A cracking jaw is often caused by the jaw joint (TMJ) shifting or a displaced disc. It is usually harmless unless painful.
Causes
- Temporomandibular joint (TMJ) disc displacement. The disc shifts and makes clicking or popping.
- Teeth grinding (bruxism).
- Arthritis.
- Jaw injury.
- Misaligned bite.
When it’s harmless
Cracking without pain is common and usually needs no treatment.
When to see a dentist or doctor
If it hurts, the jaw locks, you can’t open fully or there’s swelling.
Self-care
Soft foods, avoid wide yawning and gum, apply heat and do gentle jaw exercises.
Treatments
Night guard, physical therapy, medications or surgery in rare cases.
How common
TMJ disorders affect about 10 million Americans (NIDCR).
Stress
Reduces clenching.
What happens in the jaw
The jaw joint, the temporomandibular joint (TMJ), is a hinge and sliding joint on each side of the head, connecting the lower jaw to the skull in front of the ear. A small disc of cartilage cushions the joint. Clicking or popping happens when the disc shifts out of place and snaps back as the jaw opens or closes, or when ligaments move over bone. TMJ disorders affect about 5% to 12% of people, according to the NIDCR, and are twice as common in women.
Causes
- Disc displacement in the joint.
- Teeth grinding (bruxism) and clenching, often during sleep and from stress.
- Arthritis of the jaw joint.
- Jaw injury, whiplash or dislocation.
- Misaligned bite or dental work.
- Chewing gum or hard food often.
- Muscle tension and stress.
- Hypermobility of joints, as in Ehlers-Danlos syndrome.
When it is harmless
A click or pop without pain, with normal jaw movement and no locking, usually needs no treatment. Many people have clicking jaws without problems.
When to see a dentist or doctor
- Pain in the jaw, face, ear or temples.
- The jaw locks open or closed, or you cannot open your mouth fully (normal opening is about 40 to 55 millimeters, or three fingers).
- Difficulty chewing, swelling or a change in bite.
- Headaches, ringing or ear pain.
- Dislocation after yawning or trauma.
Self-care
- Eat soft foods and avoid chewing gum, ice and tough meat.
- Cut food into small pieces and avoid wide yawns.
- Apply moist heat or ice packs for 10 minutes.
- Do gentle jaw stretching and relaxation exercises.
- Take ibuprofen as directed for pain.
- Manage stress with relaxation techniques.
Treatments
- Night guard or splint for grinding, which cuts muscle strain.
- Physical therapy.
- Muscle relaxants or low-dose antidepressants for pain.
- Injections of corticosteroid or botulinum toxin in some cases.
- Arthrocentesis or surgery for severe cases, which is rare.
How common
About 10 million Americans are affected at any time, according to the NIDCR. Symptoms peak between ages 20 and 40, and many cases improve without treatment.
Stress
Stress raises muscle tension and grinding. Mindfulness, exercise and therapy can help.
Joint anatomy and how common it is
The temporomandibular joint (TMJ) connects the jawbone to the skull and has a small cartilage disc that cushions movement. Clicking or popping occurs when the disc shifts out of place and snaps back. Around 5 to 12 percent of people have temporomandibular disorders, which are twice as common in women as in men and peak at ages 20 to 40, according to the NIDCR. Clicking without pain, locking or limited opening usually needs no treatment. Teeth grinding (bruxism), chewing gum a lot, stress, arthritis, jaw injury and a bite misalignment may contribute. Home care includes soft foods, avoiding wide yawns, heat packs for 10 to 15 minutes, gentle jaw stretches and a night guard if prescribed. A dentist or oral surgeon should evaluate if the jaw locks, hurts at rest, or you cannot open your mouth more than about 35 mm, which is roughly two fingers wide.
Based on data from the NIDCR and the American Dental Association
