and tmd and burning mouth syndrome. atypical odontalgia is similar in nature to afp, but the latter term generally is used where the pain is confined to the teeth or gums, and afp when the pain involves other parts of the face. other sources use atypical odontalgia and afp as synonyms, or describe atypical odontalgia as a sub-type, variant, or intra-oral equivalent of afp. sometimes "phantom tooth pain" is listed as a synonym for ao, and sometimes it is defined as toothache which persists after a tooth has been extracted. it has been suggested that it is likely that these terms do not represent a single, discrete condition, but rather a collection of misdiagnosed and as yet unidentified causes. this pain is often similar to pain from organic dental disease such as periapical periodontitis, or pulpitis (toothache), but unlike normal dental pain, it is not relieved in the long term by dental treatments such as endodontic therapy (root canal treatment) or tooth extraction, and it may even be worsened, return soon after, or simply migrate to other areas in the mouth following dental treatment. atypical facial pain there is no universally accepted definition of afp, and it is defined less by what it is as what it is not. various definitions of afp include: "a nonmuscular or joint pain that has no detectable neurologic cause." "a condition characterized by the absence of other diagnoses and causing continuous, variable-intensity, migrating, nagging, deep, and diffuse pain." "a continuous unilateral deep aching pain sometimes with a burning component." "facial pain not fulfilling other criteria" (previous ihs definition, which now uses the term "persistent idiopathic facial pain", see below). "persistent pain in the maxillofacial region that does not fit the diagnostic criteria of any other orofacial pain and has no identifiable cause." (neville et al.) atypical odontalgia there are no globally accepted definitions of ao, but some suggested definitions are listed below: "continuous pain in the teeth or in a tooth socket after extraction in the absence of any identifiable dental cause," (international headache society, description included as a side note of "persistent idiopathic facial pain" in the ichd-2, i.e. with is no separate diagnosis for atypical odontalgia). "severe throbbing pain in the tooth without major pathology" (iasp definition in the "classification of chronic pain", listing ao as "tooth pain not associated with lesions"). "pain and hypersensitive teeth in the absence of detectable pathology". "pain of an unidentifiable cause that is perceived to be originating in a tooth or teeth". naming controversy and proposed replacement terms the term "atypical facial pain" has been criticized. originally, afp was intended to describe a group of individuals whose response to neurosurgical procedures was not typical. some experts in facial pain have suggested that the term afp be discarded, as it may serve as a catchall phrase to describe either individuals who have not had an adequate diagnostic assessment or individuals whose pain is purely psychogenic. afp has also been described as an inappropriate term since many cases in this category conform to a recognizable pattern. another cited reason for discontinuing use of the term afp is that some cases appear to follow surgeries or injuries involving the face, teeth and gums, possibly suggesting infectious or traumatic etiologies. some classifications of facial pain avoid the term in favor of other similar terms. the ihs now use the term "persistent idiopathic facial pain" in the ichd-2, defining it as "persistent facial pain that does not have the characteristics of the cranial neuralgias ... and is not attributed to another disorder." the iasp's 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 classification scheme for trigeminal neuralgia (tn) and related facial pain syndromes. typedescription tn1classic or typical tn. idiopathic, spontaneous facial pain which is predominantly episodic in nature tn2atypical tn, or tn type 2. idiopathic, spontaneous facial pain which is predominantly constant in nature tn3trigeminal neuropathic pain. results from unintentional injury to the trigeminal nerve from trauma or surgery. tn4trigeminal deafferentation pain. results from intentional injury to the nerve in an attempt to treat either tn or other related facial pain. tn5symptomatic tn. results from multiple sclerosis tn6postherpetic tn. follows a cutaneous herpes zoster outbreak in the trigeminal distribution. tn7"atypical facial pain." facial pain secondary to a somatoform pain disorder, requiring psychological testing to confirm. 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. they theorized that this type was a progression of untreated classic trigeminal neuralgia, and represented worsening neural injury. there were seven proposed sub-types of trigeminal neuralgia (tn) in this classification (see table), and the final category was reserved for facial pain caused by somatoform disorder. this last category (tn7) was termed atypical facial pain, although many cases that would otherwise be traditionally labelled as afp would fall into other groups in this classification, especially into the second group. in a publication of the trigeminal neuralgia association (tna), the following was said about this new classification and afp: "the term atypical facial neuralgia or pain was a wastebasket term applied by a serious contributor of a former era to a group of patients he did not understand. many of these patients were our trigeminal neuralgia type 2 patients. it is unfortunate that many of these people were told they had psychological problems. many developed psychological problems after the fact when told by everyone that such was their problem. over the years, our areas of ignorance have progressively narrowed. ... a non-pejorative and, hopefully, reasonable term for the ever-narrowing group of undiagnosed face pain problems: facepain of obscure etiology (foe or poe) to replace atypical facial pain in the burchiel classification." as a result, some sources list terms such as "atypical trigeminal neuralgia", "trigeminal neuropathic pain" and "atypical facial neuralgia" as synonyms of afp. ichd-2 diagnostic criteria the ichd-2 lists diagnostic criteria for "persistent idiopathic facial pain" (the term that replaces afp in this classification): a. 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. medication analgesics antidepressants centrally acting muscle relaxants anticonvulsants surgical some have suggested that surgery is not an appropriate for treatment for afp, however the frequent failure medical treatment to relieve pain has occasionally lead surgeons to attempt surgical treatments. surgery may give a temporary remission from pain, but rarely is there a long term cure achieved via these measures. sometimes the pain may be increased or simply migrate to an adjacent area following a surgical procedure. descriptions of procedures such as removal of a portion of the affected branch of the trigeminal nerve, or direct injections of a caustic substance (e.g. phenol, glycerol, alcohol) into the nerve have been reported. proponents of the so-called "neuralgia inducing cavitational necrosis" suggest surgical exploration of the bone marrow surrounding the intra-bony course of the affected nerve to discover diseased marrow. prognosis research suggests that people with afp are not helped greatly by health care professionals. one study reported that on average, individuals had consulted 7.5 different doctors. 91% had seen dentists, 80% physicians, 66% neurologists, 63% ear, nose and throat surgeons, 31% orthopedic and maxillofacial surgeons, 23% psychiatrists, 14% neurosurgeons and 6% ophthalmologists and dermatologists. in this study, the individuals had been subjected to a wide variety of different treatments, from surgery, antidepressants, analgesics and physical therapies. none of the persons reported that surgery was beneficial, and in many cases the pain was worsened by surgery. the article cited as the source of this information was withdrawn from publication, saying the information was out of date and not meeting cochrane methodological standards. it has been suggested that the onset of chronic facial pain will likely be a life changing development for those affected. epidemiology afp is sometimes described as being fairly common, and one estimated prevalence is about 1–2% of the general population. however, the iasp described pifp as being rare, less common than trigeminal neuralgia (which has a prevalence of about 0.01–0.3% in the general population), and possessing no available epidemiologic data for estimated prevalence in the general population. the predominant age group is 30–50, and females are more often affected than males, with most reports stating that about 80% of people with afp are female.