Increased somatosensory amplification is associated with decreased pressure pain thresholds at both trigeminal and extra-trigeminal locations in healthy individuals.

BACKGROUND The diagnosis of temporomandibular disorders (TMD) is based on patient history and physical exam, and may require medical imaging. Masticatory muscle palpation is essential to make a diagnosis of TMD. However, the response of masticatory muscles to mechanical pressure stimuli depends on many physical and psychological factors. OBJECTIVE This study aimed at determining the impact of somatosensory amplification (SSA)-an estimate of somatic awareness and bodily hypervigilance-on pressure pain thresholds (PPTs) measured at both trigeminal and extra-trigeminal locations in healthy individuals. METHODS PPTs were measured at the right anterior temporalis and superficial masseter, and the thenar eminence of the right hand in one hundred individuals (69F, 31M), divided in three groups based on their SSA scores: low (N=32), intermediate (N=34), and high (N=34). General linear models were used to test between-group differences in PPTs including sex as a covariate. The level of significance was set at p 0.05). CONCLUSION Increased somatosensory amplification is associated with decreased pressure pain thresholds at both trigeminal and extra-trigeminal locations in healthy individuals. SSA could be a potential confounder while diagnosing TMD and evaluating treatment outcomes.