Braz Oral Res. 2026 Nov 9;40:e092. doi: 10.1590/1807-3107bor-2026.vol40.092. eCollection 2026.
ABSTRACT
Conditioned pain modulation (CPM) assesses descending pain inhibition in humans and has been shown to be clinically relevant. However, the possible contribution of the CPM response to the efficacy of local anesthetics remains poorly understood. This study aimed to evaluate the association between the CPM response and the efficacy of topical anesthesia applied to the trigeminal region in females with chronic orofacial pain and healthy participants. Thirty-five females with painful temporomandibular disorder (TMD) and twenty healthy females were included. Somatosensory sensitivity of the masseter region was assessed at baseline and after the application of 4% lidocaine and placebo creams in three separate sessions. A sequential CPM protocol was assessed at baseline. The test stimulus (TS) was the pressure pain threshold of the anterior temporalis, and the conditioning stimulus was immersion of the forearm in hot water for 1 minute. CPM magnitude was calculated as the relative change between the unconditioned and conditioned TS, which was correlated with the relative changes in somatosensory sensitivity between the lidocaine/placebo and baseline sessions. The significance level was set at 0.2% following a Bonferroni correction (p = 0.002). There was a moderate, positive correlation (r = 0.54; p = 0.001) between the relative change in the cold detection threshold in the lidocaine session and CPM for participants with chronic painful TMD. There was no correlation between the degree of anesthesia and CPM in healthy females. The efficiency of descending pain inhibition may influence the effectiveness of topical anesthesia in patients with chronic orofacial pain.
PMID:43017982 | DOI:10.1590/1807-3107bor-2026.vol40.092
