下颌升支矢状劈开截骨术矫治下颌前突体会

下颌升支矢状劈开截骨术矫治下颌前突体会山东莱钢医院口腔科吴洪敏，陶书振１９８９年以来我科采用下颌升支矢状劈开截骨术（Ｓａｇｉｔｔａｌｓｐｌｉｔｒａｍｕｓｏｓｔｅｏｔｏｍｙ，ＳＳＲＯ）矫治下颌前突畸形１０例，取得良好效果，现总结如下。临床资料本组１０例...     

双侧升支矢状劈开截骨后退下颌术中去骨的评估研究

目的:评估双侧升支矢状劈开截骨后退下颌术中去除的颊侧骨皮质形状与垂直截骨线的方向和前牙覆变化间的关系,指导临床去骨操作。方法:在头影测量侧位描记图的下颌体部设计3种不同方向的垂直截骨线,用头影测量裁剪预测方法先旋转再后退下颌到术前设计位置,分析最终垂直截骨线与初始垂直截骨线间的角度关系,运用几何学原理计算此角度的大小。评价后退下颌时所需要去除骨皮质大致形状同初始垂直截骨线方向及前牙覆变化间的关系。结果:近心骨段不发生矢状向移位情况下,最终垂直截骨线与初始垂直截骨线间的角度大小与上下颌平面交角保持一致,与初始截骨线的方向和下颌后退的距离大小无关。去除的骨皮质形状与前牙覆变化相关。结论:近心骨段去骨形状与前牙覆变化密切相关,与截骨线方向和下颌后退的距离大小无明显相关。     

双侧下颌升支矢状劈开截骨(BSSRO)后退术对下颌角区的影响

目的:研究BSSRO后退术后下颌角区形态的变化。方法:通过38例骨性下颌前突患者BSSRO后退手术前后头颅定位正侧位片及口腔X线计算机体层摄影(CBCT)片对硬组织结构定点测量。结果:2种测量均显示术后下颌角角度较术前减小,下颌升支坡度亦减小;下颌骨的宽度将增加。结论:BSSRO术后下颌角变小,下颌骨宽度增加;将使患者的面貌变宽,咬合功能有所改善。     

双侧下颌升支矢状劈开后退术后骨稳定性评价

目的 探讨影响双侧下颌升支矢状劈开后退术并行坚固内固定后骨稳定性的因素。方法 对进行双侧矢状劈开后退术后的15例患者于术后1周及术后1年摄头影测量侧位片,对其相关角度及线距进行测量,并作统计学处理。结果 下颌矢状劈开后退术1年后的平均复发量为2.5mm,后退量>6mm组与后退量<6mm组两者变化量之间无显著性差异。结论 下颌双侧矢状劈开后退术并行坚固内固定是矫正下颌前突最有效的方法之一。     

基于三维CT配准技术的下颌矢状劈开去骨术的临床研究

目的探讨下颌矢状劈开去骨术后下颌骨的形态学变化。方法选择2006年1月至2008年4月行下颌矢状劈开去骨术的10例患者为研究对象,完整采集每例患者术前、术后即刻、术后半年的头面部CT数据,应用逆向工程软件Surfacer V9,利用三维CT分体重建和配准分割技术,对下颌矢状劈开去骨术后半年的效果及下颌骨局部骨质的再生情况进行评价。结果1）下颌矢状劈开去骨术后半年,下颌骨局部有明显凹陷,比术前平均凹陷（3.64±1.67）mm,以下颌骨外斜线部位最为明显;术后半年去骨区域体积缩小率为55%±9%。2）与术后即刻相比,术后半年局部骨质有再生,去骨区域有84.6%±7.3%的骨质属新生骨,增生的主要部位为下颌角区。结论行下颌矢状劈开去骨术可达到缩小面下部宽度的目的,术后应尽量减少咬肌活动。     

改良双侧下颌支矢状劈开术固定法在矫正面部不对称畸形中的初步应用

目的: 研究双侧下颌支矢状劈开术(BSSRO)中保留凹陷侧近心端骨板联合双皮质螺钉固定法在矫正面部不对称畸形中应用价值。方法：选择2013年1月—2013年7月间在上海交通大学医学院附属第九人民医院行正颌手术治疗的8例成年偏突颌畸形患者作为研究对象,术前进行临床检查和三维CT检查,确定双侧咬肌区的不对称情况,术中常规行BSSRO和(或)上颌骨Le Fort I型截骨术。在下颌骨旋转后退后,肥大侧去除近心端多余骨板行4孔小钛板固定,凹陷侧保留近心端多余骨板用双皮质螺钉固定。术后3个月检查患者面部对称性的改善情况,并通过正位片测量、计算患者手术前、后两侧结构的对称性,评估该方法的有效性。利用SPSS 20.0 软件包对数据进行配对t检验。结果：8例患者的面部不对称性均得到很好改善,未出现钛钉脱落、骨块移位和复发等情况。手术前、后患者面部对称性相关指标的差值具有统计学意义(P<0.05)。结论：BSSRO中保留凹陷侧近心端骨板联合双皮质螺钉固定法能更有效地矫正面部不对称畸形,可安全应用。     

下颌矢状劈开截骨术相关下颌管空间定位的三维CT研究

目的：应用三维CT影像测量下颌管解剖位置与骨皮质和磨牙的关系,为避免下颌矢状劈开截骨术中损伤下齿槽神经血管提供指导。方法：选择50名正常成人下颌骨三维CT扫描图像,应用AW4．4图像处理软件分别在第二前磨牙,第一、第二磨牙正中,下颌磨牙后区处测量下颌管的解剖位置。结果：通过获得的CT数据研究中国人下颌神经管的解剖位置与骨皮质和磨牙的联系,在第二磨牙区域下颌管距离颊侧骨皮质最远（平均7．82mm,最小4．9mm）。结论：在第二磨牙区域下颌体最厚,对于下颌矢状劈开截骨术的颊侧垂直切口须在下颌第二磨牙区域,这个区域骨质最厚并且下颌管距离颊侧骨皮质最远。对于下颌矢状劈开截骨术颊侧垂直切口的安全深度是4．9mm。     

下颌支矢状骨劈开术并发症防治的专家共识

下颌支矢状骨劈开术（SSRO）是正颌外科中最为常用的一类矫治下颌骨畸形的手术。由于局部解剖和操作步骤的复杂性,SSRO出现各类并发症的可能性较大,甚至可能造成严重的不良后果。诊疗策略的选择及转归与并发症的类型及其临床表现密切相关。为此,国内相关专家编写本共识,对SSRO各类常见并发症的原因、预防、处置措施进行阐述,以期提高广大同行对SSRO并发症的认识,确保手术安全进行并获得良好效果。     

下颌支矢状骨劈开术的数字仿真及其稳定性研究

下颌支矢状劈开截骨术(SSRO)是最早被提出的口内进路的正颌外科手术,广泛应用于矫治下颌后缩、下颌前突、小颌畸形等各类牙颌面畸形。目前临床上对于下颌支矢状骨劈开术采用了不同的内固定方式,其稳定性的差异仍存在争议。近年来随着计算机技术的推广应用,特别是数字仿真技术运用在口腔医学领域,为下颌支矢状骨劈开术的稳定性分析提供了新的研究着手点。从骨劈开术式到内固定方式都在不断地改良与完善,提高了正颌手术效果、降低了复发率及颞颌关节功能紊乱综合征等并发症的发生。本文就下颌支矢状骨劈开术坚强内固定术的数字仿真及其生物力学稳定性研究进展作一综述。     

The silent period in the masseter and the anterior temporalis muscles in adult patients with mild or moderate mandibular dysfunction symptoms

The electromyographical silent period in the masseter and the anterior temporalis muscles during tooth tapping and jaw jerk were studied in patients with fairly mild temporomandibular joint dysfunction symptoms. The length of the silent periods in the patient group did not differ generally from that in a control group. During tooth tapping, however, patients with distinct muscular disorders had shorter silent period duration (7.7 ms) than patients with other symptoms or when compared with control subjects (10.5 and 11.3 ms, respectively). The duration returned to normal after correction of the muscular disorders. This finding suggests that the duration of the silent period is affected by the muscle condition. Patients with obvious muscular disorders of mild to moderate magnitude, thus, may show a shorter silent period duration during tooth tapping.     

A split ostectomy of mandibular body and angle reduction

Combined mandibular angle resection with angle-splitting ostectomy (ASO) is more effective than conventional simple or multistaged ostectomy. Removal of the outer cortex of the mandibular body by ASO lessens the protuberance of the masseter muscle. In this study, the anatomy of the mandibular canals in seven human cadavers was studied in detail, and a guideline for ASO and mandibular angle ostectomy was set up so as to avoid injury to the inferior alveolar nerve. The most vulnerable area of the inferior alveolar nerve is the line from the gonion (G) to the junction (O) of the intersecting vertical line along the anterior border of the ramus and the horizontal line on the alveolar crest because of the thin anterior distance (AD) between the buccal surface of the mandible and the outer wall of the mandibular canal. The resection line should not be above 17.5 mm at the GO line to ensure a safe inferior distance, the distance between the inferior border of the mandible and the floor of the mandibular canal (21.6 +/- 4.1 mm). The body of the mandible was less vulnerable to injury to the inferior alveolar nerve in ASO because of the relatively thicker AD at the second molar (8.3 mm) and first molar (6.8 mm). Pilot surgery was performed in five cadavers. The lateral cortex was safely split off, avoiding injury to the inferior alveolar nerve, and angle ostectomy was then done. This method was applied in two clinical cases without any complications. The "split ostectomy of mandibular body and angle reduction" is a new and safe method of avoiding the injury to the inferior alveolar nerve.     

Treatment of condyle fracture caused by mandibular angle ostectomy

A prominent mandibular angle is considered to be unattractive in Asian countries because it gives the face a square and muscular appearance. Successful correction by angle ostectomy has been reported, but one of the serious complications of angle reduction ostectomy is fracture of the mandibular condyle. If the ostectomy line is misdirected vertically, the condyle may be fractured. The authors experienced two cases of condylar fracture during angle reduction. Case 1 was a pulled-out condylar fracture, where an L-shaped miniplate was then attached by external approach, and intermaxillary fixation (IMF) with arch bar was used on postoperative day 14. With release of the IMF, a systematic approach for a jaw-opening exercise was begun. On postoperative day 21, the elastics were placed to assist in guiding protrusion of the mandible anteriorly 24 hours a day. After postoperative day 28, it was possible to completely abandon daytime elastic fixation. The exercise was modified to lateral movement. Case 2 was green-stick condylar fracture, with the IMF with arch bar applied on postoperative day 10. After releasing the IMF, the exercise involved the daily use of several tongue blades, and range of motion increased by wedging additional blades until postoperative day 21. More aggressive stretching was continued with 22 blades on postoperative day 28. On the removal of the arch bar, the occlusion was stable and followed by more aggressive stretching and physical therapy. Both cases were successfully restored and had good results. The authors believe the exercise protocols and algorithms they used may serve as a standard procedure of treatment in condylar fracture caused by angle ostectomy.     

Management of bilateral masseter muscle hypertrophy

Masseter muscle hypertrophy is characterized by unilateral or bilateral enlargement of the masseter muscles affecting both females and males after puberty. Limitations on mouth opening, swollen cheek, and also tension in the region of the hypertrophied muscle are symptoms reported. Also, masseter hypertrophy can cause aesthetic and functional problems. A 40-year old woman was referred to our clinic with the chief complaint of facial appearance with square-face type. To eliminate undesirable facial appearance, surgical intraoral approach compromising reduction of deep masseter muscle with monocortical and bicortical ostectomy of the angle of the mandible was performed. The patient was satisfied with both functional outcomes and aesthetic outcomes on both facial profile and frontal view. No complication was seen intraoperatively and postoperatively after a 12-month follow-up period. This treatment modality would be suggested to gain optimal aesthetic results especially in a square face from the lateral profile.     

Reduction mandibuloplasty: ostectomy of the lateral cortex around the mandibular angle

Many surgical techniques have been applied toward correcting the prominent mandibular angle. One of the most popular methods is mandibular angle ostectomy. However, gross asymmetry, mandibular condylar fracture, and unnatural contouring of the mandibular angle are frequent consequences. Therefore, we perform ostectomy of the lateral cortex around the mandibular angle in patients with wide and squared lower faces. Seventeen female patients with ages ranging from 23 to 35 years underwent surgery. Ostectomy of the lateral cortex of the mandible and mandible angle ostectomy were performed in five patients (group I). Ostectomy of the lateral cortex only was performed in the remaining 12 patients (group II). The follow-up period ranged from 1 to 5 years. Postoperatively, the bigonial distance was effectively reduced in both groups (group I, mean 13 mm; group II, mean 12 mm). Compared with group I, the gonial angle and mandibular plane-sella-nasion angle were within normal ranges in group II. We therefore conclude that the ostectomy of the lateral cortex alone allows the reduction to be achieved without changing the angle of the mandible itself. Moreover, although the resection of the mandibular angle was not performed, the contour of mandibular angle became soft, giving a more natural appearance.     

Application of the 3D digital ostectomy template (DOT) in mandibular angle ostectomy (MAO)

Background

Mandibular angle ostectomy (MAO) is a standard approach in reconstruction of facial contour that is commonly used in East Asian patients with prominent mandibular angles (PMA). MAO is commonly performed via an intraoral approach to reduce scar visibility and risk of facial nerve injury. Since this intraoral approach for MAO has limited visual guidance during the procedure, plastic surgeons often perform the operation based on personal clinical experience. Therefore, we designed a 3D digital ostectomy template (DOT) for guidance during surgery to improve the accuracy and safety of MAO.