Nerve to mylohyoid branched from the lingual nerve: previously undescribed case.

The lingual nerve is a branch of the mandibular division of the trigeminal nerve. It descends medial and anterior to the inferior alveolar nerve through the pterygomandibular space, runs by the lingual plate and lingual crest at the lower third molar closely, and supplies sensory fibers to the anterior two-thirds of the tongue. Therefore, injury of this nerve is occasionally induced by wisdom tooth extraction and could lead to paralysis of the tongue. The inferior alveolar nerve gives rise to the nerve to mylohyoid just before entering the mandibular foramen, which supplies the mylohyoid and anterior belly of the digastric muscle. We present an extremely rare anatomical variation where the nerve to mylohyoid arose from the lingual nerve near the submandibular duct during routine oral dissection.