Is phantom tooth pain a deafferentation (neuropathic) syndrome? Part I: Evidence derived from pathophysiology and treatment.

Phantom tooth pain is a syndrome of persistent pain or paresthesia in teeth and other oral tissues that may follow dental or surgical procedures such as pulp extirpation, apicoectomy, tooth extractions, or exenteration of the contents of the maxillary antrum. It can also occur when nerves are injured after trauma to the face or even after routine inferior alveolar nerve blocks if the needle pierces the nerve sheath. In the case of tooth extraction, the pain is found in the edentate area. After periodontal surgery, pain or paresthesia is located in the gingiva. The incidence of phantom tooth pain after extirpation may be as high as 3% of cases. Clinically, phantom tooth pain is similar in many essential characteristics to deafferentation pain syndromes also known as phantom pain syndromes. A limitation to this taxonomy is the lack of definitive information with respect to the pathophysiology of deafferentation pain in the trigeminal nerve. This article amplifies previous clinical descriptions of phantom tooth pain. Current concepts in the pathophysiology of neuropathic pain are reviewed as they pertain to phantom tooth pain. Treatments are described that use three routes of drug administration: oral, nerve blocks by injections, and intranasal applications. Reasons are discussed for the high rates of morbidity after dental and neurosurgery in attempts to treat phantom tooth pain.