人翼外肌的肌构筑特征及其与颞下颌关节的附着关系

Characteristics of muscle architecture in human lateral pterygoid muscle and relationgships between it and attachments of tempo-romandibular joint

目的 探讨人翼外肌的肌构筑特征及其与颞下颌关节的附着关系 ,明确翼外肌上、下两头部的生物力学特性。方法 对人 10侧翼外肌的肌构筑指数作了测算和量化分析。结果 翼外肌上、下两头部均为带状短肌 ,肌纤维穿过颞下颌关节囊终止于关节盘前、内侧部 ,其余部份肌纤维与下头部纤维交织共同止于髁突的关节翼肌窝。上、下两头部各肌构筑指数比较 ,除上头部肌的生理横切面积 /肌重及肌纤维长 /生理横切面积的比值显著高于下头部 ,其余构筑指数以下头部显著高于上头部。结论 翼外肌上头部较下头部更兼备力量和速度 ,其在调控颞下颌关节盘位置及位移中起重要作用。翼外肌下头部则充当颞下颌关节运动的主体和原动肌。

Objective To explore characterisics of muscle architecture in human lateral pterygoid muscle and relationships between it and attachments of temporomandibular joint (TMJ), and to confirm properties of biomechanics in superior and inferior heads of the pterygoid muscle.Methods Muscle architecture indexes were determined for ten specimens of the pterygoid muscles, and figured out as well as analyzed by a mechanical formula.Results Superior and inferior heads of the pterygoid muscle appeared as short muscle bundles, muscle fibers of which ran parallel to tendon axle. A part of them in the supperior head penetrated TMJ capsule, firmly attaching to the anterior medial portion of the capsule. And the rest of them mingled with muscle fibers of the inferior head, in turn, all attaching to the joint pterygoid fovea on the condyle. The ratios of physiological cross- sectional area/muscle weight and of muscle fiber length/physiological cross- sectional area in the superior head were obviously higher than in the inferior head.On the contrary, the rest indexes in the inferior head were significantly higher than in the superior head.Conclusions These results demonstrate that the superior head of the pterygoid muscle is mainly involved in force and velocity production,playing an important role in the trusion of TMJ disc and the control of TMJ's location. The inferior head of the pterygoid muscle, however, serves as a mainbody and initiator for TMJ's movements.