摘要
利用张力带固定原理治疗下颌骨骨折在国外已普遍开展，国内几所医学院校也开展了此项工作，我科从2003年1月开始开展了张力带治疗下颌骨骨折，至2003年12月共收治下颌骨不同部位的骨折23例，共计47处骨折。其中下颌骨颏部骨折 26处，下颌角部骨折12 处，及髁颈部骨折 9例，经张力带固定后均未做颌间结扎固定，术后即可以进半流质食物，利于口腔卫生保健。术后7天拆线，无一例患者出现创口感染， 自由开口度均达37mm以上。47例患者中，无一处骨折固定后出现固位钉松脱，夹板折断，骨创感染，排斥反应，损伤下牙槽神经管和牙根等情况。46例骨折断端对位对线良好，咬合关系恢复；1例咬合关系恢复不良。除1例患者因下颌骨未发育完成，在术后6个月，行二次手术取出固定夹板外，其余患者均未取出夹板。2例髁颈部骨折患者术后出现不同程度的暂时性面瘫症状，术后给予维生素B1、B12口服，中频激光理疗，术后6个月复查时，面瘫症状消失。
在47处小型接骨板沿张力带固定治疗下颌骨骨折中存在的问题及分析：
1、手术入路的选择：结合47处骨折的手术治疗，作者认为应根据骨折的具体部位和坚强固定的需要选择手术入路。保证沿张力带固定的需要，同时尽量减少手术的创伤，贯彻AO倡导的无创外科的原则，保存血运，保存骨膜。
颏部及下颌角有利型骨折一般选择口内入路；髁颈部骨折采用耳屏前入路。
2、关于坚强内固定骨折复位问题：作者认为应根据骨折类型及严重程度选择相应的骨折复位方法。
在已有的治疗下颌骨骨折的文献报告中，多采用术中牵引复位的方法。
在26处颏部骨折经术中牵引复位的骨折病例中，有1 例术中牵引复位的患者经坚强固定后，咬合关系恢复不良，术后影像学检查提示骨折断端对位对线欠佳。
作者认为对于骨折线倾斜角度较大、骨折段移位明显，或双线多线骨折的病例可在术前局麻下手法复位利用上下颌弓夹板进行颌间弹性牵引3至4天，恢复患者的伤前咬合关系。这种方法的临床可行性需要更多的实践来检验。
总结47处骨折坚强内固定的治疗经验，可以认为：复位必须应以解剖复位为金标准，即三维复位，复位应以咬合关系的
恢复，骨折断端对位对线的恢复为标准。
3、固定夹板放置的位置：Champy基于解剖和生物力学研究详细地阐述了下颌骨理想固定路线，对临床实践具有重大的指导意义。但骨折类型多种多样，骨折线的走行千差万别，不能保证所有的骨折的固定夹板都完全沿张力带固定。临床实践中要根据骨折的部位、局部解剖特点选择适当的长度的夹板、夹板的具体位置和角度。
4、下颌角骨折利用小型夹板沿张力带固定时第三磨牙的去留问题：
在本研究中的12例下颌角骨折的治疗中，复位固定前4例将骨折线上的智齿拔除，避免智齿妨碍骨折的正确复位和术后的骨创感染。拔除智齿后，视拔牙创周牙槽骨存留量的多少决定固定方法。如果，拔牙创处外斜线的有足够的骨支持，选用一个小型夹板沿外斜线固定骨折断端；如果骨折线对应的外斜线处无足够的骨支持，则在下颌角部用二块小型夹板固定，单用一块小型夹板不能取得足够的固位力。同时相应选择口外入路。另外8例骨折线上智齿因不妨碍骨折的复位，牙体、牙周组织健康，术中保留智齿，沿张力带固定。术后影像学检查提示骨折复位充分，固定稳定，无一例出现骨创感染。
第三磨牙的无能为力留问题始终是治疗下颌角骨折争论的一个焦点问题，本试验的结论与大多数文献报告的观点是一致的。
5、髁状突骨折的治疗：在髁突骨折的治疗，存在有保守治疗和手术治疗２种观点。经有关学者从动物实验，Ｘ线远期观察以及临床实践证实：极大多数骨折经保守治疗后效果良好，少有颞下颌关节病的发生。
目前，达成普遍共识的是：对成角<30度无移位的骨折或由于骨折后髁状突移位，造成下颌升支高度丧失高度4mm以下者采用保守疗法；对于成角>30度，升支高度丧失在4mm以上者，或移位，脱位或开放性骨折均应手术复位，微型钢板或金属丝行内固定。同时应考虑患者的年龄对骨折手术预后的影响。
对下颌骨发育尚未完成的骨折病例应采用保守治疗，依靠关节较强的改建能力恢复垂直高度，避免手术对下颌骨发育的影响。
经治疗的 9处髁状突颈部骨折病例应用手术复位，坚强内固定治疗。术后的患者术后即可开口，进半流质食物，术后开口度平均达3.8mm。
其中 2例患者术后出现不同程度的面瘫症状，术后随访，
2例患者的面瘫症状在术后6月均消失。据此，可以认为造成面瘫的原因在于面神经位于手术入路上，术中牵拉造成的面神经功能暂时性障碍，临床上表现为低位骨折的患者出现面瘫的机率及严重程度明显高于高位及中位髁颈部骨折的病例。
2处高位髁颈部骨折，经张力带固定术后，因骨折断端皮质骨较薄弱，采用弹性绷带固定一周。作者认为高位髁颈部骨折手术时应根据可用骨皮质的量，严格掌握坚强内固定的适应证，规范技术操作，按骨折的主应力轨迹安置接骨材料。
髁颈部骨折手术治疗可以避免颌结扎固定，减轻了对关节组织结构的影响；但同时也增加了术中损伤面神经的可能性。是否可以通过口内入路治疗下颌骨髁颈部骨折或下颌骨髁颈部骨折的某些类型
Title：23 cases of the madibular fractures were treated by rigid internal fixation(RIF) along the strain belt of mandible
The mandibular fractures are very normal in our daily work in oral maxillafacial surgery.It is very commonly in some special regions,such as the angle of mandible, foramen mentale,symphysion,neck of condyloid process of mandible,and so on.Therapy of mandibular fractures is a difficult problem in oral maxillafacial surgery.Rigid internal fixation(RIF) along the strain belt of mandibular has been wildly used at abroad.Several medical college-hospitals have brought in this technique.Our faculty has put this technique into practice since 2003,Janurny.We has treated 23 patients with 47 mandibular fractures until the end of 2003.EBM has been used in the research..The results and existing problems
of the theory in practice were discussed.
There were 47 fractures in 23 patients,including 26 foremen mentale fractures,12 angle of mandibular fractures and 9 neck of condyloid process of mandiblar fractures.All the 47 fracures were treated by rigid internal fixation along the strain belt of mandibule without intermixillary fixation.After operations,these patients could eat soft food without any case infected, miniplate broken,lag screws loosen or drill into the root of teeth.Normal occluding relation and function were restored except one case.The possible causes lies in that interface s of fracture weren’t restored completely or the restoration was unstable.Anatomic restoration is demand in order to acquire normal occluding relation and function.
The author considers that operative sites should be performed according to the positions and rigid internal fixation’s demands.and minimized the injury of the osseo-menbrane.The repositions of 47 fractures were
performed in operations.The method of repositions of fracture is wildly reported.The author considers that the reposition of fracture is finished before the operations will simplify the operations.The advantages and disadvantages are discussed.
The selection of site of fixation should be along the strain belt of mandible.But in practice,this method still has many problems which needs further research.
Postoperation X-ray check shows 46 fractures have been restored completely and 1 and 47 fractures haven’t reached the anatomic restoration.The main cause might be the lose of the bone between the interfaces of fracture.
Whether the third molar in the fracture line should be extracted or not dosen’t still reach an agreement.The cause is that the third molar can lead to infection and at the same time the third molar is helpful to the stability of the rigid internal fixation.The choice of therapy needs further research and clinical practice.
The treatment of fractures of the mandibular condylar
process(es) can be conservative or surgical.
Despite of effectiveness and many adventages of closed reduction of condylar neck fracture,open reduction techniques offer the advantage of anatomic repositioning of the fracture,which may reducee resultant deformities, malocclusion and temporomandibular joint derangements in patients with complex subcondylar fractures.This objective is best achieved with rigid plate and screw fixation to obtain the stability required for immediate function.
Bony union was obtained in all fracture with permanent facial nerve injuries and good mandibular opening.We conclude that condylar fractures can be opened and fixed with plates and screws with good results without the use of intermaxillary fixation.This technique can be an effective approach for the treatment of selected condylar fracture.The non-surgical treatment of mandibular condylar fractures may occasionally result in articularimbalace and temporomandibular joint
dysfunction. This may be attributed to conylar head displacement and resorption,resulting in a shorted vertical ramus and lost posterior vertical facial height.
Restoring the vertical ramus height is essential in the treatment of such dysfunction,and may be accomplished
引文
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