Prevalence and distribution of intracapsular derangement of TMJ in an asymptomatic and a symptomatic population
INTRODUCTION: The purpose of this study was to evaluate the prevalence and distribution of intracapsular derangement of temporomandibular joint (TMJ) in an asymptomatic and a symptomatic population. METHODS: 20 clinically asymptomatic subjects (mean age of 21 years) and 38 clinically symptomatic subjects (mean age of 26 years) underwent thorough evaluation by magnetic resonance imaging (MRI). Findings were interpreted by three experienced investigators using diagnostic categories. The agreement between the investigators was validated and then the prevalence of structural abnormalities was calculated. RESULTS: The mean percentage of disk-condyle disunions in the asymptomatic group was 13% and all disunions were only partial on all MRI slice. There was no degenerative change. In the symptomatic group, the mean percentage of disunion was 65.8%, the mean percentage of disunion with reposition was 31.6% and the mean percentage of disunion without reposition was 34.2%. With regard to disunion with reposition, the mean percentage of partial disunion was 79.2%. The mean prevalence of degenerative changes was 23% and degenerative change was linked with disunion without reposition. CONCLUSION: The prevalence and distribution of structural abnormalities was very different in the asymptomatic and symptomatic population.