Alexithymia and pain in temporomandibular disorder.

Objective: To clarify the relationship of global alexithymia and its facets with pain, assessed prospectively using experience sampling methods (ESMs), in temporomandibular disorder (TMD).

Methods: People with painful TMD (n=49), pain-free somatic controls (24 people with disk displacement), and healthy controls (n = 28) completed measures of alexithymia (Toronto Alexithymia Scale-20 [TAS-20]) and depressed mood. Patients with painful TMD used ESM to record jaw pain multiple times daily for a week.

Results: The somatic and the healthy controls were equivalent on alexithymia and were combined. The painful TMD group had higher difficulty in identifying feelings but lower externally oriented thinking (EOT); only the latter effect remained after covarying depressed mood. Among patients with painful TMD, the TAS-20 total and EOT correlated positively with pain severity after controlling for depressed mood.

Conclusion: Findings highlight the complex relationships of alexithymia and its facets to TMD pain. Research should examine alexithymia facets separately and distinguish between methods that compare groups on alexithymia (e.g., pain patients versus controls) and those that correlate alexithymia with pain severity within a group.