MRI Views of the Temporomandibular Joints between Male and Female Volunteers in 20's

The purpose of this study was to compare image diagnosis made by magnetic resonance imaging with the clinical symptoms of volunteer subjects who did not have temporomandibular disorders (TMD) as chief complaint. We collected 100 male and 100 female volunteers of the 20~29-years-olds age bracket by random sampling. Each subject self- reported whether or not they had TMJ disease symptoms that include pain, joint noise in his/her TMJ, and limited mouth opening in the range between their upper and lower incisal edges. After these reports, we performed MRI of TMJ at the time of the closing and opening of the jaws. Then we decided the diagnosis and compared the TMJ status between the males and females. The mean age of males was 24.2 years ; and that of females, 23.8 years. The mouth opening range limit incidence of less than 40 mm showed a prevalence of 5.0% for the males and 21.0% for the females. The respective prevalence of joint noise for males and females was 30.0% and 28.0%. Males have a prevalence of sharp pain of 6.0% ; and females, 4.0%. Most of the subjects showed no disc displacement (NDD). Anterior disc displacement with reduction (ADDwR) occurred in 17.5% male joints and in 15.0% female joints ; and that without reduction in 6.5% male joints and 14.5% female joints (p<0.05). 1.0% male joints and 2.5% female joints showed joint effusion on T2 weighted images, which occurred only in anterior disc displacement without reduc- tion. No individuals had posterior disc displacement. Also, none had edema or osteonecrosis on all of volunteers bone marrow. The mean values of maximum opening range of NDD, total subjects and of subjects ADDwR were significantly lower in female than in male (p<0.05). In conclusion, it is demonstrated that there are many individuals who suffered from TMD in patients who did not indicate TMJ problems as a chief complaint. Thus we plan to analysis many TMJ conditions by using MRI and evaluate with TMD patient cases.