The need for secondary orthognathic surgery after high condylectomy in patients with active unilateral condylar hyperplasia

The need for secondary orthognathic surgery (OS) after a high condylectomy (HC) in patients with active unilateral condylar hyperplasia was assessed in 25 patients, reviewing patient characteristics and treatment planning. At 6–12 months after HC, 13 patients (52%) required secondary OS. The amount of mandibular dental midline shift before the HC (P = 0.037), and a dental crossbite that was present before the HC (P = 0.017) were significantly associated with the need for secondary OS. Overall, the mandibular dental midline coincided with the facial midline in eight patients (32%) at 2 weeks after HC. In 16% of the patients, no additional OS was needed despite this being the initial treatment plan. Additionally, the initially planned type of secondary OS was modified in six other patients. Early HC in skeletally immature patients provided very good results, both aesthetic and functional, with only two of them needing supplementary OS at 6–12 months after HC. The HC remains a valuable treatment in patients with active unilateral condylar hyperplasia, as it can eliminate the need for secondary OS and is very well tolerated by most patients.     

�������ƽǶȿ�����ǰ����

??In recent years??digital techniques have been developing rapidly in orthognathic surgery and orthodontics fields. With the development of digital techniques??the use of digital points design??preoperative simulation??optical scanning??digital splint??and digital osteotomy guide have greatly increased in many fields. However??many orthodontic doctors only pay attention to teeth alignment without incorporating the concept of three dimensional contour and are not able to keep foresee results of subsequent surgical procedures??which increases the difficulty of orthognathic surgery??resulting in unsatisfactory esthetics of facial contour??and unsatisfactory physiological functional occlusion for patients. This paper explains how to guide preoperative orthodontics from an orthognathic surgery view??and elicits that orthodontic doctors should plan with visions of great facial esthetics and physiological functional occlusion in mind??to avoid solely considering teeth alignment.     

Assessment of condylar changes after orthognathic surgery using computed tomography regional superimposition

This study aimed to investigate the effects of bimaxillary advancement orthognathic surgery on the condylar remodeling of the temporomandibular joint (TMJ) using voxel-based regional superimposition of cone-beam computed tomography (CBCT).In this retrospective study, the sample comprised 56 condyles from 28 healthy patients (aged from 16 to 50 years) with mandibular retrognathism treated with bimaxillary advancement. CBCT scans were taken preoperatively and at 14.3 ± 4.2 months postoperatively. The scans at the two time points were superimposed using regional voxel-based registration to assess condylar changes in the follow-up period. The linear alterations were measured in six different areas of each condyle to determine the pattern of condylar remodeling.Although no significant correlation was observed between changes in condylar surfaces, bone resorption occurred predominantly in the posterior and superior regions, while bone formation was predominantly on the anterior surface. Medial and lateral surfaces presented fewer bone changes. The overall bone changes were smaller than 1 mm bilaterally in 21 patients (75%) and, considering each condyle individually, were smaller than 1 mm in 48 condyles (85.7%).The results suggested that mild condylar remodeling in healthy patients is a common finding after orthognathic surgery. Future studies may clarify the mechanisms involved in the remodeling and help to understand the reasons for the remodeling pattern.     

Validation of a novel semi-automated method for three-dimensional surface rendering of condyles using cone beam computed tomography data

Morphological changes of the condyles are often observed following orthognathic surgery. In addition to clinical assessment, radiographic evaluation of the condyles is required to distinguish the physiological condylar remodelling from pathological condylar resorption. The low contrast resolution and distortion of greyscale values in cone beam computed tomography (CBCT) scans have impeded an accurate three-dimensional (3D) rendering of the condyles. The current study proposes a novel semi-automated method for 3D rendering of condyles using CBCT datasets, and provides a clinical validation of this method. Ten patients were scanned using a standard CBCT scanning protocol. After defining the volume of interest, a greyscale cut-off value was selected to allow an automatic reconstruction of the condylar outline. The condylar contour was further enhanced manually by two independent observers to correct for the under- and over-contoured voxels. Volumetric measurements and surface distance maps of the condyles were computed. The mean within-observer and between-observer differences in condylar volume were 8.62 mm³ and 6.13 mm³, respectively. The mean discrepancy between intra- and inter-observer distance maps of the condylar surface was 0.22 mm and 0.13 mm, respectively. This novel method provides a reproducible tool for the 3D rendering of condyles, allowing longitudinal follow-up and quantitative analysis of condylar changes following orthognathic surgery.     

Dentoskeletal parameters related to visual perception of facial asymmetry in patients with skeletal class III malocclusion after orthognathic surgery

The purpose of the study is to explore the critical parameters determining the visual perception of postoperative facial symmetry. This study retrospectively included 24 patients with skeletal class III malocclusion and double-jaw orthognathic surgery (OgS). The patients were classified according to the outcome of subjective visual perception scores (SVPS) based on the postoperative frontal images by 10 orthodontists: symmetrical surgical outcome (S group, n = 12) and facial asymmetry after surgery (A group, n = 12). The 3D dentofacial measurements from cone beam computed tomography, were compared between the S and A groups. The relationship of all variables in all patients with the SVPS was explored by Spearman correlation coefficient. Significant differences were observed in the midline parameters in the mandible, the B point, gnathion and menton, and the mandibular border axis as well as in the discrepancy of the chin morphology between the two groups (P < 0.05). The findings demonstrated that the midline parameter deviation, shape of the mandibular border, and the contour of menton morphology play the major role in the visual perceptions of postoperative asymmetry.     

Use of conservative condylectomy for treatment of osteochondroma of the mandibular condyle.

PURPOSE: The aim of the present study was to present a conservative condylectomy technique (condylectomy performed below the condylar head but high in the condylar neck) and articular disc repositioning as the surgical treatment approach for management of osteochondroma of the head of the mandibular condyle. PATIENTS AND METHODS: Six patients (4 females and 2 males) with an average age of 22.3 years (range, 13 to 32 years) and with an osteochondroma of the mandibular condyle were treated with conservative condylectomy. The remaining condylar neck stump was recontoured, and the articular disc was repositioned and stabilized over the "new" condyle. Any indicated orthognathic surgical procedures were then performed to optimize occlusion, function, and aesthetics. Clinical and radiographic evaluation was performed before surgery (T1), immediately after surgery (T2), and at the longest follow-up (T3). RESULTS: Average follow-up for the patients was 51 months (range, 22 to 108 months). No recurrence of the tumor was encountered in any of the cases. Subjective and objective evaluations of postsurgical temporomandibular joint function and range of mandibular motion were normal. Associated maxillary and/or mandibular orthognathic procedures were found to be stable in the long term. CONCLUSION: Conservative condylectomy with recontouring of the residual condylar neck to function as a condyle and repositioning of the articular disc is a viable option for treatment of osteochondromas of the mandibular condyle. The use of this method of treatment permits effective removal of the tumor and eliminates the need for autogenous grafts or total joint prostheses for temporomandibular joint reconstruction.     

A new approach in three dimensions to define pre- and intraoperative condyle–fossa relationships in orthognathic surgery – is there an effect of general anaesthesia on condylar position?

Incorrect registration of the condylar position in orthognathic surgery is supposed to cause postoperative relapse, condylar resorption and temporomandibular disorders. The aim of this prospective study was to evaluate the influence of general anaesthesia on centric relation (CR). Therefore, CR registered preoperatively in the awake patient and CR registered intraoperatively under general anaesthesia were recorded in 30 patients (14 men, 16 women) undergoing orthognathic surgery (skeletal class I: n = 3, II: n = 13, III: n = 14; symmetric: n = 20; asymmetric: n = 10). CR records were digitized and, through superimposition on the preoperative cone beam computed tomography of the patient's skull, the superior, anterior and posterior joint space and the volumetric congruence of 120 condyles were analysed. The linear measurements of joint spaces did not demonstrate any clinically relevant discrepancy between the CR measured in the awake and anaesthetized patient. In contrast, volumetric analysis revealed statistically significant differences between both states, with an intraoperative condylar sag predominantly in the posterior–inferior direction. The patient’s skeletal class or symmetry had no significant influence on the intraoperative condylar displacement. Thus, the risk of fixing the condyle in an unphysiological position supports the idea of using intraoperative condylar positioning devices to achieve predictable and stable outcomes.     

Is there a difference in judgement of facial appearance depending on ethnic background? Photographic evaluation of facial appearance in orthognathic surgery

Is there a variation in facial ideals depending on ethnic background that affects judgements of outcome in orthognathic surgery? How does the evaluation correlate with patient-reported outcome measures? Two evaluation panels, Singaporean and Swedish, judged photographs of patients undergoing orthognathic surgery taken before and after operation. Improvement in facial aesthetics was calculated between the two ratings. The result was compared between the panels and correlated with health-related quality of life (QoL) measures. Thirty male and 27 female patients aged between 18 and 28 years (mean 21) were included, and 52 subjects were eligible for comparison of health-related QoL. The photographic evaluation showed that both panels judged there to be significant improvement in facial aesthetics after treatment (p < 0.001). The Singaporean panel rated the overall facial appearance higher than the Swedish panel when evaluating photographs both before (p = 0.025) and after (p = 0.032) operation. Improvement of the overall facial appearance showed no significant difference between the panels (p > 0.30). No correlation between health-related QoL and improvement of facial appearance was found by either panel. Subjective evaluation of facial aesthetics in orthognathic surgery is unaffected by the observer’s ethnic origin. Independently of their ethnicity, the evaluation juries found that facial aesthetics improved after orthognathic surgery. Improvement reported by the juries corresponded to that reported by patients.     

Applying artificial intelligence to assess the impact of orthognathic treatment on facial attractiveness and estimated age

This observational study aimed to use artificial intelligence to describe the impact of orthognathic treatment on facial attractiveness and age appearance. Pre- and post-treatment photographs (n = 2164) of 146 consecutive orthognathic patients were collected for this longitudinal retrospective single-centre study. Every image was annotated with patient-related data (age; sex; malocclusion; performed surgery). For every image, facial attractiveness (score: 0–100) and apparent age were established with dedicated convolutional neural networks trained on >0.5 million images for age estimation and with >17 million ratings for attractiveness. Results for pre- and post-treatment photographs were averaged for every patient separately, and apparent age compared to real age (appearance). Changes in appearance and facial attractiveness were statistically examined. Analyses were performed on the entire sample and subgroups (sex; malocclusion; performed surgery). According to the algorithms, most patients’ appearance improved with treatment (66.4%), resulting in younger appearance of nearly 1 year [mean change: ?0.93 years (95% confidence interval (CI): ?1.50; ?0.36); p = 0.002), especially after profile-altering surgery. Orthognathic treatment had similarly a beneficial effect on attractiveness in 74.7% [mean difference: 1.22 (95% CI: 0.81; 1.63); p < 0.001], especially after lower jaw surgery. This investigation illustrates that artificial intelligence might be considered to score facial attractiveness and apparent age in orthognathic patients.     

髁突骨软骨瘤的正颌外科治疗

目的 探讨正颌外科技术在髁突骨软骨瘤治疗中的应用效果。方法 利用正颌外科方法治疗12例髁突骨软骨瘤患者,进行Le Fort Ⅰ型截骨术修正上颌骨,采用口内入路患侧升支垂直截骨术切除病变髁突,健侧行升支矢状切开术及颏成形术矫正咬合及偏斜。结果 12例患者术后面型均得到矫正,随访2年以上无1例复发。结论 利用正颌外科技术治疗髁突骨软骨瘤,可以避免常规口外切口面部留有的瘢痕,并在切除肿瘤的同时矫正了面型。     

Condylar positions before and after bilateral mandibular distraction osteogenesis in children with Pierre Robin sequence

This study aimed to analyze the changes in mandibular morphology after bilateral mandibular distraction osteogenesis (BMDO) in children with Pierre Robin sequence. The positions of the condyles were analyzed in reconstructed three-dimensional craniomaxillofacial images obtained for 18 children before and 8–12 weeks after BMDO. Differences between pre- and postoperative parameters were assessed using paired t-tests. After surgery, a significant decrease in superior joint space was detected (P < 0.05), but no change in anterior joint space or posterior joint space was observed. The ratio of the distance between gonia and distance between condylion points (GoL–GoR/CoL–CoR) (P < 0.001) and the distances between the condyle and midsagittal plane (P < 0.001) increased after surgery, while the condylar horizontal angle decreased (P < 0.05). No change in condylar vertical angle was noted. After BMDO, the condyle displayed an outward and upward shift, as well as outward rotation along the proximal segment. The mandible body exhibited forward movement with a more significant opening range. These changes were consistent with the extent of the newly formed bone tissue and the improvement in coordination and appearance of the children’s facial structures. The long-term effects of changes in condylar position on the development of the maxillofacial structures needs to be studied further.     

Evaluation of effects of activator treatment on mandibular growth by analyzing components of condylar growth and mandibular rotation

PurposeThe objective of this study is to clarify the effects of activator treatment on mandibular growth in relation to condylar growth and total rotation of the mandible, and to investigate the relationships between the treatment responses and pretreatment facial morphology.Materials and methodsThirty Japanese girls with Class II division 1 malocclusion treated with activator were examined. Mean age at the start of treatment was 9.6 ± 1.6 years. Mean treatment duration was 19 ± 4 months. Lateral cephalograms obtained before and after treatment were used to analyze skeletal changes during treatment. Regional superimposition analysis was performed to evaluate activator effects by decomposing the mandibular growth into condylar growth and mandibular total rotation.ResultsThe changes in intermaxillary relationships were significantly correlated with vertical condylar growth and mandibular total rotation (P < 0.05 and P < 0.01). The changes in the forward displacement of the mandible were significantly correlated with sagittal condylar growth and mandibular total rotation (P < 0.05 and P < 0.01). Vertical condylar growth and mandibular total rotation were significantly correlated with pretreatment mandibular morphology (P < 0.05 and P < 0.01).ConclusionBoth the sagittal condylar growth and counterclockwise mandibular total rotation attributed to activator treatment contribute to forward displacement of the mandible. The activator effects are expected greater in patients with flat mandibular plane, small gonial angle, backwardly inclined mandibular ramus and long posterior facial height.     

Osteochondroma of the mandibular condyle: surgical excision followed by occlusal stabilization

Osteochondroma of the mandibular condyle in adults can be treated by surgical excision, condylectomy followed by costochondral graft or orthognathic surgery. Such complex treatment plan may not be appropriate for patients with old age, affected with chronic osteochondroma of the condyle. In this clinical report, we present a patient with osteochondroma of the condyle treated by surgical excision. The patient's postoperative occlusion was a contraindication for orthognathic surgery because of the severe abrasion of the teeth and the chronic compensation of the dentition to the deviated mandible. Surgical excision of the lesion was carried out under general anesthesia, and the remaining condylar head was salvaged as much as possible. No graft materials or posthodontic condyle reconstruction was carried out. Because there was no occlusal stop to secure the mandible in a centric relation position of the condyle, a stabilization splint was delivered to position the condyle in a relatively stable position. The stability of the condyle position was evaluated by follow-up cone beam computed tomographic scans of the pathologic and the contralateral condyle, along with clinical factors such as occlusal contact points and mandible movements assayed by ARCUSdigma (KaVo). After significant condylar position was achieved, full prosthodontic reconstruction was performed to both the patient's and the dentist's satisfaction.     

功能板影响错伴特发性髁突吸收正颌术后稳定性的初步研究

目的:探讨特发性髁突吸收（idiopathic condylar resorption, ICR）患者在关节功能板治疗结合正颌-正畸联合治疗后下颌骨及髁突位置的改变,为后期研究提供依据。方法:回顾分析2008—2012年收治的13例特发性髁突吸收患者的临床数据,所有患者均在正颌手术前接受关节功能板治疗7.5±1.5个月。对患者正颌术前(T0)、正颌术后即刻(T1)、正颌术后至少12个月(T2)的咬合、头颅侧位片、MRI检查结果进行测量,采用SPSS 22.0软件包对数据进行统计学分析,评价正颌术后髁突和下颌骨的位置变化。结果:正颌手术(T1)纠正了所有患者的骨性Ⅱ类错畸形,建立了正常的咬合关系、前伸运动及侧方斜导运动。正颌手术平均下颌骨前移量(Y Axis-B, T1-T0)为（5.05±3.54）mm。与T1相比,T2时颞下颌关节间隙参数无显著改变。下颌骨位置参数中, 仅Y轴到B点的距离（Y轴-B）在T2与T1间存在统计学差异,其改变量平均值为（-1.64±2.48）mm,其余参数均无显著差异。13例患者中,11例患者Y轴-B 改变值<2 mm（84.6%）,仅 2例患者出现>2 mm的后退（15.4%）。结论:关节功能板治疗可增加ICR患者正颌手术的稳定性,可能是关节功能板保守治疗能够稳定ICR患者髁突在关节窝内的位置。     

Condylectomy as the treatment for active unilateral condylar hyperplasia of the mandible and severe facial asymmetry: retrospective review over 18 years

Unilateral condylar hyperplasia (UCH) of the mandible is a disorder affecting the condyle size, resulting in facial asymmetry. This study was a retrospective review of 27 patients with UCH who underwent condylectomy between 2000 and 2017 at Yonsei University Dental Hospital. Patient demographic characteristics were summarized. UCH was divided into three subtypes: hemimandibular elongation (HE, n = 15), hemimandibular hyperplasia (HH, n = 4), and osteochondroma (OC, n = 8). Of the 27 patients, only one with the HE type and five (18.5%) with the OC type complained of joint pain. Bone scans of all patients showed higher uptake on the UCH side. Lip and maxillary canting was prominent in the HH and HE types. Five patients (18.5%) underwent condylectomy alone, 13 (48.1%) underwent condylectomy with orthodontic treatment, and nine (33.3%) underwent adjunctive jaw surgery with orthodontic treatment. The treatment modalities varied according to the subtype. In all OC type patients, removal of the hyperplastic condyle treated the facial asymmetry. Additional post-surgical orthodontic treatment was necessary in only three cases (37.5%). All HH type patients required mandibuloplasty. All patients showed a stable occlusal outcome without relapse and an improvement in subjective symptoms, despite a decrease in mouth opening of 2.2 mm. These findings might be useful in treatment planning for UCH patients.     

One-year assessment of surgical outcomes in Class III patients using cone beam computed tomography

The purpose of this study was to apply a novel method to evaluate surgical outcomes at 1 year after orthognathic surgery for Class III patients undergoing two different surgical protocols. Fifty patients divided equally into two groups (maxillary advancement only and combined with mandibular setback) had cone beam computed tomography (CBCT) scans taken pre-surgery, at splint removal, and at 1-year post-surgery. An automatic cranial base superimposition method was used to register, and shape correspondence was applied to assess, the overall changes between pre-surgery and splint removal (surgical changes) and between splint removal and 1-year post-surgery at the end of orthodontic treatment (post-surgical adaptations). Post-surgical maxillary adaptations were exactly the same for both groups, with 52% of the patients having changes >2 mm. Approximately half of the post-surgical changes in the maxilla for both groups were vertical. The two-jaw group showed significantly greater surgical and post-surgical changes in the ramus, chin, and most of the condylar surfaces (P < 0.05). Post-surgical adaptation on the anterior part of the chin was also more significant in the two-jaw group (P < 0.05). Regardless of the type of surgery, marked post-surgical adaptations were observed in the regions evaluated, which explain the adequate maxillary–mandibular relationship at 1-year post-surgery on average, with individual variability.     

Evaluation of treatment with unilateral mandibular sagittal split ramus osteotomy and maxillary osteotomy in patients with condylar osteochondroma and mandibular asymmetry: A retrospective case series

The aim of the study was to describe an approach where condylar resection with condylar neck preservation was combined with Le Fort I osteotomy and unilateral mandibular sagittal split ramus osteotomy (SSRO).Patients with a unilateral condylar osteochondroma combined with dentofacial deformity and facial asymmetry who underwent surgery between January 2020 and December 2020 were enrolled. The operation included condylar resection, Le Fort I osteotomy and contralateral mandibular sagittal split ramus osteotomy (SSRO). Simplant Pro 11.04 software was used to reconstruct and measure the preoperative and postoperative craniomaxillofacial CT images. The deviation and rotation of the mandible, change in the occlusal plane, position of the “new condyle” and facial symmetry were compared and evaluated during follow-up. Three patients were included in the present study. The patients were followed up for 9.6 months on average (range, 8–12). Immediate postoperative CT images showed that the mandible deviation and rotation and occlusion plane canting decreased significantly postoperatively; facial symmetry was improved but still compromised. During the follow-up, the mandible gradually rotated to the affected side, the position of the “new condyle” moved further inside toward the fossa, and both the mandible rotation and facial symmetry were more significantly improved.Within the limitations of the study it seems that for some patients a combination of condylectomy with condylar neck preservation and unilateral mandibular SSRO can be effective in achieving facial symmetry.     

Outcomes of treatment for intracapsular fractures of the mandibular condyle: recommendation for a new classification

We know of no universally accepted classification for intracapsular condylar fractures. We propose here a new classification based on the concept of a “disc-condyle” unit, and validate the classification based on outcomes of treatment. From 1 January 2010 - 31 December 2014, 55 patients with unilateral intracapsular condylar fractures were classified into three types: type A has no reduction in mandibular height or displacement of the disc (n = 7); type B has displacement of the disc with no reduction in mandibular height (n = 17); and type C has reduced mandibular height with or without displacement of the disc (n = 31). We treated types B and C by open reduction and fixation, while type A fractures were managed non-surgically. At six month follow-up, we found no significant differences in the vertical height of the ramus, mandibular deviation, protrusion, or lateral protrusion between the fractured and healthy sides. All patients had normal occlusion postoperatively and only one patient (type C) reported pain. Magnetic resonance imaging and computed tomography showed good osseous healing and disc-condylar relations in all cases. Our results show that this new classification of intracapsular condylar fractures is a safe and easy way to obtain satisfactory outcomes of treatment. However, it needs further independent validation.     

Comparative study of skeletal stability between bicortical resorbable and titanium screw fixation after sagittal split ramus osteotomy for mandibular prognathism

IntroductionResorbable screw fixation for orthognathic surgery is widely used in oral and maxillofacial surgery and has several advantages. However, surgeons are concerned about using resorbable screws in orthognathic surgery because of possible postoperative complications such as relapse, screw fracture, and infection. The purpose of this study was to evaluate the skeletal stability of bicortical resorbable screw fixation after sagittal split ramus osteotomies for mandibular prognathism.Materials and methodsThis study included 25 patients who underwent mandibular setback surgery fixed with resorbable screws after sagittal split osteotomy at the Department of Oral and Maxillofacial Surgery at Seoul National University Dental Hospital. Five resorbable screws (Inion CPS^®, Inion Ltd., Finland) were applied bicortically at each osteotomy site via a transbuccal approach. No rigid intermaxillary fixation was applied on the first postoperative day. Passive mouth opening exercises were allowed, using two light, rubber elastics for guidance. The control group was 25 patients fixed with four titanium screws. The follow-up period was 12–22 months (mean 17.8 months). Postoperative skeletal changes on lateral cephalometric radiographs were analyzed and compared between the two groups preoperatively, immediately postoperatively, and 6 months postoperatively.ResultsThe average setback was 6.9 mm and no major intraoperative complications occurred. One patient experienced infection immediately after surgery that was controlled uneventfully. The data did not demonstrate any significant difference in postoperative skeletal stability between the two groups. Differences between the immediate postoperative state and 6 months after surgery were not significant. In earlier cases, especially for patients with severe mandibular prognathism, immediate postoperative elastic traction was needed for stable occlusal guidance.ConclusionsThe results of this study indicate that bicortical resorbable screws offer a clinically stable outcome for the fixation of mandibular sagittal split osteotomies in mandibular prognathism. However the resorbable screws showed less stable results vertically than the titanium screws.     

Changes in condylar and joint disc positions after bilateral sagittal split ramus osteotomy for correction of mandibular prognathism

The effect of combined orthodontic and orthognathic treatment was studied retrospectively in 24 patients with skeletal class III malocclusions with mandibular hyperplasia, particularly the effect on temporomandibular joint (TMJ) disc position. The patients underwent preoperative orthodontic treatment, orthognathic surgery, and postoperative orthodontic treatment. The patients were studied clinically, radiographically with lateral cephalometric radiograph and MRI to locate the position of the TMJ disc in relation to the glenoid fossa. One patient had less pain after treatment, one lost abnormal joint clicking sounds after treatment. There were no TMJ symptoms in 20 of the 24 preoperatively and postoperatively. 48 sagittal MRI images showed that the disc length before treatment was 3.040–12.928 (mean 8.289 ± 2.028) and after treatment was 3.699–11.589 (mean 8.097 ± 1.966); results were not significant (p > 0.05). Maximum disc displacement before treatment was 6.090 (mean 1.383), after treatment it was 11.931 (mean 2.193); results were not significant (p > 0.05). The results suggest that combined orthodontic and orthognathic treatment (including bilateral SSRO and rigid internal fixation) can be used safely to correct skeletal class III malocclusion with mandibular hyperplasia without causing additional TMJ symptoms.