RESUMEN
OBJECTIVE: Compare heart rate variability (HRV) indices in participants with and without myogenic temporomandibular disorder (TMD). Secondarily, we correlated HRV indices with pain and quality of life variables. METHODS: This is a comparative observational cross-sectional study. Individuals of both genders with and without a history of TMD were included. Short-term heart rate variability was assessed using a Polar V800. Central sensitization was assessed using the Central Sensitization Inventory. Pain through the numeric pain scale and the impact of oral health on quality of life using the OHIP-14 questionnaire. RESULTS: A total of 80 participants were enrolled in the study: most individuals included in both groups were young adults, women and slightly overweight. We observed a decrease in HRV in the TMD group (p < 0.01) when compared to the control group. In addition, we observed a greater impact of oral health on quality of life, central sensitization in addition to high resting pain scores (p < 0.01). We observed significant correlation between the LF index of HRV and the FAI score (r = 0.311; p = 0.05). The NPS, CSI and OHIP-14 scores did not correlate with any of the HRV indices (p > 0.05). CONCLUSION: The short-term HRV in individuals with TMD is significantly lower when compared to a control group. Furthermore, there seems to be a relationship between the severity of the dysfunction and the HRV variables. CLINICAL RELEVANCE: Using portable and low-cost devices, the HRV can be easily collected and analyzed, without the need for an arsenal of equipment such as the conventional electrocardiogram. This measure can contribute to the therapy adopted and identify individuals prone to unfavorable outcomes involving ANS modulation.