顎関節内障患者の咀嚼時における外側翼突筋に関する筋電図学的研究

抄録

The purpose of this study was to investigate the relationship between internal derangement of temporomandibular joint and EMG activity of the superior (SLpt) and inferior (ILpt) heads of the lateral pterygoid muscles.
Subjects consisted of 5 normal controls, 4 patients with painless click, and 3 patients with closed lock. Together with condylar and incisal movements, EMG was recorded together with at the SLpt and ILpt, the anterior belly of the digastric muscle (Da), the temporal muscle (Tp), and the masseter muscle (Mm).
EMG activity of the SLpt and ILpt was considerably decreased in order of patients with click and closed lock. These patients also showed disorderd synchronization of EMG activity with condylar movement. It became clear that EMG activity of the SLpt and ILpt decreased in accordance with the deterioration of internal derangement of TMJ. It is suggested that malfunction of the lateral ptergoid muscle could participate the deterioration of internal derangemant of TMJ.