The mental nerves, on each side of the chin, are the final branches of the lower part of the trigeminal nerve, and carry sensation from the chin.
Diseases that affect the nerve anywhere along its path can result in numbness of the chin.
Chin numbness can indicate the presence of a serious medical problem, and can be the first symptom of cancer.
Often a bad prognostic sign and indicates progression of the underlying disease.
When associated with cancer, survival is about one year.
The most common types of cancers associated are metastatic breast cancer and lymphoma.
Prostate and lung cancers can also result in chin numbness.
The nerves in the chin can be damaged by injuries to the jaw.
Dental procedures, such as tooth extractions, can damage the inferior alveolar nerve ending in the mental nerve and causing numbness and tingling in the lower jaw and chin.
Abscess in the lower gums can also lead to neuropathy, either of the inferior alveolar nerve, or of the mental nerve.
Can be a sign of multiple sclerosis.