双侧升支矢状劈开截骨后退下颌术后骨的稳定性的研究

目的：探讨双侧升支矢状劈开截骨术（BSSRO）后退下颌骨以钢丝结扎固定两骨段加颌间固定术后骨的稳定性，了解导致复发的有关因素。方法：双侧下颌升支矢状劈开截骨手术后退下颌的患者14例，于手术前1周，手术后1周，术后6个月分别拍摄定位头颅侧位片及许勒位X线片，用于测量下颌移动的距离及确定下颌骨髁状突的位置。结果：双侧下颌升支矢状劈开截骨后退术后，6个月的复发率为27.2%，多元逐步回归分析示下颌后退的距离与复发相关。结论：BSSRO后退下颌骨的距离越大，术后下颌骨向前移位的可能越大。     

下颌支矢状骨劈开术数字模型的建立及不同固定方式的稳定性分析

目的:建立下颌支矢状骨劈开术数字模型,探讨3种不同固定方式的应力及位移改变.方法:CT扫描数据导入三维重建软件Mimics以及Geomagic中,建立下颌骨三维实体模型,并进行矢状劈开、坚固内固定,ANSYS进行网格划分,建立三维有限元模型.边界约束后,进行双侧下颌第一磨牙咬合力(132 N)加载.结果:建立了双侧下颌支矢状骨劈开术3种不同固定方式三维有限元模型,获得术前下颌骨及矢状骨劈开后咬合力加载的应力及位移生物力学特点.结论:下颌支矢状骨劈开术倒L形固定应力分布最均匀,劈开处位移最小,与其他2种方式相比,其固定稳定性最佳.     

双颌手术升支截骨后退术后下颌稳定性及与关节关系的研究

目的　探讨升支矢状劈开截骨术(BSSRO)小钛板坚固内固定与口内入路升支垂直截骨术(BIVRO)下颌后退术后颌稳定性的不同规律,了解导致复发的有关因素特别是髁状突移位在不同手术后复发过程中的意义。方法　升支截骨手术后退下颌的患者共38例,皆为双颌手术,其中下颌BSSRO19例,BIVRO后退术19例。于手术前1周(T1),手术后1周(T2),3个月(T3)及1年(T4)分别拍摄定位头颅侧位片及定位颞下颌关节薛氏位片用于测量下颌移动幅度及关节髁状突的手术后移位。结果　双颌手术下颌升支截骨后退术后,BSSRO坚固内固定组1年时的复发率为25%,而BIVRO组大部分患者1年时下颌发生了与手术目的相同的移动,两组的不稳定主要发生在术后3个月内。结论　手术使髁状突移位术后位置的调整可导致BIVRO术后的下颌继续后移而不稳定,而髁状突近心骨段术中向后旋转术后位置的调整可导致BSSRO术后的下颌骨继续向前而不稳定     

下颌升支矢状劈开截骨术后髁突和下颌角横向变化的研究

目的 观察下颌升支矢状劈开截骨后退术后下颌骨近心骨段的横向变化及长期稳定性。方法 对42例行双颌手术＋坚固内固定治疗的Ⅲ类错[牙合]畸形患者术前、术后一周以及术后12个月以上的后前住头颅定位片进行描记、定点测量，并作统计学分析。结果 下颌角间距及髁突间距在术中分别增加了4．04mm（P〈0．01）和2．11mm（P〈0．01）；在术后观察期，二者分别减小了1．45mm（P〈0．01）和1．80mm（P〈0．01）；下颌角间距术中增宽量越大，观察期减小的幅度越大。结论 经过升支矢状劈开截骨后退下颌骨远心骨段后，下颌骨近心骨段在横向上发生了一定的移位，后前住头颅定位片上表现为下颌角间距及髁突间距的明显增加；在平均20个月的观察期内，二者有不同程度的回复，下颌角间距较术前呈明显的净增宽。     

下颌升支矢状劈开截骨术后下颌骨短期稳定性的三维分析

目的:本研究利用三维测量方法分析下颌骨在下颌升支矢状劈开截骨术后短期内的复发趋势.方法:收集在北京大学口腔医院接受正颌-正畸联合治疗并行下颌升支矢状截骨手术的患者共49例,分为下颌前徙患者22例,下颌后退患者27例,收集术前4 d(T0)、术后4 d(T1)、术后4～6周(T2)、3个月(T3)的CBCT数据,利用计算机辅助设计软件Pro Plan进行三维头颅重建,建立坐标系并测量下颌骨相关指标.利用SPSS 20.0软件对T1、T2时的测量结果进行配对t检验.结果:在接受下颌升支矢状劈开截骨术的患者中,下颌前徙患者的下颌骨在B点、Pg点存在水平向的复发趋势,下颌平面存在顺时针旋转的倾向.下颌后退患者的下颌骨在B点存在水平向的复发趋势,Pg点存在水平向和垂直向的复发趋势.结论:下颌升支矢状劈开截骨术后术后下颌骨在短期内存在复发倾向,但在临床可接受范围内.     

双侧下颌骨升支矢状劈开截骨术治疗下颌前突畸形

目的探讨口内进路双侧下颌骨升支矢状劈开截骨后退小钛板内固定治疗重度下颌前突畸形的临床疗效。方法9例上颌骨发育正常、下颌骨真性前突、严重反He关系的患者，行术前牙齿正畸治疗后，采用口内进路双侧下颌骨升支矢状劈开截骨后退小钛板内固定，术后正畸治疗，恢复尖窝咬He关系。结果所有病例均取得满意的疗效，获得协调的上下颌骨关系，术后随访1年，未见下颌前突复发。结论重度下颌前突畸形采用口内进路双侧下颌骨升支矢状劈开截骨术及正畸治疗是有效的，值得临床推广应用。     

骨性下颌前突正畸—正颌联合治疗前后髁突位置变化的研究

目的:研究骨性下颌前突正畸-正颌联合治疗前后髁突位置的变化,探讨下颌双侧升支矢状劈开后退术对于治疗骨性下颌前突的可靠性和安全性。方法:15例骨性下颌前突的安氏Ⅲ类错牙合畸形病人,行下颌双侧升支矢状劈开后退术(bilateral sagittal split ramus osteotomy,BSSRO)与正畸矫治联合治疗,分别在术前两周和术后半年拍摄许勒式X线片,测量BSSRO术前、术后双侧髁突在关节窝内前、后、上间隙的距离,进行统计学分析比较术前术后髁突位置的变化情况。结果:15例病例经BSSRO配合正畸治疗后均达到正常的咬合关系,恢复了口腔功能,改善了面部容貌;正颌术前:左侧关节前、后、上间隙均数为1.91、2.30、2.51 mm;右侧前、后、上间隙均数为2.14、2.65、2.98 mm;正颌术后:左侧关节前、后、上间隙均数为1.99、2.38、2.62 mm;右侧前、后、上间隙均数为2.14、2.66、2.60 mm。术后半年双侧髁突在关节窝内的上、前、后间隙与术前两周相比,差异均无统计学意义。结论:下颌双侧升支矢状劈开后退术(BSSRO)配合正畸治疗,能够安全有效的矫治骨性下颌前突,并且未使其出现新的关节症状。     

双侧下颌升支矢状劈开截骨后退术对下颌骨宽度及形态的影响

目的通过对下颌前突患者行双侧下颌升支矢状劈开截骨后退术前后头颅正侧位定位片硬组织结构变化的洲量分析,评价手术对患者下颌骨宽度及形态的影响。方法选择1997年至2001年在我中心行双侧下颌升支矢状劈开术的下颌前突患者18例,男性9例,女性9例,平均年龄22．22岁,所有患者手术前、术后一周、术后一年拍摄静止位头颅正侧位定位片,在正位片上测量下颌骨宽度(Go-Go),并从头颅正侧位定位片上测量与下颌骨宽度变化有关的参数数值。结果①下颌骨宽度由107．30mm±5．84mm(术前)增加至109．24mm±5．72mm(术后一周)、109．31mm±5．66mm(术后一年),其中有4例宽度减小,1例保持不变。13例增加,②下颌骨宽度术前、术后一用、术后一年的方差分析结果表明差别有显著性。③分析表明下颌骨宽度变化与各参数变化之间没有线性相关。结论①下颌骨宽度在双侧下颌升支矢状劈开截骨术后较术前有轻微增大,但对容貌没有大的影响。②下颌骨宽度变化机制可能与颞下颌关节功能改变有关。     

双侧下颌支矢状劈开截骨术后咽腔气道的变化

目的：通过头影测量分析骨性下颌前突患者双侧下颌支矢状劈开截骨术后咽腔气道的变化,为术后保持与防止复发提供依据。方法骨性下颌前突患者20例,均接受口内入路的下颌支矢状劈开截骨术。术前1周、术后1周、术后6个月拍摄标准颅颌侧位片进行头影测量,通过治疗前、后对照,比较下颌支矢状劈开截骨术后咽腔气道的改变。采用SPSS 17.0 软件包对数据进行统计学分析。结果术后1周与术前1周相比,软腭长度显著增加,咽腔气道显著减小;术后6个月咽腔气道有所恢复,与术后1周相比软腭长度显著减小,咽腔气道显著增加;术后6个月与术前1周相比,软腭长度及咽腔气道变化无显著差异。结论骨性下颌前突患者行双侧下颌支矢状劈开截骨术后短期内咽腔气道较术前显著减小,可能加大发生睡眠呼吸暂停综合征的几率。但经过一段时间的组织适应和改建后,咽腔气道有恢复至术前宽度的趋势。     

正畸正颌联合治疗唇腭裂继发牙颌面畸形

目的评价正畸正颌联合治疗唇腭裂继发牙颌面畸形的疗效。方法回顾性研究2000年7月～2005年9月广东省口腔医院治疗的20例唇腭裂继发牙颌面畸形患者。20例患者均行术前及术后正畸治疗,单纯采用上颌骨LeFortⅠ型截骨前移者1例,单纯采用双侧下颌升支矢状劈开后退术者1例,行LeFortⅠ型截骨前移术 双侧下颌升支矢状劈开后退术者15例,行LeFortⅠ型截骨前移术 双侧下颌升支矢状劈开后退术 颏成型术者3例。17例患者在正颌手术前行牙槽裂植骨。结果经治疗患者上颌前移(5.5±1.2)mm,下颌后退(7.2±2.5)mm。患者唇颏关系改善明显,咬合关系良好,但大部分患者鼻部仍有塌陷及偏斜畸形。患者术前后语音状况经语音师评估均无明显变化。结论正畸正颌联合治疗唇腭裂继发牙颌面畸形,可以较好地改善患者的容貌并取得良好的咬合关系。     

Stability after surgical-orthodontic correction of skeletal Class III malocclusion. I. Mandibular setback

Postsurgical stability of mandibular setback to correct mandibular prognathism was compared for three approaches: transoral vertical ramus osteotomy, bilateral sagittal split osteotomy with wire osteosynthesis and maxillomandibular fixation, and bilateral sagittal split osteotomy with rigid internal fixation via bone screws. In the transoral vertical ramus osteotomy group, the mean postsurgical change in chin position was almost zero, but nearly 50% of the patients did have clinically significant changes in chin position; two thirds of these movements were posterior and one third anterior. In the bilateral sagittal split osteotomy groups, the chin either stayed in its immediately postsurgical position or moved anteriorly. In one fourth of the patients who received maxillomandibular fixation and in nearly half of the patients who received rigid internal fixation, the chin moved forward more than 4 mm.     

Evaluation of skeletal stability following surgical correction of mandibular prognathism

This retrospective study was designed to assess skeletal stability after the correction of mandibular prognathism by sagittal split osteotomy (SSO) and intraoral vertical subsigmoid osteotomy (VSO). We used lateral cephalographs of 31 patients taken before, immediately after, and at least one year after the operation. We recorded euclidean distance matrix analysis, linear and angular measurements, and x and y co-ordinates of cephalometric landmarks for each cephalograph. There were no significant differences in extent of the mandibular retrognathia or magnitude of change between the two groups. The main significant changes in both groups were reduction of the total mandibular length, and posterior shifting in the mandible. One year after the operation the main change was the mean forward relapse of 2.5 mm in the SSO group and the mean posterior relapse of 0.5 mm in the VSO group. The difference in skeletal stability between the groups was significant (P< 0.05), and we conclude that VSO is the more effective technique for correcting mandibular prognathism.     

Skeletal stability after mandibular advancement with rigid versus wire fixation.

PURPOSE: This study examined the stability of skeletal changes after mandibular advancement surgery with rigid or wire fixation up to 2 years postoperatively. PATIENTS AND METHODS: Subjects for this multisite, prospective, clinical trial received rigid (n = 78) or wire (n = 49) fixation. The rigid cases were fixed with three 2-mm bicortical position screws and 1 to 2 weeks of skeletal maxillomandibular fixation with elastics, and the wire fixation subjects were fixed with inferior border wires and had 6 weeks of skeletal maxillomandibular fixation with 24-gauge wires. Cephalometric radiographs were obtained before orthodontics, immediately before surgery, and at 1 week, 8 weeks, 6 months, 1 year, and 2 years after surgery. Linear cephalometric changes were referenced to a cranial base coordinate system. RESULTS: Before surgery, both groups were balanced with respect to linear and angular measurements of craniofacial morphology. Mean anterior sagittal advancement of the mandibular symphysis was 4.92 +/3.01 mm in the rigid group and 5.11 +/- 3.09 mm in the wire group, and the inferior vertical displacement was 3.37 +/- 2.44 in the rigid group and 2.85 +/- 1.78 in the wire group. The vertical changes were similar in both groups. Two years postsurgery, the wire group had 30% sagittal relapse of the mandibular symphysis, whereas there was no change in the rigid group (P < .001). Both groups experienced changes in the orientation and configuration of the mandible. CONCLUSIONS: Rigid fixation is a more stable method than wire fixation for maintaining mandibular advancement after sagittal split ramus osteotomy.     

Stability of skeletal class III malocclusion after combined maxillary and mandibular procedures: rigid internal fixation versus wire osteosynthesis of the mandible.

PURPOSE: The aim of this study was to evaluate skeletal stability after double-jaw surgery for correction of skeletal Class III malocclusion to assess whether there were any differences between wire and rigid fixation of the mandible. PATIENTS AND METHODS: Thirty-seven Class III patients had Le Fort I osteotomy stabilized with plate and screws for maxillary advancement. Bilateral sagittal split osteotomy for mandibular setback was stabilized with wire osteosynthesis and maxillomandibular fixation for 6 weeks in 20 patients (group 1) and with rigid internal fixation in 17 patients (group 2). Lateral cephalograms were taken before surgery, immediately after surgery, 8 weeks after surgery, and 1 year after surgery. RESULTS: Before surgery, both groups were balanced with respect to linear and angular measurements of craniofacial morphology. One year after surgery, maxillary sagittal stability was excellent in both groups, and bilateral sagittal split osteotomy accounted for most of the total horizontal relapse observed. In group 1, significant correlations were found between maxillary advancement and relapse at the posterior maxilla and between mandibular setback and postoperative counterclockwise rotation of the ramus and mandibular relapse. In group 2, significant correlations were found between mandibular setback and intraoperative clockwise rotation of the ramus and between mandibular setback and postoperative counterclockwise rotation of the ramus and mandibular relapse. No significant differences in postoperative skeletal and dental stability between groups were observed except for maxillary posterior vertical position. CONCLUSIONS: Surgical correction of Class III malocclusion after combined maxillary and mandibular procedures appears to be a fairly stable procedure independent of the type of fixation used to stabilize the mandible.     

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.     

Technical modification of the sagittal split mandibular ramus osteotomy.

The sagittal split mandibular ramus osteotomy is a versatile surgical option for the correction of mandibular prognathism, retrognathism, and asymmetry. At the same time, it enables the use of internal rigid fixation. However, surgical complications including injury to the inferior dental neurovascular bundle and unfavorable fracture can occur. A technical modification and a concept in instrumentation is suggested with the view of minimizing such complications.     

Masticatory function and neurosensory disturbance after mandibular correction by bilateral sagittal split ramus osteotomy: a comparison between miniplate and bicortical screw rigid internal fixation

Bilateral sagittal split osteotomy is commonly used to treat mandibular prognathism. Several fixation methods for bony segments have been described. The present study compared masticatory function and neurosensory recovery patterns after mandibular correction between two methods of rigid fixation, bicortical screw (n = 38) and monocortical miniplate (n = 32). Patients who had undergone bilateral sagittal split osteotomy for Class III malocclusion were reviewed, and masticatory function and neurosensory recovery were studied with the appropriate indicators at 1, 3, 6 and 12 months postoperatively. Minimal differences were seen between groups at 1-year postoperatively, and although patients treated with miniplate fixation tended to recover faster, with regard to masticatory function and neurosensory disturbance, than those treated with screw fixation, no significant differences were identified. As the two methods seem to provide equal comfort and reliability, the choice should be made by the individual surgeon.     

A comparative study of temporomandibular symptoms following mandibular advancement by bilateral sagittal split osteotomies: rigid versus nonrigid fixation

Rigid fixation to attach proximal and distal segments during bony healing of osteotomy sites has become increasingly popular. The effects of rigid fixation on the temporomandibular joints have been questioned. The purpose of this study was to evaluate the effects of rigid fixation after bilateral sagittal split osteotomies on temporomandibular dysfunction symptoms. Forty patients who had mandibular advancement surgery were evaluated for temporomandibular joint dysfunction. Twenty had received rigid fixation, and twenty had received nonrigid fixation. It was determined that there was no statistically significant difference in temporomandibular signs or symptoms between patients who were treated with rigid internal fixation for bilateral sagittal split osteotomies for mandibular advancement and those patients who were treated with nonrigid wire fixation.     

Radiographic stereophotogrammetric evaluation of intersegmental stability after mandibular sagittal split osteotomy and rigid fixation

PURPOSE: The purpose of this study was to determine if rigid fixation with bicortical screws and/or miniplates with monocortical screws prevent mobility at the osteotomy site after bilateral mandibular sagittal split osteotomy. PATIENTS AND METHODS: Three metal bone markers were inserted in the proximal and the distal segments of the mandible during the sagittal split operation in 10 patients. These served as measurement points in postoperative follow-up by radiographic stereophotogrammetry. The patients were examined at intervals during the first postoperative year. At each examination, 2 sets of radiographic stereograms were obtained: 1 in rest position and 1 with stress applied to the osteotomy sites. The difference in the position of the proximal segment in relation to the distal segment between the 2 sets of stereograms was recorded. Findings greater than 0.4 degrees and 0.2 mm change indicated true displacement of the bone segments. RESULTS: Immediately after surgery, mobility at of the osteotomy site(s) was found in 8 of 10 patients, and after 1 year it was still present in 4 patients. CONCLUSIONS: Fixation with bicortical screws or miniplates and monocortical screws does not prevent mobility at the osteotomy site after sagittal split osteotomies. This mobility may remain as long as 1 year after surgery. The term "rigid fixation" is thus not a proper term for this kind of fixation.