Short lingual osteotomy without fixation: a new strategy for mandibular osteotomy known as “physiological positioning”

We describe the strategy of physiological positioning, which we regard as a new alternative treatment to conventional orthognathic operations, and treated 18 patients with skeletal mandibular prognathism using it. The positions of SNB, FMA, and Me were measured postoperatively to assess skeletal stability, changes in the angle and perpendicular length of the upper and lower central incisors were measured to assess dental stability, and we confirmed that both skeletal and dental stability were excellent. The width to which the jaw could be opened recovered early, and we saw only one case of disorder of the temporomandibular joint. Short lingual osteotomy with physiological positioning is an effective new approach to the treatment of deformities of the mandible.     

骨性安氏Ⅲ类错下颌单颌手术后软硬组织的变化

目的:探讨正畸-正颌联合治疗成人骨性安氏Ⅲ类错,上、下颌软、硬组织的变化及其变化的相关性。方法:选取骨性安氏Ⅲ类错患者20例,手术前、后拍摄X线头颅侧位片,手术方式为双侧下颌骨矢状劈开截骨术(BSSRO)。采用SPSS13.0软件包对数据进行配对t检验。结果:治疗后SNB、B点和Pog点到Y轴的距离变小,ANB变大;软组织颏唇角、TLL点、SB点和TC点到Y轴的距离均变小,且均有显著差异(P<0.01)。SB点到Y轴的距离与B点到Y轴的距离存在线性关系,比值为1∶1,决定系数R2=0.96;TC点到Y轴的距离与Pog点到Y轴的距离比为0.84,决定系数R2=0.97。结论:单纯下颌前突患者经正畸和BSSRO治疗后,上颌软组织无明显变化,上、下唇长度不受影响。颏前点软组织与骨组织变化比值为0.84,颏唇沟点为1:1,相关强度均在0.9以上。     

Changes in condylar long axis and skeletal stability after bilateral sagittal split ramus osteotomy with poly-L-lactic acid or titanium plate fixation

This study was designed to assess skeletal stability after bilateral sagittal split ramus osteotomy (BSSO) and fixation with a poly-l-lactic acid (PLLA) plate, as compared to that after BSSO and fixation with a titanium plate, and to analyze the change in the condylar long axis after these procedures. The study group comprised 40 patients who had mandibular prognathism (20, titanium group; 20, PLLA group). The groups were randomized to show similar distributions of preoperative SNB. All patients underwent BSSO setback by the Obwegeser method. Fixation was done with bent titanium plates or bent PLLA plates, applied in a similar manner. Lateral, frontal, and submental-vertical cephalograms were analyzed preoperatively and postoperatively. The maximum mouth opening range and the incidence of temporomandibular disorders were also evaluated. There was no significant difference in the right condylar angle or width between the two groups, but the left condylar angle and width, gonial angle, and ramus inclination differed significantly between them (P<0.05). SNA, SNB, and ANB were similar in both groups. There was no significant difference between the groups in maximum mouth opening range or temporomandibular disorders. We conclude that the change in condylar angle after BSSO and fixation with a titanium plate is greater than that after BSSO and fixation with a PLLA plate, but skeletal stability related to the occlusion is similar for the two procedures.     

Progressive condylar resorption after mandibular advancement

Progressive condylar resorption is an irreversible complication and a factor in the development of late skeletal relapse after orthognathic surgery. We have evaluated cephalometric characteristics, signs and symptoms in the temporomandibular joint (TMJ), and surgical factors in six patients (one man and five women) who developed it after orthognathic surgery. The findings in preoperative cephalograms indicated that the patients had clockwise rotation of the mandible and retrognathism because of a small SNB angle, a wide mandibular plane angle, and a "minus" value for inclination of the ramus. There were erosions or deformities of the condyles, or both, on three-dimensional computed tomography (CT) taken before treatment. The mean (SD) anterior movement of the mandible at operation was 12.1 (3.9)mm and the mean relapse was -6.4 (2.5)mm. The mean change in posterior facial height was 4.5 (2.1)mm at operation and the mean relapse was -5.3 (1.8)mm. Two patients had click, or pain, or both, preoperatively. The click disappeared in one patient postoperatively, but one of the patients who had been symptom-free developed crepitus postoperatively. In the classified resorption pattern, posterior-superior bone loss was seen in three cases, anterior-superior bone loss in two, and superior bone loss in one. Progressive condylar resorption after orthognathic surgery is multifactorial, and some of the risk factors are inter-related. Patients with clockwise rotation of the mandible and retrognathism in preoperative cephalograms; erosion, or deformity of the condyle, or both, on preoperative CT; and wide mandibular advancement and counterclockwise rotation of the mandibular proximal segment at operation, seemed to be at risk. The mandible should therefore be advanced only when the condyles are stable on radiographs, and careful attention should be paid to postoperative mechanical loading on the TMJ in high-risk patients.     

Mandibular antegonial and ramus notch depths and condylar bone change

The present study sought to clarify the relationship between antegonial and ramus notch depths and condylar bone change, and analyse the effects of such change on craniofacial structure. The study sample was of 28 pre-orthodontic patients with signs and symptoms of temporomandibular joint (TMJ) disorders, who underwent helical computed tomography to diagnose their TMJ pathology. Craniofacial structures were compared between 14 subjects with bilateral condylar bone change (BBC group: two male and 12 female) and 14 subjects with no bone change (NBC group: two male and 12 female). Sella-nasion-point B (SNB) and point A-nasion-point B (ANB) angles were significantly smaller in BBC than in NBC, with ramus height and mandibular body lengths significantly shorter in BBC than in NBC. The BBC lower facial height and SN-Go-Ar angle, as well as antegonial and ramus notch depths, were significantly greater than in NBC, and the mandible was significantly more retruded in BBC than in NBC. These results showed that condylar bone change might be related not only to mandibular size (e.g. retrusion) but also to mandibular outline (including antegonial and ramus notch depth).     

Clinical and magnetic resonance findings in the temporomandibular joints of patients before and after orthognathic surgery

It is difficult to achieve the correct position of the condyle in the temporal fossa during orthognathic surgery in angle class II patients with disorders of the temporomandibular joint. This led us to examine the TMJ of 25 of our own patients before and shortly after orthognathic operations. We recorded the clinical and magnetic resonance imaging findings of the temporomandibular joint preoperatively and three months postoperatively. The patients had skeletal class II dysgnathia and had been treated with fixed orthodontic appliances for a mean of two years and three months before operation. Operation resulted in a mean reduction of maximal incisor distance of 12 mm. In five of the 25 patients, the pattern of mouth-opening changed. Nine patients had less pain than before surgery, and nine had fewer abnormal joint sounds. The magnetic resonance imaging showed displacement of the articular disc in 38 of the 50 joints preoperatively and in 28 postoperatively. Degenerative joint changes were not improved by operation. Improvement of the disc position was achieved by repositioning of the condylar-disc complex during orthognathic surgery in angle class II patients. Clinical and magnetic resonance imaging findings regarding the temporomandibular joint in class II patients correlated significantly both preoperatively and postoperatively.     

正颌外科技术治疗TMJ后OSAS(英文)

目的 评估正颌外科技术矫治14例颞颌关节强直所致OSAS的效果。方法 手术采用患侧关节成形,下颌升支、体部的“L”形半层截骨及健侧矢状截骨术,将患侧下颌升支加高固定,下颌前部整体前移。结果14例颞颌关节强直伴OSAS患者术后张口度达2.5～3.5cm,术后2年随访张口度仍维持在2.5～3.2cm之间。所有患者的AHI指数下降了20以上,12例患者的打鼾症状消失,持续血氧饱和度平均提高了18.45％（P<0.01）,达到了正常人的范围,持续血氧饱和度最低值由术前的58％提高至术后的95％以上,OSAS得以治愈。结论 颞颌关节强直伴OSAS患者通过正颌外科手术可以在关节成形的同时,解决患者下颌后缩的缺陷,解除上气道狭窄,从而缓解或纠正患者的低氧血症。     

骨性Ⅱ类错伴颞下颌关节紊乱矫正后的长期稳定性

目的:研究骨性Ⅱ类错伴颞下颌关节紊乱患者在正颌-正畸联合治疗后面型和咬合的长期稳定性。方法:选择10例在本院正颌-正畸中心治疗结束3年以上、资料齐全的骨性Ⅱ类错患者,男2例,女8例,平均年龄(22.3±2.9)岁,治疗结束平均随访期(2.63±1.36)a。治疗方案为术前正畸、正颌手术、术后正畸,手术根据面型测量数据采用双颌手术或上颌手术+颏成形,术中采用坚强内固定。比较治疗前(T0)、治疗结束(T1)和随访结束(T2)的X线头影测量数据,评价颞下颌关节(TMJ)症状量表和MRI的变化。采用SPSS16.0软件包分别对治疗前、随访结束与治疗结束的测量数据进行配对t检验。结果:覆盖平均增加0.62mm,有显著性差异,其余骨性、牙性复发和软组织改建无统计学意义;随访结束UI-NA距离、覆盖和覆变化>2mm占10%,Go-Co长度变化>2mm占20%,软组织颏前点的变化量>2mm占40%,LI-NB距离和颏唇沟的深度变化均小于2mm;所有患者关节症状无加重,MRI未见髁突吸收加重,盘髁关系未见明显改变。结论:骨性Ⅱ类错伴TMD患者通过正颌-正畸联合治疗,能获得面型美观和正常的咬合关系,远期面型结构及咬合关系未见明显复发趋势,未发现TMJ症状加重趋势。     

Physiological positioning strategy alters condylar position after mandibular ramus sagittal split osteotomies for mandibular prognathism

Objective: The aim of this study was to elucidate the physiological position of the proximal segment for postoperative jaw movement in patients with mandibular prognathism.

Methods: Twenty-two patients with mandibular prognathism were treated by orthognathic surgery using bilateral mandibular sagittal split ramus osteotomies (SSRO) with a physiological positioning strategy. The skeletal stability was assessed, and the movement of the proximal segment was evaluated by cephalography and computed tomography performed preoperatively, immediately postoperatively, and one year postoperatively.

Results: The patients were divided into two groups: the stable group (SNB relapse <1.5°) and the relapse group (SNB relapse ≥1.5°). In the stable group at one year postoperatively, the average SNB relapse was only 0.29° (7%), the condylar head had moved posteriorly by 0.75 mm, and the proximal segment had rotated counterclockwise by 1.2°.

Conclusion: This new physiological positioning strategy improves the position of the condyle compared with the preoperative position in patients with mandibular prognathism.     

Effect of bimaxillary orthognathic surgery on dysfunction of the temporomandibular joint: a retrospective study of 500 consecutive cases

We investigated the effect of bimaxillary orthognathic surgery on symptoms in the temporomandibular joint (TMJ) and predictive factors for postoperative dysfunction. A total of 500 patients with different craniofacial deformities who were having bimaxillary orthognathic surgery were assessed for overjet, overbite, maximal mouth opening, maximal protrusion, maximal lateral movement to both sides, and symptoms of TMJ dysfunction (pain on palpation, clicking, or crepitus) before operation and one year postoperatively. The panoramic radiographs taken on the same dates were assessed for reduction in the height of the ramus. Other variables were age, sex, segmentation of the maxilla, and additional genioplasty. Changes in the symptoms of dysfunction were investigated with the McNemar test. Measurements of the maximum mandibular movements taken preoperatively and postoperatively were compared using the paired t test. Multivariate logistic regression was used to assess the influence of the variables on symptoms preoperatively and postoperatively. The effect of occlusal stability (overjet and overbite) on postoperative symptoms in the TMJ was investigated with the unpaired t test. Women and class II patients had significantly more pain on palpation preoperatively, and a significant reduction in pain on palpation and clicking after operation. Predictive factors were preoperative crepitus for postoperative pain, and preoperative clicking for postoperative clicking. Patients with and without symptoms showed no significant differences in overjet and overbite postoperatively. Condylar resorption was found in 29 patients (5.8 %), and only 14 of them had symptoms in the TMJ. In patients with no preoperative symptoms or radiological abnormalities of the condyle, condylar resorption was rare (0.8 %). Orthognathic surgery has a beneficial effect on dysfunction of the TMJ as it reduces pain and clicking considerably. Patients should be informed, however, that TMJ disorders could still develop even if they had no symptoms preoperatively.     

无托槽隐形矫治骨性Ⅱ类错HE畸形的临床研究

目的研究无托槽隐形矫治器治疗青少年骨性Ⅱ类下颌后缩错HE畸形的疗效及颞下颌关节的变化,为临床方案的设计提供依据。 方法选择2018—2021年苏州口腔医院正畸科就诊的30例骨性Ⅱ类下颌后缩的青少年患者（男13例、女17例,平均11.5岁）,采用时代天使A6矫治器进行矫治,收集治疗前与治疗后的头颅侧位片及CBCT数据,进行测量,采用配对t检验进行统计学分析,P<0.05为差异有统计学意义。 结果30例青少年骨性Ⅱ类下颌后缩错HE畸形患者采用无托槽隐形矫治器治疗后,SNB增大（t = -2.382,P = 0.021）、ANB减小（t = 7.138,P<0.001）、U1-SN减小（t = 5.195,P<0.001）、面凸角减小（t = 3.443,P = 0.001）、Pog前移（t = 6.048,P<0.001）和Pos前移（t = 6.127,P<0.001）,差异均有统计学意义。SNA、FMA、Z角、UL-Gall和IMPA变化差异无统计学意义（P>0.05）。关节前间隙减小（t = 7.812,P<0.001）、关节后间隙增加（t = -5.636,P<0.001）、髁突垂直高度增加（t = -2.257,P = 0.028）,差异均有统计学意义。上颌尖牙间宽度增加,差异也有统计学意义（t = -2.938,P = 0.005）。 结论无托槽隐形矫治器治疗青少年骨性Ⅱ类下颌后缩患者,可以达到预期效果,应结合影像学资料定制个性化方案,降低治疗风险。     

Long-term stability of surgical-orthodontic correction of class III malocclusions with long-face syndrome

Objectives: In the first place, to evaluate skeletal changes of the maxilla and mandible induced by surgical-orthodontic correction of malocclusions class III with long-face syndrome and secondly, to analyze the stability of these skeletal changes in the long term (more than 6 years). Design of Study: A retrospective, unicentric and longitudinal study of 19 patients who had undergone surgical and orthodontic therapy for class III skeletal malocclusion with long-face syndrome was undertaken. A cephalometric analysis based on 8 angle measurements, and statistical analyses at three different points in time (before orthodontic treatment, after orthognathic surgery and after a retention period of at least 6 years) were carried out. Results: The changes produced following surgery show that, with the exception of the maxillary plane and the facial axis, all other variables presented changes of great statistical difference. Conclusions: Skeletal changes after orthodontic-surgical correction present maxillary advance, mandibular regression and mandibular anterorotation. The angles that represent the mandibular vertical position (ramus angle, goniac angle and mandibular plane angle) showed statistically significant relapses and no stability in contrast to the facial axis. Key words:Long term results, stability, relapse, orthognathic surgery, class III, long face.     

骨性Ⅲ类错牙合患者后退接触位的头影测量分析

目的:评价骨性Ⅲ类错牙合患者牙尖交错位与后退接触位的头影测量数据差异。方法:选择16例伴下颌有功能性移位的骨性Ⅲ类患者,(RCP位ANB<0°),测量分析治疗前ICP位与RCP位的头颅侧位片。使用SPSS17.0统计软件对数据进行统计分析。结果:在ICP位与RCP位,骨性指标SNB角、颌突角、FMA角、MP-SN角、Y轴角及N-per to Pog距离、ANB角、Wits值、APDI值、反覆盖、ODI值均有显著性统计学差异(P<0.001)。牙性指标U1-L1角(P<0.01),FMIA角(P<0.001)有统计学差异。软组织指标颏前点至零子午线距离(P<0.001),Z角(P<0.01)也有统计学差异。结论:对于存在功能性移位的骨性Ⅲ类患者,术前RCP位头颅侧位片分析对诊断错牙合严重程度和制定治疗方案有重要意义。     

Orthodontic effects on dentofacial morphology in women with bilateral TMJ disk displacement

OBJECTIVE: To determine the difference in skeletal response to orthodontic treatment between patients with bilateral disk derangement and normal disk position of the temporomandibular joint (TMJ). MATERIALS AND METHODS: Subjects consisted of 46 women whose malocclusions were treated only by orthodontics. All patients had TMJ magnetic resonance imaging (TMJ MRI) taken prior to orthodontic treatment. They were classified into three groups according to results of the TMJ MRI: bilateral normal disk position (BN), bilateral disk displacement with reduction (BDDR), and bilateral disk displacement without reduction (BDDNR). Twenty cephalometric variables were evaluated by the Kruskal-Wallis test to identify any differences in morphological changes between the three groups during orthodontic treatment. RESULTS: This study showed that patients with BDDNR had more severe sagittal and vertical skeletal discrepancies than those with BN and BDDR at the pretreatment stage with discrepancies maintained after treatment. Compared to patients with BN, BDDR patients exhibited significant changes in SNB, N perpendicular to pogonion, SN to mandibular plane angle, total anterior facial height, ramus inclination, and effective mandibular length during treatment. This means that patients with BDDR showed more backward movement and rotation of the mandible than those with BN. In contrast, patients with BDDNR who had the most severe skeletal discrepancies did not show any significant skeletal changes during orthodontic treatment compared to those with BN or BDDR. CONCLUSION: In patients with bilateral TMJ disk displacement, orthodontic treatment should be undertaken carefully to prevent backward rotation and movement of the mandible.     

Extraoral vertical ramus osteotomy combined with internal fixation for the treatment of mandibular deformities

Extraoral vertical ramus osteotomy (EVRO) is used in orthognathic surgery for the treatment of mandibular deformities. Originally, EVRO required postoperative intermaxillary fixation (IMF). EVRO has been developed using rigid fixation, omitting postoperative IMF. We examined retrospectively the long-term stability and postoperative complications for patients with mandibular deformities who underwent EVRO with internal rigid fixation. Patients who were treated with EVRO for a mandibular deformity in the period 2008–2017 at the Clinic of Oral and Maxillofacial Surgery, Mölndal, Sweden were included (N = 26). Overjet and overbite were calculated digitally and cephalometric analyses were performed preoperatively, and at three days, six months, and 18 months postoperatively. There was a general setback of the mandible, decreased gonial angle and reduced degree of skeletal opening. Excellent dental and vertical skeletal stabilities were seen up to 18 months postoperatively, although relapse was seen sagitally up to six months postoperatively. Since the overjet did not show any significant change over time, the sagittal skeletal changes have been attributed to dental compensation. There was no permanent damage to the facial nerve and 5.8% neurosensory damage to the inferior alveolar nerve was observed.     

Morphologic outcome of bimaxillary surgery–An anthropometric appraisal

Objectives: To adequately perform orthognathic surgery procedures, it is from basic interest to understand the morphologic changes caused by orthognathic surgery. Anthropometric analyses of standardized frontal view and profile photographs could help to investigate and understand such changes. Study Design: We present a pre- to postoperative evaluation of orthognathic surgery results based on anthropometric indices described by Farkas and cephalometric measurements. 30 Class III patients undergoing maxillary advancement by Le Fort I Osteotomy and mandibular setback by bilateral sagittal split osteotomy were evaluated. Preoperative as well as three and nine months postoperative lateral cephalograms as well as standardized frontal view and profile photographs were taken. On the photographs 21 anthropometric indices given by Farkas were evaluated. In cephalograms SNA and SNB angle as well as Wits appraisal were investigated. Results: The investigated anthropometric indices showed a significant increase of the vertical height of the upper lip without changing the relation of the upper vermilion to the cutaneous upper lip. The lower vermilion height increased relatively to the cutaneous lower lip without vertical changes in the lower lip. Due to maxillary advancement the upper face height increased meanwhile the lower face height decreased due to mandibular setback. SNA and SNB angle and Wits appraisal showed typical changes related to surgery. Conclusions: The investigated photo-assisted anthropometric measurements presented reproducible results related to bimaxillary surgery. Key words:Orthognathic surgery, bimaxillary surgery, anthropometry, Class III.     

不同正颌外科方案对骨性Ⅲ类伴前牙开垂直向稳定性的影响

目的 比较不同正颌外科手术方案对骨性Ⅲ类错牙合伴前牙开牙合术后垂直向稳定性的影响。方法 收集入院接受手术的骨性Ⅲ类错牙合伴前牙开牙合畸形患者122例,分别采用双侧下颌升支矢状劈开（BSSRO）（50例）、下颌升支垂直骨劈开（IVRO）（30例）、BSSRO+Le FortⅠ（22例）、IVRO+Le FortⅠ（20例）作为手术方案,并且除IVRO方案外其他所有方案病例均接受钛板颌骨内坚固内固定术。术后正畸完成时及完成后6、24个月时随访接受临床检查与头影测量分析评估垂直向复发情况,观察指标包括覆牙合、下颌平面角、颌间夹角。结果 1）BSSRO+Le FortⅠ与IVRO+ Le FortⅠ组覆牙合显著减小的比率在6、24个月都少于BSSRO与IVRO组。2）BSSRO+Le FortⅠ组与IVRO+ LeFortⅠ组下颌平面角显著增加的比率在6、24个月都少于BSSRO与IVRO组。3）6个月时BSSRO+Le FortⅠ组与IVRO+Le FortⅠ组颌间夹角显著增加的比率少于BSSRO组与IVRO组,而24个月时无统计学差异。结论 双颌外科（BSSRO+ Le FortⅠ与IVRO+Le FortⅠ）均比单颌外科（BSSRO与IVRO）能更加有效地减少垂直向复发的数量和幅度。     

Appearance on face reading (cheek line) after orthognathic surgery

The cheek line (face reading) is an aesthetic element of the facial profile. The purpose of our study was to investigate the changes in the cheek line after mandibular setback surgery. Forty patients (20 female and 20 male, mean (SD) age 22 (5) years) were diagnosed with mandibular prognathism and treated by intraoral vertical ramus osteotomy alone. Cephalograms were obtained before operation (T1), at least a year postoperatively (T2), and final surgical changes over a year (T2-T1). The cheek line and landmarks (soft and hard tissues) were compared using the paired t test. The hypothesis was that the cheek line did not change significantly after mandibular setback. At the time of the final follow-up (T2-T1), the mean (SD) horizontal setback of pogonion (Pog) was 12.3 (3.5) mm for women and 11.7 (4.3) mm for men. The ratios of soft:hard tissue, labrale inferius:incisor inferius, labiomental sulcus:point B, soft tissue Pog:Pog, and cheek point:Pog in women were 0.96, 0.98, 0.98, and 0.08, and in men 0.91, 1.01, 0.94, and 0.13, respectively. The nasolabial and cervicomental angles in women were significantly increased by 11.1° and 11.4°, respectively, and in men the nasolabial angle was significantly increased by 11.1° and the mentolabial angle reduced by 9.9°. The cheek line (T2-T1) was moved significantly forwards. The hypothesis was therefore rejected. In conclusion, the cheek line was advanced significantly after isolated mandibular setback.     

The skeletal stability after maxillo-mandibular osteotomy with a “physiological positioning strategy”

The aim of this study was to estimate skeletal and dental stability after maxillomandibular osteotomy with physiological positioning. Ten patients (7 men and 3 women) with skeletal mandibular prognathism were treated by conventional Le Fort I osteotomy for the maxilla and unfixed short lingual osteotomy for the mandible together with physiological positioning. We used cephalometric analysis to evaluate the skeletal and dental stability preoperatively, immediately after maxillomandibular osteotomy, and more than 1 year later. The immediately postoperative measurements for the SNA and the SN-palatal planes were 0.15^o (p = 0.67) and 1.0 ^o (p = 0.17), respectively. The positions of the anterior nasal spine, posterior nasal spine, and A point showed minimal changes 1 year postoperatively. The postoperative difference for SNB was 0.76 ^o (p = 0.04). Dental stability was apparent postoperatively. We conclude that reliable stability of both the maxilla and the mandible was achieved after maxillomandibular osteotomy with physiological positioning in patients with mandibular prognathism.     

Risk factors related to aggressive condylar resorption after orthognathic surgery for females: retrospective study

Objective: The aim of the present study was to identify the risk factors for aggressive condylar resorption (ACR) after orthognathic surgery.

Methods: A total of 25 female patients with osteoarthritis (OA) scheduled for orthognathic surgery were divided into two groups: those who exhibited ACR (ACR (+), n = 8) and those who did not exhibit ACR (ACR (?), n = 17) after surgery. Clinical indices were used to determine the extent of mandibular advancement, the presence of temporomandibular disorder (TMD), and relevant medical treatment histories (including the use of oral contraceptive (OC) medication. TMJ dysfunction was clinically evaluated in terms of pain, the presence of sounds (clicks or crepitus), and disc displacement, joint effusion (JE), and synovial hyperplasia (SH); these were further investigated with the aid of magnetic resonance imaging (MRI). The cephalographic findings were compared with the normal profiles of Japanese subjects.

Results: The mean (with SD) extent of mandibular advancement was 11.4 mm (2.4) in ACR (+) and 4.1 mm (1.8) in ACR (?). The TMD medical history of ACR (+) was much more extensive than that of ACR (?); all patients in ACR (+) had a history of OC use. More patients in ACR (+) than in ACR (?) had TMJ dysfunction and disc displacement, JE, and SH on MRI. Preoperative cephalograms showed that ACR (+) patients exhibited counterclockwise rotation of the mandible and retrognathism that was attributable to a small sella–nasion–B (SNB) angle, a wide mandibular plane angle, and a negative inclination of the ramus.

Conclusions: The present findings suggest that the development of ACR after orthognathic surgery to treat mandibular retrognathism may be associated with coexisting TMJ pathologic abnormality.