Longitudinal changes in temporomandibular disorders in young adults: indication for systematic temporomandibular joint screening.

OBJECTIVE: The aim of this study was to investigate longitudinal changes in temporomandibular joint function in young adults in terms of clinical and subclinical temporomandibular disorders (TMD), and to identify patients at risk for clinically manifest TMD.

SUBJECTS AND METHODS: Ninety-one consecutive dental students were surveyed over a mean period of 2.4 years. The temporomandibular joint and masticatory muscles were analyzed by means of the Manual Functional Analysis. Examinations took place during the first (T1) and sixth (T2) terms of dental training.

RESULTS: The prevalence of subclinical TMD decreased from 16.5% to 15.4%, while that of clinical TMD rose from 19.8% (T1) to 24.2% (T2). Subjects with subclinical TMD at T1 showed the most pronounced fluctuation, and were about equally likely to improve, remain stable or deteriorate. The incidence of clinical TMD in the subclinical TMD-group was 28.6%, that is, almost every third subject developed clinical TMD over a 2.4-year period.

CONCLUSIONS: Should clinical TMD become apparent during orthodontic treatment, the patient might attribute it to the therapy, rather than to the subclinical disorder at baseline. It thus makes therapeutic and forensic sense to carry out systematic TMJ-screening in all adult patients prior to orthodontic treatment, in order to identify patients at risk.