Pain in the face, present daily and persisting for all or most of the day, fulfilling criteria B and C,B. Pain is confined at onset to a limited area on one side of the face, and is deep and poorly localized,C. Pain is not associated with sensory loss or other physical signs,D. Investigations including x-ray of face and jaws do not demonstrate any relevant abnormality.There are presently no accepted medical tests which consistently discriminate between facial pain syndromes or differentiate Atypical Facial Pain from other syndromes. However, a normal Radiograph, CT, and MRI may help to exclude other pathology such as arterio-veinous malformation, tumor, temporomandibular joint disorder, or MS.

Management
Psychosocial interventions
Psychosocial interventions for AFP include cognitive behavioral therapy and biofeedback. A systematic review reported that there was weak evidence to support the use of these treatments to improve long-term outcomes in chronic orofacial pain, however these results were based primarily upon temporomandibular joint dysfunction and burning mouth syndrome rather than ATP and AO. Psychosocial interventions assume 2 models of chronic facial pain, namely "inactivity" and "over activity". The former is where people with pain become conditioned to avoid physical activity as a result of exacerbating their pain. These negative thoughts and behaviors in fact prolong and intensify their symptoms. Some psychosocial interventions work on this fear-avoidance behaviour to improve functioning and thereby alleviate symptoms. The over activity model involves factors such as anxiety, depression or anger acting to increase pain by triggering autonomic, visceral and skeletal activity.
The IASPs Classification of Chronic Pain does not have a diagnosis that corresponds to AFP, although it is listed in the differential diagnosis of "Glossodynia and sore mouth" (Burning mouth syndrome). However, in another IASP publication from 2011, the term PIFP is used and defined almost identically to the above. Despite the controversy surrounding the use of the term, it has a long history, and it is still in common use by clinicians to refer to chronic facial pain that does not meet any diagnostic criteria and does not respond to most treatments. Re-classification of trigeminal neuralgia
Trigeminal neuralgia is another example of a cause of facial pain. Neuralgia refers to pain in the distribution of a nerve (or nerves), and commonly implies paroxysmal (sudden) pain, although the accepted IASP definition specifies that the term should not be restricted to mean paroxysmal pain. Classic trigeminal neuralgia refers to sudden, shooting pain in the face, which is usually short lived and brought on by accidental stimulation of trigger points on the face, as may occur when washing. Trigeminal neuralgia has been described as one of the most painful conditions possible. Trigeminal neuralgia and AFP are traditionally considered separate, since AFP typically involves constant, often burning pain and trigeminal neuralgia classically shows paroxysmal, shooting pain, but in reality there is some overlap in their features. In 2005 researchers proposed a new classification of trigeminal neuralgia which described a type of trigeminal neuralgia where the pain was constant and burning.