Temporomandibular joint and muscle disorders (TMJ/TMD)

Definition

Temporomandibular disorder (TMD) is a painful condition of the joint in the jaw. The temporomandibular joints are the small joints in front of each ear. They attach the lower jaw (mandible) to the skull. The disorder may affect the joint in the jaw or the muscles surrounding it. The disorder can include:

• Damage to the joint surface or intra-articular disc
• Displacement or complete dislocation of jaw bones
• Muscle spasm

The Temporomandibular Joint

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Causes

The exact cause of TMD is often unclear. Possible causes include:

• Injury of the jaw or face
• Excess tension in the jaw muscles
• Faulty alignment between the upper and lower teeth
• Disturbed movement of the jaw joint
• Displacement or abnormal position of the jaw joint or cartilage disc inside the jaw joint
• Arthritis or similar inflammatory process in the joint
• Excess or limited motion of the joint

Risk Factors

TMD is more common in women aged 30-50 years old. Other factors that increase your chance of TMD include:

• Clenching or grinding of teeth
• Stress
• Arthritis
• Poorly fitting dentures or crowns
• Fibromyalgia

Symptoms

TMD may cause:

• Pain in the temporomandibular joint, jaw, or face
• Pain may be worse with chewing, yawning, or opening the mouth
• Clicking, popping, or grating sounds with movement of the jaw
• A sensation of the jaw catching or locking briefly, while attempting to open or close the mouth, or while chewing
• Difficulty opening the mouth completely
• A bite that feels off, uncomfortable, or as though it is frequently changing
• Headache
• Earache
• Neck pain

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done. The physical exam may include:

• Range of motion of the jaw tests
• Listening for sounds of popping or clicking in the temporomandibular joints
• Visual inspection of your teeth, temporomandibular joints, and muscles of your face and head
• Palpation of the joints and the muscles of the face and head

Images may be needed of your jaw to check for abnormalities causing TMD. This can be done with:

• X-rays
• Arthrography—jaw movements videotaped with x-rays taken after dye is injected into the joint
• MRI scan
• CT scan

Treatment

Usually, the least invasive measures will be tried first. Treatment may include:

Lifestyle Measures

The area will need time to heal:

• Rest the jaw with a soft diet
• Restrict movement with smaller bites, avoiding wide yawning, and gum chewing
• Apply ice or heat packs for pain relief
• Gentle jaw stretching and exercises

Medications

The most commonly used medications include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen
• Muscle relaxants
• Antidepressants

Some medication may be injected into the jaw such as:

• Pain relievers, such as cortisone or lidocaine
• Botulinum toxin (Botox)—may offer temporary relief if pain or clicking are major symptoms

Physical Therapy

To help reduce pain and allow muscles to relax:

• Gentle massage or stretching exercises
• Gentle strengthening exercises or muscle balance exercises to retain alignment
• Transcutaneous electrical nerve stimulation (TENS)

Stress Reduction

Some may benefit from counseling to learn stress management and relaxation techniques, such as:

• Biofeedback
• Cognitive behavioral therapy

Dental Procedures

A splint or mouth guard can be made to relax the jaw muscles, and prevent clenching and grinding of the teeth. The guard is usually worn at night. Unfortunately, there is not a lot of proof it works.

Correction of bite abnormalities by a dentist or orthodontist is sometimes needed.

Surgical Procedures

Surgical correction is a last resort. Many of the available procedures have not been well-studied for their effectiveness.

Prevention

There are no current guidelines to prevent TMD.