Chronic Facial Pain

There are four recognisable symptom complexes of chronic orofacial pain, which may coexist. They may be considered as medically unexplained symptoms affecting four regions of the mouth and face:

• Temporomandibular disorder (myofascial face pain)
• Atypical facial pain (atypical facial neuralgia)
• Atypical odontalgia (phantom tooth pain)
• Burning mouth syndrome (oral dysaesthesia, glossodynia, glossopyrosis)

This is currently the most controversial condition as it is likely to be a very heterogeneous group. This diagnosis is often made when all other causes of facial pain had been excluded and in those patients who do not report pain round the temporomandibular joint (TMJ). 80% of sufferers are women and the highest prevalence is in the age group 40–50 years.

This remains largely unknown but several proposals have been put forward:

• Orofacial form of migraine
• Medically unexplained symptoms
• Psychogenic origin

Psychologic factors are implicated in all pain conditions, irrespective of etiology or duration, and this group of patients are probably no different from other chronic pain sufferers. It is probable that some of these patients do have neuropathic pain related to previous trauma, infection or dental treatment.

Pain is generally described as nagging, dull, throbbing, sharp or aching in nature. Severity varies from mild to severe but not unbearable. It is generally poorly localized and deep and can be unilateral or bilateral. Pain may be constant or intermittent. Provoking factors include chewing, stress, fatigue but not touch. There are generally no autonomic symptoms.

Ninety five per cent of patients with atypical facial pain complain of other symptoms, including headache, neck and backache, dermatitis or pruritis, irritable bowel, and dysfunctional uterine bleeding. This prevalence is much greater than in the normal population.

Atypical odontalgia has a similar character but is localised to one or more premolar or molar teeth, simulating pulpitis. There may be a history of inappropriate dental treatment, including extraction, and subsequent recurrence of symptoms apparently from another tooth. Patients often attribute their pain to an antecedent event such as a dental procedure, or minor trauma to the face. Despite the notorious unreliability of such retrospective reports, these attributions have led to the suggestion that chronic facial pain may be a deafferentation syndrome (compare phantom tooth pain).

A multi disciplinary team approach is recommended. It may be more helpful to assess patients in terms of disability and coping strategies, rather than pain intensity itself.

TENS and acupuncture may be helpful in some patients suffering from chronic orofacial pain.

Anti neuropathic medication is the main stay of treatment in orofacial pain. These agents include:

• Tricyclic antdepressants
• Gabapentin
• Pregabalin
• Selective noradrenaline reuptake inhibtors (SNRIs)