Meth causes compulsive clenching and grinding of the teeth, known as "bruxing".

Bruxing is a common condition that causes wear patterns on teeth that resemble facets on a precious stone, can crack and break teeth, aggravate gum disease, and cause TMJ (jaw joint) problems. Additional causes can include stress, anxiety, or uneven bite problems.

Treatment of bruxing includes resolution of bite problems, custom fabrication of appliances called occlusal guards, and sometimes physical therapy to relax muscles that we chew with.

Meth abuse has been show to cause signficant wear of molar teeth. Bruxing on a tooth that has deep decay can eventually break the tooth off.

Dental patients with broken teeth often complain that the tooth broke during some minor incident, like chewing on a crunchy food. An engineer explains such an event as "fatigue", where stressful incidents cause microfractures, and when enough microfractures connect in a chain, a final microfracture completes the chain, and a large chunk breaks away. A wall of a tooth can suffer from fatigue, explaining the surprise of a broken tooth while eating.

Compulsive bruxing caused by meth abuse is a reliable way to wear teeth down and weaken them with "fatigue". Most structures in our body can heal themselves over time. Teeth do not have a way to heal from microfractures, which accumulate over time.

Patients with meth mouth will often say that it seemed like a tooth rotted from the inside out, then broke off. One explanation: Enamel forms the outer layer of a tooth, and it is normally very acid resistant. Decay begins when acid waste products from bacteria concentrate acid in the enamel over a long period of time. Decay advances more quickly in the underlying dentin, so quickly in some cases that the enamel is left as a shell over a soft mass of decay.

Severe bruxing over a long enough period of time can cause the teeth to lose half of their height or more. The height of the face is reduced, and the chin actually gets closer to the nose! This can cause serious problems with the jaw joints that are difficult to treat. Severe cases often require full mouth rehabilitation, with up to 28 crowns to restore tooth height.

Those who are succeeding in recovery, but still bruxing, should ask a dentist about making an occlusal guard to protect their teeth from wear and fatigue.

Bruxing caused by meth abuse should be studied more extensively. It would be helpful to know how long compulsive bruxing continues after quitting meth.