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女受试者三叉神经痛阈的差异.三叉神经区域电流知觉和痛阈的测量1）电流知觉阈测量的重测信度2,000、250和5 Hz刺激后三叉神经的组内相关性分别为0.62、0.80和0.86。2）电流知觉和痛阈的性别差异无论刺激频率如何，女性的电流知觉阈显著低于男性，而女性的平均电流痛阈低于男性，但不显著。三叉神经热觉和痛阈的测量1）冷热刺激感觉阈的性别差异女性对冷热刺激的平均感觉阈低于男性，但性别差异不显著。由于p值略大于0.05，预计在较大样本中差异将是显著的。2）冷热刺激痛阈的性别差异冷热刺激痛阈没有性别差异。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，A δ、C纤维等痛相关神经纤维痛阈的性别差异可以忽略。口面部疼痛患者的性别差异可能不是由外周机制解释的，而是由疼痛感知的中枢机制解释的。

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.