Psychological Factors in Subjects With and Without TMD History

Objectives: Studies on the role of psychological factors in temporomandibular disorders (TMD) have been equivocal. In a double blind RCT by Le Bell et al. (2002) subjects with a previous TMD history reacted differently to artificial interferences compared to subjects with no TMD history. In the present study, we further investigated these subjects. Methods: The study sample consisted of 26 women (mean age 24yrs) without and 21 women (mean age 31) with TMD history. The subjects with TMD history had been treated earlier and they felt healthy when the intervention started. Both groups were divided into true interference and placebo interference subgroups. Before the intervention, the subjects filled in questionnaires regarding psychological and somatic symptoms, coping strategies (COPE), personality characteristics (Karolinska Scales of Personality) and health beliefs (HHI-questionnaire). Every day during the 2-week intervention, the subjects rated the intensity of their symptoms on 10 VAS scales (occlusal discomfort, chewing difficulty, tender teeth, fatigue in the jaws, headache, facial pain, opening difficulty, bruxism, ear and other symptoms). Results: In general, the two groups did not differ in their personality traits. However, there were some differences. TMD-history seemed to be associated with more frequent reports of several somatic symptoms, but less frequent reports of psychological ones (e.g. depressive symptoms). The subjects with TMD history were also less socialised and reported less control over their health. The subjects with TMD history and exposed to true interferences reacted more strongly with occlusal discomfort compared to the other groups. Conclusions: The higher sensitivity towards occlusal interferences in subjects with TMD history is associated with psychological factors.