Trigemino-gustatory interactions: a randomized controlled clinical trial assessing the effects of selective anesthesia of dental afferents on taste thresholds.

OBJECTIVES: This study aimed at analyzing the effect of the temporary removal of trigeminal dental afferents on electrogustometric thresholds (EGMt). MATERIAL AND METHODS: EGMt were measured in 300 healthy subjects randomized in three groups, in nine loci on the right and left side (RS, LS) of the tongue surface before and after anesthesia. Group IAN (n = 56 RS, n = 44 LS) received intraosseous local anesthesia of the inferior alveolar nerve (IAN). Group MdN received mandibular nerve (MdN) block targeting IAN before its entrance into the mandibular foramen (n = 60, RS, and n = 40, LS); group MxN receiving maxillary nerve (MxN) anesthesia (n = 56 RS and n = 44 LS) was the control group. Differences between mean EGMt were analyzed with the Wilcoxon test; correlation between type of anesthesia and EGMt was performed with Spearman's rho, all with a level of significance set at p </= 0.05. RESULTS: Significant EGMt (muA) differences before and after anesthesia were found in all loci with MdN and IAN on the ipsilateral side (p < 0.05), but not with MxN. Anesthesia of the MdN was positively correlated with the increase in EGMt (p < 0.001). Selective anesthesia of IAN was positively correlated only with the increase in EGMt measured at posterior and dorsal loci of the tongue surface (p < 0.01). CONCLUSION: The increase in EGMt following IAN anesthesia suggests a participation of dental afferents in taste perception. CLINICAL RELEVANCE: Extraction of teeth may impair food intake not only due to impaired masticatory ability but also to alteration of neurological trigemino-gustatory interactions. TRIAL REGISTRATION NUMBER: PACTR201602001452260.