正畸正颌联合治疗骨性Ⅲ类患者髁突位置变化的长期观察研究

目的 测量骨性Ⅲ类患者经过正畸正颌联合治疗后各个阶段关节间隙的变化,分析髁突在关节窝中的位置,探讨正畸正颌联合治疗后髁突位置的长期稳定性.方法 选择15例经过正畸正颌联合治疗后的骨性Ⅲ类患者,收集患者术前（T1）、术后1周（T2）、术后正畸结束时（T3）、3～12年随访复诊时（T4）的双侧关节许勒位片,采用国内外常用的两种方法对各个阶段关节间隙进行测量,计算各个阶段关节间隙ln（p/A）值,通过配对样本t检验,分析T2-T1、T3-T1、T4-T1的变化.结果 15例患者经过正畸正颌联合治疗后双侧关节的前、后、上间隙均发生明显变化;采用国内常用的张震康法测量左侧关节的前、后、上间隙术后一周分别为（2.22±0.30） mm、（5.14±1.49） mm、（5.00±0.63） mm,术前分别为（1.87±0.45） mm、（2.96±0.32） mm、（2.83±0.67） mm,P值分别为0.025、0.005、0.003,有统计学意义;右侧关节的后、上间隙术后1周分别为（6.02±0.19） mm、（6.05±1.27） mm,术前分别为（2.88±0.98） mm、（3.32±0.18） mm,P值均＜0.001,有统计学意义;T3、T4分别与T1比较,关节前、上、后间隙的差异均无统计学意义.采用国外常用的Kamelchuk法测量结论一致.结论 正颌手术后1周关节间隙有一定程度增大,尤其是关节后间隙和上间隙,而到了治疗结束时,关节间隙恢复至术前状态并会维持长期（3～12年）稳定,在各个阶段髁突位置均表现为中性位.     

外科—正畸联合矫治骨性下颌前突

为探讨正畸治疗处外科手术在矫治骨性下颌前突中的作用相互关系，作者对１５９例患者的治疗计划及矫治结果进行分析，总结出正畸治疗在外科－正畸联合矫治下颌前突中的作用。     

外科－正畸联合矫治骨性下颌前突

为探讨正畸治疗和外科手术在矫治骨性下颌前突中的作用及相互关系，作者对１５９例患者的治疗计划及矫治结果进行分析，总结出正畸治疗在外科－正畸联合矫治下颌前突中的作用。主要包括：去除前牙代偿、排齐牙列、调整牙弓的相容性、调整关系、保持的稳定性，并强调去代偿是术前正畸治疗的主要目的。术前正畸治疗与后退下颌骨或（和）骨段的外科术式的选择之间有着密切关系，下颌体部截骨和升支部垂直截骨构成了经术前正畸准备后矫治下颌骨前突的主要外科术式。     

成人骨性Ⅰ类错双颌前突的正颌—正畸联合治疗

目的采用正畸—正颌手术联合治疗成人骨性Ⅰ类错(牙合)前突患者,以期取得面貌及咬合关系的改善。方法选择10例成人骨性Ⅰ类错(牙合)双颌前突患者,通过术前正畸—正颌手术—术后正畸的联合治疗,对治疗前后的头颅侧位片进行测量分析。结果建立良好的上下颌咬合关系,面型改善；SNA、SNB显著减小。结论成人Ⅰ类骨性错(牙合)畸形患者采用正颌—正畸联合治疗,能快速地、有效地获得满意的咬(牙合)功能及侧貌效果。     

正颌外科中的髁状突固位装置

正颌外科手术可能会引起髁状突移位,从而引起术后骨骼/咬合不稳定和颞颌关节病变。为解决这一问题,许多作者在正颌外科术中设计了种种髁状突固位装置,以保证髁状突能固定于术前正中关系位。     

骨下颌前突术前正畸去代偿治疗效果的研究

目的：探讨术前去代偿性在骨性下颌前突畸形矫治中的应用。方法：18例已接受过正畸－外科联合治疗的骨性下颌前突患者，以X线头影测量方法对其术前正畸去代偿的前后结果进行研究。结果：在骨性下颌前突患者，普遍存在牙齿的代偿现象，牙代偿不仅存在于下颌，而且存在于上颌；并同时存在于前牙和后牙；去代偿后，上、下牙齿相对于基骨的位置得到了明显的改善。结论：术前去代偿为外科手术后退下颌骨至正常位置打下良好的基础。术前正畸法代偿，是治疗骨性下颌前突畸形的重要步骤。也是获得高质量手术结果的可靠保证。     

正颌外科和正畸联合治疗下颌前突畸形

目的：总结分析下颌升支部和下颌体部截骨矫正下颌前突畸形的手术和正畸治疗特点。方法：根据手术设计需要，将125例下颌前突畸形患者分下颌升支部截骨和下颌骨体部截骨两组，并分别进行内容不同的术前术后的正畸治疗。结果：两种术式均获得满意的治疗效果。下颌升支部截骨和下颌骨体部截骨满意率分别为88.3%和83.3%。2例下颌体部截骨术后2年复发，行二次手术予以矫正。结论；必需根据不同的术工，设计不同的术前术后正畸方案。一方面保证下颌前突畸形患者获得满意的美学改善，同时在新建的颌位上应具有良好的he关系。     

骨性下颌前突患者正畸与外科联合治疗前后颌面软硬组织变化研究

目的 探讨骨性下颌前突畸形联合治疗后其颌面软硬组织的变化情况。方法 对20例骨性下颌前突患者行正畸与外科联合治疗后,通过X线头影测量方法分析治疗前后软硬组织变化情况。结果 仅下齿槽座点与下唇沟点在治疗前后的变化量在垂直方向的分量之间无相关性,其余各组软硬组织对应点的变化量之间均有相关性,其中在前后方向上,软硬组织对应点（除上齿槽座点与上唇沟之间）之间均呈高度相关性。结论 骨性下颌前突畸形经联合治疗后,其颌面部软硬组织对应点的变化量是基本一致的,这种一致性在前后方向上比垂直方面上更为理想。     

骨性下颌前突术前正畸去代偿治疗效果的研究

目的　探讨术前去代偿在骨性下颌前突畸形矫治中的作用。方法　 18例已接受过正畸—外科联合治疗的骨性下颌前突患者 ,以X线头影测量方法对其术前正畸去代偿的前后结果进行研究。结果　在骨性下颌前突患者 ,普遍存在牙齿的代偿现象 ,牙代偿不仅存在于下颌 ,而且存在于上颌 ;并同时存在于前牙和后牙 ;去代偿后 ,上、下牙齿相对于基骨的位置得到了明显的改善。结论　术前去代偿为外科手术后退下颌骨至正常位置打下良好的基础。术前正畸去代偿 ,是治疗骨性下颌前突畸形的重要步骤。也是获得高质量手术结果的可靠保证     

正颌外科中的髁状突固位装置

正颌外科手术可能会引起髁状突移位，从而引起术后骨骼／咬合不稳定和颞颌关节病变。为解决这一问题，许多作者在正颌外科术中设计了种种髁状突固位装置，以保证髁状突能固定于术前正中关系位。     

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.     

下颌前突患者下颌支矢状劈开截骨术后髁突运动轨迹的改变

目的:研究双侧下颌支矢状劈开截骨术对下颌前突患者髁突运动轨迹的影响。方法:采用ARCUSdigma下颌三维运动轨迹描记仪,以髁突运动中心为参考点,研究30例正常受试者、14例下颌前突患者手术前后开口、前伸和左右侧向髁突运动的轨迹。用SPSSV11.0统计软件包进行配对t检验和成组t检验。结果:下颌前突患者术前、术后、正常组左侧髁突的运动轨迹与右侧基本相同,左侧髁突与右侧的开口、前伸和侧方运动范围无显著性差异(P>0.05)。术前组与正常组髁突运动轨迹差别较大,术前开口、前伸和侧方运动范围均小于正常组(P<0.05);术后与正常组髁突运动轨迹接近,术后开口、前伸和侧方运动范围与正常组无统计学差异;术前与术后组髁突运动轨迹差别较大,术前开口、前伸和侧方运动范围均显著小于术后组(P<0.05)。结论:下颌前突患者手术后,随着术后正畸治疗及咬合自我调整,建立了正常的咬合引导关系,使下颌功能运动趋向正常。     

髁突矢状骨折的特征和治疗

目的探讨髁突矢状骨折(SFMC)的临床特征和治疗。方法对21例SFMC患者(23侧)的外伤情况、治疗方式、影像学资料进行了研究,并进行了随访。结果SFMC的主要的症状和体征是颞下颌关节区的疼痛(21/21)、张口受限(18/21)、前牙开(13/21)、咬合偏斜(12/21)。SFMC在2D-CT和3D-CT上具有明显的特征,对SFMC的诊断有重要的意义。所有患者治疗后下颌均能进行良好的前伸运动、侧向运动及开颌运动。结论SFMC应根据骨折片的移位情况和患者的年龄选择治疗方式,通过有效的治疗,髁突可以获得良好的功能。     

Surgical morbidities of sagittal split ramus osteotomy versus intraoral vertical ramus osteotomy for the correction of mandibular prognathism: a randomized clinical trial

The sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) are two common orthognathic procedures for the treatment of mandibular prognathism. This randomized clinical trial compared the surgical morbidities between SSRO and IVRO for patients with mandibular prognathism over the first 2 years postoperative. Ninety-eight patients (40 male, 58 female) with a mean age of 24.4 ± 3.5 years underwent bilateral SSRO (98 sides) or IVRO (98 sides) as part or all of their orthognathic surgery. IVRO presented less short-term and long-term surgical morbidity in general. The SSRO group had a greater incidence of inferior alveolar nerve deficit at all follow-up time points (P <  0.01). There was more TMJ pain at 6 weeks (P =  0.047) and 3 months (P =  0.001) postoperative in the SSRO group. The SSRO group also presented more minor complications, which were related to titanium plate exposure and infection. There were no major complications for either technique in this study. Despite the need for intermaxillary fixation, IVRO appears to be associated with less surgical morbidity than SSRO when performed as a mandibular setback procedure to treat mandibular prognathism.     

Position of the mandibular canal before and after bilateral sagittal split ramus osteotomy: a cone beam computed tomographic study

The aim of this study was to evaluate the position of the mandibular canal (MC) before and after bilateral sagittal split ramus osteotomy (BSSRO) using cone-beam computed tomography (CT), and to compare the position of the MC in Class II and Class III patients in the preoperative period. Patients were divided into two groups: Class II (n = 38) and Class III (n = 41). Measurements of the superior, inferior, buccal, and lingual distances of the MC in relation to the cortical bone were taken at three levels in the proximal segment of the mandible. Results were analysed using the Kruskal–Wallis test (p < 0.05). In the Class II group the superior distance of the MC at levels 2 and 3, and the inferior distance at level 3 significantly decreased after BSSRO. In the Class III group, no significant differences were found at any level, and the inferior distances at all levels were smaller preoperatively than those in the Class II group. In the Class II group the position of the MC altered in relation to superior and inferior cortical bone after BSSRO. However, the position of the MC remained stable in the Class III group. Our results also suggest a deeper cut in inferior cortical bone in Class III patients.     

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.     

Unilateral sagittal split ramus osteotomy: an alternative for some cases of asymmetric mandibular prognathism

The objective of this study was to propose a treatment protocol for patients with lateral prognathism based on the unilateral sagittal split ramus osteotomy (USSRO). This was a prospective study involving 31 patients with lateral prognathism, who required a bilateral sagittal split ramus osteotomy (BSSRO). Two groups were formed using the proposed protocol, with specific inclusion criteria for each group: BSSRO (n = 17) and USSRO (n = 14). Occlusal parameters (dental midline deviation, overbite, and overjet) were measured preoperatively (T0), at model surgery (T1), 1 month postoperative (T2), and 1 year after surgery (T3) and compared. P-values of <0.05 were considered significant. No significant difference was found between the USSRO and BSSRO groups for all occlusal parameters (T0, T1, T2, and T3). In both groups, there was a significant difference between T0 and T1 and no significant difference between T1 and T2 or T1 and T3 in all of the occlusal parameters; the exception was overbite between T1 and T2 in the BSSRO group, which showed a significant difference. No patient in either group showed signs or symptoms of temporomandibular joint dysfunction at T0 or T3. USSRO was found to be a stable alternative in patients with asymmetric mandibular prognathism. At the same time, it reduced the operating time and morbidity when compared to BSSRO.     

Skeletal stability and condylar position related to fixation method following mandibular setback with bilateral sagittal split ramus osteotomy

PurposeTo investigate postoperative intersegmental displacement and relapse following bilateral sagittal split ramus osteotomy (BSSRO) by comparing three different fixation methods: group A (sliding plate), group B (miniplate) and group C (bicortical screws).Materials and methodsThe present retrospective study included 55 patients with mandibular prognathism who were treated with BSSRO. To evaluate skeletal changes, cone-beam computed tomography was taken before surgery (T0), three days after surgery (T1), and 6 months after surgery (T2). Differences among the three groups were assessed using a one-way analysis of variance, where P < 0.05 was accepted as statistically significant.ResultsThere were no significant differences among the three groups in demographic data and the amount of mandibular setback. In skeletal changes and condylar axis changes, there were no statistically significant differences among the three groups. However, there were statistically significant postoperative skeletal changes in group C (bicortical screws) at all landmarks. The mean horizontal relapse rate was 1.9% in group A (sliding plate); 4.8% in group B (miniplate); and 15.4% in group C (bicortical screws).ConclusionThe sliding plate system has good adaptability to the proximal segment after mandibular setback with BSSRO, and behaves according to semi-rigid fixation principles.     

Three-dimensional condylar displacement and remodelling in patients with asymmetrical mandibular prognathism following bilateral sagittal split osteotomy

This study aims to assess the postoperative condylar displacement and the long-term condylar remodelling in patients with mandibular prognathism with transverse asymmetry after bilateral sagittal split ramus osteotomy (BSSRO). Forty-one consecutive patients (82 condyles) with a transverse mandibular asymmetry of more than 4 mm without occlusal canting treated by BSSRO were included. The preoperative (T1), immediate postoperative (T2) and long-term follow-up of an average of 16.2 months (T3) spiral computed tomography scans were gathered and processed to measure the condylar displacement and remodelling based on cranial base voxel-based and rigid regional registrations. The statistical analysis revealed that the majority of condyles (T1–T2) were transitionally displaced forwards, downwards and laterally, and were not fully returned to the preoperative position at T3. Condylar lateral displacement was significantly higher on the deviated side (DS) (P = 0.035). Non-deviated side (NDS) condyles were mainly subjected to upward pitch, medial yaw and medial roll compared with downward pitch, lateral yaw and lateral roll on DS. Condylar remodelling at T3 was observed, with the superior and posterior surfaces commonly subjected to bone resorption, whereas the anterior and medial surfaces were commonly subjected to bone apposition. Condylar volumetric changes were relatively comparable on NDS (3 ± 85.2 mm³) and DS (8.3 ± 111.7 mm³) condyles. Age, amount of preoperative asymmetry and follow-up period were not correlated with the condylar remodelling. Transitional and rotational displacements were to some extent significantly correlated with the condylar remodelling on both sides. Consequently, passive condylar seating without torque might prevent the long-term unfavourable condylar remodelling.     

A long-term comparative study of two rigid internal fixation techniques in terms of masticatory function and neurosensory disturbance after mandibular correction by bilateral sagittal split ramus osteotomy

Bilateral sagittal split ramus osteotomy (BSSO) is widely used to treat mandibular prognathism. Several methods have been described for fixation of the bony segments. This study compared two methods of rigid fixation (bicortical screws and monocortical miniplates) to identify differences in postoperative masticatory function and neurosensory disturbance after 5 years of mandibular set-back correction. 77 women who had undergone BSSO for Class III malocclusion were reviewed, and masticatory functions and neurosensory recovery were examined with the appropriate indicators pre- and postoperatively (at approximately 1 month, and 1, 2, 3, 4, and 5 years). Masticatory function exhibited similar recovery patterns in both groups. Orthognathic surgery improved occlusal force and occlusal contact area, but longer than 4 years after surgery may be required for postoperative occlusal functions in prognathic patients to reach the level of healthy subjects. The groups showed no significant differences in the recovery of parameters of masticatory functions and neurosensory disturbance even 5 years after surgery. In the evaluation of temporomandibular joint function using the Helkimo index, the score was significantly higher for the screw group than for the miniplate group. This suggests that BSSO fixed with miniplates may offer a relatively safe and reliable procedure yielding adequate results and high patient satisfaction.