International Comparative Study on Pain Cognition and Pain Sensitivity in the Orofacial Region

本研究的目的是比较健康男性和女性志愿者三叉神经区的痛阈值。三叉神经区电流知觉阈值和痛阈值的测量1)电流知觉阈值测量的重测信度三叉神经组内相关系数分别为0.62、0.80和0.86。无论刺激频率如何，女性的当前知觉阈值显著低于男性，而女性的平均当前痛觉阈值低于男性，但并不显著。三叉神经区热知觉和痛觉阈值的测定1)热、冷刺激知觉阈值的性别差异女性对热、冷刺激的平均知觉阈值低于男性，但性别差异不显着。2)热刺激和冷刺激痛阈值的性别差异在热刺激和冷刺激的痛阈值上没有性别差异。这些结果表明，与健康男性相比，健康女性对触觉或压力感觉更敏感，而与疼痛相关的神经纤维如A-δ和C纤维的痛阈值的性别差异可以忽略不计。口面部疼痛患者群体的性别差异可能不是由外周机制而是由痛觉的中枢机制来解释的。

The purpose of this study was to compare of the pain threshold in the trigeminal nerve region between healthy male and female volunteers.1. Measurements of current perception and pain thresholds in the trigeminal nerve region1) The test-retest reliability of current perception threshold measurementsIntra-class correlations for the trigeminal nerve following 2,000, 250, and 5 Hz stimulation were 0.62, 0.80, and 0.86, respectively. Reliability was therefore favorable for all three frequencies.2) Gender differences of current perception and pain thresholdsIrrespective of stimulation frequencies, the current perception threshold was significantly lower in females than in males, whereas the mean current pain threshold was lower, but not significant, in females than in males.2. Measurements of thermal perception and pain thresholds in the trigeminal nerve region1) Gender differences of perception threshold for hot and cold stimuliThe mean perception thresholds for hot and cold stimuli were lower in females than in males but the gender differences were not significant. Since the p-values were slightly bigger than 0.05, it is anticipated the differences would be significant in bigger samples.2) Gender differences of pain threshold for hot and cold stimuliThere were no gender differences in pain threshold for hot and cold stimuli.These results suggest that, compared to healthy-males, healthy females are more sensitive to tactile or pressure sensations, and that the gender differences on the pain threshold with pain-related nerve fibers such as A δ and C fibers can be ignored. The gender difference of patient population with orofacial pain might be explained by not the peripheral mechanism, but the central mechanism of pain perception.