颞下颌关节髁状突向前生理运动范围的探讨

<正> 众所周知,下颌生理运动极为复杂,但仍可归纳为三种基本形式:即开闭运动、前后运动及侧方运动。在这三种基本生理运动形式中,以开口运动中的最大开口时,下颌骨髁状突的向前生理运动范围最广。传统的观点认为:在最大开口时,髁状突皆同关节盘运动至关节结节的下方或稍前下方而不超过。但当翼外肌功能紊乱或关节结构病变时,在开口末,翼外肌再继续收缩以至

A STUDY ON THE PHYSIOLOGIC RANGE OF THE FORWARD MOVEMENT OF THE CONDYLE OF THE TEMPORO-MANDIBULAR JOINT

114 (71males,43 females)college student' temporo-mandibular joint without click,pain and limitation of movement were studied by X-ray video fluoroscopy,roentgenogram and X-ray television recording.The results were outlined as follows: During maximal opening of the mouth,the relationship regarding the movement position between the condyle and articular eminence may be divid- ed into four types,namely:1.Type Ⅰ,the condyle of both sides move antero-superior to the articular eminence;2.TypeⅡ,antero-inferior;3. TypeⅢ,inferior;4.TypeⅣ,posterior. Among the 114 cases,64 cases belong to type Ⅰ (56.14) ,29cases typeⅡ (25.44%),20 cases typeⅢ(17.50%) and 1 case typeⅣ(0.88%). Type Ⅰ is the most common,which occurs in 36 males and 28 femal- es,no significant difference were found (P>0.05) between the males and females. Contrary to subluxation and dislocation maxinal opening of the mouth can pull the condyle moving antero-superiorly to the articular eminence and then it can return to the glenoid fossa without click,pain and limitation of the movement,so that under the normal condition,it is emphasized that the condyle moves antero-superiorly to the articular eminance could be consider- ed as physiologic position,rather than the traditional ideas such as sublu- xation or dislocation.