When Demi Moore claimed on the June 12th episode of the Tonight Show that stress “sheared off” her teeth, many alarmed viewers and dental professionals wondered what she was talking about. But leaving aside the mystery of what exactly happened to her, there are, in fact, there are two ways in which stress is known to be a factor in tooth damage: periodontal disease and teeth-grinding. To lose an entire crown or more would only happen in the most extreme cases, but weak teeth and enamel erosion are not uncommon among people suffering from chronic stress.
Gingivitis is defined as inflammation of the gums. Whether stress contributes directly to inflammation has been the subject of several recent studies which are not yet conclusive. However, it is known that stress weakens the immune system, which would consequently have a harder time resisting bacterial infections. When bacteria multiply excessively they trigger more severe and widespread inflammation, called periodontitis, which damages the jaw structure. This can cause teeth to come loose as their gum and bone support recedes, and tooth loss is not out of the question. But no matter how bad stress gets, periodontitis requires bacterial infection, so maintaining proper oral hygiene is the best line of defense against it.
The better-evidenced way in which stress contributes directly to tooth damage is teeth-grinding, which is medically referred to as bruxism. This behavior is often done involuntarily during sleep without the patient even being aware of it. One cause of bruxism is sleep apnea, which the body may respond to by pushing the jaw forward in order to keep the airways open. But sleep apnea is believed to be more a cause of stress than a result of it. On the other hand, stress is usually a contributor to temporomandibular joint disorders (TMD or TMJ disorders), which cause a person to clench their jaws together. Pressure and grinding on the teeth will cause the cuspids to wear away and the enamel to rub off, leaving teeth flat and with less material protecting their internal layers. Grinding and clenching can also cause teeth to migrate or become misaligned, which weakens the structure supporting them, and conversely, misaligned teeth are another cause of grinding.
The most serious cases of weak or severely eroded teeth would likely be due to a combination of factors. Dry mouth, for example, which is a common side-effect of anxiety medications, also makes it more difficult for the body to resist oral infections. Teeth that have already been replaced with implants are vulnerable to inflammation and dentists debate the role of bruxism in implant failure. One common way of avoiding the damage of TMJ is with a custom-fitted mouthguard, which keeps a patient’s jaws in place and shields the teeth from being rubbed against. TMJ patients are also commonly prescribed stretching exercises and may need psychological help for dealing with stress. But, as Moore said, modern dentistry has many ingenious ways of repairing and replacing damaged teeth.