Objective:To compare the efficacy of maxillary distraction osteogenesis (DO) and Le FortⅠ osteotomy (LFⅠ) in patients with complex cleft lip and palate.Methods:A retrospective study was conducted, clinical data were collected involving patients with complex cleft lip and palate who required combined orthodontic and orthognathic treatment and were treated at the Stomatological Hospital of Chongqing Medical University from January 2015 to December 2022. Patients were divided into three groups based on the surgical method used for the maxilla: total maxillary distraction (TMD, group A), anterior maxillary distraction (AMD, group B), and Le Fort Ⅰ osteotomy (LFⅠ, group C). Cone-beam CT scans and lateral cephalograms were obtained preoperatively and at 3 months postoperatively. Three-dimensional reconstructions were performed using Mimics 21.0 and Dolphin Imaging 11.9 software to evaluate changes in craniofacial morphology and airway. Data analysis was conducted using SPSS 25.0. Intragroup comparisons before and after surgery were performed using the Wilcoxon rank sum test, and intergroup comparisons among the three groups were conducted using the Kruskal-Wallis H test. Results:A total of 15 patients were included, with 5 patients in each group. The cohort comprised 8 males and 7 females, aged between 15 and 21 years. There were no statistically significant differences in the distribution of gender, age, or cleft lip and palate classification among the three groups ( P>0.05). Postoperatively, all three groups showed improvement in maxillary hypoplasia. Compared to preoperative measurements, the angle formed by the points A (subspinale), N (nasion), and B (supramentale) (ANB angle) increased in all three groups (all P<0.05). The vertical distance from point A to the nasion perpendicular (A-Nperp) increased in groups A and B ( P<0.05 for both) but not in group C ( P>0.05). The area of the alveolar gap showed an increasing trend in all three groups ( P>0.05). The mandibular plane angle (FMA) decreased postoperatively in group B but showed an increasing trend in the other two groups, though the differences were not statistically significant ( P>0.05). Postoperative airway volume increased or showed an increasing trend in groups A ( P<0.05) and B ( P>0.05) but decreased in group C ( P>0.05). Intergroup comparisons showed significant differences in the angle formed by the sella (S), nasion (N), and point A (SNA angle) and the vertical distance from the anterior nasal spine to the coronal plane (ANS-CP) ( P<0.05). Group A had significantly larger SNA angles and ANS-CP values than group B, and the ANS-CP value in group A was significantly larger than in group C (all P<0.05). There were no other statistically significant differences among the groups ( P>0.05). Conclusion:For patients with severe maxillary hypoplasia due to complex cleft lip and palate, TMD can correct sagittal discrepancies between the upper and lower jaws, increase upper airway volume, but may potentially enlarge the alveolar gap area and increase vertical height of the maxilla. AMD result in less change in maxillary position compared to TMD and is mainly used for patients with severe maxillary dental crowding, needing increased arch length, having minor sagittal discrepancies, or with preexisting velopharyngeal dysfunction. LFⅠ result in changes in maxillary position similar to AMD but less than TMD, making it suitable for patients with moderate maxillary hypoplasia and mild maxillary dental crowding. The advantage of LFⅠ lies in its precise postoperative occlusal design and accurate three-dimensional movement of the jaw.

Objective:To compare the efficacy of maxillary distraction osteogenesis (DO) and Le FortⅠ osteotomy (LFⅠ) in patients with complex cleft lip and palate.Methods:A retrospective study was conducted, clinical data were collected involving patients with complex cleft lip and palate who required combined orthodontic and orthognathic treatment and were treated at the Stomatological Hospital of Chongqing Medical University from January 2015 to December 2022. Patients were divided into three groups based on the surgical method used for the maxilla: total maxillary distraction (TMD, group A), anterior maxillary distraction (AMD, group B), and Le Fort Ⅰ osteotomy (LFⅠ, group C). Cone-beam CT scans and lateral cephalograms were obtained preoperatively and at 3 months postoperatively. Three-dimensional reconstructions were performed using Mimics 21.0 and Dolphin Imaging 11.9 software to evaluate changes in craniofacial morphology and airway. Data analysis was conducted using SPSS 25.0. Intragroup comparisons before and after surgery were performed using the Wilcoxon rank sum test, and intergroup comparisons among the three groups were conducted using the Kruskal-Wallis H test. Results:A total of 15 patients were included, with 5 patients in each group. The cohort comprised 8 males and 7 females, aged between 15 and 21 years. There were no statistically significant differences in the distribution of gender, age, or cleft lip and palate classification among the three groups ( P>0.05). Postoperatively, all three groups showed improvement in maxillary hypoplasia. Compared to preoperative measurements, the angle formed by the points A (subspinale), N (nasion), and B (supramentale) (ANB angle) increased in all three groups (all P<0.05). The vertical distance from point A to the nasion perpendicular (A-Nperp) increased in groups A and B ( P<0.05 for both) but not in group C ( P>0.05). The area of the alveolar gap showed an increasing trend in all three groups ( P>0.05). The mandibular plane angle (FMA) decreased postoperatively in group B but showed an increasing trend in the other two groups, though the differences were not statistically significant ( P>0.05). Postoperative airway volume increased or showed an increasing trend in groups A ( P<0.05) and B ( P>0.05) but decreased in group C ( P>0.05). Intergroup comparisons showed significant differences in the angle formed by the sella (S), nasion (N), and point A (SNA angle) and the vertical distance from the anterior nasal spine to the coronal plane (ANS-CP) ( P<0.05). Group A had significantly larger SNA angles and ANS-CP values than group B, and the ANS-CP value in group A was significantly larger than in group C (all P<0.05). There were no other statistically significant differences among the groups ( P>0.05). Conclusion:For patients with severe maxillary hypoplasia due to complex cleft lip and palate, TMD can correct sagittal discrepancies between the upper and lower jaws, increase upper airway volume, but may potentially enlarge the alveolar gap area and increase vertical height of the maxilla. AMD result in less change in maxillary position compared to TMD and is mainly used for patients with severe maxillary dental crowding, needing increased arch length, having minor sagittal discrepancies, or with preexisting velopharyngeal dysfunction. LFⅠ result in changes in maxillary position similar to AMD but less than TMD, making it suitable for patients with moderate maxillary hypoplasia and mild maxillary dental crowding. The advantage of LFⅠ lies in its precise postoperative occlusal design and accurate three-dimensional movement of the jaw.

Objective:To compare the impact of orthodontic treatment on pulp volume in adolescents and adults.Methods:Cone-beam CT data of 62 patients undergoing orthodontic treatment at the Department of Orthodontics, Stomatological Hospital of Chongqing Medical University, from January 2019 to March 2022 were collected. Patients were divided into two age groups (31 patients in each group): adolescent group (aged 13-17, 17 males and 14 females) and adult group (aged 21-25, 12 males and 19 females). Pre-and post-treatment reconstructions of the pulp and dental tissues of upper first molars (UM1) and lower central incisors (L1) were performed. Measurements included pulp volume for UM1 (UM1 P) and L1 (L1 P), pulp chamber volume (UM1 PC) and root canal volume (UM1 RC) for UM1, root length for L1 (L1 RL), and mesiobuccal root length for UM1 (UM1 RL), as well as chamber heights at specific landmarks [the lengths from the central fossa fusion site to the roof of the pulp chamber (H1), the floor of the pulp chamber (H2), the nearest point of root divergence as well as crown-root bifurcation (H3), the farthest point of root divergence (H4), and the pulp chamber height (H5)] in UM1. Changes in these indices were calculated and analyzed using paired and independent sample t-tests for within-group and between-group differences, respectively. Pearson correlation was used to assess potential associations among H5, root length, and pulp volume changes. Results:Before and after orthodontic treatment, no significant difference was observed in the adult group for L1 P ( t=-0.03, P=0.975), while significant differences were noted for UM1 P, UM1 PC, and UM1 RC ( t=9.98, P<0.001; t=9.04, P<0.001; t=6.69, P<0.001). In the adolescent group, significant differences were found for both L1 P and UM1 P ( t=2.25, P=0.029; t=6.30, P<0.001). After orthodontic treatment, the absolute value changes of UM1 P, UM1 PC, and L1 P in the adolescent group were (19.75±9.58), (15.07±7.65) and (1.89±6.29) mm 3, respectively, and in the adult group were (13.33±9.41), (9.16±7.05) and (0.02±4.66) mm 3, respectively ( t=3.77, P<0.001; t=4.48, P<0.001; t=2.34, P=0.048). There was no significant absolute difference in the amount of UM1 RC between the two groups after orthodontic treatment ( t=0.86, P=0.391). Before and after orthodontic treatment, the absolute value changes of L1 RL, H1 and H5 in the adolescent group were (0.54±0.41), (0.38±0.27) and (0.71±0.33) mm, respectively, and the absolute value changes in the adult group were (0.78±0.62), (0.26±0.20) and (0.57±0.28) mm, respectively ( t=-2.43, P=0.017; t=2.96, P=0.004; t=2.57, P=0.011). Whereas no significant differences were observed for UM1 RL, H2, H3, and H4 ( t=-0.85, P=0.400; t=0.43, P=0.669; t=-0.50, P=0.619; t=1.46, P=0.148). Additionally, significant correlations were found between changes in H5 and UM1 RL with UM1 P ( r=0.35, P<0.001; r=0.19, P=0.030), but not between Changes in L1 RL and L1 P ( r=0.11, P>0.05). Conclusions:The effect of orthodontic treatment on pulp volume in adolescents and adults were different.