• Neuropathic pain, specifically identifies conditions affecting the head and neck.

    Common causes of trigeminal neuralgia include:

    • Nerve compression
    • Tumors
    • Multiple sclerosis
    • Physical injury

    The cause of atypical odontalgia is unknown, though the condition may be a result of nerve deafferentation: the interruption or elimination of nerve fibers.

    Oral nerve injury is a common complication of dental procedures including extraction of the third molar, also known as the wisdom tooth. It can also occur as a result of an injection of local anesthetic for procedures including fillings, crowns and root canals. Incorrect implant placement may also damage the inferior alveolar or lingual nerve. This damage to these nerves running along the lower jaw can cause pain, tingling or numbness in the tongue, mouth and lower lip.

    Complex regional pain syndrome (CRPS) is thought to originate by an injury to tissue or nerves, which is then perpetuated by irregular behavior in the sympathetic nervous system.

    Recent research suggests that in cases of CRPS, when an injury to tissue or nerve is sustained, an unknown mechanism results in the sympathetic nervous system maintaining active pain pathways. Another theory suggests that CRPS may be a disruption of the healing response whereby an injury triggers an immune response resulting in inflammation, redness and swelling. More than likely, CRPS is the result of multiple causes occurring at once.