Nausea control by needling at acupuncture point Neiguan (PC6) during an intraoral impression-taking procedure

The objective of this study was to evaluate the effectiveness of acupuncture point PC6 (Neiguan) in controlling nausea during intraoral impression taking. This study was conducted in Piracicaba, São Paulo, Brazil. The sample consisted of 33 adult volunteers with nausea, who were randomly divided into control and study groups, and treated with nonpenetrating sham acupuncture and real acupuncture, respectively, at acupoint PC6. The two groups had two maxillary impressions taken, one prior to acupuncture and the other after acupuncture. The nausea assessment was made using the visual analog scale, Gagging Severity Index (GSI), and Gagging Prevention Index. Volunteers' expectation that nausea would be reduced through acupuncture was also assessed. For statistical analysis, we used the t test and the Spearman correlation (p < 0.05). When assessed by Gagging Severity Index/Gagging Prevention Index, nausea was reduced in the real acupuncture group (p < 0.01). In the visual analog scale assessment, similar reductions of nausea were noted in both groups (p > 0.05). No correlation existed between the expected and the actual reductions in nausea. Our results indicate that acupoint PC6 was effective for controlling nausea during the maxillary impression-taking procedure. Patients' expectation did not influence the results.