Traumatic injury to the teeth and jaws of canine and feline patients frequently occurs through fights with other animals, automobile impacts, getting caught on fences, or falling onto hard surfaces. Mandibles can also suffer spontaneous pathological fractures due to severe periodontitis around the teeth (e.g. mandibular first molars) or due to neoplasia.
A fractured tooth with a red or black spot in the center of an irregular crown surface may indicate pulp exposure. A missing tooth after trauma may be avulsed or fractured with retained tooth root fragments. Dental radiography or other diagnostic imaging modalities, such as CT, can assist in diagnosing whether retained tooth material is still present beneath the gingiva.
Fractured teeth are treated as described under endodontic disease. Treatment options are dictated by the extent of the fracture, age of the patient, and duration of time from the traumatic incident to presentation for treatment. Dental extraction, vital pulp therapy, root canal therapy, and dentinal sealant are potential treatment options.
Avulsed teeth can be replaced if treated promptly (ideally within 1 hour of the trauma). The tooth should be immediately placed in saliva, milk, or a transport medium (eg, Hank's balanced salt solution), without touching the root surface. Limited contact with the root surface and helping to keep the surface hydrated will help protect the periodontal ligament cells and encourage reimplantation.
The alveolus and root surface should be gently flushed with lactated Ringer's solution, and then the tooth replaced into the alveolus and stabilized for 2–4 weeks with interdental wiring or a semirigid splint. Rigid stabilization with acrylic or composite is less ideal for the periodontal ligament repair because it encourages ankylosis of the reimplanted tooth. Root canal therapy is recommended within 1–3 weeks of the reimplantation.
Soft tissue trauma of the tongue, lip, buccal mucosa, and other soft tissues is repaired using primary closure with absorbable sutures. Oral soft tissues are vascular and heal quickly.
Oral flushes with dilute chlorhexidine solution every 2 days may help decrease oral bacteria during healing. Pain medication should be prescribed for patient comfort. An Elizabethan collar may also assist in healing because it will help protect the lesion from the pet's self-traumatizing the area.
Diagnostic imaging with CT can assist with assessing the extent of the injuries regardless of whether they are caused by fracture or dislocation, or whether they involve the maxilla, mandible, or both.
Fracture of the mandible can cause an acute malocclusion, pain, and an inability to eat. The midline of the mandible is usually displaced toward the side of the fracture. The mouth may droop open, particularly in bilateral mandibular fractures.
A dislocation of the temporomandibular joint can also be observed with clinical signs similar to an acute malocclusion, difficulty eating, and discomfort. In this condition, the midline of the mandible is displaced toward the opposite side of the injury.
Maxillary fractures can be stabilized with wire, sutures, or an acrylic splint, focusing on maintaining appropriate occlusion of the teeth. Mandibular fractures can be more challenging. Frequently, mandibular fractures can be repaired with interdental wiring and an intraoral splint made of bis-acryl composite resin.
Other potential treatment options for fractures include tape muzzling, cerclage wiring, interarch splinting, intraosseus wiring, external skeletal fixation, interfragmentary wiring, bone plates, labial buttons, and miniplates. Again, preservation of the normal occlusion is imperative. With stabilization, the pet can usually eat soft food readily until the appliance is removed in 6–8 weeks.
Caudal mandibular body fractures in the area of, or caudal to, diseased molars requiring dental extraction are much more problematic because of the lack of teeth on both sides of the fracture and the thinner bone caudal to the body of the mandible. Bone plates or miniplates can be used, but the prognosis is guarded.
Interarch splinting, or maxillomandibular fixation (ie, fixation between the upper dental arch and the lower dental arch, predominantly with the use of canine teeth), can be successful; however, there is a risk of aspiration while the splint is in place if the patient vomits. A labial button technique has also been suggested in place of the interarch splinting.
A feeding tube is frequently placed until the splint is removed to help supplement nutrition and administer pain medication and antimicrobials during the time of fracture healing.
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Also see pet health content regarding dental disorders of dogs and dental disorders of cats.
