Evidence for Sustained Mechanical Pain Sensitization in Women With Chronic Temporomandibular Disorder Versus Healthy Female Participants

Generalized dysfunction of the nociceptive system has been hypothesized to be an important pathophysiologic process underlying temporomandibular disorder (TMD) pain. Studies have not identified sensitization to painful stimuli administered prospectively across consecutive days among participants with TMD with chronic pain. We attempted to isolate an empirically derived laboratory-based marker of sustained mechanical pain sensitization. We examined whether this index accounted for variance in prospective assessments of clinical TMD pain. Participants were women with a clinical diagnosis of chronic TMD (n = 30) and healthy female controls (n = 30). Pain thresholds were assessed using digital algometry 4 times at 12-hour intervals over 48 consecutive hours and clinical TMD pain via follow-up telephone assessments. Sustained mechanical pain sensitization, defined by statistically significant linear decrements in pressure pain thresholds across the consecutive testing sessions, discriminated chronic TMD and control participants. An index of sustained sensitization at the masseter accounted for unique variance in clinical TMD pain over the subsequent 3-month assessment period, even controlling for mean pain threshold and baseline pain severity. These preliminary findings highlight discriminant and predictive validity characteristics of a novel marker of protracted pain sensitization among women with chronic TMD pain. Perspective A laboratory-based and empirically defined marker of sustained mechanical pain sensitization over the course of days with acceptable discriminant and predictive validity was identified. This marker may represent a clinically useful marker of chronic TMD pain in women.