WORN TEETH (ATTRITION AND ABRASION)

Two terms are used in veterinary dentistry to describe worn teeth. “Attrition” is the term used to describe teeth that are worn due to abnormal contact with other teeth (usually seen with malocclusions) while “Abrasion” is used to describe teeth that exhibit wear due to contact with substances outside of the mouth. Dogs that chew their hair due to pruritus often have abrasion of the and sometimes canines. Any teeth can be affected if the dog is an aggressive chewer of tennis balls, toys, bones, etc. The distal aspects of the canine teeth often show wear in a dog that chews on fences or cages.

Figure 1: Attrition on the distal aspect of the right maxillary lateral (103) is due to contact with the right mandibular canine (404).

Worn teeth may resemble fractured teeth. However, if the process of reducing the hard substance of the tooth is slow enough (in the instance of a pruritic dog or a “tennis ball chewer”) the tooth may be able to compensate by producing extra tooth substance (reparative ). Reparative dentin is a protective mechanism by which the ondontoblasts of the can produce a barrier to the “outside world”. If the pulp detects that it is in danger of exposure, the odontoblasts are stimulated to produce reparative dentin to protect against ingress of bacteria. If successful, the tooth remains vital despite losing a significant portion of the normal hard structure of the tooth. Reparative dentin tends to stain easily and thus affected teeth often have a discolored brown area associated with the dentin. A tooth that is fractured acutely (or wears too quickly) will likely result in pulp exposure necessitating extraction or endodontic therapy. The only exceptions are uncomplicated fractures (those that do not reach the pulp canal).

Figure 2: Chronic wear of the of the right mandibular first (409) has resulted in the deposition of reparative dentin on the tip of the and the flat occlusal surface.

Worn teeth should be radiographed to determine that they are indeed still vital. Non-vital teeth will appear discolored. Radiographically they may have a larger pulp canal than other vital teeth and some may have periapical lucency indicating pulp necrosis.