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Introduction: Third molars (M3) remaining impacted in Class II malocclusion characterised with sagittal mandibular deficiency is a high probability. The null hypothesis of this study is that mesioangular M3s changes position through the eruption way in Class II malocclusion treatment requiring moderate anchorage with four first premolars extraction. The aim of this study is to reconsider the decision to surgically extract impacted third molars in four premolars extraction treatment of Class II malocclusion., Material and Methods: The materials consisted of the pre-treatment and post-treatment lateral cephalograms and orthopantomographs of 30 individuals with skeletal and dental Class II malocclusion with a mean chronological age of 13.48 years, who were treated by the same clinician (H.G.) with four first premolar extractions via the straight wire technique at the Ankara University Faculty of Dentistry Department of Orthodontics, Ankara, Turkey. The sagittal position of the upper and lower incisors and molars, M3 position and M3 space were evaluated with the paired-t test; the relationship between the sagittal position of the upper and lower incisors and molars and the change in M3 position were evaluated with correlation analysis.  Results: The study found the retroclination and mesial movement of the upper incisors and molars, and an increase in the M3 space by the fixed orthodontic treatment. An insignificant steepening of both the upper right M3 position and the lower right M3 position was found. A statistically significant increase in the lower right and left side M3 spaces was found. Positive correlations between lower right M3 angulation and the sagittal position of the lower incisors and first molars were found., Conclusion: Improvement in the mesioangulation of the M3s and an increase in the M3 space were achieved in this study. Based on the findings, it is useful to review the decision for prophylactic surgical extraction of the M3s before orthodontic treatment in such cases, taking into account the risks of postoperative complications.

Background: Natural head position (NHP), pharyngeal airway and maxillofacial growth pattern are correlated. The author's previous studies proved that following surgical correction of Skeletal Class II malocclusion, the over-extended NHP returned upright, and the pharyngeal airway space (PAS) dimension expanded., Objective: The present study compares the post-operative change in NHP and PAS after orthognathic surgery in Skeletal Class II and III malocclusion patients., Methods: Patients receiving orthognathic procedures to correct Skeletal Class II or III malocclusions were reviewed in this retrospective study. Pre-operative and 6-week post-operative cone-beam computed tomography datasets were collected. Variables representing the craniofacial pattern, the NHP and the PAS were measured three-dimensionally. Post-operative variables were compared with their pre-operative counterparts using either repeat-measure 2-way analysis of variance or Wilcoxon matched-pairs signed rank test., Results: Thirty cases of Skeletal Class II malocclusion and 13 cases of Skeletal Class III malocclusion were collected. Preoperatively, the inter-group differences were significant in craniofacial pattern (68.14 ± 3.552 degree vs. 79.63 ± 2.497 degree, p < .0001) and the NHP (68.77 ± 11.02 degree vs. 82.83 ± 7.738 degree, p = .0002) while not significant in PAS; after surgery, the intergroup differences in craniofacial pattern and the NHP between groups decreased, and the PAS increased in both groups., Conclusion: Orthognathic surgery may improve compromised NHP and increase PAS in Skeletal Class II and III malocclusion patients., (© 2024 The Author(s). Journal of Oral Rehabilitation published by John Wiley & Sons Ltd.)

Objectives: To compare the facial asymmetry after bimaxillary surgery between mild craniofacial microsomia (CFM) and non-syndromic class II asymmetry., Materials and Methods: Cone-beam computed tomography scans of adults with Pruzansky-Kaban types I and IIA CFM (CFM groups, n = 20), non-syndromic skeletal class II asymmetry (Class II group, n = 20), and normal controls (control group, n = 20) were compared. The area asymmetry of lower face and jaw bones was quantified. Landmark-based method was used to evaluate the lower facial asymmetry regarding midline, cants, and contour., Results: There were no significant postoperative differences in the hemi-facial and hemi-jaw area asymmetry between CFM and Class II groups, both of which were significantly larger than the control group. No significant difference was found in the midline deviation and lip and occlusal cants between CFM and Class II groups. The vertical contour asymmetry in CFM group became significantly larger than Class II group. Compared to the control group, the deviation of pronasale, subnasale, and soft-tissue menton, lip and occlusal cants, and sagittal and vertical contour asymmetry in CFM group were significantly larger, as were the deviation of subnasale and soft-tissue menton and vertical contour asymmetry in Class II group., Conclusions: The vertical contour asymmetry of mild CFM was significantly larger than non-CFM class II after surgery, while the area asymmetry, midline deviation, cants, and sagittal contour asymmetry of lower face showed no significant difference., Clinical Relevance: Be aware that correcting vertical asymmetry of contour, lip, and dentition in CFM is still challenging., (© 2024. The Author(s).)

Background: One of the key features of orthognathic surgery is altering temporomandibular joint (TMJ) condylar positions., Purpose: This multivariate study aimed to identify surgical interventions and patient factors significantly associated with changes in TMJ spatial dimensions after the surgical correction of skeletal Class II deformities., Study Design, Setting, Sample: This is a retrospective cohort study including patients who had undergone an isolated bilateral sagittal split ramus osteotomy (BSSO) or a bimaxillary osteotomy (BMO) for mandibular advancement and a control sample of patients treated with the removal of odontogenic cysts in the mandibular posterior region. Excluded were those who presented with specific radiographic signs of TMJ osteoarthrosis, severe facial asymmetry, or deformity secondary to trauma., Predictor/exposure/independent Variable: The primary predictors were condylar position at baseline (anterior, concentric, and posterior), time points (T0, preoperatively; T1, immediately after surgery; and T2, 1-year follow-up), and surgical intervention type (BSSO, BMO, and control group)., Main Outcome Variables: The primary outcomes were changes in posterior spatial dimension (PSD), superior spatial dimension, and medial spatial dimension assessed by cone-beam computed tomography preoperatively, immediately after surgery, and at 1-year follow-up., Covariates: Covariates included sex, age, and amount of mandibular advancement., Analyses: Estimations of independent effects of primary predictors on outcome variables were made by applying generalized estimation equation models. The value of statistical significance was P < .05., Results: The study sample included 88 participants. The BSSO samples included 39 patients, and the BMO group included 22 patients; the control group comprised 27 subjects. The average age was 31.2 years; the majority were female (61.4%). Adjusted generalized estimation equation models yielded a significant time interaction between BSSO and spatial dimensions over time (PSD, P < .001). Key predictors of spatial dimension changes were the baseline posterior (PSD, P < .001) and the central condylar position (PSD, P < .001)., Conclusion and Relevance: This controlled study, for the first time, provides scientific evidence on the effects of surgical intervention type and baseline condylar position on spatial dimension changes in the TMJ. It shows a more favorable outcome in long-term spatial dimension changes for patients treated by a BMO procedure., (Copyright © 2024 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Introduction: Mandibular advancement surgery corrects bone bases while establishing patients' functional and aesthetic rehabilitation. However, little is known about the results of this procedure in the structures that make up the stomatognathic system, as the condyles., Objective: This study aimed to evaluate the structural and positional changes of mandibular condyles in ortho-surgical patients who underwent mandibular advancement surgery., Material and Methods: A prospective investigation was conducted with cone-beam computed tomography images. Using Dolphin Imaging® software, seven ortho-surgical patients with Angle Class II malocclusion and mandibular deficiency were evaluated. The images assessed were obtained at pre-surgical phase and after, at least, 1 year of the procedure. To study the structural and positional changes of condyles, linear and angular measurements were obtained, and the right and left sides of patients were compared. Descriptive statistical analysis was performed and, in order to verify possible significant differences, normality tests (Kolmogorov-Smirnov) were applied, followed by a paired t-test to define significance., Results: For all measures evaluated in this study, no statistically significant differences were found., Conclusion: The ortho-surgical procedure performed did not change the structure and position of the condyles of patients who underwent surgical mandibular advancement. Right and left mandibular condyles behaved similarly, suggesting stability and condylar adaptation after surgery.

Objectives: Currently, there is no reliable automated measurement method to study the changes in the condylar process after orthognathic surgery. Therefore, this study proposes an automated method to measure condylar changes in patients with skeletal class II malocclusion following surgical-orthodontic treatment., Methods: Cone-beam CT (CBCT) scans from 48 patients were segmented using the nnU-Net network for automated maxillary and mandibular delineation. Regions unaffected by orthognathic surgery were selectively cropped. Automated registration yielded condylar displacement and volume calculations, each repeated three times for precision. Logistic regression and linear regression were used to analyse the correlation between condylar position changes at different time points., Results: The Dice score for the automated segmentation of the condyle was 0.971. The intraclass correlation coefficients (ICCs) for all repeated measurements ranged from 0.93 to 1.00. The results of the automated measurement showed that 83.33% of patients exhibited condylar resorption occurring six months or more after surgery. Logistic regression and linear regression indicated a positive correlation between counterclockwise rotation in the pitch plane and condylar resorption (P < .01). And a positive correlation between the rotational angles in both three planes and changes in the condylar volume at six months after surgery (P ≤ .04)., Conclusions: This study's automated method for measuring condylar changes shows excellent repeatability. Skeletal class II malocclusion patients may experience condylar resorption after bimaxillary orthognathic surgery, and this is correlated with counterclockwise rotation in the sagittal plane., Advances in Knowledge: This study proposes an innovative multi-step registration method based on CBCT, and establishes an automated approach for quantitatively measuring condyle changes post-orthognathic surgery. This method opens up new possibilities for studying condylar morphology., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology and the International Association of Dentomaxillofacial Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

There are several treatment options to treat a class II dentofacial deformity with a pronounced chin. A total subapical osteotomy is one of these options. This type of osteotomy was refined to total subapical and ramus (TSAR) osteotomy. In this technical note, a detailed and schematic presentation of the TSAR osteotomy is presented step by step. The surgical approach to the TSAR osteotomy is divided into three parts. The first part consists of the horizontal osteotomy at the level of the ramus, the second part approaches the corticotomy to release and protect the mental nerve and the third part consists of connecting the horizontal ramus osteotomy and the local corticotomy around the mental nerve. In this third part, it is important that the inferior alveolar nerve (IAN) is actively sought and protected., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: Computer-assisted surgical simulation (CASS) allows more precise orthognathic surgery. However, few studies have evaluated associations between CASS-designed bilateral sagittal split osteotomy (SSO) and bone contact surface in class II mandibular asymmetry. This study aims to evaluate the effects of using computer-assisted simulation and design modification of SSO to improve bony contact in skeletal class II asymmetry., Methods: This retrospective analysis reviewed 28 patients with class II asymmetry who underwent orthognathic surgery, including 15 with modified SSO (group CS) and 13 with conventional SSO (group C). Modified SSO was designed under CASS. Operative characteristics, postoperative outcomes, and complications were collected and compared between the two groups., Results: Bony contact was found at the distal end of the proximal segment in all group CS patients, while bone gap was noted in all group C patients ( P < 0.05). Moreover, bone graft was used in four group C patients but was not used in all cases in group CS patients ( P < 0.05). A trend toward lower operative time or perioperative bleeding was noted in group CS, but without statistical significance. After 1-year follow-up, inferior alveolar nerve disturbances were noted in two group CS patients and one group C patient. Palpable bone gap with uneven jaw line was noted in two group C patients 1 year after surgery and one patient received fat graft treatment., Conclusion: The simulation-based SSO modification provides appropriate contact surface and eliminates the bone gap between proximal and distal segments in class II asymmetry., Clinical Question/level of Evidence: Therapeutic, III., (Copyright © 2023 by the American Society of Plastic Surgeons.)

The patient presented in this case report is a 10-year-old boy with hyperdivergent skeletal Class II associated with familial genetic agenesis of the second premolars. The treatment plan chosen was to close the spaces of agenesis using a bimaxillary appliance fixed buccally. The advantages and disadvantages of this treatment option were discussed. The result was stable and made it possible to avoid an implant-prosthetic solution, which would undoubtedly have been more restrictive over time., (Copyright © 2024 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Objectives: To present an interdisciplinary case treated with a surgery-first orthognathic approach, followed by orthodontic and prosthodontic treatment., Clinical Considerations: After an accurate pre-operative virtual planning, a young patient with skeletal class II, retrognathia, and an anterior open bite was treated with bimaxillary orthognathic surgery without pre-surgical orthodontic decompensation. Orthodontic treatment was carried out post-operatively. The treatment was completed with a prosthodontic phase to improve the final esthetic outcome of the smile., Conclusions: A surgery-first approach allowed to achieve esthetic and functional results in a reduced treatment duration that remained stable over the course of 1 year. The outcomes were consistent with prior research in terms of advantages brought by following an accurately planned surgery-first protocol. Nevertheless, longer-term follow-up was required to evaluate the treatment stability., Clinical Significance: An accurately planned surgery-first approach significantly helped in shortening the duration of the treatment, while providing a stable, functional, and esthetic solution to the patient's problems., (© 2024 Wiley Periodicals LLC.)

A thick periodontal phenotype with thick gingiva and alveolar bone volume is required for safe orthodontic tooth movement and long-term stability. A high incidence of dehiscence and fenestration in the labial aspect of mandibular anterior teeth may limit the correction of deformity and orthodontic treatment, especially when the lower anterior teeth are needed to have a large range of movement. This study reports a combination of periodontal therapy and orthodontic therapy with periodontal corticotomy regenerative surgery (PCRS) in a 25-year-old patient suffering from skeletal Class II malocclusion and periodontitis. The patient received periodontal therapy 5 years ago and commenced orthodontic treatment 4.5 years ago. During the 4 years of follow-up for PCRS, the clinical and radiographic evaluations revealed significant improvements in the periodontal phenotype of the mandibular anterior region. The periodontal phenotypes in the mandibular incisors region were all modified from thin to thick. Supplementing orthodontic treatment with labial PCRS could be a promising treatment strategy to maintain long-term periodontal health in adult patients with alveolar deficiency and thin gingiva tissue.

Introduction: The objective of this study was to investigate the 2-year postoperative change and influencing factors of the upper airway after mandibular advancement with maxillary setback surgery for patients with a skeletal Class II relationship., Methods: Fifty-seven participants who underwent mandibular advancement with maxillary setback surgery were enrolled consecutively. Cone-beam computed tomography was performed preoperatively, 3 months postoperatively (T1), and 2 years (T2) postoperatively. All parameters were measured using Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif)., Results: The total volume (V), minimum cross-sectional area (CSA min ), and glossopharynx increased significantly in both the short-term (V, 13.33%; CSA min , 33.03%; glossopharynx, 26.73%) and long-term (V, 10.19%; CSA min , 23.18%; glossopharynx, 18.27%) after the surgery. Mandibular advancement, mandibular width increase, preoperative CSA min , and body mass index (BMI) significantly affected 2-year postoperative V increases. Mandibular advancement and BMI significantly affected 2-year postoperative glossopharynx increases. Backward movement of point PNS may lead to a reduction of the nasopharynx; however, downward movement of point PNS, upward movement of point A, and increased maxillary width may compensate for this effect by increasing the likelihood of the nasopharynx opening. Furthermore, mandibular body length at T1 is positively associated with relapse rate ([T2 - T1] / T1) of V and CSA min ., Conclusions: Mandibular advancement amount, mandibular width increase, preoperative CSA min , and BMI are the 4 factors for long-term V changes. Patients with a longer mandibular body length might have a lower relapse rate., (Copyright © 2023 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Class II malocclusion with mandibular retrognathia is a common complication of paediatric obstructive sleep apnoea (OSA), often accompanied by transverse maxillary deficiency. In early orthodontic treatment, a twin block (TB) is a regular functional appliance for correcting this malocclusion. For paediatric OSA, the most common risk factor is adenotonsillar hypertrophy (AHT). Untreated AHT may lead to the persistence and worsening of obstructive sleep-disordered breathing traits, including habitual mouth breathing. Additionally, the clockwise mandibular rotation associated with AHT-induced pharyngeal crowding can undermine the effectiveness and stability of TB treatment. Adenotonsillectomy (T&A) is currently the first-line treatment for paediatric OSA. This proposed trial will investigate the impact of T&A surgery timing on the efficacy and stability of TB functional treatment in children with class II mandibular retrognathia and ATH., Methods and Analysis: This will be a single-centre, parallel-group, superiority randomised controlled trial with participants randomised to intervention (T&A followed by TB treatment) or control arms (TB treatment followed by T&A) in a 1:1 ratio. A total of 40 patients aged 8-14 years, diagnosed with class II mandibular retrognathia and co-existing ATH-induced OSA, and indicated for both T&A surgery and TB treatment, will be recruited at the School and Hospital of Stomatology, Wuhan University. The primary outcomes will be the changes in the apnoea-hypopnoea index and the point A-nasion-point B angle from baseline to postorthodontic treatment between the two groups. Secondary outcomes will include other dental, skeletal, upper airway and soft tissue changes, as well as subjective sleep-related and oral-related quality of life. Outcome changes within each group and between groups will be analysed., Ethics and Dissemination: This study is approved by the Ethics Committee of the School and Hospital of Stomatology, Wuhan University (no. 2022-D07). The research findings will be faithfully disseminated through scientific conferences or published articles., Trial Registration Number: ChiCTR2200061703 (https://www.chictr.org.cn)., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To three-dimensionally evaluate post-operative mandibular stability following bilateral sagittal split ramus osteotomies between hybrid and non-hybrid rigid internal fixation techniques., Materials and Method: Seventy adults with skeletal class II deformity who underwent bilateral split sagittal osteotomy with mandibular advancement were included. Patients were divided into four groups based on their fixation techniques: hybrid technique (HT) groups I, II, and IV received a 4-hole 2 mm miniplate with either a bicortical screw (BS), additional 2 mm 4-hole miniplate, or two-hole miniplate, while non-HT group III received a 4-hole 2 mm miniplate with four mini-screws (MS). Measurements were taken pre-operatively (T0), immediately postoperatively (T1), and ≥1 year after surgery (T2) using 3D Slicer software., Results: Age, sex, and follow-up period did not correlate significantly with postoperative relapse or stability. Significant differences were observed in the advancement on the right side between groups II, III, and IV and on the left side between groups I, III, and IV. However, the type of surgical intervention showed no significant effect on postoperative relapse and stability. All groups of fixations showed satisfactory stability with irrelevant relapse (< 2 mm or 2°)., Conclusion: The study demonstrated satisfactory and comparable stability among different fixation groups on patients undergoing mandibular advancement following bilateral split sagittal osteotomy. The results highlighted the importance of considering the degree of advancement when planning orthognathic surgery and managing postoperative outcomes., Competing Interests: Declaration of Competing Interest The authors declared no potential conflicts of interest concerning this article's research, authorship, and publication., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

The aim of this study was to explore whether mandible-first sequencing increases the surgical accuracy in bimaxillary orthognathic surgery for patients with skeletal class II malocclusion concomitant with the unstable condyle-fossa relation. A retrospective evaluation of 19 patients who had undergone virtually planned double-splint orthognathic surgery with different operation sequences was performed: maxilla-first (n=9) or mandible-first (n=10) surgery. The centroid position, translational, and rotational differences in the maxilla were evaluated by comparing the virtual plans with actual results. The stability was assessed by comparing the actual results with the follow-up outcomes 6 months postoperatively. The accuracy of the maxilla centroid position was improved in mandible-first sequencing surgery: mandible-first 1.87±0.94 mm versus maxilla-first 2.70±0.75 mm ( P <0.05). Moreover, no significant difference was detected in the translational and orientational discrepancies between the 2 groups. Neither sequencing procedure differed in the overall stability: maxilla-first (1.48±1.13 mm) versus mandible-first (1.57±0.90 mm). This study indicated that the mandible-first surgery leads to a more accurate maxilla position than the maxilla-first surgery for patients with skeletal class II malocclusion concomitant with the unstable condyle-fossa relation., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

Purpose: Anterior segmental osteotomy (ASO) following the surgery-first approach is a long-established treatment modality to resolve lip protrusion in patients with skeletal class II patterns. However, the indications and effectiveness of ASO still remain uncertain. The objective of this study is to investigate the effectiveness of ASO in Asian skeletal class II patients by evaluating the skeletal and soft tissue changes and analyzing pre-treatment variables that determine successful outcomes in occlusal as well as esthetic aspects., Methods: The lateral cephalograms of 44 skeletal class II patients who underwent ASO and orthodontic treatment for resolving lip protrusion were retrospectively collected. Hard and soft tissue variables of two groups, normalized (NG) and unnormalized (UNG) ANB after treatment were compared and analyzed. The rotational effect of the anterior segment on the hard and soft tissue was also investigated., Results: ASO was successful in correcting the skeletal class II relationship and lip protrusion (ΔANB - 2.3°, 4-5 mm lips retraction) in most cases. However, for patients with severely camouflaged skeletal class II incisors involving a large ANB and SNA, a large ANB still remained post-treatment. The study also found that rotation of the upper and lower anterior segments further augmented the amount of lip retraction., Conclusions: ASO was found to successfully correct ANB of skeletal class II patients under the following conditions (ANB 5.3° ± 1.5°, SNB 77.3° ± 4.5°, U1 to FH 115° ± 7.5, L1 to FH 48.0° ± 4.6). However, patients with larger ANB and SNA values may require bi-maxillary surgery. In addition, ASO has limitations in correcting gummy smile in cases of extreme maxillary excess. For patients requiring a large amount of lip retraction, rotation of the anterior segment may be beneficial in conjunction with bi-maxillary surgery., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Orthognathic surgery often requires extensive orthodontic preparation and a prolonged postoperative recovery that can be stressful for patients and their families. Parents are a primary source of support for patients; accordingly, a better understanding of the parents' experience of orthognathic surgery can help inform clinical care. Using a prospective cross-sectional qualitative study design, 4 focus groups (2 English and 2 Spanish; mean length 65 min) were held with parents of patients who had completed orthognathic surgery for class II/III malocclusion. Thematic content analysis of the group transcriptions was conducted. Participants were 10 mothers and 3 fathers of 12 children (50% with cleft lip/palate) ages 17 to 23 who completed LeFort I (41.7%), LeFort I with bilateral sagittal split osteotomy (BSSO; 41.7%), or BSSO (16.7%) within the prior 3 to 16 months. Themes fit within a chronological framework: (1) Preparing for Surgery included their larger health context, anticipating surgery, surgery preparation by team and family, and religious faith; (2) Challenges after Surgery consisted of complications, pain, frustration, nutritional challenges, parental anxiety, activity changes, sleep, breathing issues, swelling, and unanticipated aspects of surgery; and (3) Supports after Surgery were nutritional support, appreciation of medical team, postoperative improvements, appearance changes, communicating, supporting patient, and patient coping. Parents also offered advice for families and medical teams. Surgeons and other providers who are part of orthognathic surgical preparation can implement recommendations based on parental experiences to increase patient and family readiness for surgery by providing early education, assisting with advocacy, focusing on nutrition, and supporting coping., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

Background: The aim of the present study was to compare periodontal support changes during retraction of mandibular anterior teeth for skeletal Class II malocclusion with different facial divergence and to analyze relevant factors influencing bone remodeling by applying three-dimensional (3D) cone-beam computed tomography (CBCT) reconstruction technology., Methods: Forty-eight patients with Class II malocclusion requiring surgical orthodontic treatment enrolled in the study were divided into the hyperdivergent group (n = 16), normodivergent group (n = 16) and hypodivergent group (n = 16) according to their vertical skeletal patterns. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T1) and after presurgical orthodontic treatment (T2). The two-dimensional (2D) alveolar bone morphology, movement of mandibular central incisors and volume of the alveolar bone around incisors were measured on the labial and lingual sides by 3D CBCT reconstruction technology. Statistical analyses were performed with one-way ANOVA, paired t tests and multiple linear regression., Results: During presurgical orthodontic treatment, the alveolar bone height on the labial side of the hyperdivergent group decreased significantly (P ≤ 0.05), but was maintained in the normodivergent and hypodivergent groups (P > 0.05). However, the alveolar bone volume, alveolar bone thickness at each level and alveolar bone height on the lingual side decreased significantly for all the groups. Apart from the initial morphometric measurements at T1, the morphology of lingual alveolar bone at T2 was significantly influenced by the direction and amount of tooth movement. Horizontal retraction and vertical protrusion of the root apex were negatively related to the alveolar bone on the lingual side after presurgical orthodontic treatment., Conclusion: For Class II malocclusion patients undergoing presurgical orthodontic treatment, the changes in the periodontal support of the lower central incisors varied in different vertical skeletal patterns. There exists a great periodontal risk of alveolar bone resorption on the lingual side for various vertical types. To avoid alveolar bone deterioration, it is essential to investigate the bone remodeling of patients with different alveolar bone conditions and cautiously plan tooth movement prior to orthodontic treatment. Moreover, 3D measurements based on CBCT construction can provide complementary information to traditional 2D measurements., (© 2023. The Author(s).)

Objective: To evaluate the long-term effects of mandibular symphyseal distraction osteogenesis (MSDO) on the correction of class II malocclusion correction and dental crowding., Materials and Methods: Twenty-two patients received MSDO and presented class II malocclusion with transverse mandibular discrepancy. The authors collected data on 2 different cephalometric analyses. On Tweed analysis, The authors recorded ANB, SNA, SNB, and FMA angles. On Delaire analysis, we recorded the distance from Pti (pterygoid inferior) to ENAt (anterior nasal spine) and the distance from Cos (superior condyle) to Pog (pogonion). Superimpositions studies were performed at pre-treatment phase (T1) and post-treatment phase (T2) to evaluate the new position and changes in the dimensions of the mandible and maxilla., Results: On superimposition of Tweed analysis of T1 and T2, reduction of ANB was seen in 18 patients, no change in ANB in 2 patients, and increase in ANB (by 1 deg) in 2 patients. Superimposition of Delaire analysis showed a mean difference of 0.3 mm (SD, 3.6 mm) between T1 and T2 for the maxilla and a mean difference of 6.0 mm (SD, 7.3 mm) for the mandible., Conclusions: Mandibular symphyseal distraction osteogenesis performed after the pubertal growth peak can effectively correct class II malocclusion and dental crowding with a single light surgical procedure., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

This study included 46 patients with class II malocclusion ranging in age from 19 to 39 years old treated with bilateral sagittal split ramous osteotomy (BSSRO). Left and right temporomandibular joints (TMJs) of each subject were evaluated independently with cone-beam computed tomography (CBCT) before operation (T1), 1 week after operation (T2), and 1 year after operation (T3) and assessed the effects of orthognathic surgery (OGS) on the temporomandibular joint disease (TMD) symptoms. Temporomandibular joint morphology evaluation included condylar volume, condylar area, cortical bone thickness, depth of the mandibular fossa, fossa thickness, joint nodule angle, joint space, and condyle-fossa relationship, which were calculated by using the Mimics software and 3-matic software. Data were statistically analyzed with SPSS software (P <0.05 means statistically significant). In our study, bilateral TMJs have no difference in T3. Bilateral sagittal split ramous osteotomy had no significant effect on the articular fossa. The condyle volume and surface area decreased from T1 to T3, but the cortical thickness of the bone did not change significantly. More anterior condyle positions in T1 and more posterior in T3.21 patients had at least 1 sign or symptom of TMD in T1 and 27 patients in T3. Four patients who were asymptomatic in T1 developed pain after surgery, 10 developed noises, 12 showed limited mouth opening, and 8 had abnormal opening patterns. It is concluded that more condylar posterior position after BSSRO and the reduction of condyle may be related to the enlargement of anterior space. The number of patients with joint symptoms increased postoperative, and the impact of BSSRO on TMD may be negative., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

This case report describes a complex full-step class II high angle case in an adult patient treated with lingual straight-wire appliance, premolar extractions and orthognathic surgery. With the twofold aim of obtaining ideal occlusal relationship and aesthetic improvement, surgical treatment with appropriate biomechanical strategies, including extraction choice and torque control during space closure, are needed to achieve the planned results. This case report demonstrates the possibility of solving successfully severe sagittal, transverse and vertical discrepancies in an adult patient with surgical treatment by means of an invisible technique. This report also underlines the need for precise biomechanical control, including set-up overcorrections and an auxiliary spring to manage teeth inclination, in lingual orthodontics extraction cases., (Copyright © 2023 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Introduction: This study aimed to analyze the effects of premolar extraction treatment with vertical control on changes in the anatomy and aerodynamics of the oropharynx in Class II hyperdivergent malocclusion with nonsevere crowding., Methods: Thirty-nine patients with Class II hyperdivergent malocclusion were enrolled consecutively. All the participants underwent 4 premolar extractions. The high-pull J-hook and mini-implants were used to provide vertical control. Cone-beam computed tomography was performed before and after treatment. The participants were divided into a decreased lower vertical facial height group (n = 23) and an increased lower vertical facial height group (n = 16) on the basis of superimposition. The aerodynamic characteristics, including airway resistance (inspiration, R in ; expiration, R ex ) and maximum velocity (inspiration, Vmax in ; expiration, Vmax ex ) at inspiration and expiration, were calculated using computational fluid dynamics. Anatomic characteristics, including volume and cross-sectional area (CSA min ), were measured using the Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif)., Results: After treatment, the median volume and CSA min increased by 2357 mm 3 and 43 mm 2 , respectively, and median R in and Vmax ex decreased by 0.15 Pa/L/min and 0.24 m×s -1 , respectively, in decreased lower vertical facial height group. In contrast, the median CSA min decreased by 9.5 mm 2 in the increased lower vertical facial height group. All the changes were statistically significant (all P <0.05). Significant differences in volume, CSA min , R in , and Vmax ex were observed between the 2 groups., Conclusions: Vertical control might improve the anatomic and aerodynamic characteristics of the oropharyngeal airway during premolar extraction treatment of Class II hyperdivergent malocclusion with nonsevere crowding., (Copyright © 2023. Published by Elsevier Inc.)

Objectives: This study aimed to determine the positional changes in the condyle in the temporomandibular joint (TMJ) of severe skeletal class II malocclusion patients treated with surgical-orthodontics., Materials and Methods: The measurements of TMJ space in 97 severe skeletal class II malocclusion patients (20 males, 77 females, mean age, 24.8 years, mean ANB = 7.41°) were assessed using limited cone-beam computed tomography (LCBCT) images acquired before orthodontics (T0) and 12 months after surgery (T1). 3D remodeling of the TMJ and measurements of the anterior space (AS), superior space (SS), and posterior space (PS) were performed to determine the position of the condyle for each joint. All data were analyzed by t test, correlation analysis, and Pearson correlation coefficient., Results: The mean AS, SS, and PS values after the therapy changed from 1.684 to 1.680 mm (0.24%), 3.086 to 2.748 mm (10.968%), and 2.873 to 2.155 mm (24.985%), respectively. The decreases in SS and PS were statistically significant. Positive correlations were found in the mean AS, SS, and PS values between the right and left sides., Conclusions: The combination of orthodontic and surgical treatment makes the condyle move counterclockwise in the TMJ in severe skeletal class II patients., Clinical Relevance: Studies of temporomandibular joint (TMJ) intervals changes in patients with severe skeletal class II after sagittal split ramus osteotomy (SSRO) are limited. The postoperative joint remodeling, resorption, and related complications remain unstudied., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Orthodontic treatment with premolar extractions is typically used to relieve dental crowding and retract anterior teeth for lip profile improvement. The aim of the study is to compare the changes in regional pharyngeal airway space (PAS) after orthodontic treatment with Class II malocclusion and to identify the correlations between questionnaire results and PAS dimensions after orthodontic treatment. In this retrospective cohort study, 79 consecutive patients were divided into normodivergent nonextraction, normodivergent extraction, and hyperdivergent extraction groups. Serial lateral cephalograms were used to evaluate the patients' PASs and hyoid bone positions. The Pittsburgh Sleep Quality Index and STOP-Bang questionnaire were used for sleep quality evaluation and obstructive sleep apnea (OSA) risk assessment, respectively, after treatment. The greatest airway reduction was observed in hyperdivergent extraction group. However, the changes in PAS and hyoid positions did not differ significantly among three groups. According to questionnaire results, all three groups had high sleep quality and low risk of OSA, with no significant intergroup differences. Moreover, pretreatment-to-posttreatment changes in PAS were not correlated with sleep quality or risk of OSA. Orthodontic retraction with premolar extractions nither exhibit significant reduction in airway dimensions nor increase their risk of OSA., (© 2023. The Author(s).)

The aim of this case report is to illustrate the fixed orthodontic, surgical and periodontal implant management of a young adult with multiple agenesis associated with a class II division 2 malocclusion. The challenge here was the multidisciplinary synchronisation in order to achieve a coordinated treatment with the best possible aesthetic, prosthetic and functional prognosis. The patient suffered from a total of 10 agenesis including third molars and underwent implant replacement with bone grafting and periodontal planning of the 6 missing premolars. The orthodontic treatment lasted 22months and was followed by a period of just under a year for periodontal and implant prosthetic completion. The 3-year follow-up after the orthodontic phase showed an excellent prognosis in terms of aesthetics, function and stability., (Copyright © 2023 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Introduction: The purpose of this study was to compare the effects of mandibular advancement (MA), bichectomy, jawline, and their combination on facial attractiveness. The 3-dimensional (3D) visual sculpting is a method to perform the task., Methods: FaceBuilder software, a Blender 2.93 LTS add-on, was used to generate a 3D head and face model of a female patient with Class II Division I malocclusion. MA, bichectomy, jawline, and combination modifications were performed on the model using a 3D virtual sculpting tab, and 4 new head models were created. Five hundred thirteen participants scored lateral and frontal views of the modified and reference models. The Mann-Whitney U, Kruskal-Wallis, and Wilcoxon tests were used for statistical analysis., Results: MA modification received the highest frontal and lateral image scores. The raters found the jawline frontal photograph to be the least attractive. Significant differences were observed between the lateral and frontal attractiveness scores in all modifications except bichectomy. The combination of 3 modifications in both frontal and lateral images received the second-lowest score., Conclusions: Facial esthetic modifications receive different attractiveness scores in lateral or frontal evaluations. MA outperforms bichectomy and jawline augmentation in terms of improving facial attractiveness., (Copyright © 2023 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

This case report illustrates the successful nonsurgical and nonextraction treatment of a 12-year-old boy with skeletal Class II deep bite malocclusion undergoing two-phase clear aligner treatment. During A6 mandibular advancement phase, Class II buccal segment relationship was corrected by differential forward growth of the mandible, unplanned distalization of maxillary posterior teeth, and unplanned mesialization of mandibular posterior teeth. The maxillary sagittal curve of occlusion was deepened, the mandibular curve of Spee was not fully levelled, and the maxillary arch experienced downward-backward rotation resulting in premature contact on anterior and posterior open bite. Buccal crown tipping of maxillary posterior teeth was observed after arch expansion. The forward growth of the mandible improved the skeletal relationship, and the advancement of the chin position and sagittal movements of the incisors altered the nose-lip-chin relationship, resulting in an improved profile of the patient. During refinement phase, the posterior open bite was corrected. The mandibular plane angle did not increase throughout the treatment. The patient was satisfied with the aesthetic and functional outcome., (Copyright © 2023 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Condylar displacement and remodelling are phenomena closely related to orthognathic surgery and critically involved in occlusal and skeletal stability. The aim of the present case report is to describe over time condylar displacement and surface remodelling after bilateral split sagittal osteotomy (BSSO) in an adult patient with severe class II skeletal malocclusion treated with ortho-surgical approach. A male of 21years comes to our observation. The extraoral examination shows a symmetrical square-shaped face, a convex profile, an acute nasolabial angle and a deep labiomental fold. Intraoral examination reveals a class II division 2 with a 2mm deviation of the mandibular midline to the left and the presence of a scissor bite of the bicuspids between quadrants II and III. The Spee curve and overbite are extremely accentuated (OV 14.3mm) as the overjet (11.1mm). Axiographic reconstructions of CBCT show a normal shape and position of both condyles. The cephalometric analysis shows a reduced lower facial height, a normal upper jaw position, a mandibular underdevelopment masked by a very developed symphysis and an extremely low divergence (FMA 11.2°). BSSO for mandibular setback was performed in the 13th month of orthodontic therapy. Original CBCT data before surgery (T0), at the end of treatment (T1), 2years postoperatively (T2) and 5years postoperatively (T3) were collected and reconstructed for 3-dimensional (3D) qualitative analyse. At the end of the surgical-orthodontic treatment (26months), good function and good aesthetics were achieved. The qualitative and comparative analysis of the superimpositions and the cuts made on the CBCT at T0, T1, T2, T3 showed a physiological remodelling and adaptation of the condyles., (Copyright © 2023 CEO. Published by Elsevier Masson SAS. All rights reserved.)

The current standard approach to treat class II malocclusion is orthodontic preparation followed by a mandibular advancement through bilateral sagittal split osteotomy associated or not with a genioplasty. However, when a malocclusion with an important incisors' axis deviation is associated with a chin malposition, an alternative technique can be considered: simultaneous mandibular anterior segmental osteotomy and genioplasty. This technique is performed without a bony bridge between osteotomies. Care must be taken not to wound the lingual mucosa. If preserved, this technique is safe. The result is stable and predictable., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by Mutaz B. Habal, MD.)

Objective: To introduce a guideline for selecting proper surgical modalities for correction of skeletal Class II malocclusion with moderate-to-severe vertical height deficiency (VHD) of the condyle/ramus complex (CRC) using bimaxillary surgery in conjunction with total joint replacement (TJR) or inverted-L osteotomy (ILO) assisted by 3D virtual surgical planning and CAD/CAM technologies., Cases: Four cases of severe skeletal Class II patients with moderate-to-severe VHD of CRC were presented. They underwent bimaxillary surgery using Le Fort I osteotomy in the maxilla and TJR or ILO in the mandible, with the help of virtual surgical planning (VSP) and computer-aided design/computer-aided manufacturing (CAD/CAM)-printed surgical guides and osteosynthesis plates. Guidelines are as follows: (1) if a patient has a moderate degree of VHD and the function of the temporomandibular joint (TMJ) is normal, ILO would be preferred for vertical elongation of the ramus; (2) if a patient has congenitally small condyle or severe condylar resorption, TJR would be preferred to resolve severe VHD of CRC; and (3) when a patient has a metal allergy, foreign body reaction or anatomic limitations (ie, thin cranial base cortex for fossa fixation), ILO would be a better option than TJR., Results: TJR or ILO using VSP and CAD/CAM-printed surgical guides, wafers, and customized plates can provide a proper selection of the surgical plan, accurate transfer of surgical plans to actual surgical procedures, and esthetic improvement of the facial profile., Conclusion: This guideline based on the degree of VHD and functional aspects of CRC might help clinicians to select effective surgical modality for correction of skeletal Class II malocclusion with moderate-to-severe VHD of CRC., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

Objective: To evaluate the decompensation effectiveness and alveolar bone remodeling of mandibular anterior teeth after preoperative orthodontic treatment in high-angle patients with skeletal class Ⅱ malocclusion using lateral cephalogram and cone-beam computed tomography (CBCT)., Methods: Thirty high-angle patients with skeletal class Ⅱ malocclusion who had received preoperative orthodontic treatment and orthognathic surgery in Peking University School and Hospital of Stomatology between Ja-nuary 2017 and August 2022 and had taken lateral cephalogram and CBCT before and after preoperative orthodontic treatment were selected. Items were measured with lateral cephalogram including: The lower central incisor (L1)-Frankfort plane angle (L1-FH), the L1-mandibular plane angle (L1-MP), the L1-nasion-supramental angle (L1-NB) and the vertical distance from the incisal edge of lower central incisor to NB line (L1-NB distance), etc . The incidence of dehiscence/fenestration and the length of dehiscence at labial side (d-La) and lingual side (d-Li) were measured using CBCT. Pearson correlation analysis was used to evaluate the correlation between the changes of d-Li of L1 and age, duration of preoperative orthodontic treatment and the cephalometric measurements before preoperative orthodontic treatment to screen out risk factors affecting the periodontal risk of preoperative orthodontic treatment in high-angle patients with skeletal class Ⅱ malocclusions., Results: After preoperative orthodontic treatment, L1-FH, L1-MP, L1-NB and L1-NB distances changed by 11.56°±5.62°, -11.13°±5.53°, -11.57°±5.43° and (-4.99±1.89) mm, respectively, and the differences were all statistically significant ( P < 0.05). Among the 180 measured mandibular anterior teeth, 45 cases with labial dehiscence/fenestration before preoperative orthodontic treatment (T0) had no longer labial dehiscence/fenestration after preope-rative orthodontic treatment (T1); 142 cases without lingual dehiscence/fenestration at T0 had lingual dehiscence/fenestration at T1. After preoperative orthodontic treatment, the d-La of lower lateral incisors (L2), lower canines (L3) and lower anterior teeth (L1+L2+L3) decreased by (0.95±2.22) mm, (1.20±3.23) mm and (0.68±2.50) mm, respectively, and the differences were statistically significant ( P < 0.05); the d-Li of L1, L2, L3 and L1+L2+L3 increased by (4.43±1.94) mm, (4.53±2.35) mm, (3.19±2.80) mm and (4.05±2.46) mm, respectively, and the differences were statistically significant ( P < 0.05). The increase of d-Li of L1 was positively correlated with L1-FH ( r =0.373, P =0.042)., Conclusion: This study showed that high-angle patients with skeletal class Ⅱ ma-locclusion could achieve ideal decompensation effect of mandibular anterior teeth after preoperative orthodontic treatment with bilateral mandibular first premolars extracted, but the lingual periodontal risk of mandibular anterior teeth was increased. This risk could be correlated to L1-FH before preoperative orthodontic treatment, which should be paid more attention in the design of orthodontic-orthognathic surgical treatment.

The Aim the Study: This study aims to assess the postoperative condylar displacement after orthognathic surgery using three-dimensional analysis of computed tomography., Material and Methods: This retrospective study included 64 condyles from 32 patients with skeletal Class II (Group 1, n =16) and III (Group 2, n =16) deformities. All patients underwent a bimaxillary surgery. The three-dimensional CT images were evaluated to assess condylar displacement., Results: The condyle exhibited mainly superior and lateral torque immediately after surgery. Posterior displaced condyles were found in two cases in group 1 (Class II malocclusion)., Conclusion: The present study found the condyle displacement that can be mistaken as posterior displacement of condyle in analysis of sagittal sections of CT scans.

Objectives: Relapse after orthognathic surgery seems to depend on diverse factors. Proffit et al. postulated in 2007 a "hierarchy of stability" (Head Face Med 6:66, 2007), ranking posttreatment stability after various orthognathic procedures, but no systematically reviewed evidence was provided. Therefore, the aim of this review was to investigate the extent of class II relapse in orthognathic surgery of Angle class II patients depending on the surgical procedure used., Materials and Methods: Seven databases were searched for randomized and controlled clinical trials to compare relapse in surgical procedures for Angle class II patients. After duplicate study selection, data extraction and risk of bias assessment were performed with the ROBINS-I tool as well as data synthesis by frequency distribution, followed by assessment of the quality of evidence with GRADE., Results: Four non-randomized cohort-studies with a total of 132 patients were included. Bimaxillary procedures as well mandibular advancement procedures proved to be highly stable. Single jaw interventions at the maxilla achieved mostly stable results at sagittal dimension and problematic stability in the vertical dimension. However, there were only limited data available with low quality of evidence., Conclusions: Limited existing evidence of low quality partly support the postulated hierarchy of stability of Proffit et al. (Head Face Med 6:66, 2007) and indicates that a surgical correction of class II dysgnathia with bimaxillary procedures and mandibular advancement seems to be highly stable. However, additional studies are needed to address the relation between relapse and surgical orthognathic intervention. Trial registration PROSPERO 2019 CRD42019144873., (© 2022. The Author(s).)

Introduction: This study aimed to evaluate the dentoskeletal and soft-tissue changes after molar distalization using modified C-palatal plates in patients with severe maxillomandibular arch length discrepancies., Methods: Twenty-four patients with Class I and II malocclusion (19.0 ± 7.3 years; 17 females and 8 males), who had severe maxillary crowding of >10 mm, and moderate mandibular crowding of >6 mm, underwent molar distalization using modified C-palatal plates and buccal miniscrews with approximately 300 g of force per side. Models were made, and cephalograms were taken before and after treatment. Cephalometric variables and arch dimensions were measured. Paired t test and Wilcoxon rank sum test were used for statistical analysis., Results: In the maxillary dentition, an average of 12.4 mm of crowding was resolved by molar distalization of 4.4 mm, interproximal stripping of 0.7 mm, and arch expansion. In the mandibular dentition, crowding of 6.7 mm was alleviated by molar distalization of 2.4 mm, an interproximal of 1.5 mm, and additional arch expansion. The incisor positions were maintained (SN-U1, 101.3°; IMPA, 88.8°), and soft-tissue profiles were improved (LL/E-line -1.1 mm; P < 0.001) after treatment., Conclusions: Maxillary and mandibular tooth-size arch length discrepancy of 12.4 mm and 6.7 mm, respectively, were resolved by molar distalization, interproximal reduction, and arch expansion, whereas incisor positions were maintained, and soft-tissue profiles were improved. This could be a viable treatment option in patients with moderate-to-severe crowding., (Copyright © 2022 American Association of Orthodontists. All rights reserved.)

Objectives: To investigate canine retraction (CR) and anchorage loss (AL) among average facial height (AFH) and high facial height subjects (HFH) with or without piezocision surgery (PS)., Materials and Methods: This was a split-mouth, randomized clinical trial. Twenty-three females (aged 19.05 ± 2.95 years) who presented with Class II division I malocclusion requiring bilateral maxillary extraction and who fulfilled eligibility criteria were included and categorized into two groups: AFH (12 participants) and HFH (11 participants). Atraumatic extractions were performed 10 weeks following bonding. Before space closure, impressions were taken to fabricate models, which were scanned to generate digital models. Each participant had PS on the randomly assigned side. Space closure was undertaken using 100-g nickel-titanium coil closing springs on 0.019 × 0.025-inch stainless steel archwire. Digital models were collected 6 and 12 weeks post-PS. They were superimposed using reliable reference points and a region of interest on the palate, and crown movements were analyzed in three dimensions., Results: Three months post-PS, intergroup comparisons showed that rates of CR for control sides (mean = 1.88 ± 0.83 mm for AFH, mean = 1.76 ± 0.62 mm for HFH) and intervention sides (mean = 1.48 ± 0.74 mm for AFH, mean = 1.40 ± 0.85 mm for HFH) were not significantly different. AL was not significantly different (P &gt; .05) between groups., Conclusion: Regardless of whether the patient underwent PS, CR and AL rates for AFH and HFH patients were not significantly different., (© 2022 by The EH Angle Education and Research Foundation, Inc.)

Purpose: To evaluate the effects of upper occlusal plane (UOP) inclination and incisor decompensations on the outcome of surgical Class II patients., Materials and Methods: Pretreatment (T0), preoperative (T1), and posttreatment (T2) cephalograms of 30 surgical Class II patients were included. Cephalometric measurements were performed using the Dolphin Imaging Software in this retrospective study. The differences between time points were analyzed with repeated measures ANOVA. Spearman correlation test was used to determine any correlations between either the UOP alterations or incisor decompensations and the cephalometric variables., Results: A significant improvement was obtained in the sagittal skeletal, dental variables, and soft tissue B point. Significant correlations were found between the decompensation achievement ratio and the change of the convexity angle. The relative percentage ratio (RPR) of the lower incisor was correlated with Wits appraisal, ANB, and Convexity Angle at the T2 stage. The RPR of the upper incisor was found to be correlated with lip strain. The relative surgical correction ratio of the UOP angle was found to be correlated with the surgical change of Wits appraisal and convexity angle. The RPR of the UOP angle was correlated with the SNB, ANB, and SN-GOGN angles at the T2 stage., Conclusions: Significant improvement in the incisor inclinations was achieved, but the incisors were inadequately decompensated at the preoperative phase. Surgical correction was limited by the inadequate presurgical decompensation. The surgical alteration of the UOP should be taken into consideration for the surgical planning to obtain better outcomes for Class II patients., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by Mutaz B. Habal, MD.)

Aim: Class II extraction approach by means of maxillary first premolars represents a common treatment strategy in order to reduce the overjet and create a stable Class I canine relationship and Class II molar relationship. The objective of this paper is to describe digital planning protocol and complete clinical phases of space closure in Class II malocclusion treatment in adult patient., Materials and Methods: The accuracy of movements and correction of dental parameters has improved exponentially in recent years, as a result of continuous research performed in aligner orthodontics. However, the most complex movement to realize with aligners is the apical movement, but the application of the G6 protocol for managing extractive cases allows to obtain the final parallelism of the roots with a control of the tipping managed on the digital plan as an overcorrection (overtipping) of the roots adjacent to the extraction site. Through the description of two cases, this article will present the application of the specific protocol for first premolars extraction in order to manage anchorage and closure of extraction spaces., Results: All patients finished with proper OVJ and OVB with a Class II molar relationship and Class I canine relationship respecting face balance and smile arc., Discussion: The Invisalign G6 protocol through the use of SmartStage™ technology combined with SmartForce™ features provides vertical control during anterior sector retraction and teeth body movement maintaining maximum posterior anchorage.

Objectives: The objective of this trial was to evaluate the dental changes, periodontal health, and tooth vitality in mini-screw-supported en-masse retraction with two corticotomy-based acceleration techniques. Study Design . The sample included 38 adult patients presenting with class II division 1 malocclusion (three males, 35 females; age range between 18 and 30 years), needing the extraction of upper first premolars followed by en-masse retraction. The sample was divided randomly and equally into two groups. Randomization was carried out by random numbers generated by the computer with a 1 : 1 allocation ratio. The allocation concealment was carried out by sequentially numbered, opaque, sealed envelopes. The interventions were traditional corticotomy (TC) versus flapless corticotomy (FC). Mini-screws were inserted between the upper second premolar and first molar, bilaterally. The primary outcome was evaluating dental changes. Secondary outcomes were the periodontal health and pulp vitality of the maxillary teeth. Mann-Whitney U test and two-sample t -test with Bonferroni correction were used to analyze the data., Results: The en-masse retraction rate in the first three months was higher in the TC group than the FC group (1.82, 1.66, and 1.39 mm/month vs 1.60, 1.42, and 1.22 mm/month, respectively) with statistically significant differences ( P < 0.001, P < 0.001, P =0.001, respectively). The en-masse retraction amount was greater in the TC group than the FC group (6.84 mm vs 6.18 mm, respectively) with statistically significant differences ( P =0.002). There was an increase in the inter-canine and inter-molar widths with a minor distal movement of the upper first molar in the two groups, with no significant differences between them ( P > 0.008). The values of gingival, papillary bleeding and plaque indices in the TC group were significantly greater than those in the FC group after performing the corticotomy ( P < 0.001, P < 0.003, P =0.002, respectively). No gingival recession was found on any of the examined teeth in both groups. All teeth maintained their vitality at all measurement times in both groups. No severe harms were noticed in any group., Conclusions: Both traditional and flapless corticotomy techniques resulted in clinically similar rates of the en-masse retraction of upper anterior teeth, with similar dental changes and no significant periodontal complications or tooth vitality loss. The minimally invasive flapless corticotomy appeared to be a good alternative to the more invasive traditional corticotomy. This trial is registered with https://www.clinicaltrials.gov (Identification code: NCT04847492), retrospectively registered., Competing Interests: The authors declare that they have no conflicts of interest in the submitted manuscript., (Copyright © 2022 Hanin Nizar Khlef and Mohammad Younis Hajeer.)

Purpose: To retrospectively evaluate skeletal stability after Le Fort I maxillary impaction surgery and mandibular autorotation without bilateral sagittal split osteotomy (BSSO) in high-angle class II patients., Materials and Methods: Seven female high-angle class II patients who underwent maxillary impaction surgery and mandibular autorotation without bilateral sagittal split osteotomy were included in this study. Surgical changes and relapse were measured on lateral cephalograms taken preoperatively and at 1 month, 6 months and 1 year postoperatively., Results: The horizontal movement of the maxilla at point A was 5.8 ± 3.3 mm backward, and the upward movement at the posterior nasal spine was 3.3 ± 1.4 mm. The mean horizontal change at point A during the 1-year follow-up period was 0.1 ± 0.2 mm, and the vertical change at posterior nasal spine was 0.2 ± 1.3 mm, which were not statistically significant. The horizontal surgical change at point B was 4.0 ± 1.8 mm forward and the vertical surgical change at point B was 4.7 ± 1.8 mm upward. Postoperative relapse was 10.9% and 13.7% in the horizontal and vertical directions, respectively., Conclusions: Le Fort I maxillary impaction surgery with mandibular autorotation may be 1 of the suitable procedures for high-angle class II patients., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

Background: The purpose of this study was to evaluate the stability on dental and skeletal aspect after surgical advancement and counterclockwise rotation for the correction of the mandibular deficiency in patients with high mandibular plane angle (MPA)., Methods: We analyzed the records of patients who had undergone surgical treatment for dentofacial deformities with mandibular deficiency and high MPA. Clinical and radiological data were taken 1 month before surgery (T0), 6 weeks after surgery (T1) and 1 year after surgery (T2). Cephalometric values of the MPA were recorded and compared. The cephalometric changes in the different time periods were defined as follows: A: postsurgical changes (T0-T1), B: one-year changes (T1-T2), and C: short term changes (T0-T2)., Results: Twenty-seven patients had prominent mandibular deficiency with an MPA of over 35° (high angle). The mean age of patients at surgery was 29.7 years. Seven patients had a single jaw procedure, 20 patients had bilateral sagittal split osteotomy (BSSO) combined with a Le Fort I osteotomy, and 14 patients had additional genioplasty. MPA values differed significantly between the time periods (p < 0.05) with an observed relapse of the angle. However, satisfactory clinical improvement was achieved in the dental and skeletal presentation. The overjet improvement was evident from 8.815 ± 2.085 mm (T0) to 3.426 ± 1.253 mm (T2)., Conclusion: Counterclockwise surgical advancement of the mandible to correct mandibular deficiency in patients with a high mandibular plane angle showed an overall acceptable stability during one-year follow-up., Competing Interests: Conflicts of interest No conflicting relationship exists for all authors., (Copyright © 2021 Chang Gung University. Published by Elsevier B.V. All rights reserved.)

Introduction: Studies on the pharyngeal airway space (PAS) changes using three-dimensional computed tomography (CT) have shed more light on patients with Class III than Class II malocclusion. This paper focuses on analyzing the long-term changes in the PAS and evaluating the postoperative association between these PAS and skeletal changes in patients with skeletal Class II malocclusion who have undergone orthognathic surgery., Methods: The records of 21 patients with skeletal Class II malocclusion who had undergone orthognathic surgery were included. The anatomical modifications in both jaws, changes in volume, sectional area (SA), minimum sectional area (MSA), and anterior-posterior (AP) and transverse (TV) width in the airway at one month before surgery ( T 0), and one month ( T 1) and one year ( T 2) after surgery were analyzed using CT images. The association between the skeletal and airway changes was evaluated between T 0, T 1, and T 2., Results: After surgery, the ANS, A point, and PNS demonstrated significant posterior and superior movement. The B point and the pogonion exhibited substantial anterior and superior movement. The total and inferior oropharyngeal volumes (vol 3, vol 4) notably increased, while the nasopharyngeal volume (vol 1) decreased. The anterior-posterior movement at the ANS and PNS after surgery was significantly associated with the total volume, vol 2, vol 3, SA 1, MSA, and TV width 1, while substantial association with the total volume was found at the pogonion., Conclusion: Thus, an ideal treatment plan can be formulated for patients with skeletal Class II malocclusion by considering the postoperative PAS changes., Competing Interests: The authors have no conflict of interest to declare that is relevant to this review paper., (Copyright © 2022 Moonhwan Kim et al.)

Background and Objective: The aim of the study was to detect postoperative changes in the temporomandibular joints (TMJs) and masticatory muscles of Angle class II malocclusion patients who underwent mandibular advancement surgery., Material and Methods: Twenty-three patients were selected for mandibular advancement by bilateral sagittal split ramus osteotomy (BSSO). Cephalograms and clinical evaluation were performed before the surgery as well as fourteen days and six months after surgery. Clinical examination included measurement of overjet, overbite and of the amplitude of mandibular movements, registration of deviation on mouth opening, of TMJ pain and pathological sounds and of tenderness of masticatory muscles on palpation. Mandibular position was determined by cephalometric analysis. Statistical analyses were performed using a mixed-level longitudinal random intercept model with a confidence level of 95% and a P-value of 0.05 to reveal significant differences., Results: Statistical results showed a mean mandibular advancement of 4 mm (3.1-5.0). Cephalometric measurements, overjet and overbite remained stable six months after surgery. Postoperative amplitude of mandibular movements was limited and did not completely recover 6 months later. Mouth opening was the most affected, showing an average reduction of 7.5 mm six months after surgery. Deviation on mouth opening, pathological TMJ sounds, TMJ pain and masticatory muscle tenderness did not show significant changes., Conclusions: Moderate mandibular advancement surgery offers stable results, yet the amplitudes of mandibular movements, were significant smaller after surgery and did not completely recovered 6 months following surgery. TMJ and masticatory muscles symptoms did not change after the surgery, suggesting that mandibular advancement surgery does not change the course of TMD.

Abstract: No randomized controlled trial has compared the treatment outcome between surgical mandibular advancement and premolar extractions in class II malocclusion. This 2-arm parallel randomized controlled trial evaluated the treatment effects and lip profile changes in skeletal class II adult patients subjected to bilateral sagittal split ramus osteotomy for mandibular advancement and those treated with premolar extractions. Seventy skeletal class II patients were accessed and forty-six subjects who fulfilled inclusion criteria were distributed randomly into Group CG (patients: 23, mean age: 21.28 ± 2.69 years) and Group SG (patients: 23, mean age: 21.15 ± 2.64 years). Group CG was subjected to extraction of maxillary first premolars and mandibular second premolars followed by implant supported space closure and Group SG was managed by surgical mandibular advancement. Skeletal, dental, and soft-tissue changes were analyzed. The study was single-blinded (statistical analyzer). Groups were closely matched for baseline parameters. In the present trial there was no loss to follow-up. Though overjet and overbite were optimized in both the groups but significant improvement was seen in surgical cases. Group CG demonstrated statistically significant point "A" remodeling, dentoalveolar changes, and increase in nasolabial angle. Group SG exhibited significant sagittal and vertical skeletal improvement and lip position change. Surgical mandibular advancement was found to be a better treatment modality compared to premolars extraction for managing skeletal class II div 1 malocclusion as it permits greater improvement of the profile and skeletal relationship., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

Aim: The purpose of the study was to evaluate the efficacy of infrazygomatic (IZ) implants along with mini-implants for full-arch distalization of maxilla and reduction of gummy smile in patients with class II division I malocclusion., Materials and Methods: Ten orthodontic patients were taken from the department of orthodontics and dentofacial orthopedics. Each patient required distalization and intrusion of the complete maxillary arch as a part of the treatment plan. Patients were of class II malocclusion with gummy smile. Initial leveling and alignment were done by using 0.22″ slot Mclaughlin Bennett Trevisi (MBT) prescription. Fav Anchor infrazygomatic crest (IZC) implants of 2 mm of head diameter and 14 mm length were inserted between first and second molar and 2 mm above the mucogingival junction in the alveolar mucosa and in the anterior region, two titanium mini-implants of 1.4 mm head diameter and 6 mm length. The screws were loaded immediately with e-chain with a minimal force from mini-implants in the anterior region to crimpable hook placed between lateral and canine and continuing the same till the IZ implants. To measure the amount of distalization and reduction of gummy smile, pre- and postlateral cephalograms were taken and assessed. Pre- and postdistalization and intrusion readings of all patients were obtained and calculated statistically for quantifying the amount of distalization of maxillary arch and intrusion for reduction of gummy smile., Results: The distalization of the maxillary arch achieved was 4.6 mm which is clinically and statistically significant. The anterior teeth in the study were intruded with a minimum of 3.8 mm which is clinically and statistically significant; the gingival smile line was reduced with a mean of 3.4 mm which is clinically and statistically significant. Overbite correction of 4 mm was done with the mean difference of 4 mm which is also statistically significant., Conclusion: The IZ bone screws can be effectively used as an absolute anchorage to correct class II skeletal discrepancy with gummy smile devoid of premolar extraction with noninvasive procedure., Clinical Significance: The use of IZC implants along with anterior implants, a biomechanical approach is effective in achieving full-arch distalization of maxilla and intrusion as the force vectors allow that the line of action passes through the center of resistance (Cr) of the entire maxillary arch, facilitates the distalization and intrusion of the maxillary arch, establishes ideal occlusion, and improves the smile esthetics.

Objectives: The aim of the study is to evaluate the ultrasonographic dimensional changes of the anterior belly of the digastric muscle (ABDM), occurring after intramuscular botulinum toxin A (BTX-A) injection during orthognathic surgery, in a series of five Class II malocclusion patients., Methods: All the patients received 20 units of BTX-A, into both ABDM, intraoperatively. The length, width and cross-sectional area (CSA) of the ABDM were ultrasonographically measured at three different time points: T 0 (preoperatively), T 1 (postoperatively at 2 weeks after the surgical intervention), and T 2 (postoperatively at 6-9 months)., Results: A statistically significant higher length of the ABDM was noted postoperatively, at T 1 and T 2 compared to T 0 . The patients showed an increased length by 12.2% at 2 weeks postoperatively and continued to increase, reaching 24.6% at 6 months. A decreased width of ABDM by 6.5% at T 1 compared with T 0 was also found., Conclusions: Postoperative ultrasound (US) follow-up measurements in patients with Class II malocclusion, orthognathic surgery and intraoperative BTX-A injection in the ABDM, showed dimensional changes of the muscle, with elongation and thinning. The muscular modifications were more pronounced at 6 months postoperatively, indicating consistency and potential benefit of using BTX-A in reducing the risk of surgical relapse. Further data on longer-term follow-up and larger number of cases are necessary., (© 2021. Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd.)

Purpose: To evaluate the effect of different temporomandibular joint (TMJ) disc repositioning surgeries for the treatment of anterior disc displacement (ADD) in juvenile patients with skeletal Class II malocclusion., Patients and Methods: Patients (< 20 years, cervical vertebral maturation stage, IV-V) who had bilateral TMJ ADD with skeletal Class II malocclusion were treated by disc repositioning surgery (mini-screw anchor, [MsA]; or opening suturing, [OSu]). Magnetic resonance imaging (MRI) and lateral cephalometric films before and more than 12 months after surgery were collected from all patients. Changes of SNA, SNB, ANB, incisor overjet, pogonion position (pg'-G'), and condylar height were measured before and after surgery in different disc reposition surgeries and compared by statistical analysis., Results: Eighty-four patients with an average age of 16.44 years and follow-up time of 14.60 months (12 to 33 months) were included in the study. Among them, 16 patients had a mean follow-up of 14.8 months without treatment before disc repositioning. Their condylar height was significantly decreased (P = .004) by MRI measurement. Six patients who had cephalometric films showed significantly decreased SNB (P = .042) and increased overjet (P = .037). After disc repositioning by either OSu (54 cases) or MsA (30 cases), condylar height, SNB were significantly increased and overjet, Pg'-G', ANB were decreased in both groups (P < 0.001). There was more new bone height in OSu than MsA (P = .004), but no significant differences in SNB, ANB, overjet and Pg'-G' between the 2 groups (P > .05). The new bone height was significantly correlated with the surgical method (P = .029), age (P = .015), SNB (P = .008), overjet (P = .048) and pg'-G' (P = .001)., Conclusions: Both types of disc repositioning method can effectively promote condylar regeneration and improve skeletal Class II malocclusion in adolescents with ADD. Disc repositioning by OSu obtained more new bone height than MsA., (Copyright © 2021 The American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Treatment of skeletal Class II patients with dual bite and idiopathic condylar resorption (ICR) is challenging for orthodontists because of the unstable position of the mandible as well as skeletal relapse attributed to improper seating of the mandibular condyles. This case report describes the successful treatment of an 18-year-old Mongolian man diagnosed with centric relation-maximum intercuspation discrepancy and ICR. After making a definitive diagnosis from verified centric relation using bilateral manipulation, orthodontic treatment was initiated followed by three-dimensional computer-aided design/computer-aided manufacturing prebent titanium plate-guided sagittal split ramus osteotomy and genioplasty. Postoperative 3D superimposition demonstrated that this surgical guide approach provided accurate repositioning of the condyles, which were well positioned in the fossae. Complete orthodontic and surgical treatment time was 24 months. The patient's facial appearance and occlusion improved significantly, and a stable result was obtained with a 1-year follow-up., (© 2021 by The EH Angle Education and Research Foundation, Inc.)