Q) My partner grinds his teeth at night. Apart from keeping me awake, I'm worried about the effects this will have on his teeth. What causes teeth-grinding and is there a cure?-G.C., Devon
A) You're right to be worried. Although it's often viewed as nothing more than an annoying habit, teeth-grinding-or bruxism-can, in fact, have serious consequences for the sufferer. Most obviously, when the teeth are ground from side to side in a clenching action, severe damage is done to tooth enamel and at an alarming rate; it can even cause teeth to fracture, loosen or fall out. As one expert observes, "By 40 or 50 years of age, most bruxers . . . have worn their teeth to the degree that extensive tooth restorations must be performed" (J Am Dent Assoc, 1999; 130: 1229-30).
Grinding may also lead to toxic mercury release from amalgam fillings. There is evidence of higher levels of mercury in the blood of some bruxers most likely dueto dental fillings (Eur J Oral Sci, 1997; 105: 251-7). Other problems include jaw pain and tenderness, temporo-mandibular joint (TMJ) disorders, fatigue of the facial muscles, headache, neckache and earache. In severe cases, bruxism can result in hearing loss and even changes in facial appearance (J Oral Sci, 2001; 43: 73-83).
No one knows exactly what causes bruxism, but it's thought to be related to anxiety, stress or tension, sup-pressed anger or frustration, as well as to an aggressive, competitive or hyperactive personality type. Another possible cause is the abnormal alignment of the upper and lower teeth, known as malocclusion (The Duke Encyclopedia of New Medicine. New York: Rodale Books, 2006).
Bruxism may also be a sign of a nutrient deficiency (see box), or a side-effect of certain drugs, including selective serotonin reuptake inhibitors (SSRIs) (Ned Tijdschr Tandheelkd, 2007; 114: 388-90).
Before embarking on any form of treatment, your partner should first visit his doctor or dentist to establish what could be causing his night-grinding.
What to do
Sadly, there's no accepted cure for bruxism. The most widely used 'cure' by far is the oral splint, a removable device that is usually custom-made and worn on the top teeth. Some oral splints are designed to relax the jaw, while others prevent the rear top and bottom teeth from touching, which can reduce grinding. However, a recent review concluded, "There is not sufficient evidence to state that the occlusal splint is effective for treating sleep bruxism" (Cochrane Database Syst Rev, 2007; 4: CD005514). Moreover, the splint may be uncomfortable to wear, and some can have an adverse effect on a person's bite (Br Dent J, 1999; 186: 217-22). Over-the-counter mouth guards are also available, but they generally don't fit well and can dislodge during bruxing.
More promising treatments are offered by alternative medicine. If you suspect stress may be the cause of your partner's grinding, then relaxation techniques such as yoga, meditation and massage may help (The Duke Encyclopedia of New Medicine. New York: Rodale Books, 2006).
In young children, psychological techniques to control stress, including directed muscle relaxation, significantly reduced signs of bruxism after six months (J Oral Rehabil, 2001; 28: 354-60). Indeed, bruxers receiving muscle-aware-ness relaxation training saw more improvement than the controls (J Oral Rehabil, 1999; 26: 280-7).
Acupuncture and transcutaneous electrical nerve stimulation (TENS) may also help by reducing the muscle tension associated with bruxism (Minerva Med, 2003; 94 [4 Suppl 1]: 9-15; Fortschr Kieferorthop, 1995; 56: 245-53).
Biofeedback has proved effective, and often involves an electromyographically (EMG) activated alarm that sounds when certain muscles are tensed. There are compact, user-friendly devices available for home use such as MyoTrac (www.thoughttechnology.com), which costs around lb250. It can reduce night-grinding for up to six months after treatment (Appl Psychophysiol Biofeedback, 2004; 29: 141-7). One periodontist reported a 90-per-cent success rate with an oral splint used in conjunction with biofeedback training (J Am Dent Assoc, 2001; 132: 1275-7).
The magnesium link
Some researchers believe that night teeth-grinding is caused by magnesium deficiency or an imbalance between calcium and magnesium levels, causing permanent tension in the muscles of the face and neck. According to Dr C. Ploceniak and his more than two decades of clinical experience, prolonged magnesium supplementation has nearly always provided a cure for bruxism (Rev Stomatol Chir Maxillofac, 1990; 91 Suppl 1: 127). Calcium and vitamin B5 (pantothenic acid) may also be beneficial for bruxism, but further study is needed.
Based on the findings so far, Dr Moti Nissani, at Wayne State University in Detroit, MI, recommends: magnesium (approximately 100 mg), calcium (150 mg) and pantothenic acid (50 mg) combined with vitamins A (1000 IU), C (300 mg), E (60 mg) and iodine (0.1 mg or 100 mcg). Patients should continue taking these supplements even when the bruxism subsides. Improvement should
be evident by eight weeks; if not, the approach should be abandoned (J Oral Sci, 2001; 43: 73-83).