计算机辅助设计二次牵引成骨术修复下颌骨缺损

目的 探讨计算机辅助设计(CAD)在定向二次牵引成骨术修复半侧下颌骨缺损中的应用及效果.方法 8例因肿瘤术后致下颌骨缺损患者,采用三维螺旋CT扫描结合CAD,制定手术方案,定制牵引器,Ⅰ期手术牵引下颌骨体部,Ⅱ期手术牵引下颌骨升支部.结果 手术过程顺利,创口均Ⅰ期愈合,下颌外形恢复良好,局部成骨较满意,无感染等并发症.下颌骨体部单侧最大牵引幅度为5.5 cm,平均4.9 cm,升支部最大4.5 cm,平均3.6 cm.张口度3～5 cm,健侧咬合良好,均取得了满意的治疗效果.牵引完成8个月后拆除牵引器.结论 对肿瘤术后导致半侧下颌骨缺损的患者,通过CAD实现定向二次牵引成骨,效果稳定可靠.为准确诊断、确定治疗方案提供指导,为实现手术导航和下颌骨缺损的精确修复重建提供仿真平台.缺点是整个治疗时间长,需3次手术.     

个体化内置式牵引器在修复下颌骨部分缺损中的应用

目的：应用个体化设计的内置式下颌骨牵引器,通过牵引成骨技术修复下颌骨部分缺损。方法：对因肿瘤行下颌骨部分切除的2例患者,术前根据头颅三维模型,设计个体化内置式牵引器,同期（1例）行肿瘤切除与牵引成骨手术,或二期1例行牵引成骨手术,运用转移盘牵引方式修复下颌骨部分缺损,固定期8～9个月,行X线及CT检查。结果：2例患者均成功进行了牵引器植入手术,术后牵引顺利,其中（1例）出现伤口感染,给予抗生素后得到控制,未影响牵引成骨治疗的进行。2例患者新骨形成均良好,转移盘远端骨质连接间隙处在拆除牵引器时需以植骨或钛板固定。结论：个体化设计的内置式下颌骨牵引器,可以根据不同患者颌骨缺损情况,进行一次性复杂牵引成骨,修复下颌骨部分缺损。     

应用三焦点牵引成骨术重建下颌骨缺损的初步临床研究

目的:探讨三焦点牵引成骨技术在下颌骨骨段缺损重建中的应用和在重建骨行种植义齿修复牙列缺失的可行性。方法:4例下颌体骨段切除患者,使用内置式三焦点牵引器同期行下颌骨缺损牵引成骨重建。牵引间歇期8天,牵引速度0.25mm×4次/d,稳定期4个月;1例于稳定期结束后在成骨区行种植义齿修复。结果:下颌骨牵引成骨最长45mm。牵引成骨区骨量充足,组织结构及硬度接近正常颌骨。牵引成骨区种植义齿可满足正常功能的需要。结论:三焦点牵引成骨技术可成功用于下颌骨骨段缺损的功能性重建,并可满足种植义齿修复的要求。     

口内入路的颌骨牵引成骨技术

目的 探讨口内入路的颌骨牵引成骨技术在牙颌面畸形矫治中的应用。方法 使用６种不同类型的口内牵引器分别水平向延长上颌骨和下颌骨体,水平垂直双向延长下颌骨升支以及垂直向延长牙槽嵴,以矫正重度上颌后缩畸形、小下颌畸形、半侧颜面发育不全畸形以及颌骨缺损畸形等,共１２例。结果 １２例不同类型的颌骨牵引成骨除１例牵引器故障,中途更换,另１例发生下颌下缘骨折并发症外,无感染、成骨不良、骨不愈合开Ｈｅ等并发症,１     

牵引成骨技术对颌骨畸形伴发OSAS未成年患者疗效评价

目的：探讨牵引成骨技术治疗颌骨畸形伴发OSAS青少年患者的疗效。方法：采用牵引器治疗颌骨畸形20例,包括颞下颌关节强直,第一、二鳃弓综合症,小下颌畸形和Crouson综合征。1例行上颌骨Le Fort Ⅲ型截骨外置式牵引成骨;19例行下颌骨体部截骨牵引成骨,其中同期行下颌支牵引成骨1例,二期颏成形术4例。牵引幅度5mm～35mm,平均16.79mm。从面容变化、咀嚼功能评价、X线头颅定位侧位片、身高体重、AHI等方面进行疗效评估。结果：20例病例面部外形改善满意、上气道直径和咽腔面积增大,睡眠暂停指数（AI）降级显著,身高体重增加显著;但存在咬合能力降低,部分病例错加重。结论：牵引成骨可以有效改善面形,扩大狭窄的咽腔,改善患者缺氧状况,促进生长发育。     

三焦点牵引成骨下颌骨缺损重建的实验研究

目的探讨采用内置式三焦点牵引器在犬下颌骨骨段缺损功能重建中牵引成骨的特点、规律。方法使用内置式三焦点牵引器对4只成年犬下颌骨骨段缺损进行牵引成骨重建。制作3cm下颌骨缺损区,同期植入内置式三焦点牵引器。牵引间歇期8天,牵引速度0.5mm×2次/天,稳定期3个月。结果下颌骨牵引成骨约30mm,牵引成骨过程中无感染、成骨不良等并发症。牵引完成后第3个月X线片、组织学观察及扫描电镜观察均可见新生骨的形成,新生骨的形态、组织结构接近正常下颌骨。结论三焦点牵引成骨技术重建的颌骨形态、组织结构和功能接近正常颌骨,牵引成骨区和压力成骨区局部应用rh-BMP2可以促进新骨的形成及钙化。     

口内入路个体化三焦点圆弧牵引器修复下颌骨大型缺损

目的:根据下颌骨缺损类型,设计个体化内置式圆弧牵引器,通过三焦点牵引成骨技术修复下颌骨缺损畸形。方法:对患成釉细胞瘤行下颌骨部分切除的患者,确定手术切除范围及修复后下颌骨形态,在快速原型模型上设计个体化内置式圆弧形牵引器,应用三焦点转移盘牵引方式,在肿瘤切除同期行牵引成骨手术,牵引前间歇期7d,牵引参数为0.4 mm/次,2次/d,固定期6个月。拆除牵引器后,二期行牙列修复。结果:牵引器植入后牵引过程顺利,固定6个月后X线片显示新骨形成均良好,但2个转移盘间见纤维愈合,拆除牵引器时需行钛板内固定。牙列修复前,发现下颌骨形态略小、矢状向后缩,再次行双侧下颌支矢状劈开前移下颌骨,到达设计位置并稳定后,行覆盖义齿修复。结论:个体化内置式圆弧牵引器可以有效修复下颌骨大型缺损,避免传统骨移植手术造成的供区创伤,但在前期设计时,需要适当矫枉过正。     

下颌骨正中牵引成骨系统有限元模型的建立

目的:建立使用3种不同牵引器(牙支持式、骨支持式和混合支持式)的下颌骨正中牵引成骨系统的有限元模型。方法:使用人体颌面部标准解剖模型,通过激光扫描,建立下颌骨、牙列和颞下颌关节盘的三维几何模型。描绘出颞下颌关节囊轮廓并生成关节囊几何模型。将下颌骨几何模型和3种牵引器简化几何模型导入有限元建模软件中,建立3种牵引器的下颌骨正中牵引成骨系统的有限元模型。结果:成功建立了使用3种牵引器下,颞下颌关节可自行旋转的下颌骨正中牵引成骨的有限元模型。结论:该模型仿真程度高,接近临床实际,为后续研究下颌骨正中牵引成骨对颞下颌关节的生物力学影响,提供了良好的实验平台。     

应用双向内置式牵引器矫正下颌骨短小畸形

目的:观察应用双向内置式下颌骨牵引器矫正下颌骨短小畸形结果.方法:下颌骨短小畸形2 例.在下颌角部位截骨,以下颌角为中心将双向内置式下颌骨牵引器上、下活动翼分别固定于升支和体部骨表面.术后第7 天开始牵引,各牵引螺杆的牵引速度为0.5~1.0 mm/d.待下颌骨升支高度和体部长度恢复较为理想后停止牵引,固定牵引装置3 个月. 结果:2 例患者均按计划完成牵引,无并发症.牵引升支和体部长度均为15 mm,下颌骨形态恢复理想.结论:双向内置式下颌骨牵引器可以在二维方向对下颌骨短小畸形的患者进行下颌骨形态重建,可以作为治疗不同类型下颌骨短小畸形的优选牵引装置之一.     

牵引成骨技术在肿瘤术后下颌骨重建中的应用

目的 探讨牵引成骨术在功能性颌骨重建中的应用。方法 使用３种不同类型的国产颌骨牵引器（２种是为颌骨不同类型重建而专门设计）及德国Ｍａｒｔｉｎ公司生产的垂直牵引器,共完成６例不同类型的颌骨缺失重建,其中２例升支大部切除,１例下颌骨体左侧缺失,３例分别为右侧及颏部保留下颌骨下缘的方块切除术后及下颌骨体左侧切除术后髂骨移植而骨量不足者。结果 ５例按术前设计的要求顺利完成牵引成骨重建,１例因牵引器一侧固定     

Three-dimensional finite element analysis of the mandible and temporomandibular joint on simulated occlusal forces before and after vertical ramus elongation by distraction osteogenesis

Distraction osteogenesis has recently become a mainstay for treatment of mandibular hypoplasia. Thorough knowledge about changes in the temporomandibular joint (TMJ) and the surrounding parts of the mandible and the skull after mandibular distraction is still lacking. The purpose of the current study was to investigate the stress distribution in the mandible and the TMJ before and after skeletal correction by intraoral unilateral vertical mandibular ramus distraction, using a finite element (FE) model. The FE models were based on computed tomography scans and magnetic resonance imaging scans of a patient with unilateral hypoplasia of the right mandibular ramus caused by juvenile idiopathic arthritis. The character of stress distribution in the mandible and TMJ before and after skeletal correction by 15 mm of vertical distraction of the mandibular ramus was analyzed quantitatively and compared during centric occlusion. Before the distraction osteogenesis treatment, the condyles, articular discs, and glenoid fossa regions are loaded with a different stress pattern. The affected right condyle, disc, and fossa are loaded diffusely and externally in comparison with the anterior and with centralized loading on the normal left side. After unilateral mandibular distraction osteogenesis, the load became more centric and symmetrical. The results suggest that correction of the mandibular deformity by distraction osteogenesis tends to normalize the stress patterns in the TMJ.     

牵张成骨术矫正单侧真性关节强直偏颌畸形1例

对1例因关节强直导致的偏颌畸形患者行下颌骨体牵张成骨器植入术,术后1周开始牵张右侧下颌骨,牵张20 d后右侧下颌升支及下颌体高度明显增加,牵张器维持4个月,右侧上颌骨自动向下生长,上下颌咬合关系恢复正常,取出下颌牵张成骨器,在牵张成骨新骨上植入MEDPOR假体并行颏成形术。手术完成后患者颜面不对称及畸形咬合关系均得到明显改善。     

内置自加载牵张器重建兔下颌支的实验研究

目的 :探索牵张成骨重建下颌支缺损的新方法。方法 :以成年新西兰兔为实验动物 ,手术切除下颌骨一侧部分升支及髁状突 ,造成 1.5cm的节段性骨缺损 ,骨断端”L”形截骨形成传送盘 ,安置可完全埋置于组织内的镍钛记忆合金牵张器 ,术后 2个月时处死实验动物 ,取下颌骨观察骨缺损修复情况。结果 :镍钛记忆合金牵张器能自动完成牵张成骨 ,初步重建了缺损的下颌支 ,组织学检查可见牵张区有良好的新骨再生。结论 :内置镍钛记忆合金牵张器可自动持续弹性加载牵张成骨 ,可望成为一种具有良好应用前景的简便实用技术。     

下颌角部牵张成骨的有限元分析

目的应用力学相似性较高的下颌骨三维有限元模型,分析角部牵张成骨对下颌内部应力分布及位移趋势的影响。方法在有限元模型的下颌角部模拟骨皮质切开并加载。结果获得角部单、双侧牵张成骨条件下,下颌骨内部应力分布和各部分位移的趋势。发现下颌骨角部牵张成骨应力集中在牵张部位。(牙合)平面有顺时针旋转的趋势,单侧加载较双侧加载下颌整体向对侧的位移趋势大。     

基于快速原型技术的导航辅助下颌骨内置式牵张成骨术的实验研究

目的：应用自主研发的导航手术系统,在快速原型技术制作的三维头颅模型上进行内置式下颌骨牵张成骨术的实验研究,通过三维定点测量,分析该导航手术的精度。方法：对1例单侧下颌骨发育不足的患者行螺旋CT扫描后,采用快速原型技术制作5个相同的头模,按导航配准原则植入定位钉后再行CT扫描。应用AccuNavi 1.0软件对三维图像进行测量,并与游标卡尺实体测量的相应指标进行头模制作精度检测。然后进行下颌骨三维测量分析与虚拟单侧内置式下颌支牵张成骨术,将制定的手术规划通过实时TBNavis-CMFS导航系统在三维头模上实施,牵引到位后,行CT扫描图像重建,应用AccuNavi1.0软件与Surgicase5.0软件进行三维测量与牵引长轴间成角测量,采用SPSS13.0软件包对结果进行配对t检验。结果：快速原型制作的三维头模与AccuNavi1.0软件重建的三维图像间各测量指标无统计学差异（P〉0.05）。模型手术平均牵引长度12.40mm（11.79～12.68mm）,模拟手术与导航模型术后牵引长轴间成角均值为4.67°（2.01°～6.49°）。导航术后各项指标中,除CoL-CoR（P=0.037）、CoL-GoL（P=0.017）与模拟手术值间有显著性差异外,其余指标间均无显著性差异（P〉0.05）。结论：应用快速原型技术制作的三维头颅模型与AccuNavi1.0软件的三维重建图像精度相仿。通过TBNavis-CMFS导航系统平台,建立了导航辅助下颌骨牵引成骨术的实验方法,准确地将手术规划转移到模型手术中。     

Backward distraction osteogenesis of condylar segment in patient with mandibular ramus deficiency--report of a case

A backward distraction osteogenesis (BDO) of the condylar segment for treatment of mandibular ramus deficiency was developed. This report describes the clinical progress of a patient with mandibular ramus deficiency in whom satisfactory occlusion was achieved and maintained by gradual posterosuperior repositioning of the displaced condyles into the glenoid fossae during intermaxillary fixation. Findings of pre- and postoperative clinical and magnetic resonance imaging indicate that the effect of BDO on the temporomandibular joint was negligible.     

A longitudinal three-dimensional evaluation of the growth pattern in hemifacial microsomia treated by mandibular distraction osteogenesis: a preliminary report

This study analyzed in three dimensions the longitudinal growth pattern of young patients with hemifacial microsomia (HFM) before and after mandibular distraction osteogenesis (DO). Six individuals with HFM (five boys and one girl; age at distraction, 12.5 +/- 2.4 years) were treated with similar procedures (surgery, type and direction of distraction, no functional orthodontic treatment before and after DO). Two individuals who did not undergo DO until late in their growth were used to compare growth patterns. In addition, one individual besides the six previously chosen sample in whom no DO was performed was also used to compare longitudinal growth patterns. Lateral and posteroanterior (PA) cephalograms were utilized preoperatively, spanning a period of 9 years. Computerized three-dimensional models were constructed from the lateral and PA cephalograms using a vector intercept algorithm. In the comparison group, for a period of 8 years on the affected side, the ramus height, body length, and total mandibular length increased at an average rate of 1.3, 1.9, and 3.0 mm per year respectively. On the unaffected side, the ramus height increased by 2.1 mm per year, 1.9 mm in the body, and 2.9 mm per year in total mandibular length. On average, the gonial angle on the affected side was increased by 1 deg per year, yet decreased by 1 deg per year on the unaffected side. The proportions between the affected to the unaffected side were maintained. In the six individuals 18 months after DO, it was found that the ramus height was reduced by 1.0 mm, whereas the body was found to resume its growth with a faster rate on the distracted side, maintaining its proportion. Angular changes demonstrated closing of the gonial angle on both the unaffected (0.5 deg) and distracted (3.5 deg) sides. Observed in three dimensions were the following: (1) On average, unoperated patients with isolated HFM tend to maintain their asymmetrical facial proportions and do not worsen substantially with time. (2) Different treatment effects were seen on the ramus, body, and total length of the mandible: changes in body length > ramus height > total length. (3) Eighteen months after DO, the correction was stable but with some degree of settling back from the initial overcorrection (< 5%). (4) Eighteen months after DO the mandibular body was found to have greater growth than the ramus. (5) Evaluating changes in three dimensions provides an improved understanding of the growth pattern and distraction effects on the mandible and its structural components. (6) Additional studies on the effect of mandibular distraction on other conditions involving mandibular deformities are required. In addition, the effect of various distractor devices should also be evaluated. Three-dimensional evaluation is recommended for improved accuracy.     

颞下颌关节强直的牵引成骨治疗

目的探讨牵引成骨技术在颞下颌关节强直治疗中的应用。方法应用内置式牵引器治疗8例单侧颞下颌关节强直患者,患侧升支区制备一个1.5～2.0cm颊舌向等宽的骨间隙,并去除喙突,恢复开口度,升支后缘方块截骨,截骨块保留翼内肌附着,与下颌骨间安装牵引器,术后采用升支牵引成骨术,每日牵引1mm,分2次完成,重建颞下颌关节结构及恢复颞下颌关节功能,并坚持开口训练18个月以上。结果经牵引成骨后,患者牵引间隙成骨良好,新形成的关节形态得到改建,升支高度延长1.2～2.1cm,开口度达到正常。结论牵引成骨是治疗颞下颌关节强直的有效方法。