Analysis of clinical observations in patients of temporomandibular joint dysfunction

Abstract

The etiology of temporomandibular joint (TMJ) dysfunction remains unclear in spite of recent progress in several diagnostic methods. In order to obtain more information of this disease, we performed this study.
Patients of TMJ dysfunction who visited our clinic from 1981 to 1988 amounted to 1408, occupying from 9 to 10% of all outpatients in the last 3 years. The 1408 cases from 1981 to 1988 were analyzed regarding their age and sex, and 108 cases of first half of the year in 1988 were analyzed more extensively by use of the classification which the 7th TMJ workshop (Gakukansetu-kenkyukai 1987) proposed.
We have found several findings as follows.
1) The sex ratio of TMJ dysfunction patients was 1:2.6. The incidence of TMJ dysfunction patients showed highest frequency from 15 to 19 year of age.
2) Type III of TMJ dysfunction was most frequent (61%). Typle III was further divided into III a (anterior displacement of the disk with reduction) (31%) and III c (anterior displacement of the disk without reduction) (30%). Type I was 21%, type II was 16% and type IV was 2%.
3) In males there were few patients of TMJ dysfunction type III c.
4) 77% of TMJ dysfunction patients had muscle symptoms.
5) 84% of TMJ dysfunction patients had occlusal problems, Occlusal interferances in lateral and protrusive movements were observed in every type of TMJ dysfunction, but disturbance of centric occlusion were more frequently observed in type III of TMJ dysfunction.
6) Treatment methods were evaluated for each type of TMJ dysfunction.