Commonly from chewing on cage doors, airplane crates, or chain-link fences. Also implicated are hard chew toys, ice cubes, and horse hooves. Auto accidents, aggressive Schutzhund training, and dog fights can additionally lead to fractures.
In the mature dog or cat, the maxillary canines are most commonly broken, followed by the mandibular canines, the maxillary fourth premolars, and incisors. In the immature dog, deciduous canine teeth commonly fracture.
The lesions that develop vary. Many times a tooth fracture will occur that does not enter the pulp chamber and only the enamel or dentin is affected. Even so, trauma that caused the enamel and dentin to fracture may be sufficient to cause direct vascular damage and hemorrhage that can lead to inflammation and tissue destruction. Bacteria can then move in through anachoresis (the process of bacteria lodging in an area of previously damaged tissue), causing a myriad of problems ranging from internal inflammation to an apical abscess.
Therapy decisions depend on which parts of the tooth are exposed. If the fracture involves only enamel, the treatment of choice is to smooth the sharp edges with fine white stone burs and sanding disks, in order to prevent trauma to the lips and tongue. Intraoral radiographs should be taken to get baseline images of the apex and to check for apical fractures The tooth should be re-radiographed at six and twelve months for evidence of periapical pathology.