Health care associated Sometimes dental treatment or surgical procedures in the mouth appear to precede the onset of<unk> , or sometimes persons with<unk>  will blame clinicians for their<unk> . Organic disease Diagram of the divisions of the trigeminal nerve, the nerve which supplies sensation to the face. Dermatomes of the head (paired on either side). Green- ophthalmic division, red- maxillary division, yellow- mandibular division. Many persons with<unk>  blame organic disease for their<unk> . Research in individuals with<unk>  showed that there is increased cerebral activity (demonstrated during positron emission tomography), possibly suggesting that there is an overactive alerting mechanism to peripheral stimuli. It has been theorized that this can trigger neuropeptides to be released, and the formation of free radicals (capable of damaging cells), the release of eicosanoids (e.g. prostaglandins). There is some suggestion that<unk>  is an early form of trigeminal neuralgia.<unk>  may be referred from other parts of the head or other parts of the body to cause facial<unk> . Nowhere in the body is referred<unk>  more well illustrated than in the face, and this is due to the richly and complexly innervated nature of the head and neck. "Neuralgia-inducing cavitational osteonecrosis" Neuralgia-inducing cavitational osteonecrosis (NICO) is a controversial term, and it is questioned to exist by many. Osteonecrosis of the jaws refers to the death of bone marrow in the maxilla or the mandible due to inadequate blood supply. It is not necessarily a<unk> ful condition,<unk> ly there will be no<unk>  at all unless bone necrotic bone becomes exposed to the mouth or through the facial skin, and even then this continues to be<unk> less in some cases. When<unk>  does occur, it is variable in severity, and may be neuralgiform or neuropathic in nature. The term NICO is used to describe<unk>  caused by ischemic osteonecrosis of the jaws, where degenerative extracellular cystic spaces (cavitations inside the bone) are said to develop as a result of ischemia and infarctions in the bone marrow, possibly in relation to other factors such as a hereditary predisposition for thrombus formation within blood vessels, chronic low-grade dental infections and the use of vasoconstrictors in local anesthetics during dental procedures. This proposed phenomenon has been postulated to be the cause of<unk>  in some patients with<unk>  or trigeminal neuralgia, but this is controversial. NICO is said to be significantly more common in females, and the lesions may or may not be visible on radiographs. When they are visible, the appearance is very variable. About 60% of the lesions appear as a "hot spot" on an technetium 99 bone scan. Proponents of NICO recommend decortication (surgical removal of a section of the cortical plate, originally described as a treatment for osteomyelitis of the jaws) and curettage of the necrotic bone from the cavitation, and in some reported cases, this has relieved the chronic<unk> . However, NICO appears to show a tendency to recur and develop elsewhere in the jaws. The American Association of Endodontists Research and Scientific Affairs Committee published a position statement on NICO in 1996, stating: "Most affected sites with a postoperative NICO diagnosis have been in edentulous areas where the teeth have been lost. However, some patients with long, frustrating histories of<unk>  associated with endodontically treated teeth have been presented the treatment option of tooth extraction followed by periapical curettage in an attempt to alleviate<unk> . The American Association of Endodontists cannot condone this practice when NICO is suspected. Because of the lack of clear etiological data, a NICO diagnosis should be considered only as a last resort when all possible local odontogenic causes for facial<unk>  have been eliminated. If a NICO lesion is suspected in relation to an endodontically treated tooth, if possible, periradicular surgery and curettage should be attempted, not extraction. In addition, the practice of recommending the extraction of endodontically treated teeth for the prevention of NICO, or any other disease, is unethical and should be reported immediately to the appropriate state board of dentistry."<unk>  trigeminal neuralgia Some suggest that<unk>  is an early form of trigeminal neuralgia. Psychologic Sometimes stressful life events appear to precede the onset of<unk> , such as bereavement or illness in a family member. Hypochondriasis, especially cancerophobia, is also often cited as being involved. Most people with<unk>  are "normal" people who have been under extreme stress, however other persons with<unk>  have neuroses or personality disorders, and a small minority have psychoses. Some have been separated from their parents as children. Depression, anxiety and altered behavior are strongly correlated with<unk> . It is argued whether this is a sole or contributing cause of<unk> , or the emotional consequences of suffering with chronic, unrelieved<unk> . It has been suggested that over 50% of people with<unk>  have concomitant depression or hypochondria. Furthermore, about 80% of persons with psychogenic facial<unk>  report other chronic<unk>  conditions such as listed in the table.
Atypical facial pain
Nablus mask-like facial syndrome
Necrospermia
Symmastia
Dogger Bank itch
Pellagra
Trypophobia
Focal hyperhidrosis