Teeth Grinding & Clenching
Bruxism
Bruxism can perhaps be best defined as the involuntary, unconscious, and excessive grinding, tapping, or clenching of teeth. When it occurs during sleep, it may be best called nocturnal bruxism. A few people, on the other hand, grind or clench their teeth while they are awake, in which case the condition may be called diurnal bruxism.
It's important to note that the difference between bruxers and non-bruxers is one of degree, not kind. If the habit is persistent enough, frequent enough, long enough, or intense enough to damage the teeth, then it is imperative that an occlusal device be made so that the oral structures can be protected. For patients with crowns or bridges, bruxism may cause porcelain fracture and failure of the restoration. Implant complications are more likely in people who habitually clench or grind their teeth. In one study, more than 75% of observed implant fractures occurred in patients with signs and histories of chronic bruxism.
How Common is Tooth Grinding?
Most people unconsciously grind or clench their teeth now and then, so the key factor in deciding whether someone is a bruxer is not the presence or absence of the habit, but the frequency, destructiveness, social discomfort, or physical symptoms of the condition.
Over 80% of those who grind their teeth are unaware of the habit or ashamed of it, so they may dismiss evidence that they do in fact engage in self-destructive behavior. It may take years for the first visible signs of worn teeth to appear; yet, it is these signs which lead to a diagnosis of past or present bruxism. For these reasons, estimates of the prevalence of bruxism range from 5% to 100%. For the U.S. population, current estimates are in between 5 and 20%.
Signs, Symptoms, & Consequences of Bruxims
Chronic grinding and clenching may lead to sensitive, worn-out, decayed, fractured, loose, or missing teeth. Grinding or clenching breaks down enamel, and in severe cases, can reduce teeth to stumps. The back teeth of some chronic bruxers often lose their natural contours, appearing flat as if they had been worked over with a file or sandpaper. When anterior teeth are affected, their biting surfaces are damaged and the teeth appear flat and short. The absence of enamel makes it easier for bacteria to penetrate the softer part of the tooth and produce cavities. With time, the condition worsens and may necessitate the use of bridges, crowns, root canals, implants, partial dentures, and even complete dentures. As long as bruxism continues, the situation keeps getting worse. Thus, by 40 or 50 years of age, most bruxers have worn their teeth to the degree that extensive tooth restorations must be performed.
Long-term bruxism often causes changes of appearance, in at least three different ways...
To begin with, damaged, worn-out teeth are not as appealing as healthy teeth.
Second, as the teeth wear out, they become shorter. As a result, when the mouth is closed, the upper and lower jaws are nearer than they used to be, and so are the nose and chin. The skin now may bag below the eyes and curl around the lips, causing the lips to seemingly disappear. The chin recedes, and the person looks comparatively old.
Fig. 1. The young man (left frame) has normal teeth. By middle age (middle frame), bruxism has flattened this mans teeth and changed his appearance somewhat. By old age (right frame), the change is even more remarkable (Source: Gelb, 1994, p. 227).
Third, bruxism involves excessive muscle use, leading to a build-up or enlargement (hypertrophy) of facial muscles, specifically, the masseter (see below). In long-term bruxers, this build-up may lead to a characteristic, square-jaw, appearance. Like body building, bruxism involves muscle overuse.
Fig. 2. Masseter muscle
Long-term bruxers sometimes experience jaw tenderness, jaw pain, fatigue of facial muscles, headaches, neck aches, earaches and hearing loss.
Bruxism may also damage the temporomandibular joints (TMJs). Bruxism is therefore believed by most researchers to be one of the leading causes of temporomandibular disorders (TMDs).
Fig. 3. The temporomandibular Joint (TMJ)
Besides bruxism, TMDs may be caused by such things as whiplash, a hard blow to the chin, malocclusion, nearby tumors, orthodontic treatment, arthritis, long-term scuba diving, or prolonged violin playing. Often, the first warning signs of TMDs are TMJ discomfort or pain, soreness of jaws and muscles, clicking or popping sounds when opening the jaws or while chewing, and difficulties in fully opening the mouth. If bruxism continues at this point, these symptoms become more severe. TMDs are often associated with chronic jaw pain which may last months or years. A sufferer may wake up, for example, totally unable to open the mouth. In other instances, the jaw may suddenly lock or dislocate during chewing. Eventually, a difficult surgery of uncertain efficacy may be required.
It is worth remembering that a "TM disorder, although not being life threatening, is certainly life altering. First, patients must contend with chronic pain and other symptoms. Second, often, there is much anguish and humiliation before the condition is correctly diagnosed. The average TM disorder patient has been seen by at least seven physicians, dentists, psychologists, or other health professionals. Of these patients, 7 out of ten have been incompletely diagnosed or misdiagnosed. Third, it is unrealistic to expect a cure for TMDs. At best, dentists are only managing signs and symptoms to the best of our ability within the framework of the patient's ability to cope with the disorder. The best thing we can do for bruxing patients is to help them control bruxism and thereby minimize the chances of temporomandibular complications.
Conversely, when TMDs are traceable to bruxism, it is more or less useless to treat these disorders without addressing their underlying cause: Surgical procedures that alter anatomic relationships without addressing factors contributing to pathogenesis may be more prone to failure and recurrence of [TMD] symptoms. It is clear that excessive loading on articular tissues is one of the causative factors that must be identified and addressed by all clinicians treating patients with TMJ pathology.
< Back to Services