Ｐｉｒｏｇｏｆｆ三角是指颌下三角内的由舌下神经、下颌舌骨肌后缘和二腹肌后腹 (或中间腱 )共同围成 ,以舌骨舌肌为底的一个小的三角区。据Ｈｏｍｚｅ统计 ,Ｐｉｒｏｇｏｆｆ三角的出现率为 5 8.2 % ,当舌下神经低于二腹肌中间腱上缘时 ,该三角即不存在[1] 。Ｐｉｒｏｇｏｆ? The Pirogoff triangle is a small triangular area enclosed by the hypoglossal nerve, the posterior border of the hyoida of the hyoid, and the posterior abdomen (or middle tendon) of the hypothalamus in the submaxillary triangle. According to Homze statistics, Pirogoff triangle incidence of 52.2%, when the hypoglossal nerve is lower than the upper edge of the middle of the tendon, the triangle that does not exist [1]. Pirogof?