Malocclusion and Headache

Essentials

• A dentist should be consulted if a patient with headaches reports that he/she severely grinds or clenches his/her teeth or if he/she presents with
  • symptoms that are associated with jaw movements
  • abnormal or restricted jaw movements, rasping or loud clicking or popping sounds
  • pain and tenderness on palpation of the temporomandibular joint or muscles associated with mastification
  • clear occlusal discrepancy, i.e. for example wide open bite maloccolusion or jaw asymmetry
  • earache or tinnitus the cause of which cannot be confirmed by the findings of ear and pharynx examination.
• Infections of dental origin should also be excluded.
• Apnoea associated with obstructive sleep apnoea syndrome Sleep Apnoea in the Adult may also cause headache especially in the mornings. On the other hand, sleep apnoea is usually associated with bruxism. Additionally, an occlusal splint may worsen sleep apnoea by moving the mandibula backwards.

Malocclusion as a cause of headache

• Dental malocclusion is thought to act as a source of peripheral stimulation which may lead to increased tonus of the masticatory muscles, abnormal co-ordination and articular disc displacement. Powerful grinding of the teeth at night or severe malocclusion may also cause pain in the masticatory muscles, and hence headache.

Symptoms

• Headache, neck pain, pain in the masticatory muscles or in the temporomandibular joint, tenderness of teeth, swallowing difficulty, hoarseness
• Headache caused by malocclusion usually occurs in the frontal or temporal region.
  • Symmetrical or unilateral
  • The pain is usually aching.
• Abnormal sensations around the face and head, particularly at the preauricular region. Abnormal movements of the jaw and audible joint movements.
• Tinnitus, blocked ears, earache and sensation of impaired hearing (not uncommon symptoms).
• Symptoms are rarely totally symmetrical. The intensity of symptoms often shows circadian variation. Symptoms are provoked by cold, damp and drafts, muscular exertion (chewing), stress and occasionally the wearing of dentures.
• The dysfunction is not characterised by paroxysmal attacks of pain. Some patients are aware of their habit of grinding their teeth at night or unnecessary clenching of teeth at daytime. However, most patients are not aware of, or deny, such a habit.

Examination

• A short clinical examination will confirm diagnosis.

1. Range of movement of the mouth
   • The patient should be able to open his/her mouth without problems and deviation at least 40 mm, measured from the tip of the front teeth.
   • The maximal lateral and forward movement of the jaw should be at least 7 mm, and the movement should be quite symmetrical.
2. Palpation (picture 1)
   • The dorsal aspect of the temporomandibular joints are palpated through the external auditory canals and the lateral aspects from in front of the ears. The palpation will reveal any tenderness or abnormality during jaw movements, such as asymmetry, movement of the articular disc, clicks or crepitus. Stethoscopic auscultation will reveal even the quietest crepitus.
   • Of the masticatory muscles, the easiest to palpate are the masseter muscle and temporal muscle. The attachment of the temporal muscle to the coronoid process of the mandible can be verified intraorally (picture 2).
3. Examination of the teeth
   • The appearance of teeth may give clues of mandibular dysfunction if dental wearing is abnormally severe.
   • However, observation alone does not suffice to confirm the existence of functionally important malocclusion. A balanced occlusion does not exclude the possibility of dysfunction.
4. Radiography
   • In addition to clinical examination, x-rays may be required for the purposes of differential diagnosis
   • Pantomography and, as necessary, x-rays of temporomandibular joints provide important information on the status of temporomandibular joints and possible disease in the joint(s) (arthritis, for example). Both inflammatory (arthritis) and bruxism-related (arthrosis) changes may occur in the temporomandibular joints.
   • In addition to the aforementioned examinations, a dentist may request, as necessary, cone-beam CT or MRI imaging of the temporomandibular joints.
   • are of little help in the diagnosis of mandibular dysfunction.

Indications of referral to a dentist

• A patient with headaches is unlikely to have dysfunction of the masticatory system if there is no history of symptoms associated with jaw movements, the jaw movements are normal without deviation and no sounds or tenderness on palpation are noted in the joints or masticatory muscles, and if the patient has no tenderness or wear of teeth or hoarseness or throat pain.
• If these symptoms are present the patient should be referred to the care of a dentist with relevant expertise.

Treatment

• Symptomatic treatment consists of anti-inflammatory drugs, preparation of an occlusal appliance, physiotherapy, as well as physical and relaxation exercises for the masticatory muscles.
• Treatment of possible dental malocclusion may be considered if needed. Additionally, if inflammatory changes are detected in the temporomandibular joints, the patient should be referred as far as these changes are concerned to, for example, a rheumatologist for treatment.
• If a suspicion arises of sleep apnoea as the cause of headache and bruxism, the patient should be referred through primary care for sleep apnoea investigations.
• An occlusal splint should be checked annually by a dentist.