While the teeth and jaws are strong, they also play a prominent role in the interaction of animals with their environment. This predisposes them to traumatic injury, most commonly fights with other animals, automobile impacts, getting caught on fences, or falling onto hard surfaces. Mandibles can also suffer spontaneous pathologic fractures due to severe periodontitis around the mandibular first molars or to mandibular neoplasia.
A fractured tooth with a red or black spot in the center of a fractured surface indicates pulp exposure. A missing tooth after trauma might be avulsed or may be fractured with persistent root fragments. This is determined radiographically. Fractured mandibles cause acute malocclusion and inability to eat. The midline of the mandible is usually displaced toward the side of the fracture. The mouth may be held open.
Fractured teeth are treated as described above (see Endodontic Disease in Small Animals). Avulsed teeth can be replaced if treated immediately. The owner should immediately place the tooth in a tooth transport medium or milk, without touching the root. The alveolus and root surface should be gently flushed with sterile saline to remove dirt, and then the tooth placed into the alveolus and stabilized for 1 mo with interdental wiring. Rigid stabilization with acrylic or composite is less ideal for the periodontal ligament repair (encourages ankylosis), but it may be a good idea to protect against abuse of the recently replaced tooth. Root canal treatment is done when the fixator is removed.
Soft-tissue trauma is repaired using primary closure with absorbable sutures. Oral soft tissues are vascular and heal quickly. Oral flushes with 0.12% chlorhexidine solution every 2 days helps decrease the oral bacteria during healing.
Maxillary fractures can be stabilized with wire and sutures. Mandibular fractures can be more challenging; when possible, they can be repaired with a combination of interdental wiring and an overlay of composite resin or acrylic as an external fixator holding the teeth. This positions the fixator on the distraction side of the fractured bone, while avoiding damage to the roots that is common with bone screws and plates. Preserving normal occlusion is important. With rigid stabilization, the pet can usually readily eat soft food until the appliance is removed in 6–8 wk.
Caudal mandibular fractures behind the molars are much more problematic because of the lack of teeth on both sides of the fracture and the very thin bone caudal to the body of the mandible. Plates can be used, but the prognosis is guarded. Interarch wiring (ie, wiring the upper dental arch to the lower arch) can be successful, but there is a risk of aspiration while the wiring is in place if the animal vomits. A feeding tube is used until the wiring is removed.
Last full review/revision March 2012 by Jack Easley, DVM, MS, DABVP (Equine); Gregg A. DuPont, DVM, Fellow AVD, DAVDC