \u003csub\u003emin\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e97.00 (135.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e54.00 (94.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.004*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV \u003csub\u003eNA\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1811.00 (2203.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e430.00 (2734.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.001*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV \u003csub\u003eVE\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4598.00 (4107.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e112.00 (4647.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV \u003csub\u003eGL\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4164.00 (3709.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1502.00 (3242.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.003*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eLong-term Upper Airway Changes at 2 Years (MAWMP vs MAWMS)\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMAWMP (N\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMAWMS (N\u0026thinsp;=\u0026thinsp;57)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8258.00 (9842.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3152.00 (6812.09)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.015*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCSA \u003csub\u003emin\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e82.00 (87.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e49.00 (118.87)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.084\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV \u003csub\u003eNA\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1026.00 (2149.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e204.00 (2158.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.040*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV \u003csub\u003eVE\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2421.00 (5875.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e459.00 (4256.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.104\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eV \u003csub\u003eGL\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1475.00 (4114.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1571.00 (2963.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.247\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eGrowing evidence indicates that skeletal Class II patients face a greater risk of obstructive sleep apnea (OSA) due to narrowed upper airways, in addition to dental and facial discrepancies\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. Given the significant impact of OSA on quality of life and systemic health, optimal orthodontic and orthognathic treatments for these patients should aim to increase upper airway volume and reduce OSA risk. While many studies have investigated how bimaxillary surgery affects upper airway morphology, long-term data on single-jaw surgery, particularly mandibular advancement without maxillary posterior displacement (MAWMP), are lacking\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eIn this study, we assessed both short-term and long-term upper airway changes following MAWMPs. Our data revealed a significant 37.0% increase in total upper airway volume at 3 months postsurgery, which is in line with previous research \u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Despite some reduction in airway volume from 3 months to 2 years postoperatively, it remained significantly greater than it was preoperatively, indicating the long-term stability of the MAWMP in enhancing airway morphology\u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e. Similarly, Parsi et al. and Yamashita et al. reported sustained airway improvements with mandibular advancement procedures\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eOur study also underscores the critical role of mandibular advancement in upper airway reconstruction. Hernandez-Alfaro et al. reported that patients who underwent mandibular advancement (69.8%) or bimaxillary advancement (78.3%) exhibited significantly greater increases in upper airway volume than did those who underwent maxillary advancement alone (37.7%)\u003csup\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e. Similarly, studies on mandibular advancement appliances, such as the Twin-Block, have demonstrated positive effects on airway volume and OSA symptom alleviation\u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. However, Pereira et al. reported no significant correlation between mandibular advancement and airway volume after a 4-year follow-up, underscoring the need for larger sample sizes and extended observation periods\u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eIn the short term, the MAWMP resulted in significant anterior and upward displacement of the hyoid bone (H point) and a reduction in the soft-palate angle. These changes were positively correlated with increases in airway volume at 3 months postsurgery. However, these soft-tissue changes became nonsignificant by the 2-year follow-up, likely due to adaptive remodeling of the velopharyngeal musculature. The velopharyngeal region is a common site of collapse in OSA patients, and even surgical interventions such as umbilicalopharyngoplasty often fail to prevent soft-tissue relapse. In contrast, the mandibular position remained significantly advanced at both 3 months and 2 years postoperatively, which is consistent with findings from studies on maxillomandibular advancement (MMA) and MAWMS \u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e. These findings suggest that long-term improvements in airway volume are driven primarily by hard-tissue changes, whereas the velopharyngeal region may be more susceptible to relapse.\u003c/p\u003e\u003cp\u003eThe increase in the volume of various parts of the upper airway caused by the MAWMP was significantly greater than that caused by the MAWMS, which is consistent with previous findings\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. Brunetto et al. reported that changes in the upper airway were more unpredictable when the maxilla and mandible were moved in different directions than when they were moved in the same direction\u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e. This study, which used MAWMS as a control, confirmed the unique advantages of MAWMP in improving the upper airway. Intriguingly, at 2 years postsurgery, no significant intergroup differences were observed in the volume changes in the upper airway, except for V and VNA. The postoperative changes in the upper airway may exhibit a compensatory effect; that is, the greater the volume of the upper airway in the short term after surgery (T1), the greater the degree of relapse over time (T1\u0026ndash;T2)\u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. The long-term relapse rate of the MAWMP was greater than that of the MAWMS, which may be related to the disappearance of the intergroup differences in the increase in VVE and VGL at 2 years postsurgery.\u003c/p\u003e\u003cp\u003eA novel finding of this study is the robust predictive value of combined PNS and B point advancements for long-term airway changes. While previous research has focused primarily on the individual movements of landmarks such as the PNS, A, or B, this study is the first to explore the correlation between the sum of the PNS and B point advancements and upper airway volume\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. Our results indicate that even at 2 years postsurgery, this combined measurement remained significantly correlated with increases in multiple airway segments. This finding provides valuable guidance for orthodontists and orthognathic surgeons in designing jaw movements to optimize airway outcomes.\u003c/p\u003e\u003cp\u003eThis study has several limitations. First, the relatively small sample size of the MAWMP group (n\u0026thinsp;=\u0026thinsp;25) may limit the statistical power and generalizability of the findings. Second, the retrospective design introduces potential selection bias and residual confounding factors. Third, the exclusion of obese patients (BMI\u0026thinsp;\u0026gt;\u0026thinsp;35 kg/m\u0026sup2;) restricts their applicability to high-risk OSA populations. Additionally, although standardized, CBCT-based measurements could be influenced by subtle variations in head posture or tongue positioning during scans. Finally, soft-tissue adaptations have transient effects, necessitating longer-term monitoring to elucidate relapse mechanisms. Future prospective studies with larger cohorts, broader BMI inclusion, and multimodal imaging protocols could address these limitations and refine surgical strategies for sustained airway improvements.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study demonstrated that mandibular advancement without maxillary posterior displacement (MAWMP) significantly improved oropharyngeal airway morphology in skeletal Class II patients, with sustained benefits observed over a 2-year follow-up period. V, CSA\u003csub\u003emin\u003c/sub\u003e, and segmental volumes (V\u003csub\u003eNA\u003c/sub\u003e, V\u003csub\u003eVE\u003c/sub\u003e, V\u003csub\u003eGL\u003c/sub\u003e) exhibited substantial increases at both 3 months and 2 years postoperatively compared with baseline, despite a partial relapse in velopharyngeal and glossopharyngeal volumes over time. Multivariate regression analysis highlighted the critical role of combined PNS and B-point advancements in driving long-term airway expansion, with each millimeter of advancement correlating with quantifiable increases in airway volume. Notably, the MAWMP outperformed the MAWMS in both short-term and long-term upper airway improvements, particularly in total volume and nasopharyngeal stability. These findings underscore the clinical value of prioritizing mandibular advancement and coordinated maxillomandibular repositioning in skeletal Class II patients, especially those at risk of OSA. Future studies should explore the mechanisms of soft-tissue adaptation and relapse to optimize surgical protocols for sustained airway patency.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the National Nature Science Fond(China, fond number 81000440).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll procedures performed in the study were approved by the Ethics Committee of Peking University Stomatological Hospital (Approval No. PKUSSIRB-202167121), conducted in accordance with the 1975 Declaration of Helsinki as revised in 2013. Informed consent was obtained from all participants included in the study or from a parent and/or legal guardian for study participation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eHong-Yi Tang and Zi-Rui Zhou contribute equally to this work.All authors contributed substantially to data interpretation, manuscript drafting, critical revision, final approval, and accountability for the work. Additionally, JHJ, LG, HYT and ZRZ conceived and designed the study; HYT and ZRZ collected data and developed methodology; JFF and QWL analyzed data; LG. coordinated the project with JHJ led the manuscript writing.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e\u003cp\u003eThis work was supported by the National Nature Science Fond(China, fond number 81000440).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eJordan A S, Mcsharry D G, Malhotra A. Adult obstructive sleep apnoea[J]. Lancet, 2014, 383(9918): 736-47.\u003c/li\u003e\n\u003cli\u003eL\u0026eacute;vy P, Kohler M, Mcnicholas W T, et al. Obstructive sleep apnoea syndrome[J]. Nat Rev Dis Primers, 2015, 1: 15015.\u003c/li\u003e\n\u003cli\u003eNeelapu B C, Kharbanda O P, Sardana H K, et al. Craniofacial and upper airway morphology in adult obstructive sleep apnea patients: A systematic review and meta-analysis of cephalometric studies[J]. Sleep Med Rev, 2017, 31: 79-90.\u003c/li\u003e\n\u003cli\u003eTang H, Zhou Q, Zheng F, et al. The Causal Effects of Lipid Profiles on Sleep Apnea[J]. Front Nutr, 2022, 9: 910690.\u003c/li\u003e\n\u003cli\u003eCai S, Li S, Zhou Y, et al. The association between sedentary behavior and obstructive sleep apnea: a cross-sectional study from the NHANES (2007-2008 to 2015-2020)[J]. BMC Oral Health, 2024, 24(1): 224.\u003c/li\u003e\n\u003cli\u003eSchwab R J, Pasirstein M, Pierson R, et al. Identification of upper airway anatomic risk factors for obstructive sleep apnea with volumetric magnetic resonance imaging[J]. Am J Respir Crit Care Med, 2003, 168(5): 522-30.\u003c/li\u003e\n\u003cli\u003eTang H, Zhou Q, Li H, et al. Exploring long-term changes and influencing factors of the upper airway in patients with a skeletal Class II relationship after mandibular advancement with maxillary setback surgery: A comprehensive 2-year follow-up investigation[J]. Am J Orthod Dentofacial Orthop, 2024, 165(5): 520-532.e3.\u003c/li\u003e\n\u003cli\u003eParsi G K, Alsulaiman A A, Kotak B, et al. Volumetric changes of the upper airway following maxillary and mandibular advancement using cone beam computed tomography[J]. Int J Oral Maxillofac Surg, 2019, 48(2): 203-210.\u003c/li\u003e\n\u003cli\u003eYamashita A L, Iwaki Filho L, Leite P C C, et al. Three-dimensional analysis of the pharyngeal airway space and hyoid bone position after orthognathic surgery[J]. J Craniomaxillofac Surg, 2017, 45(9): 1408-1414.\u003c/li\u003e\n\u003cli\u003eRaffaini M, Pisani C. Clinical and cone-beam computed tomography evaluation of the three-dimensional increase in pharyngeal airway space following maxillo-mandibular rotation-advancement for Class II-correction in patients without sleep apnoea (OSA)[J]. J Craniomaxillofac Surg, 2013, 41(7): 552-7.\u003c/li\u003e\n\u003cli\u003eSambale J, Koehler U, Conradt R, et al. Is sleep bruxism in obstructive sleep apnea only an oral health related problem?[J]. BMC Oral Health, 2024, 24(1): 565.\u003c/li\u003e\n\u003cli\u003eBiradar J M, Kumar M, N S, et al. Assessment of Posterior Pharyngeal Airway Changes After Orthognathic Surgery Using Barium Sulfate[J]. Cureus, 2023, 15(8): e42836.\u003c/li\u003e\n\u003cli\u003eValladares-Neto J, Silva M A, Bumann A, et al. Effects of mandibular advancement surgery combined with minimal maxillary displacement on the volume and most restricted cross-sectional area of the pharyngeal airway[J]. Int J Oral Maxillofac Surg, 2013, 42(11): 1437-45.\u003c/li\u003e\n\u003cli\u003eFang L, Tuohuti A, Cai W, et al. Changes in the nasopharyngeal and oropharyngeal microbiota in pediatric obstructive sleep apnea before and after surgery: a prospective study[J]. BMC Microbiol, 2024, 24(1): 79.\u003c/li\u003e\n\u003cli\u003eHern\u0026aacute;ndez-Alfaro F, Guijarro-Mart\u0026iacute;nez R, Mareque-Bueno J. Effect of mono- and bimaxillary advancement on pharyngeal airway volume: cone-beam computed tomography evaluation[J]. J Oral Maxillofac Surg, 2011, 69(11): e395-400.\u003c/li\u003e\n\u003cli\u003eShete C S, Bhad W A. Three-dimensional upper airway changes with mandibular advancement device in patients with obstructive sleep apnea[J]. Am J Orthod Dentofacial Orthop, 2017, 151(5): 941-948.\u003c/li\u003e\n\u003cli\u003eRyan C F, Love L L, Peat D, et al. Mandibular advancement oral appliance therapy for obstructive sleep apnoea: effect on awake calibre of the velopharynx[J]. Thorax, 1999, 54(11): 972-7.\u003c/li\u003e\n\u003cli\u003ePereira P K N, De Castro Rocha V, Degan V V, et al. Upper airways after mandibular advancement orthognathic surgery: A 4-year follow-up[J]. Am J Orthod Dentofacial Orthop, 2021, 159(6): 743-749.\u003c/li\u003e\n\u003cli\u003eFairburn S C, Waite P D, Vilos G, et al. Three-dimensional changes in upper airways of patients with obstructive sleep apnea following maxillomandibular advancement[J]. J Oral Maxillofac Surg, 2007, 65(1): 6-12.\u003c/li\u003e\n\u003cli\u003eAbramson Z, Susarla S M, Lawler M, et al. Three-dimensional computed tomographic airway analysis of patients with obstructive sleep apnea treated by maxillomandibular advancement[J]. J Oral Maxillofac Surg, 2011, 69(3): 677-86.\u003c/li\u003e\n\u003cli\u003eBrunetto D P, Velasco L, Koerich L, et al. Prediction of 3-dimensional pharyngeal airway changes after orthognathic surgery: a preliminary study[J]. Am J Orthod Dentofacial Orthop, 2014, 146(3): 299-309.\u003c/li\u003e\n\u003cli\u003eTrevisiol L, Bersani M, Sanna G, et al. Posterior airways and orthognathic surgery: What really matters for successful long-term results?[J]. Am J Orthod Dentofacial Orthop, 2022, 161(5): e486-e497.\u003c/li\u003e\n\u003cli\u003eChang M K, Sears C, Huang J C, et al. Correlation of Airway Volume With Orthognathic Surgical Movement Using Cone-Beam Computed Tomography[J]. J Oral Maxillofac Surg, 2015, 73(12 Suppl): S67-76.\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":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Skeletal Class II, MAWMP, MAWMS, Oropharyngeal airway","lastPublishedDoi":"10.21203/rs.3.rs-6932425/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6932425/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study assessed 2-year oropharyngeal airway changes in skeletal Class II patients after mandibular advancement without maxillary posterior displacement (MAWMP) versus mandibular advancement with maxillary setback (MAWMS).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and methods\u003c/strong\u003e A total of 25 MAWMP and 57 MAWMS patients underwent CBCT preoperatively (T0) and at 3 months (T1) and 2 years postoperatively (T2). The total upper airway volume (V), minimum cross-sectional area (CSA\u003csub\u003emin\u003c/sub\u003e), and volumes of the nasopharynx (V\u003csub\u003eNA\u003c/sub\u003e), velopharynx (V\u003csub\u003eVE\u003c/sub\u003e), and glossopharynx (V\u003csub\u003eGL\u003c/sub\u003e) were measured via Dolphin Imaging.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e MAWMP significantly increased V, CSA\u003csub\u003emin\u003c/sub\u003e, V\u003csub\u003eNA\u003c/sub\u003e, V\u003csub\u003eVE\u003c/sub\u003e, and V\u003csub\u003eGL\u003c/sub\u003e by 38.86%, 69.49%, 22.31%, 46.05%, and 46.94%, respectively, at T1 (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.01) and 21.85%, 43.11%, 13.85%, 19.73%, and 25.38%, respectively, at T2 (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.05). From T1 to T2, V, CSA\u003csub\u003emin\u003c/sub\u003e, V\u003csub\u003eVE\u003c/sub\u003e, and V\u003csub\u003eGL\u003c/sub\u003e\u0026nbsp;decreased by 12.24%, 15.56%, 18.02%, and 14.67%, respectively (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.05). Multivariate regression revealed that each 1 mm advancement of the PNS and B points increased V by 1038.18 mm³ and V\u003csub\u003eVE\u003c/sub\u003e\u0026nbsp;by 519.11 mm³; PNS advancement increased V\u003csub\u003eNA\u003c/sub\u003e\u0026nbsp;by 708.30 mm³ (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.05). Compared with MAWMS, MAWMP yielded greater short-term improvements (V: +11175.00 vs. +3638.00 mm³;\u0026nbsp;\u003cem\u003eP\u003c/em\u003e\u0026lt;0.001) and superior long-term stability in V and V\u003csub\u003eNA\u003c/sub\u003e\u0026nbsp;(\u003cem\u003eP\u003c/em\u003e\u0026lt;0.05). Intriguingly, the combined advancement of PNS and B point may be a robust predictor for postoperative changes of the upper airway volume.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e MAWMP induces sustained upper airway expansion for 2 years, which is driven primarily by hard-tissue advancements. Compared with MAWMS, this technique has superior short- and long-term efficacy, providing guidance for the optimized management of skeletal Class II patients.\u003c/p\u003e","manuscriptTitle":"Comparing short- and long-term effects of mandibular advancement with versus without maxillary setback on the oropharyngeal airway in skeletal Class II individuals: An extensive 2-year follow-up study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-30 05:08:20","doi":"10.21203/rs.3.rs-6932425/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-01T08:47:37+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-31T09:16:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"86493354191286215687183920814880581482","date":"2025-07-31T08:29:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"263100893376640466488172957921137134283","date":"2025-07-30T17:02:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"58456716836776266412854798276771185266","date":"2025-07-30T05:47:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"250829657856009211025622329172651572167","date":"2025-07-29T12:29:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-29T07:28:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"72424665366495460423771321329251790599","date":"2025-07-29T06:40:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"307836871795060429275678229317591619083","date":"2025-07-28T06:07:56+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"279130134044900332395862146188357673973","date":"2025-07-28T05:10:42+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"130727819565179543959063164669264688138","date":"2025-07-28T05:08:25+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-28T04:51:20+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-07-28T04:28:55+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-02T06:26:18+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-02T06:24:59+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Oral Health","date":"2025-06-19T15:00:17+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5b54c780-26a6-4049-86e3-72be3bae069a","owner":[],"postedDate":"July 30th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-12-15T16:02:16+00:00","versionOfRecord":{"articleIdentity":"rs-6932425","link":"https://doi.org/10.1186/s12903-025-07462-5","journal":{"identity":"bmc-oral-health","isVorOnly":false,"title":"BMC Oral Health"},"publishedOn":"2025-12-12 15:57:53","publishedOnDateReadable":"December 12th, 2025"},"versionCreatedAt":"2025-07-30 05:08:20","video":"","vorDoi":"10.1186/s12903-025-07462-5","vorDoiUrl":"https://doi.org/10.1186/s12903-025-07462-5","workflowStages":[]},"version":"v1","identity":"rs-6932425","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6932425","identity":"rs-6932425","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}