Evidence suggests that orthodontic treatment as a child is not related to later TMD

Abstract

Design Prospective cohort study of 402 randomly-selected individuals aged 7, 11 and 15 years at baseline. A total of 320 completed a questionnaire after 20 years of which 100 patients, who were aged 15 at initial examination, were re-examined. Orthodontic treatment in the oldest age group was scrutinised by individual case records. Outcome measure The questionnaire dealt with the presence of symptoms such as headaches, frequent stress or depression, previous trauma to the face, experience of temporomandibular disorders (TMD) during the 20 years of observation and current demand for TMD treatment. The clinical examination was conducted to measure any TMD signs and symptoms including limitation to range of movement, temporomandibular joint sounds and pain. Tooth wear was recorded on a five-point scale where 1 indicated no wear and 5 indicated wear of more than one-third of the clinical crown. Results One hundred and two patients had received orthodontic treatment, 192 no orthodontic treatment and 26 did not know. Correlations between signs and symptoms of TMD and different malocclusions were weak. Lateral forced bite and unilateral crossbite were correlated with TMD signs and symptoms at the 10- and 20-year follow-ups (r2=0.38, P<0.05 and r2=0.34, P<0.01, respectively). Subjects who had malocclusion over a long period of time tended to report more symptoms of TMD and to show a higher dysfunction index, compared with subjects with no malocclusion at all. Conclusions There were no statistically-significant differences in the prevalence of TMD signs and symptoms between subjects with or without previous experience of orthodontic treatment.