Differential diagnosis of chronic facial pain.

The differential diagnosis of chronic facial pain is facilitated by a knowledge of anatomy. Nasal and dental conditions are prevalent causes of facial pain. Orbital discomfort with ophthalmoplegia or Horner's syndrome generally has a vascular etiology. The lower-half headache or atypical facial neuralgia also is vascular in origin and should be referred to as facial migraine. Previously, chronic iatrogenic trigeminal neuralgia has been erroneously included in the category of lower-half headaches. This disabling condition is due to repeated trauma to the trigeminal nerve.