Buccal Nerve Trunk Block Anesthetizes the Buccal Mucosa Beyond the Papilla of the Parotid Duct

The limited area of anesthesia of the buccal mucosa with concomitant conventional buccal nerve block (conventional BNB) may be involved in failed inferior alveolar nerve block (IANB). The aims of this study were to examine the extent of anesthesia by buccal nerve trunk block (BNTB) and compare the success rates of IANB with BNB.

This prospective parallel-group randomized single-blinded clinical trial included patients scheduled for removal of a mandibular third molar at the Nippon Dental University Hospital between September 2021 and March 2022. The primary predictor variable was the approach for BNB (BNTB vs conventional BNB). The primary outcome was the extent of tactile sensory loss and anesthesia of the buccal mucosa. The secondary outcomes included onset time and duration of BNBs and the success rate of the IANB with concomitant BNB for third molar extraction, assessed by the proportions of intraoperative pain perception and supplemental infiltration anesthesia. The other study variables were sex, age, and injection side. Comparisons were analyzed by Fisher's exact test or the Mann-Whitney U test. The P value was set to .05.

A total of 38 patients (14 male, 24 female) with a mean age of 28.9 years (range, 18 to 67 years) were enrolled, with 19 patients each in the BNTB group and conventional BNB group. The effective tactile sensory loss rates at ∼5 mm above the height of the papilla of the parotid duct of the premolar and molar regions were greater following BNTB (71 and 95%, respectively) than following conventional BNB (37%; P < .01 and 58%; P < .01, respectively). The proportions of intraoperative pain perception of the BNTB group and the conventional BNB group were 10 and 42% (P = .06), respectively, and those of supplemental infiltration anesthesia were 5 and 26% (P = .18), respectively.

BNTB provided a wider extent of anesthesia of the buccal mucosa than conventional BNB and may improve the anesthesia success of IANB for removal of mandibular third molars.