(191) Stress Dysregulation in Temporomandibular Disorder: A Study on Autonomic Reactivity and Recovery

Abstract

Mental stress is a common trigger for worsening pain symptoms in temporomandibular disorder (TMD) and related pain conditions. The cumulative effect from dysregulated stress response (reactivity) and stress recovery is a key factor that links stress to chronic diseases. Although dysregulations in major stress systems have been shown in TMD, little is known about physiological recovery after mental stress exposure in TMD. This pilot study aimed to systematically assess differences in heart rate variability (HRV), a physiological marker of stress reactivity and recovery to mental stress in TMD cases and controls. Based on the Diagnostic Criteria for TMD, 26 females (11 controls and 15 cases) were recruited. Participants completed the Trier Social Stress Test (TSST) which consisted of 3 phases: 1) 15 minutes baseline, 2) 15 minutes of stress exposure, and 3) a recovery period lasting up to 60-minute post stress exposure. Time and frequency domain HRV measures were assessed. Mixed-model ANOVA with repeated measure and Friedman test, along with a two-sample t-test and the Wilcoxon rank-sum test, were used when appropriate to test group (2), time (11 time points) and group x time effects on stress reactivity and recovery (alpha = 0.05). At baseline, a group main effect was noted with the control group showing greater values in SDNN, VLF, LF, TP, and LF/HF ratio HRV measures. During stress exposure and recovery phases, a group main effect was observed with the control group expressing greater SDNN, RMSSD, LF, HF, and TP HRV values compared to TMD participants. Post hoc analysis revealed that the largest group differences were observed in the recovery period during minutes 10 to 30. A group x time interaction was not observed for any HRV measure. These results indicated dysregulations in stress reactivity and recovery that both should be considered when develop TMD intervention strategies.