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Purpose: This study aimed to analyze changes in the pharyngeal airway structure and function in patients with skeletal Class III malocclusion one year after orthognathic surgery. Materials/methods: In this research, cone-beam computed tomography (CBCT) images of 30 patients (14 men and 16 women; mean age 20–30 years) with skeletal Class III malocclusion who underwent Lefort I osteotomy and bilateral sagittal split osteotomy were obtained before and one year after the surgery. Changes in pharyngeal airway structure were achieved by comparing CBCT data, and changes in function were achieved by comparing fluid dynamics models. The pharyngeal airway was analyzed by Element 3D (E3D) and the nasal airway 3D model was reconstructed. The meshing was implemented in ICEM-CFD (ANSYS, Canonsburg, PA, USA), and improved the mesh quality. The meshes were imported into Fluent (ANSYS, Canonsburg, PA, USA) to stimulate a fluid analysis. Results: The minimal anteroposterior diameter, minimal cross-sectional area and volume of pharyngeal airway were significantly reduced after surgery. There was no significant difference in the nasopharyngeal cross-sectional area. Pharyngeal airway resistance increased significantly after surgery, wall shear stress changed little before and after surgery. The anatomic structure of pharyngeal airway changed after surgery, but the morphological change of pharyngeal airway was not significant. Conclusions: One year after surgery, the anatomical structure and function changed compared with those before surgery, and the changes of minimal cross-sectional area of pharyngeal airway should be considered when designing the treatment plan for the patients. [ABSTRACT FROM AUTHOR]

An 18-year-old Chinese woman presented with chief complaints of crowded teeth and mild mandibular prognathism. Clinical and imaging examinations revealed a concave profile, a protruded chin, increased lower anterior facial height mild, skeletal Class III and Angle's Class III malocclusion, with anterior crossbites, and crowded teeth. Extraction camouflaged therapy combined with miniscrews skeletal anchorage was employed to relieve crowding and retract the mandibular anterior teeth. The total active treatment time was 31 months. After treatment, functional occlusion and smile esthetics were significantly improved. [ABSTRACT FROM AUTHOR]

Background and Objectives: The aim of this prospective study was to assess the effects of rapid maxillary expansion (RME) and/or face mask (FM) treatments on the pharyngeal airway in patients with skeletal Class III malocclusion caused by maxillary deficiency. This study utilized cone beam computed tomography (CIBT) for a three-dimensional (3D) analysis of airway changes, comparing the results with those of a control group consisting of untreated skeletal Class III patients. Materials and Methods: The study included 60 participants (34 boys, 26 girls) aged 9 to 14 years, all diagnosed with skeletal Class III malocclusion due to maxillary underdevelopment. The participants were divided into four treatment groups, each consisting of 15 individuals: Group 1—RME; Group 2—RME/FM; Group 3—FM; Group 4—Control group. The pharyngeal airway measurements were evaluated using CBCT and analyzed with Dolphin 3D software (version 11.9). Volumetric parameters and minimal axial area (MAA) were measured in the nasopharyngeal, retropalatal, retroglossal, and total airway regions. The collected data were statistically analyzed using SPSS 20.0 software. Results: The results indicated significant changes in pharyngeal airway volumes across all treatment groups compared to the control group. A statistically significant increase in nasopharyngeal, retropalatal, and total airway volume were observed in all treatment groups. Only the RME group demonstrated a significant increase in retroglossal volume. Significant increases in MAA were found in the RME/FM and FM groups in the nasopharyngeal and retropalatal regions. However, minimal changes were observed in the retroglossal region across all treatment groups. The control group showed no significant changes in any of the measured parameters, underscoring the effects of the treatments. Conclusions: The findings of this study suggest that both RME and/or FM treatments result in significant positive changes in the pharyngeal airways, particularly in the nasopharyngeal and retropalatal regions. The retroglossal region showed more limited response to the treatments. The combined RME/FM therapy was found to be particularly effective in improving airway dimensions in the anterior and mid-pharyngeal regions. These results highlight that early orthodontic interventions, such as RME and FM, can improve both airway patency and overall respiratory function, in addition to addressing skeletal Class III malocclusion. [ABSTRACT FROM AUTHOR]

Background/Objectives: Skeletal Class III malocclusion (Cl III) presents a significant orthodontic challenge, particularly in growing patients, requiring interceptive treatment to achieve effective functional and aesthetic correction. This review aims to compare various orthopedic devices and therapeutic protocols used in Cl III correction, identifying the most effective options in an interceptive context. Methods: We searched the PubMed, Scopus, and Web of Science databases for studies published between 1 January 2003, and 19 July 2023. Inclusion criteria included English language, human studies, open access, and studies addressing Cl III correction with interceptive orthopedic devices. Results: Exclusions included in vitro, animal, off-topic studies, reviews, meta-analyses, and articles in languages other than English. After removing duplicates, 30 articles were selected from a total of 1193 results. Conclusions: The application of orthopedic devices in growing patients can lead to rapid improvement of Cl III malocclusion, although each device has specific effects on the surrounding skeletal structure. [ABSTRACT FROM AUTHOR]

Abstract An 18-year-old Chinese woman presented with chief complaints of crowded teeth and mild mandibular prognathism. Clinical and imaging examinations revealed a concave profile, a protruded chin, increased lower anterior facial height mild, skeletal Class III and Angle’s Class III malocclusion, with anterior crossbites, and crowded teeth. Extraction camouflaged therapy combined with miniscrews skeletal anchorage was employed to relieve crowding and retract the mandibular anterior teeth. The total active treatment time was 31 months. After treatment, functional occlusion and smile esthetics were significantly improved.

Objective To evaluate the skeletal effect, dental effect, soft tissue and airway changes of a digital 3D printed maxillary protraction combined with alternate maxillary rapid expansion and constriction in the treatment of skeletal Class Ⅲ patients during mixed dentition. Methods Twenty-two mixed dentition patients(mean age of (11.33±0.88) years, 9 males and 13 females) of skeletal Class Ⅲ malocclusion with maxillary hypoplasia were collected from 2018 to 2023. Treatment was performed using a digital 3D printed protraction device combined with maxillary rapid expansion and constriction. Cone-beam CT were obtained before and after treatment to assess the orthopedic treatment of hard tissue, dentition, soft tissue and airway in three dimensional direction. Results After treatment, hard tissue measurements of SNA, ANB, Wits, Co-A, and Co-Gn distance increased significantly with a statistical difference, whereas there were no statistically significant changes in SNB, FMA, Occ plane to FH and Y-axis angle. There was a statistically significant increase in U1-SN, whereas there was no significant change in U1-NA. Soft tissue measurements of upper lip distance from the E line improved with a statistically significant difference while no significant changes in nasolabial angle were detected. The volume of the posterior palatal region of the upper airway increased significantly. Conclusion The digital 3D printed maxillary protraction combined with alternate rapid maxillary expansion and constriction promotes maxillary development, inhibits mandibular development, essentially maintains vertical dimension and improves skeletal Class Ⅲ patients’ deformity and profile. The volume of the posterior palatal region of the upper airway is also significantly improved.

Objective·To compare the effects of bone-anchored rapid expansion and tooth-borne rapid expansion combined with protraction on craniofacial sutures, skeletal points, bones and maxillary dentition using three-dimensional finite element analysis, and provide guidance for the clinical selection of appropriate traction methods and sites.Methods·A cone beam computed tomography (CBCT) image of one adolescent with skeletal class Ⅲ malocclusion and maxillary hypoplasia during the mixed dentition period was selected to establish a three-dimensional finite element model of the maxillary complex (including craniofacial sutures, skeletal points, bones and maxillary dentition). Based on this, the three-dimensional finite element models of bone-anchored and tooth-borne rapid expansion combined with protraction were respectively established. Then, the aforementioned models were assembled into a three-dimensional finite element model of maxillary complex with bone-anchored rapid expansion combined with protraction (Model 1), and a three-dimensional finite element model of maxillary complex with tooth-borne rapid expansion combined with protraction (Model 2). According to the different expansion methods and protraction sites, the following conditions were set up: ① Based on the expansion methods, Model 1 was set as Group A, and Model 2 was set as Group B. ② Based on the protraction sites, Group A and B were further divided into experimental group Ⅰ(protraction hooks were placed buccally on both sides of the maxillary canines), experimental group Ⅱ(protraction hooks were placed buccally on both sides of the maxillary first premolars) and experimental group Ⅲ (protraction hooks were placed buccally on both sides of the maxillary second premolars), respectively. Additionally, as a control, Group A0 used bone-anchored rapid expansion alone without protraction, while Group B0 used tooth-borne rapid expansion without protraction. The stress distribution characteristics of craniofacial sutures in groups A and B at different protraction sites, as well as the displacement trends of craniofacial skeletal points, craniofacial bones and maxillary dentition were analyzed by using charts and tables.Results·In terms of stress distribution characteristics of craniofacial sutures, pterygomaxillary suture′s equivalent strain was maximal in both groups A and B, and it increased when protraction hooks were placed backwards. The maximum principal strain value of each suture in Group AⅠ was larger than that in Group BⅠ. In terms of the displacement trend of craniofacial bones, as the protraction sites shifted posteriorly, both the nasal bones and maxilla in the horizontal direction moved rightward with decreasing displacement trends in both groups A and B. In the sagittal direction, the nasal bones moved posteriorly with decreasing displacement trends, while the maxilla moved anteriorly with increasing displacement trends in groups A and B. In the vertical direction, the nasal bones moved downward with decreasing displacement trends, and the maxilla moved upward with decreasing displacement trends in groups A and B. In terms of displacement trends of craniofacial skeletal points (ANS, PNS), the maxillary plane (ANS-PNS plane) in Group A underwent clockwise rotation, with the clockwise rotation trend decreasing as the protraction sites shifted posteriorly, while the maxillary plane (ANS-PNS plane) in Group B underwent counterclockwise rotation, with the counterclockwise rotation trend becoming more apparent as the protraction sites shifted posteriorly. In terms of the displacement trend of the maxillary dentition, the displacement of the central incisors in the horizontal, sagittal and vertical directions in the experimental groups A and B was all negative, presenting a tendency to move distally, labially and extrusively. The displacement of the first molar in the horizontal direction was also negative, indicating a trend of buccal displacement. Additionally, as the protraction site shifted posteriorly, the labial movement trend of the central incisors′ crown increased, and the crowns of the first molars changed from mesial to distal movement.Conclusion·Clinically, placing protraction sites posteriorly is beneficial for the anterior movement of the maxilla. Adolescent with skeletal class Ⅲ malocclusion can choose different rapid expansion with protraction to achieve maxillary anterior displacement while realizing favorable rotation of maxillary plane.

Our study aimed to evaluate a stepwise treatment of class III malocclusion accompanied with flat nasal deformity, using orthodontics, orthognathic surgery, and rhinoplasty, as well as stability during long-term follow-up. In total, 27 patients with nasomaxillary hypoplasia and skeletal class III malocclusion were enrolled in this study. All patients had accepted orthodontic and orthognathic surgery, followed by rhinoplasty with costal cartilage as the second surgical procedure. Clinical results were evaluated by radiography, medical photography, questionnaire, and cephalometric analysis. All patients were satisfied with the surgical results and no serious complications occurred. During the follow-up, the patients showed well-corrected midface contour and nasal projection, and stable occlusion. The costal cartilage grafts were well fixed, without obvious absorption deformation. Lateral cephalometric analysis and overlay results showed that the postoperative point A had advanced approximately 5.20 ± 1.43 mm and the SNA angle had increased by approximately 5.59 ± 2.86°. Soft-tissue measurements showed a 14.22 ± 6.56° decrease in the facial lobe, while the nasolabial angle had increased by 16.83 ± 6.65° postoperatively. The results suggested that stepwise orthodontic-orthognathic surgery and rhinoplasty produce a predictable and stable result in long-term follow-up. [ABSTRACT FROM AUTHOR]

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Objectives: This study aims to investigate the changes in alveolar bone following the simultaneous performance of labial and lingual augmented corticotomy (LLAC) in patients with insufficient alveolar bone thickness on both the labial and lingual sides of the mandibular anterior teeth during presurgical orthodontic treatment. Materials and methods: Thirth-five surgical patients with skeletal Class III malocclusion were included: 19 (LLAC group) accepted LLAC surgery during presurgical orthodontic treatment, and 16 (non-surgery group, NS) accepted traditional presurgical orthodontic treatment. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T0) and at the completion of presurgical orthodontic treatment (T1). The amount of vertical alveolar bone and contour area of the alveolar bone in the labial and lingual sides of mandibular incisors were measured. Results: After presurgical orthodontic treatment, the contour area of the alveolar bone at each level on the lingual side and alveolar bone level on both sides decreased significantly in the NS group (P < 0.001). However, the labial and lingual bone contour area at each level and bone level increased significantly in the LLAC group (P < 0.001). The bone formation rate in the lingual apical region was the highest, significantly different from other sites (P < 0.001). Conclusions: During presurgical orthodontic treatment, LLAC can significantly increase the contour area of the labio-lingual alveolar bone in the mandibular anterior teeth to facilitate safe and effective orthodontic decompensation in skeletal Class III patients. Clinical relevance: : This surgery has positive clinical significance in patients lacking bone thickness (< 0.5 mm) in the labial and lingual sides of the lower incisors. [ABSTRACT FROM AUTHOR]

Background/purpose: The etiology of the ectopic eruption (EE) of the maxillary first permanent molars (FPM) remains unclear and controversial. This study was designed to explore the dental and skeletal factors for EE of the FPM in children. Materials and methods: Children aged 6–10 years were recruited to this study. Subjects were assigned to the ectopic eruption group (EEG) and the normal eruption group (NEG). Lateral cephalometric radiographs and panoramic radiographs were measured by angular and linear indices. Results: The prevalence of EE of maxillary FPM was higher in males and at younger ages. Subjects with skeletal class III malocclusion were more likely to be diagnosed with EE of maxillary FPM. The SNA, ANB, FMIA, Wits, Ptm-A, ANS-PNS, overbite, and overjet were significantly different between the EEG and the NEG. The length of the posterior region of the maxillary alveolar bone, U6-OP, and eruptive angulation of the maxillary FPM were statistically different between the two groups. Conclusion: Male sex, skeletal class III malocclusion, mesial inclination of the maxillary FPM, hypoplasia of the maxilla, and insufficient length of the posterior region of the maxillary alveolar bone were related to EE of the maxillary FPM.

Objective To investigate the morphological changes in the upper airway after bimaxillary surgery in patients with skeletal Class Ⅲ malocclusion and the relationship between jaw movement and airway changes using CBCT. Methods This study involved 44 individuals(21 males and 23 females)receiving Class Ⅲ bimaxillary surgery. Preoperative and 3-6-month postoperative CBCT data were examined using Dophin3D 11.95 software. The alterations before and after upper airway surgery were analysed using paired t-test and non-parametric Wilcoxon rank sum test. The association between airway alterations and jaw movement was examined using Pearson’s correlation coefficient. Results Patients who underwent Class Ⅲ bimaxillary surgery had significantly reduced upper airway volume, sagittal cross-sectional area, and minimum cross-sectional area(P7 mm, the decrease in upper airway volume increased significantly(P7 mm)may reduce postoperative upper airway capacity and increase the risk of OSAHS. Patients at risk of upper airway stenosis should have their protocol modified to reduce airway risk.

Objectives: Temporomandibular joint disorder (TMD) is a complex condition with pain and dysfunction in the temporomandibular joint and related muscles. Scientific evidence indicates both genetic and environmental factors play a crucial role in TMD. In this study, we aimed to discover the genetic changes in individuals from 4 generations of an Iranian family with signs and symptoms of TMD and malocclusion Class III. Materials and methods: Whole Exome Sequencing (WES) was performed in 4 patients (IV-8, IV-9, V-4, and V-6) with TMD according to (DC/TMD), along with skeletal Class III malocclusion. Then, PCR sequencing was performed on 23 family members to confirm the WES. Results: In the present study, WES results analysis detected 6 heterozygous non-synonymous Single Nucleotide Variants (SNVs) in 5 genes, including CRLF3, DNAH17, DOCK1, SEPT9, and VWDE. A heterozygous variant, c.2012T > A (p.F671Y), in Exon 20 of the DOCK1 (NM_001290223.2) gene was identified. Then, this variant was investigated in 19 other members of the same family. PCR-Sequencing results showed that 7/19 had heterozygous TA genotype, all of whom were accompanied by malocclusion and TMD symptoms and 12/19 individuals had homozygous TT genotype, 9 of whom had no temporomandibular joint problems or malocclusion. The remaining 3 showed mild TMD clinical symptoms. The 5 other non-synonymous SNVs of CRLF3, DNAH17, SEPT9, and VWDE were not considered plausible candidates for TMD. Conclusions: The present study identified a heterozygous nonsynonymous c.2012T > A (p.F671Y) variant of the DOCK1 gene is significantly associated with skeletal class III malocclusion, TMD, and its severity in affected individuals in the Iranian pedigree. Clinical relevance: The role of genetic factors in the development of TMD has been described. The present study identified a nonsynonymous variant of the DOCK1 gene as a candidate for TMD and skeletal class III malocclusion in affected individuals in the Iranian pedigree. [ABSTRACT FROM AUTHOR]

Background: Coordination among lip, cheek and tongue movements during swallowing in patients with mandibular prognathism remains unclear. Objectives: This study aimed to identify the temporal sequences of tongue pressure and maxillofacial muscle activities during swallowing in patients with mandibular prognathism and compared characteristics with those of healthy volunteers. Methods: Seven patients with mandibular prognathism (mandibular prognathism group) and 25 healthy volunteers with individual normal occlusion (control group) were recruited. Tongue pressures and masseter, orbicularis oris, mentalis and supra‐ and infrahyoid muscle activities while swallowing gel were measured simultaneously using a sensor sheet system with five measurement points and surface electromyography, respectively. Onset time, offset time and durations of tongue pressure and muscle activities were analysed. Results: In the mandibular prognathism group, tongue pressure was often produced first in more peripheral parts of the palate. Offset of tongue pressure in the posteromedian and peripheral parts of the palate and maxillofacial muscle activities except for orbicularis oris were delayed. Duration of tongue pressure in the anteromedian part of the palate was significantly shorter and durations of masseter, mentalis and suprahyoid muscle activities were significantly longer. Times to onset of orbicularis oris and suprahyoid muscle activities based on first onset of tongue pressure were significantly shorter. Conclusion: These results suggest that patients with mandibular prognathism may exhibit specific patterns of tongue pressure production and maxillofacial muscle activities during swallowing. [ABSTRACT FROM AUTHOR]

The etiology of the ectopic eruption (EE) of the maxillary first permanent molars (FPM) remains unclear and controversial. This study was designed to explore the dental and skeletal factors for EE of the FPM in children. Children aged 6–10 years were recruited to this study. Subjects were assigned to the ectopic eruption group (EEG) and the normal eruption group (NEG). Lateral cephalometric radiographs and panoramic radiographs were measured by angular and linear indices. The prevalence of EE of maxillary FPM was higher in males and at younger ages. Subjects with skeletal class III malocclusion were more likely to be diagnosed with EE of maxillary FPM. The SNA, ANB, FMIA, Wits, Ptm-A, ANS-PNS, overbite, and overjet were significantly different between the EEG and the NEG. The length of the posterior region of the maxillary alveolar bone, U6-OP, and eruptive angulation of the maxillary FPM were statistically different between the two groups. Male sex, skeletal class III malocclusion, mesial inclination of the maxillary FPM, hypoplasia of the maxilla, and insufficient length of the posterior region of the maxillary alveolar bone were related to EE of the maxillary FPM. [ABSTRACT FROM AUTHOR]

Background: A Class III skeletal malocclusion is a very complex condition in orthodontics practice, and its solution is often carried out orthopedically. The most used orthopedic devices include rapid maxillary expansion (RME) and the Delaire Appliances to treat not only maxillary deficiency but also to correct the position of the upper jaw. Even if these interventions become sustainable in the short term, their long-term stability remains questionable. Aim: reveal a pretty complicated relationship between orthopaedic and orthodontic surgeries and their influences on the volume of the upper respiratory tract and craniofacial correction. Methods: We searched multiple online databases including; Web of Science, Scopus, Google Scholar, PubMed, and Cochrane Library. We used the following search strategy; "Rapid maxillary expansion" OR RME AND ("sleep apnea" OR "sleep-disordered breathing" OR "sleep-related breathing disorders" OR "sleep apnea-hypopnea syndrome" OR SAHS) AND (children OR pediatric) AND ("orthodontic treatment" OR "orthopaedic treatment" OR "maxillary expansion") AND (oximetry OR polysomnography). Results: RME and the Delaire appliance were seen to be promising in the short term with an outcome of correction of maxillary transverse deficiency and skeletal relationships. Nevertheless, the issue of the long-term stability was spotted, including with regard to growth. But nevertheless both interventions exhibited some really valuable additions in general treatment of skeletal class III malocclusion. Scientific Novelty: This literature review synthesizes and summarizes the current knowledge on the effectiveness and durability of RME and the Delaire splint concerning skeletal class III malocclusion, presenting perspectives on their short-term impact and long-term performance. With its emphasis on poorly understood issues and new research, it greatly assists in updating our knowledge about orthopedic treatments. Conclusion: In a relatively short period of time, the rapid maxillary expansion method as well as the Delaire appliance can produce positive outcomes in terms of correcting the retroposition in cranial base class III malocclusion. Although, long lasting stability issues remain a worry and make the case for continued research and clinical monitoring for achieving better treatment outcomes and evidence-based practices in orthodontics. [ABSTRACT FROM AUTHOR]

Background and Objectives: The aim of this prospective study was to assess the effects of rapid maxillary expansion (RME) and/or face mask (FM) treatments on the pharyngeal airway in patients with skeletal Class III malocclusion caused by maxillary deficiency. This study utilized cone beam computed tomography (CIBT) for a three-dimensional (3D) analysis of airway changes, comparing the results with those of a control group consisting of untreated skeletal Class III patients. Materials and Methods: The study included 60 participants (34 boys, 26 girls) aged 9 to 14 years, all diagnosed with skeletal Class III malocclusion due to maxillary underdevelopment. The participants were divided into four treatment groups, each consisting of 15 individuals: Group 1—RME; Group 2—RME/FM; Group 3—FM; Group 4—Control group. The pharyngeal airway measurements were evaluated using CBCT and analyzed with Dolphin 3D software (version 11.9). Volumetric parameters and minimal axial area (MAA) were measured in the nasopharyngeal, retropalatal, retroglossal, and total airway regions. The collected data were statistically analyzed using SPSS 20.0 software. Results: The results indicated significant changes in pharyngeal airway volumes across all treatment groups compared to the control group. A statistically significant increase in nasopharyngeal, retropalatal, and total airway volume were observed in all treatment groups. Only the RME group demonstrated a significant increase in retroglossal volume. Significant increases in MAA were found in the RME/FM and FM groups in the nasopharyngeal and retropalatal regions. However, minimal changes were observed in the retroglossal region across all treatment groups. The control group showed no significant changes in any of the measured parameters, underscoring the effects of the treatments. Conclusions: The findings of this study suggest that both RME and/or FM treatments result in significant positive changes in the pharyngeal airways, particularly in the nasopharyngeal and retropalatal regions. The retroglossal region showed more limited response to the treatments. The combined RME/FM therapy was found to be particularly effective in improving airway dimensions in the anterior and mid-pharyngeal regions. These results highlight that early orthodontic interventions, such as RME and FM, can improve both airway patency and overall respiratory function, in addition to addressing skeletal Class III malocclusion.

The study compared the soft-tissue response to hard-tissue movement among different Class III vertical facial types after orthognathic surgery (OGS). The study included 90 consecutive adult patients with skeletal Class III malocclusion who underwent two-jaw OGS. Patients were divided into three groups (high, medium, and low angle) based on the presurgical Frankfort–mandibular plane angle. Cone-beam computerized tomographs were taken before surgery and after debonding. Soft- and hard-tissue linear and angular measurements were performed using three-dimensional reconstruction images. One-way analysis of variance was used for intergroup comparisons. Soft tissue tended to respond more to hard-tissue movement in the lower lip area in patients with low angle (mean = 0.089, SD = 0.047, p = 0.023), whereas no significant difference was observed for other sites. Consistently, L1/Li thickness increased most significantly in the high-angle group (mean = 1.98, SD = 2.14, p = 0.0001), and B/Si thickness decreased most significantly after surgery (mean = 2.16, SD = 2.68, p = 0.016). The findings suggest that the high-angle group had a higher chance of undergoing genioplasty to enhance chin contour. Different OGS plans should be considered for different Class III vertical facial types. [ABSTRACT FROM AUTHOR]

The article focuses on evaluating the anterior dentoalveolar relationship in skeletal Class III malocclusion patients with different vertical facial patterns using cone-beam computed tomography (CBCT). Topics include measuring and comparing labiolingual inclinations of the teeth and alveolar bone, as well as analyzing the anterior dentoalveolar inclination among patients with hypodivergent, normodivergent, and hyperdivergent facial patterns.

The surgery first approach (SFA) and clear aligners technique can address traditional treatment defects, such as prolonged waiting times for surgery and a less desirable facial appearance due to wire aligners. However, the curative effect of the combination remains uncertain. The randomized controlled study aimed to evaluate the skeletal stability of the SFA compared to the conventional orthodontic first approach (OFA), both of which were applied with clear aligners. A total of 74 participants were randomly allocated to two groups: the SFA group (experimental) and the OFA group (control). The skeletal deviation was calculated using reconstruction models from computed tomography scans taken immediately and 6 months after surgery. The largest median deviations were detected in the y-axis of the mandible for both two groups, separately 1.36 mm in the experimental group and 1.19 mm in the control group. Apart from the maxillary yaw dimension (p = 0.005), there were no significant differences between the two groups in terms of linear and angular deviation. The experimental group had an overall treatment time of 18.05 ± 2.53 months, while the control group took 22.83 ± 3.60 months (p < 0.05). Therefore, the combined surgery-first and clear aligners treatment can achieve comparable skeletal stability to the conventional approach, while also saving significant time. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate the 3D anatomical features of unilateral (UCLP) and bilateral (BCLP) complete cleft lip and palate with those of skeletal Class III dentofacial deformities. Materials and methods: In total, 92 patients were divided into cleft and noncleft groups. The cleft group comprised 29 patients with UCLP and 17 patients with BCLP. The noncleft group comprised 46 patients with Class III dentofacial deformities. 3D anatomical landmarks were identified and the corresponding measurements were made on the cone-beam computed tomography (CBCT). Results: The differences between the affected and unaffected sides of the patients with UCLP were nonsignificant. The differences between the patients with UCLP and BCLP were nonsignificant except for the SNA angle. Significant differences between the patients with clefts and Class III malocclusion were identified for the SNA, A–N perpendicular, and A–N Pog line, indicating that the maxillae of the patients in the cleft group were more retrognathic and micrognathic. Relative to the noncleft group patients, the cleft group patients had a significantly smaller ramus height. Conclusion: The affected and unaffected sides of the patients with UCLP did not exhibit significant differences. The maxillae of the patients with UCLP were significantly more retrognathic than those of the patients with BCLP. The maxillae and mandibles of the patients in the cleft group were more micrognathic and retropositioned relative to those of the noncleft Class III patients. Clinical Relevance: The maxillary and mandibular findings indicated greater deficiencies in the patients with UCLP or BCLP than in those with skeletal Class III malocclusion. Appropriate surgical design should be administered. [ABSTRACT FROM AUTHOR]

Background/purpose: Alveolar bone fenestration and dehiscence is common in untreated patients and potentially harmful. This study was to evaluate the effect of augmented corticotomy (AC) on the prevention and treatment of alveolar bone defects in skeletal class III high-angle patients during presurgical orthodontic treatment (POT). Materials and methods: Fifty patients with skeletal Class III high-angle malocclusion were enrolled, of whom 25 patients (G1) underwent traditional POT and 25 patients (G2) received AC during POT. The alveolar bone fenestration and dehiscence around the upper and lower anterior teeth were measured by CBCT. The incidence and transition of fenestration and dehiscence in the two groups were compared by the chisquare and Mann‒Whitney rank-sum tests. Results: Before treatment (T0), the incidence of fenestration and dehiscence around the anterior teeth of all patients was 39.24% and 24.10%, respectively. After POT (T1), the incidence of fenestration in G1 and G2 was 49.83% and 25.86%, respectively, and the incidence of dehiscence in G1 and G2 was 58.08% and 32.07%, respectively. For teeth without fenestration and dehiscence at T0, more anterior teeth in G1 exhibited fenestration and dehiscence at T1 than in G2. For teeth with fenestration and dehiscence at T0, most transitions in G1 were maintained or worsened, but “cure” cases were observed in G2. After POT, the cure rates of fenestration and dehiscence in G2 were 80.95% and 91.07%, respectively. Conclusion: During the POT of skeletal Class III high-angle patients, augmented corticotomy can significantly treat and prevent alveolar bone fenestration and dehiscence around anterior teeth.

Purpose This article aims to showcase the effects and benefits of a multidisciplinary treatment approach incorporating orthodontics in adult patients with jaw deformities and partially edentulous jaws. We present a case of a skeletal Class III patient with partially edentulous jaws treated through a combination of surgical-orthodontic and prosthetic procedures.Materials and Methods A 49-year-old female patient sought treatment at our clinic for prosthetic care post root cyst extraction and improvement of her mandibular protrusion. She presented with a skeletal Class III malocclusion, facial asymmetry, maxillary distal extension defect, and mandibular intercalary defect.Results The patient underwent preoperative treatment with multi-bracket appliances to correct dental decompensation of the mandibular incisors and upright the mandibular molars. Subsequently, she underwent a bilateral sagittal split ramus osteotomy, with the mandibular setback of 8 mm on the right side and 4 mm on the left side. Prior to surgery, treatment dentures were fabricated for the defect, and post-surgery, these dentures, along with an occlusal splint, were secured with intermaxillary fixation screws and the remaining teeth. The interdental space in the mandibular anterior teeth was closed by postoperative treatment. The preoperative treatment lasted for 7 months, the hospital stay was 14 days, and the postoperative treatment continued for 6 months.Conclusion The successful treatment of this patient with jaw deformity and a partially edentulous jaw was achieved through the collaborative efforts of orthodontics, oral surgery, and prosthodontics departments.

Abstract Background Skeletal class III malocclusion is a common dentofacial deformity. Orthognathic treatment changes the position of the jaws and affects the shape of the upper airway to some extent. The aim of this study was to use multislice spiral computer tomography data and orthognathic knowledge to quantify the relationship between the amount of surgical movement of the maxilla or mandible in all three spatial planes and the changes in airway volume that occurred. Methods A retrospective study of 50 patients was conducted. Preoperative and postoperative linear changes related to skeletal movements of the maxilla and mandible were measured and compared to changes in the most constricted axial level (MCA) and its anteroposterior (MCA-AP) and transverse diameters (MCA-TV). Correlation tests and linear regression analysis were performed. Results Significant interactions were observed between the anterior vertical movement of the maxilla and the MCA-AP. The anteroposterior movement distance of the mandible was significantly correlated with changes in the oropharyngeal, velopharyngeal, total airway volume, MCA, MCA-AP, and MCA-TV. The change in the mandibular plane angle was significantly correlated with the change in velopharyngeal volume, total airway volume (nasopharynx, oropharynx, velopharynx), and MCA. The linear regression model showed that oropharyngeal volume decreased by 350.04 mm3, velopharyngeal volume decreased by 311.50 mm3, total airway volume decreased by 790.46 mm3, MCA decreased by 10.96 mm2 and MCA-AP decreased by 0.73 mm2 when point B was setback by 1 mm. Conclusions Anteroposterior mandibular control is the key to successful airway management in all patients. This study provides estimates of volume change per millimeter of setback to guide surgeons in treatment planning.

BACKGROUND: Previous studies have shown that there are significant differences in occlusal and maxillofacial changes in patients with skeletal class III malocclusion of different ages after maxillary protraction treatment. However, the difference of temporomandibular joint changes in patients with different ages remains unknown. OBJECTIVE: To study the influence of age on the changes of the temporomandibular joint after maxillary protraction treatment of skeletal class III malocclusion. METHODS: Fifty-eight children with skeletal class III malocclusion aged 8-14 years were divided into two groups. Twenty-nine children aged 8-11 years were diagnosed with late mixed dentitions. Twenty-nine children aged 12-14 years were diagnosed with early permanent dentitions. X-ray lateral cephalograms were taken pre- and post-treatment, and cephalometric analysis of occlusal and maxillofacial regions and quantitative analysis of temporomandibular joint position in the coordinate system were carried out. Paired t-test was used for intragroup comparison. Independent t-test was used for intergroup comparison. Pearson correlation analysis was used to analyze the correlation between occlusal and maxillofacial changes and temporomandibular joint changes. RESULTS AND CONCLUSION: The occlusal and maxillofacial structure and the temporomandibular joint changed significantly in the two groups after treatment. In the sagittal direction of the occlusal and maxillofacial structure, subspinale-nasion-supramental angle (ANB) in the 8-11-year-old group increased by 4.76°, and nasion-subspinale line and pogonion-subspinale line angle (NA-PA) increased by 9.02°, which was significantly larger than those in the 12-14-year-old group (3.97° and 6.88°) (P < 0.05). In the vertical direction, the mandible plane and sella-nasion line angle (MP-SN) and Frankle plane and sella-nasion line angle (FH-MP) in the 8-11-year-old group increased by 1.92° and 3.02° respectively, which was significantly higher than those in the 12-14-year-old group (1.02° and 0.78°) (P < 0.05). There were significant changes in the temporomandibular joint between the two age groups. Fossa summit on the X axis (S-Fsx) in the 8-11-year-old group moved backward more significantly than that in the 12-14-year-old group. Fossa posterior on the X axis (S-Fpx) in the 8-11-year-old group moved backward, while that in the 12-14-year-old group moved forward. Condyle anterior (S-Cix) and condyle tangent on the X axis (S-T4x) in the two groups both moved backward, which were more significant in the 8-11-year-old group than the 12-14-year-old group. The changes of the temporomandibular joint were correlated with the changes of the occlusal and maxillofacial structure. In the 8-11-year-old group, there was a negative correlation between S-Fpx and sella-nasion-supramental angle (SNB), nasion-pogonion line and Frankle plane angle (NP-FH) (P < 0.05, r=-0.489; P < 0.05, r=-0.424). In the 12-14-year-old group, S-Fpx was positively correlated with the distance from the upper incisor to the nasion-subspinale line (U1-NAmm) (P < 0.01, r=0.439). In the 8-11-year-old group, S-Cix, S-T4x and the condyle superior on the X axis (S-Cox) were negatively correlated with SNB, NP-FH and MP-SN. To conclude, age has obvious effects on the changes of the temporomandibular joint in skeletal class III malocclusion following maxillary protraction. In the 8-11-year-old group, articular fossa and condyle moved backward obviously, fossa anterior moved up, and the posterior joint space increased. In the 12-14-year-old group, the fossa posterior moved forward and the condyle anterior moved down, but the joint space did not change. There are different occlusal and maxillofacial factors affecting temporomandibular joint changes at different ages. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The objective of the present study was to assess the hard and soft tissue differences of skeletal Class III malocclusion patients treated with orthodontic–orthognathic surgery treatment between two decompensation approaches including extraction of maxillary premolars in preoperative orthodontics and clockwise rotation of the maxilla in orthognathic surgery. Methods: 22 skeletal Class III patients with the crowding of maxillary dental arch less than 3mm were included in this study. These patients were divided into two groups: extraction group and non-extraction group. Lateral cephalograms taken before preoperative orthodontic treatment and after postoperative orthodontic treatment were used to analyze the differences of hard and soft tissues between two groups. Independent t test was used to evaluate the differences of variables between extraction group and non-extraction group. Results: After treatment, there was significant difference of Wits between extraction group and non-extraction group (− 4.34 mm vs − 2.82 mm, respectively, P <0.05). Co-Gn was significantly greater in non-extraction group than in extraction group (77.18 mm vs 71.58 mm, P <0.05). U1-SN and L1-MP in extraction group were significantly closer to the normal values than non-extraction group (P <0.05). Regarding the change of variables before and after orthodontic–orthognathic treatment, NLA (7.25° vs 1.46°, P <0.01) and G-Sn-Pog' (8.06° vs 4.62°, P <0.05) were significantly greater in extraction group than in non-extraction group. Conclusion: For patients with skeletal Class III malocclusion, extraction of maxillary premolars in preoperative orthodontic treatment can more effectively eliminate the dental compensation and achieve a more harmonious facial profile compared to clockwise rotation of the maxilla in orthognathic surgery. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to analyze three-dimensional dental compensation in patients with different types of skeletal Class III malocclusion with mandibular asymmetry, using cone-beam computed tomography (CBCT) and three-dimensional reconstruction measurement technology, thereby providing clinical guidance and reference for combined orthodontic and orthognathic treatment. Methods: 81 patients with skeletal Class III malocclusion with mandibular asymmetry were selected in accordance with the inclusion criteria. According to a new classification method based on the direction and amount of menton deviation relative to ramus deviation, patients were divided into three groups called Type 1, Type 2, and Type 3. In Type 1, the direction of menton deviation was consistent with that of ramus deviation and the amount of menton deviation was greater than that of ramus deviation. In Type 2, the direction of menton deviation was consistent with that of ramus deviation and the amount of menton deviation was smaller than that of ramus deviation. In Type 3, the direction of menton deviation was inconsistent with that of ramus deviation. The maxillary occlusal plane (OP), anterior occlusal plane (AOP), and posterior occlusal plane (POP) were measured on reconstructed CBCT images. The vertical, transverse, and anteroposterior distances from maxillary teeth to reference planes and the 3D angles between the long axis of these teeth and reference planes were measured. These dental variables measured from the deviated and non-deviated sides were compared within each group, as well as among each other. Results: Of the 81 patients with asymmetrical Class III malocclusion, 52 patients were categorized in Type 1, 12 patients in Type 2, and 17 patients in Type 3. There were significant differences between deviated and non-deviated sides in Type 1 and Type 3 (p < 0.05). In Type 1, the vertical distances of maxillary teeth on the deviated side were lower than those on the non-deviated side, and AOP, OP, and POP on the deviated side were larger than those on the non-deviated side (p < 0.05). In Type 3, the vertical distances of the maxillary teeth on the deviated side were lower (p < 0.05), and the AOP and OP on the deviated side were larger than those on the non-deviated side. In all three groups, the transverse distances of the maxillary teeth from the mid-sagittal plane on the deviated side were larger than those on the non-deviated side (p < 0.05), and the angles between the long axis of maxillary teeth and the mid-sagittal plane on the deviated side were larger, respectively (p < 0.05). Conclusions: The maxillary teeth on the deviated side were observed to have smaller eruption heights in Type 1 and Type 3. In Type 1, AOP, POP, and OP were greater on the deviated side, while in Type 3, only AOP and OP were greater on the deviated side. The maxillary teeth of patients in all three groups on the deviated side were buccal and buccally inclined. Larger sample observations are still needed to further verify these findings. [ABSTRACT FROM AUTHOR]

Non‐syndromic skeletal Class III malocclusion is a major craniofacial disorder characterized by genetic and environmental factors. Patients with severe skeletal Class III malocclusion require orthognathic surgery to obtain aesthetic facial appearance and functional occlusion. Recent studies have demonstrated that susceptible chromosomal regions and genetic variants of candidate genes play important roles in the etiology of skeletal Class III malocclusion. Here, we provide a comprehensive review of our current understanding of the genetic factors that affect non‐syndromic skeletal Class III malocclusion, including the patterns of inheritance and multiple genetic approaches. We then summarize the functional studies on related loci and genes using cell biology and animal models, which will help to implement individualized therapeutic interventions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Objective The aim of this study was to systematically explore the inclination of the lower central incisor and symphysis in alveolar bone in severe skeletal class III patients. Materials and methods A total of 198 severe skeletal class III patients (ANB ≤ -4°) who underwent combined orthodontic and orthognathic treatment were divided into three groups based on the mandibular plane angle (MP-SN). Pretreatment lateral cephalograms were analysed and compared among the three groups. We also assessed cone-beam computed tomography (CBCT) images of 11 samples to investigate the reliability of the cephalometric analysis. Results ANOVA showed no statistically significant differences in the angle between the long axis of the mandibular symphysis and the long axis of the lower central incisor (MIA) among the low-angle, normal-angle and high-angle groups (P > 0.05), while significant differences were found in the angle between the axis of the lower incisor and the mandibular plane (IMPA) among the three groups (P 0.05). Conclusions In severe skeletal class III patients, the long axis of the lower central incisor was highly consistent with the long axis of the mandibular symphysis, which was more obvious in the high-angle subjects. The MIA reflects the physiological inclination of the lower central incisor better than the IMPA.

Abstract Background Condyle-fossa relationships in adolescents with skeletal Class III malocclusion remain unclear. Therefore, this study used cone-beam computed tomography (CBCT) to evaluate the position and morphology of the temporomandibular joint (TMJ) in adolescents with skeletal Class III malocclusion. Methods In this cross-sectional retrospective study, CBCT images from 90 adolescents with skeletal Class III malocclusion and 30 controls were analysed. Adolescents with skeletal Class III malocclusion were divided into different groups based on (1) sex (male and female), (2) sides (right and left), (3) age (early, middle, and late adolescence), and (4) vertical skeletal patterns (hyperdivergent, normodivergent, and hypodivergent). Morphology of the condyle and fossa as well as condylar position, was compared among groups. Data were collected and submitted for statistical analysis. This study adheres to STROBE guidelines. Results Regarding the intergroup comparisons, there were significant differences in TMJ position and morphology between the skeletal Class III malocclusion with different vertical skeletal patterns and control groups (P

Objective To explore the changes in root volume and root resorption in incisor arteries from adult patients with skeletal class Ⅲ malocclusion before and after camouflaged orthodontic treatment and to provide a reference for the clinic. Methods Thirty permanent dentition adult patients with skeletal class Ⅲ malocclusion were included from the Orthodontic Department. CBCT data of each patient at pretreatment and posttreatment were acquired, and 3D digital root models were reconstructed. The whole and segmented root volumes (cervical part, bodily part and apical part) of the right incisors were calculated. Results The root volumes (whole, cervical part, bodily part and apical part) posttreatment were smaller than those pretreatment (P0.05). Mandibular central incisors and lateral incisors showed more root resorption in the apical root than in the cervical root and bodily root (P0.05). The absorption ratio showed a significant difference in the mandibular lateral incisors (P = 0.028). Conclusion After camouflaged orthodontic treatment of adult skeletal class Ⅲ malocclusion, incisor root resorption occurred mainly in the apical part, but the cervical and bodily parts should also be considered. There was a high risk of root resorption in the mandibular incisors.

Purpose: This study aimed to analyse changes in the nasal cavity and maxillary sinus structure and function in patients with skeletal class III malocclusion 1 year after bimaxillary surgery. Materials and Methods: In this study, cone‐beam computed tomography (CBCT) images of 20 patients (10 men and 10 women; mean age 24.3 ± 3.4 years) with skeletal class III malocclusion who underwent Le Fort I osteotomy and bilateral sagittal split osteotomy were obtained before and 1 year after the surgery. CBCT data were stored opened with element 3D (E3D) to establish a nasal airway model (the paranasal sinus includes only the maxillary sinus). Ansys (ANSYS) software is used for simulation and analysis. Results: The maxillary sinus and nasal cavity volumes decreased significantly 1 year after the surgery. After surgery, the volume of nasal cavity decreased by 13.5%, and the average volume of maxillary sinus decreased by 7.8%. There was no significant difference in the degree of deviation of the septum and nasal cavity resistance, and air distribution in the maxillary sinus did not change. The nasal cavity wall shear stress change was similar to that before surgery. Conclusions: The maxillary sinus volume and nasal cavity volume of patients with skeletal class III malocclusion changed significantly after bimaxillary surgery, but there was no significant change in nasal ventilation function 1 year after surgery. [ABSTRACT FROM AUTHOR]

Background: The treatment choice in adults with skeletal class III malocclusion represents a challenging task for orthodontists, especially in borderline cases. With the growth spurt being surpassed, the clinician is left between two treatment options: orthodontic camouflage or orthognathic surgery. Around the years, many studies tried to uncover a guide model which enables practitioners to distinguish between skeletal class III that can be appropriately treated by orthodontics alone and those needing surgical intervention. Aim: The aim of this study is to demonstrate the importance of cutaneous profile perception as a subjec)tive decisive parameter in the treatment of borderline skeletal class III adult patients and, as a secondary objective, to compare it with the most decisive cephalometric parameters found in previous studies. Material and methods: Among 28 skeletal class III patients found in the Saint Joseph university or)thodontics department’s data base, 10 different adult patients: 4 males and 6 females have met the inclusion criteria. Three types of data have been gathered from each patient: lateral cephalograms, profile photographs and the treatment that the patient underwent. To understand the significance of profile perception in the treatment plan for these patients, all of the 10 patients› profile photographs were put in a survey that was sent to 3 groups of people: orthodontists, dentists, and laypersons. Each participant should evaluate based only on his/her perception of the photo if the patient should be treat)ed by orthodontic-surgical treatment or if an orthodontic camouflage alone is enough. In addition, the efficiency of profile perception will be compared with the efficiency of the most decisive cephalometric parameters found in literature: ANB angle=-4°, Witts appraisal =-5.8mm. Results: A total of 158 participants were included in this study. When we compare what participants chose based on profile perception with real treatment, 75% of orthodontists have correctly classified the patients. Lower rates were noted for dentists and laypeople, respectively 65% and 64.5%. If we also consider the cephalometric values found in literature (ANB=-4°, Witts appraisal=-5.8mm) as the cor)rect treatment that should have been done, 70% of the patients were correctly treated in our faculty. Conclusion: There are no cephalometric or clinical golden standards to decide between surgical intervention or orthodontic camouflage in adult patients presenting skeletal class III malformation. Cephalometric values are very useful but insufficient tools even when many parameters are com)bined. Both objective and subjective criteria should be taken into consideration to individualize each treatment plan according to each patient. [ABSTRACT FROM AUTHOR]

Alveolar bone fenestration and dehiscence is common in untreated patients and potentially harmful. This study was to evaluate the effect of augmented corticotomy (AC) on the prevention and treatment of alveolar bone defects in skeletal class III high-angle patients during presurgical orthodontic treatment (POT). Fifty patients with skeletal Class III high-angle malocclusion were enrolled, of whom 25 patients (G1) underwent traditional POT and 25 patients (G2) received AC during POT. The alveolar bone fenestration and dehiscence around the upper and lower anterior teeth were measured by CBCT. The incidence and transition of fenestration and dehiscence in the two groups were compared by the chisquare and Mann‒Whitney rank-sum tests. Before treatment (T0), the incidence of fenestration and dehiscence around the anterior teeth of all patients was 39.24% and 24.10%, respectively. After POT (T1), the incidence of fenestration in G1 and G2 was 49.83% and 25.86%, respectively, and the incidence of dehiscence in G1 and G2 was 58.08% and 32.07%, respectively. For teeth without fenestration and dehiscence at T0, more anterior teeth in G1 exhibited fenestration and dehiscence at T1 than in G2. For teeth with fenestration and dehiscence at T0, most transitions in G1 were maintained or worsened, but "cure" cases were observed in G2. After POT, the cure rates of fenestration and dehiscence in G2 were 80.95% and 91.07%, respectively. During the POT of skeletal Class III high-angle patients, augmented corticotomy can significantly treat and prevent alveolar bone fenestration and dehiscence around anterior teeth. [ABSTRACT FROM AUTHOR]

Crossbite refers to abnormal labiolingual and buccolingual relations between the opposing teeth. This results in the imbalanced facial appearance of the patient causing varied degrees of distress based on the individual's values and self-esteem. The management of skeletal class III malocclusion with anterior and posterior crossbite can be challenging. This case report describes a case of skeletal class III malocclusion complicated with an anterior, and unilateral posterior crossbite, and severe crowding which was managed satisfactorily with a fixed orthodontic appliance. The proper clinical examination, diagnosis, problem list, and formulation of the treatment plan are of utmost importance for the proper management of the case. The diagnosis can be done through proper history, clinical examination, an orthopantomogram, and a lateral cephalogram. The patient's grin was transformed from a non-consonant to a consonant smile, and the profile was transformed from slightly concave to straight.

Objective: The aim of this study was to systematically explore the inclination of the lower central incisor and symphysis in alveolar bone in severe skeletal class III patients. Materials and methods: A total of 198 severe skeletal class III patients (ANB ≤ -4°) who underwent combined orthodontic and orthognathic treatment were divided into three groups based on the mandibular plane angle (MP-SN). Pretreatment lateral cephalograms were analysed and compared among the three groups. We also assessed cone-beam computed tomography (CBCT) images of 11 samples to investigate the reliability of the cephalometric analysis. Results: ANOVA showed no statistically significant differences in the angle between the long axis of the mandibular symphysis and the long axis of the lower central incisor (MIA) among the low-angle, normal-angle and high-angle groups (P > 0.05), while significant differences were found in the angle between the axis of the lower incisor and the mandibular plane (IMPA) among the three groups (P < 0.001). The mean IMPA decreased with increasing MP-SN in the 198 patients. The mean MIA in the low-angle and normal-angle groups was 3.70° and 3.52°, respectively, while the value (2.33°) was smaller in the high-angle group. Paired-samples t test showed no statistically significant differences between the cephalometric and CBCT measurements of the MP-SN, the angle between the mandibular plane and the Frankfort plane (FH-MP) and the MIA (P > 0.05). Conclusions: In severe skeletal class III patients, the long axis of the lower central incisor was highly consistent with the long axis of the mandibular symphysis, which was more obvious in the high-angle subjects. The MIA reflects the physiological inclination of the lower central incisor better than the IMPA. [ABSTRACT FROM AUTHOR]

This study examines the effect of the lateral bone cut end (LBCE) on the pattern of lingual split during bilateral sagittal split osteotomy (BSSO) in patients with skeletal class III malocclusion. A case-control study according to the pattern of the sagittal split osteotomy (SSO) lingual split line was conducted in patients who underwent BSSO. The primary predictor variable was the ratio of the LBCE. The primary outcome variable was the type of lingual fracture line classified according to the lingual split scale (LSS). Other variables included patients' weight, sex, age, left and right sides of the mandible, and experience of the surgeon. Logistic regression analysis or the chi-squared test was performed to determine the effect of these variables on various types of lingual fracture line. The significance level was 95% (p < 0.05). There were 271 patients enrolled in this study. The SSO lingual split lines were divided into LSS1 (329/542), LSS2 (82/542), LSS3 (93/542), and LSS4 (38/542) splits. Logistic regression analysis showed that the LSS3 split was more likely to appear when the LBCE was closer to the lingual side (p = 0.0017). The age of patients significantly affected the possibilities of LSS2 (p = 0.0008) and LSS3 (p = 0.0023) splits. A LBCE close to the lingual side was an inducer for the formation of a LSS3 split in patients with skeletal class III malocclusion during BSSO. The age of the patient also affected the possibility of LSS2 and LSS3 splits. [ABSTRACT FROM AUTHOR]

This case report presents the non-surgical orthodontic camouflage treatment of an 18-year-old male patient with skeletal Class III asymmetry and severe anterior open bite. The anterior open bite was corrected by extrusion of the maxillary and mandibular anterior teeth and clockwise and counterclockwise rotation of the maxillary and mandibular occlusal plane, respectively, using intermaxillary Class III elastics between the maxillary posterior buccal miniscrews and mandibular canines and anterior vertical elastics between the maxillary and mandibular canines. Class III dental relationships and dental asymmetry were corrected via unilateral distalization of the mandibular dentition on the left side using a closed coil spring between the buccal shelf screw and hook. The patient's smile esthetics and dental relationship were improved with a more favorable facial profile, and facial asymmetry was slightly alleviated after orthodontic camouflage treatment. The total treatment time was 15 months. A modified wraparound retainer with a scalloped labial bow, tongue crib, and tooth positioner was used simultaneously to prevent the potential relapse. [ABSTRACT FROM AUTHOR]

This study aims to investigate hard and soft tissue asymmetry in skeletal Class III patients to elucidate how soft tissue thickness alters overall asymmetry and whether menton deviation is correlated with bilateral differences in hard and soft tissue prominence and soft tissue thickness. The cone-beam computed tomography data of 50 skeletal Class III adults were divided based on menton deviation into symmetric (n = 25; deviation ≤ 2.0 mm) and asymmetric (n = 25; deviation > 2.0 mm) groups. Forty-four corresponding hard and soft tissue points were identified. Bilateral hard and soft tissue prominence and soft tissue thickness were compared using paired t-tests. The correlations between bilateral differences in these variables and menton deviation were examined using Pearson's correlation analysis. In the symmetric group, no significant bilateral differences in soft and hard tissue prominence and soft tissue thickness were observed. In the asymmetric group, both hard and soft tissue prominence were significantly greater on the deviated side than the non-deviated side at most of the points; however, no significant differences in soft tissue thickness were detected except at point 9 (ST9/ST'9, p = 0.011). The difference of hard and soft tissue prominence at point 8 (H8/H'8 and S8/S'8) was positively correlated with menton deviation, whereas the soft tissue thickness at point 5 (ST5/ST'5) and point 9 (ST9/ST'9) was negatively correlated with menton deviation (p = 0.05). Soft tissue thickness does not affect overall asymmetry in the presence of underlying hard tissue asymmetry. Soft tissue thickness at the centre of the ramus may be correlated with the degree of menton deviation in patients with asymmetry; however, this correlation needs to be confirmed by further studies. [ABSTRACT FROM AUTHOR]

Background: Insufficient evidence regarding the effects of chincup therapy on the mandibular dimensions and temporomandibular joint (TMJ) structures requires high-quality studies using three-dimensional (3D) imaging. This trial aimed to evaluate the 3D changes in the mandible, condyles, and glenoid fossa after chin cup therapy for skeletal Class III children compared to untreated controls. Methods: A 2-arm parallel-group randomized controlled trial on 38 prognathic children (21 boys and 17 girls), with mean ages 6.63±0.84 years. Patients were recruited and randomized into two equal groups; the experimental group (CC) was treated with occipital-traction chin cups in conjunction with bonded maxillary bite blocks. No treatment was provided in the control group (CON). Low-dose CT images were acquired before (T1) and after achieving (2-4 mm) positive overjet (T2), and after 16 months apart in both groups. The outcome measures of the condyle-mandibular 3D distances, the condyles-glenoid fossa postional changes, and the quantitative displacement parameters of superimposed 3D models were compared statistically. Paired- and two-sample t-tests were used for intra- and inter-group comparisons, respectively. Results: Overall, 35 patients (18 and 17 in the CC and the CON groups, respetively) were enrolled in the statistical analysis. The mean mandibular and condylar volumes increased significantly by 777.24 mm 3 and 1,221.62 mm 3, 94.57 mm 3, and 132.54 mm 3 in the CC and CON groups, respectively. No statistically significant differences were observed between the groups regarding the volumes, superficial areas, and linear changes of the mandible and condyles, and part analysis measurements, except the changes of the relative sagittal and vertical positions of condyles, glenoid fossa, and posterior joint space, which were significantly smaller in the CC group (p Conclusions: The chin cup did not affect the mandibular dimensions. Its primary action was confined to the condyles and the TMJ internal dimensions. Clinicaltrials.gov registration: NCT05350306 (28/04/2022).

Objective To explore the method of measuring root volume with cone-beam computed tomography (CBCT) three-dimensional reconstruction technology, and to study root length and root volume of upper and lower central incisors in patients with skeletal Class Ⅲ malocclusion treated by surgical orthodontic treatment. Methods Twenty patients with skeletal Class Ⅲ malocclusion undergoing surgical orthodontic treatment were selected. CBCT data at three time points, before decompensation treatment (T0), after decompensation treatment (before orthognathic surgery, T1), and the end of post-operative orthodontic treatment (T2) were collected. Three-dimensional reconstruction technology was used to measure the root length and root volume of the upper and lower central incisors (including total root volume, cervical root and apical root), calculate the percentage of reduction volume, and measure the distance of tooth movement after orthodontic treatment. Data were statistically analyzed by SPSS 20.0 software. Least significant difference (LSD) method was used for pair comparison between the groups subject to normal distribution, and non-parametric test was used for comparison between the groups not subject to normal distribution. The differences of root length and root volume of upper and lower incisors were compared, and the characteristics of root absorption were analyzed. Results Root length and root volume of the upper and lower central incisors were reduced during the surgical orthodontic treatment (P < 0.05) in cases. Both the root volume of cervical root and apical root were significantly reduced (P < 0.05), the reduction of apical root was more significant. The percentage of root volume reduction of the upper central incisor was (30.51±23.23)%, and lower central incisor (23.24±11.96)%. Compared with the upper central incisor, the root volume reduction amount and percentage of the lower central incisor were smaller, and apical root volume reduction of the upper central incisor was greater than that of the lower central incisor, which was statistically significant (P < 0.05). During pre-surgical orthodontic treatment, maxillary central incisor palatal moving was in a controlled tipping manner, and the mandibular central incisor tipped labially. Conclusion In patients with skeletal Class Ⅲ malocclusion, root length and total root volume of upper and lower central incisors decreased during surgical orthodontic treatment. Root volume measurement indicated that the cervical root also had root resorption. The difference in root resorption of the upper and lower central incisors might be related to the distance and direction of teeth movement. CBCT three-dimensional reconstruction will compensate for the limitation of root length measurement in evaluating root resorption.

Traumatic tooth avulsion can lead to ankylosis, which may interfere with growth of the alveolar bone in a growing patient. The resulting difference in alveolar bone height and position can lead to esthetic problems such as open bite.A growing 13-year-old female patient presented skeletal Class III malocclusion with bone ankylosis of a maxillary anterior tooth. Even after 2 years of orthopedic and orthodontic treatment, little improvement was achieved regarding the positions of the anterior maxillary teeth, or the vertical position of the maxillary right central incisor. Therefore, surgical treatment by single-tooth osteotomy (STO) and corticotomy for the anterior ankylosed tooth were considered and performed using a CAD/CAM surgical guide, based on presurgical computer-based simulation surgery. Orthodontic and orthopedic treatments were completed at 10 months after surgery. The patient showed a favorable course of healing, with no mobility issues or gingival recession 3 years after single-tooth osteotomy and corticotomy surgeries. A favorable outcome was finally achieved by applying orthopedic treatment combined with STO and corticotomy for the anterior ankylosed tooth. Orthodontic treatment with minimally surgical method is recommended in an adolescent patient with skeletal Class III malocclusion and anterior open bite.

Background: Insufficient evidence regarding the effects of chincup therapy on the mandibular dimensions and temporomandibular joint (TMJ) structures requires high-quality studies using three-dimensional (3D) imaging. This trial aimed to evaluate the 3D changes in the mandible, condyles, and glenoid fossa after chin cup therapy for skeletal Class III children compared to untreated controls. Methods: A 2-arm parallel-group randomized controlled trial on 38 prognathic children (21 boys and 17 girls), with mean ages 6.63±0.84 years. Patients were recruited and randomized into two equal groups; the experimental group (CC) was treated with occipital-traction chin cups in conjunction with bonded maxillary bite blocks. No treatment was provided in the control group (CON). Low-dose CT images were acquired before (T1) and after achieving (2-4 mm) positive overjet (T2), and after 16 months apart in both groups. The outcome measures of the condyle-mandibular 3D distances, the condyles-glenoid fossa postional changes, and the quantitative displacement parameters of superimposed 3D models were compared statistically. Paired- and two-sample t-tests were used for intra- and inter-group comparisons, respectively. Results: Overall, 35 patients (18 and 17 in the CC and the CON groups, respetively) were enrolled in the statistical analysis. The mean mandibular and condylar volumes increased significantly by 777.24 mm3 and 1,221.62 mm3, 94.57 mm3, and 132.54 mm3 in the CC and CON groups, respectively. No statistically significant differences were observed between the groups regarding the volumes, superficial areas, and linear changes of the mandible and condyles, and part analysis measurements, except the changes of the relative sagittal and vertical positions of condyles, glenoid fossa, and posterior joint space, which were significantly smaller in the CC group (p