Craniomandibular disorders (CMD) include different musculoskeletal conditions that involve the masticatory muscles, the temporomandibular (TM) joints and the associated structures.
These are alos known as Temporomandibular Disorders (TMD).
The various clinical conditions are characterized by similar signs and symptoms:
- Pain in the preauricular [or area in front of the ear] area, TM joints or masticatory muscles;
- Limitation or deviation in mandibular range of motion;
- TM joint sounds (clicking and crepitus) during mandibular function.
Other common complaints include headache, neck ache, face ache, ear ache, tinnitus [is there evidence for this?], ear fullness, and perceived hearing loss.
Prevalence of CMD is very high. 75% of the general population present at least one sign of dysfunction (joint noise or deviation on opening) and 33% have at least one symptom (pain).
International classification divides CMD in 3 main categories:
- Muscular pain, with or without functional limitation;
- Disc displacement (i.e. alteration of the normal position of the disc between the mandibular condyle and the eminence);
- Inflammatory and/or degenerative condition of the TM joint.
Etiology of CMD is multifactorial in nature. There is no simple cause-effect relationship between a single factor and the disorder. Many factors can impact on the masticatory system during life, and when it cannot tolerate these noxious stimuli, symptoms may appear. The various etiologic factors are classified as predisposing, initiating and perpetuating.
Genetic, structural, metabolic and psychological factors may make an individual more prone to develop a clinical condition, but mechanical overload, related to macro- or micro-trauma, is generally the last straw. Perpetuating factors may be any predisposing or initiating factors that can sustain the disorder and complicate the management.
CMD are similar to other musculoskeletal disorders: they are benign and self-limiting in nature, and generally do not produce irreversible tissue changes. Therefore, in spite of high prevalence, only a small percentage of people actually need some form of therapy. However, in presence of pain or dysfunction, it is important to consult a doctor or dentist in order to rule out more uncommon but serious conditions.
The diagnosis of CMD is based mainly on information derived from the patient’s history, clinical examination, and when indicated TM joint imaging. Adjunctive instrumental procedures are generally not required.
According to the most recent international guidelines, treatment of CMD is initially based on conservative, reversible and evidence-based therapeutic modalities. These are effective for the majority of patients, and rarely invasive and irreversible therapies are needed.
In particular there is no evidence for adjustments to teeth as being a therapy that should be provided in anything other that exceptional circumstances. Common accepted therapeutic modalities include a self-care program, in which patients learn how to manage their symptoms and reduce contributing factors.
In rest position, when we are not talking, eating, smiling or laughing, masticatory muscles should be relaxed and TM joints unloaded. Unfortunately, some people developed habits or parafunctions that prevent this rest. The following tips may help you to relax and reduce the overload on the masticatory system, and alleviate symptoms.
- Use cold or hot packs. Apply moist heat, ice or combination of both on pain area. Most of people prefer heat, but if it increases your pain, alternate ice and heat, or use ice only.
- Apply moist heat for 20 minutes 2-4 times a day. You can wet a towel with hot water and wrap it around a hot water bottle.
- Alternate ice and heat 2-4 times a day. First apply moist heat for 10 minutes, then scrub the pain area with an ice cube in a cleaner. Repeat 4-5 times.
- Apply the ice cube until tingling (generally after 10 minutes).
- Favour soft food diet and avoid chewing gum and foods that require heavy chewing. The load on the masticatory muscles and temporomandibular joints can reduced by cutting foodstuffs into small pieces, chewing on the back teeth on both sides, avoiding chewing with the front teeth.
- Relax masticatory muscles by keeping teeth apart.
- When not chewing or swallowing, the teeth should not contact. By paying attention to the position of your jaw: you will be able to determine whether you are clenching or grinding? People often clench teeth when they are nervous, drive, or concentrating on something. It is useful to keep the jaw muscles relaxed, the teeth apart and the tongue resting on palate, behind the upper front teeth.
- A good head, neck and back posture may help to keep the ideal jaw position. A pillow or a towel may act as lumbar support when you sit. Also try to keep the head upright, especially when working on a computer, Avoid the jaw resting on hands.
- Massage jaw muscles and temples. Self massage can help to relax the muscles and so reduce pain.
- Avoid bad habits that can overload muscle and joints. Do not: clench, grind or keep teeth in contact; bite cheeks or lips; bite objects; push the tongue against the teeth.
- Sleep well. The best sleep position is resting on your back. Avoid sleeping face down.
- Avoid playing wind, brass and string musical instruments that stress, retrude or strain the jaw.
- Protect yourself from cold and wind.
- Take time for you. At least once or twice a day relax and relieve tension from jaw and neck. People often benefit from simple relaxation techniques, like sitting in a quite place listening relaxing music or reading, taking a bath or a shower, breathing deeply and slowly. Gentle exercise can also be beneficial.. Structured courses, for example Yoga, may be helpful.
- Limit jaw opening. Avoid yawning and screaming.
- When you yawn, resist with a hand against your chin, or keeping the tongue against the palate.
- If possible avoid long dental sessions, and ask your dentist for frequent rests or a mouth prop.
- Medications. Some over-the-counter drugs (like NSAIDs) may be useful. If medication is needed frequently or over a long period of time, consult your physician.
Self-care instructions often may be sufficient to resolve CMD symptoms. However, when the masticatory system is overloaded, other conservative therapeutic modalities may help you. These include:
- Physical therapy. Manual techniques like massages, stretching and active exercises may be very useful. Your dentist may teach them to you or refer you to a physiotherapist if necessary.
- Occlusal splint therapy. In some cases your dentist may advise an occlusal splint. Occlusal splints should be custom made for your mouth and cover all of the teeth. The design and period of wear of the splint will be prescribed by your dentist for your specific condition.
- Pharmacologic therapy. The specific use of some class of drugs may be complementary to other therapies. You should always follow your doctor’s instructions.