Atypical trigeminal neuralgia caused by dental procedures.

Atypical Trigeminal Neuralgia (ATN), or Type 2 Trigeminal Neuralgia, is a rare form of Trigeminal neuralgia, a disorder of the fifth cranial nerve. This form of neuralgia is difficult to diagnose, as it is rare and the symptoms overlap with several other disorders.^[1] The symptoms can occur in addition to having migraine headache, or can be mistaken for migraine alone, or dental problems such as Temporomandibular joint disorder, musculoskeletal issues, or Hypochondriasis. ATN can have a wide range of symptoms and the pain can fluctuate in intensity from mild aching to a crushing or burning sensation, and also to the extreme pain experienced with the more common trigeminal neuralgia.

Symptoms
ATN pain can be described as heavy, aching, stabbing and burning. Some sufferers have a constant migraine-like headache. Others may experience intense pain in one or in all three trigeminal nerve branches, including teeth, ears, sinuses, cheeks, forehead, upper and lower jaws, "behind" the eyes, and scalp. In addition, those with ATN may also experience the shocks or stabs found in type 1 TN.
Many TN and ATN patients have pain that is "triggered" by light touch on shifting trigger zones. ATN pain tends to worsen with talking, smiling, chewing, or in response to sensations such as a cool breeze. The pain from ATN is often continuous, and periods of remission are rare. Both TN and ATN can be bilateral, though the character of pain is usually different on the two sides at any one time.

Causes

The trigeminal nerve.

ATN is usually attributed to inflammation or demyelination, with increased sensitivity of the trigeminal nerve. These effects are believed to be caused by dental procedures, infection, demyelinating diseases, or compression of the trigeminal nerve (by an impinging vein or artery, a tumor, or arterio-veinous malformation). An interesting aspect is that this form affects both men and women equally and can occur at any age, unlike typical trigeminal neuralgia, which is seen most commonly in women. Though TN and ATN most often present in the fifth decade, cases have been documented as early as infancy

Risks
Both forms of Facial Neuralgia are relatively rare, with an incidence recently estimated between 12 and 24 new cases per hundred thousand population per year.^[3][4]
ATN often goes undiagnosed or misdiagnosed for extended periods, leading to a great deal of unexplained pain and anxiety. A National Patient Survey conducted by the US Trigeminal Neuralgia Association in the late 1990s indicated that the average facial neuralgia patient may see six different physicians before receiving a first definitive diagnosis. The first practitioner to see facial neuralgia patients is often a dentist who may lack deep training in facial neurology. Thus ATN may be misdiagnosed as Tempormandibular Joint Disorder.^[5]