Somatization and pain dispersion in chronic temporomandibular disorder pain

We investigated the relationship between somatic and psychological symptoms and pain reported during a clinical examination for 220 patients with chronic temporomandibular disorder (TMD) pain. The clinical examination involved palpation of the muscles of the face and neck, as well as intraoral sites and non-TMD-related placebo sites. A distinction was drawn between somatization--the tendency to report numerous somatic symptoms--and psychological distress manifested by report of numerous affective and cognitive symptoms. Somatization was assessed with the Somatization scale of the SCL-90-R; cognitive/affective distress was assessed with the non-somatic items of the Anxiety and Depression scales. Heightened somatization and high-intensity pain were strong predictors of widely dispersed muscle palpation pain during the clinical examination. High-somatization patients were 3 times more likely than low-somatization subjects to report having a painful placebo site. Pain dispersion was more closely linked to report of number of somatic symptoms than to report of affective and cognitive symptoms of psychological distress.