Bruxism

The five major causes of pathologic, noncarious tooth wear according to Abrahamsen
Abrasion:
Bruxism
Toothpaste Abuse
Erosion
Regurgitation
Soda Swishing (Coke Swishing, Pepsi Swishing, etc.)
Fruit Mulling


It is important to remember that these causes rarely exist alone. You will find the stigmata from one major cause of tooth wear intermixed with one or more secondary causes. This page will examine the diagnostic features of bruxism. It follows closely the outline provided by Dr Abrahamsen.
Bruxism is defined as the grinding or rubbing together of the upper and lower teeth. It is caused by stress, and the other pathological effects of bruxing on the human body are discussed in my section on TMJ.


This page discusses only the wear caused by bruxism on the teeth.

Wear patterns on teeth caused by bruxism

Bruxing causes wear on occlusal and incisal surfaces of the teeth. The wear is always progressively greater from the posterior to the anterior. In other words, the more anterior the tooth, the greater the wear. The full size image can be seen on the first page of this series. However, even in this smaller image, one can see that the anterior teeth are much more worn than the posterior teeth. This is a very important point in the diagnosis of bruxing. The only exception to this rule is a patient with an anterior open bite.
Cupping or cratering on molar cusp tips is often present, but it is NOT due to bruxing. It is due to a secondary habit of toothpaste abuse since persons who brux are likely to be aggressive brushers. See figures 1 and 2 on Dr. Abrahamsen's paper.
Inspection of the teeth, or hand articulated stone models will show that the abraded areas on the maxillary teeth match abraded areas on mandibular teeth.
The type of patient who bruxes

Stress causes bruxing. Since EVERYONE suffers stress at certain points in their lives, it can be assumed that EVERYONE bruxes to one extent or another. However some people are more stressed than others and therefore suffer more bruxing wear than the "average" patient. If you make study models on any adult patient, you will find wear facets on premolars and anterior teeth at minimum.
Sleep apnea also causes night bruxing. Night bruxing can occur in the absence of sleep apnea, simply as a reaction to daytime stress, but obstructive sleep apnea produces severe night bruxing. Click here for more on obstructive sleep apnea.
Confirming your diagnosis of bruxing

You CANNOT ask your patient if he or she bruxes. They always deny the habit, and indeed, the habit is done almost entirely unconsciously.
The best method of confirming the diagnosis of bruxing is to take diagnostic study models and inspect the pattern of wear facets.
The least wear will be toward the posterior of the arch, and the most wear will be toward the anterior.
When the upper and lower models are hand articulated, you will find that they fit together well, and upper and lower wear facets will coincide.
See figures 3-6 on Dr. Abrahamsen's paper.
Treatment of bruxism

The treatment for bruxism is a traditional bruxing guard or a deprogrammer such as the NTI. These treatments work well provided that the patient gains relief from the painful symptoms of TMJ if he complies with the treatment. Unfortunately, treating bruxism in patients who have only tooth wear has not been successful in my hands since the patients cease wearing the appliance after strenuous efforts to comply.
Treating obstructive sleep apnea by referring the patient to the appropriate medical professional will generally reduce or eliminate night bruxing in patients with this problem.