What Is Mental Nerve Neuropathy?

Mental nerve neuropathy is an uncommon condition in which the skin of the chin, lower lip and/or gums feels numb. This symptom, also known as numb chin syndrome, may alert doctors to the presence of serious medical problems--including breast cancer--elsewhere in the body.

What Is the Mental Nerve?

• The mental nerve, located in the jaw, has three branches, two of which provide sensation to the lower lip and a third that supplies feeling to the chin. The mental nerve is itself a branch of the inferior alveolar nerve.

Symptoms

• This type of neuropathy most often manifests unilaterally, producing a feeling of numbness on only one side of the lower lip or chin, but is sometimes seen bilaterally.

Metastatic Malignancy

• Mental nerve neuropathy can be triggered by a metastasis of breast cancer, lymphoma or other cancer to the nerves of the mandible, or lower jaw, according to an article by Dr. Mark Marinella.

Other Causes

• Noncancerous causes of this condition, according to Dr. Marinella, include amyloidosis; aneurysm; benign tumors; dental trauma, anesthesia or abscess; diabetes; facial trauma; sarcoidosis; sickle cell anemia; and vasculitis.

Retrospective Study

• A retrospective study of 42 cancer patients with this type of neuropathy was conducted by two doctors practicing at Jerusalem's Hadassah Hebrew University Hospital. Its findings, published in a 1992 article in Neurology, showed that 64 percent of those patients had primary breast cancer that had metastasized to the mental nerve.

See Your Doctor

• Although it may seem relatively innocuous, this neuropathy should not be ignored. Seek medical attention promptly.