Attrition is the term used to describe wear on the biting surfaces of natural teeth and dental restorations. The wear itself is a diagnosis that can be treated, but it’s also a symptom of a larger problem which, if overlooked, can result in the failure of restorations performed to fix the wear. Common causes of attrition include tooth grinding (bruxism) and inappropriate alignment of the teeth (like gears that don’t mesh properly), a condition known as malocclusion.
An attempt should be made to address the source of the bruxing if present (e.g. emotional stress, etc.), which may involve medical intervention as well. If the bruxing habit cannot be eliminated, it should also be treated. Orthodontics should be considered if improper tooth alignment is noted. In the case of severe malocclusion, maxillofacial surgery (orthognathic surgery) may be recommended.
Severe attrition like that shown in Figure 1 can be a serious problem. If all the teeth are involved, the jaws may rotate together more than they should. This is known as loss of vertical dimension of occlusion (bite collapse).
Bite collapse can result in damage to the jaw joints; severe pain or dysfunction in the jaw joints (TMJ dysfunction); excessive muscle contraction forces as the closing muscles of the jaw shorten (which can accelerate the destruction); cracked or chipped teeth; aggravation of periodontal disease (secondary occlusal trauma); shortening of the lower face height (which changes one’s appearance); an inverted smile (corners of the mouth sag); frequent cracking or chapping at the corners of the mouth (angular cheilitis); and problems chewing.
Despite the obvious severe wear on the teeth, the patient in Figure 1 exhibited none of these conditions, as the back teeth had been crowned and prevented the bite from collapsing. If wear happens slowly enough, the teeth may continue erupting (moving into the mouth further) as the wear occurs, which can minimize or prevent bite collapse (and make fixing the problem more difficult, since there may be little or no room to add tooth structure). If the patient has periodontal disease, in which the tooth supporting bone is softened by the disease, some teeth may be lost, while others tip outward from the increased chewing forces applied to them. This can also lead to bite collapse, whether or not the teeth themselves become worn.