Asian women prefer to have more delicate and feminine features rather than prominent squared mandibular angles. It was proposed that a selective neurectomy of the masseteric nerve might result in muscular atrophy and subsequent reduction of the hypertrophic mass of the masseter muscle. This study is aimed at an elucidation of the precise course of the masseteric nerve and the impact of a neurectomy in case of masseter hypertrophy. Eleven heads of Korean cadavers were halved and dissected. The masseteric nerve and artery in the mandibular notch were clearly located. A selective neurectomy of the masseteric nerve was performed in four cases of masseter hypertrophy. The masseteric nerve and artery behind the temporalis muscle at the mandibular notch cross over to the masseter. The masseteric nerve was found 11.3 +/- 2.6 mm horizontally from the anterior border of the ramus and 11.3 +/- 2.6 mm above the mandibular notch and the superior masseteric artery, 25.6 +/- 3.7 mm from the ramus, and 7.8 +/- 2.6 mm above the notch. A neurectomy of the masseteric nerve can be used to reduce the hypertrophied masseter and as an ancillary procedure of mandibular angle ostectomy. One procedure can accompany another in the reduction of a prominent mandibular angle.