Acupuncture Modulates Facial Warm Sensory Thresholds

Aims: To assess the effects of four- and six-point acupuncture on facial sensory detection thresholds to thermal and electrical stimuli. Methods: Ten healthy volunteers underwent four-point acupuncture at ST6 and LI4 bilaterally for 15 minutes. A further 10 subjects underwent six-point acupuncture by adding needling at ST2 bilaterally. Sensory testing to thermal and electrical stimuli applied to mental and infraorbital nerve dermatomes was performed at baseline, 10 minutes, 1 hour, and 1 day after needling. Results: In the mental and infraorbital nerve dermatomes, six-point acupuncture significantly increased warm threshold by a peak mean of 1.1°C to 1.4°C (repeated measures ANOVA P = .001) and this effect was significant at all time points relative to baseline (P .05). No significant effects were observed by the four-point acupuncture on warm thresholds, and neither four- nor six-point acupuncture significantly altered electrical detection thresholds. Conclusion: A dose effect, related to the number of points employed, may be present when employing acupuncture. Keywords: AB-fibers, C-fibers, electrical thresholds, warm thresholds