Abstract
The purpose of this clinical investigation was to document the natural history of temporomandibular joint disc displacement without reduction (closed lock). Fifty patients with an MR diagnosis of disc displacement without reduction were identified and examined clinically. Follow-up examinations were done at six and twelve months. Treatment became necessary because of severe symptoms in two of the 50 patients and these were excluded from the study. Pain and dysfunction was evaluated with visual analog scales. The degree on joint dysfunction was classified as no, slight, moderate, and severe. The changing of the classification was compared.
The results were as followings.
1) The maximal mouth opening was significantly increased from 30mm at the initial visit to 36mm at the six months and 42mm at the twelve months follow-up.
2) Pain on chewing and on opening and closing was significantly decreased at the twelve months follow-up. Interference with daily life was significantly improved at both six and twelve months follow-up.
3) The changing of the TMJ dysfunction at the six months follow-up showed no dysfunction (11%), improved (37%), no change (11%), and worse (11%), whereas that at the twelve months follow-up revealed no dysfunction (42%), improved (26%), and no change (32%).
The results of this study suggest that approximately one-third of patients with disc displacement without reduction will show no dysfunction and another one-third will improve over a twelve month period. In about one-third of the patients the symptoms will persist unchanged. Therefore, we should take the natural alleviation of the symptoms into consideration when closed lock is treated.
