Numb chin syndrome: a nonmetastatic neurological manifestation of malignancy.

Numb chin syndrome, sometimes called numb lip syndrome, is an uncommon but well-recognized symptom in medical oncology. It may be a nonmetastatic neurological manifestation of malignancy, often with no clinically visible pathology. We report a case of a 79-year-old woman with widespread metastatic disease secondary to breast carcinoma who presented with a left-sided numb lip and chin. The patient had no clinical or radiographic pathology within the head and neck region. Numb chin syndrome is almost unknown within the dental and oral and maxillofacial community, despite being well reported in the medical literature. We urge all general dentists, oral medicine specialists, and oral and maxillofacial surgeons to consider metastatic cancer in patients with unexplained facial hypoesthesia.