口腔治疗中不同颌位与髁突位置

在口颌系统中,与颌位稳定相关的因素分别是、颞下颌关节和神经肌肉的稳定,其中髁突在关节窝中的位置与获得一个稳定的颌位密切相关。但口腔治疗中涉及到颌位的选择时,不同学者持不同的观点,对于髁突在关节窝中应处的位置也一直处于争议之中。本文对口腔修复和正畸治疗中颌位选择及“髁突前上位”、“髁突前下位”、“治疗性颌位”的适应证、理论基础及临床应用作一综述。文献复习结果提示,当关节无器质性改变或髁凹关系稳定时,髁突前上位即正中关系为传统建的理想颌位。当关节盘增生、变形、盘突关系紊乱无法寻找理想的髁突前上位时,可选择髁突前下位,缓解关节症状的同时促进骨质改建获得良好的稳定性;甚至对于部分安氏Ⅱ类高角或者轻度骨性错的病例,亦可以尝试利用髁突改建的潜力,前下定位髁突,通过掩饰性矫治简化正畸正颌手术方案;而“治疗性颌位”是针对颅下颌功能紊乱症导致的最大牙尖交错位异常或偏斜、肌肉症状和关节功能异常、颌位不稳定等,通过改变原有咬合或关节的异常引导,在有咬合支持和新的引导的基础上,建立并且稳定一个新的牙尖交错位。它摆脱了髁突定位的争论,但此颌位下髁突具体位置未见报道。不同颌位及髁突位置有不同的适用范围,临床选择时应根据患者关节是否有器质性改变及颌位的稳定性进行综合判断。但对于采用不同颌位和髁突位置进行口腔治疗的远期效果未来还需临床对照试验进一步验证。

Different jaw positions and condylar positions in oral therapy

In the stomatognathic system,a stable jaw position is influenced by occlusion,the temporomandibular joint and neuromuscular stability.The condylar position in the glenoid fossa is closely related to the jaw position,while no consensus has been reached on the optimum jaw position and its corresponding condylar position in oral therapy.This paper summarizes the controversial opinions regarding the selection of jaw position and the corresponding condylar position in prosthetics and orthodontics,including antero?superior,antero?inferior,and therapeutic positions.Their indi?cations,theoretical bases and clinical applications are also included.The literature review results suggest that,the antero?superior position,in other words,centric relation,should be chosen when the patient has a stable jaw position with?out TMD.In cases where finding an ideal antero?superior position is difficult due to hyperplasia or deformation or disar?rangement of the articular disc,the antero?inferior position is recommended to alleviate symptoms and facilitate recon?struction of the TMJ to obtain good stability.Moreover,for high?angle patients with ClassⅡmalocclusion or for patients with mild skeletal malocclusion,camouflaged orthodontic treatment combined with antero?inferior jaw repositioning through the potential of condyle remodeling can be an alternative to orthognathic surgery and can simplify the treatment plan.While the therapeutic position is specifically proposed for coping with complicated situations related to cranio?mandibular dysfunction,such as maximal intercuspal position abnormalities or deflection,muscle and TMJ dysfunction,unstable jaw position,in which changes in the original occlusion or abnormal TMJ guidance are induced,and a new in?tercuspal position can be established and stabilized on the basis of occlusal support and modified guidance.The thera?peutic position put aside the debate regarding condylar position,however,the specific position of the condyle has not been reported in this case.This review suggests that different jaw positions and condylar positions have different scopes of application,and their clinical selection should be based on based on whether the patient′s joints have organic chang?es and the stability of the jaw positions should be comprehensively considered.However,the long?term effects of oral therapy based on different jaw positions need to be further verified by controlled clinical trials in the future.