Long-term results of bovine mandibular fractures involving the molar teeth

To evaluate postoperative complications and long-term outcome of simple mandibular fractures involving the molar teeth in cattle.

Seventeen cattle with mandibular fractures involving the molar teeth with disruption of the occlusal surface.

Treatment consisted of application of AO/ASIF-Pinless External Fixators (Synthes, Paoli, PA) in 14 cows, interdental wire stabilization in 1 cow, and conservative treatment in 2 cows. Long-term outcome was determined by telephone contact with the owners, and whenever possible, cows were reevaluated by physical, intraoral, and radiographic examination of the fracture site.

Loosening of the fixation device (4 cattle) and bone sequestration (11 cattle) were the most commonly encountered complications. Oral incontinence during rumination was a minor complication in 1 cow. The mean (+/- SD) time the cattle were in production was 26 (+/- 14) months, with 10 cows still alive at follow-up examination; 9 cows were reevaluated. On intraoral examination there was a step in the occlusal surface at the level of the healed fracture site in 3 cows, wave and shear mouth formation in 3 cows, and enamel point formation in 1 cow. Radiographically, all the reevaluated fractures had healed, and there were no signs of tooth root infection.

Complications during healing were bone sequestration and loosening of the fixator. None of the cows was removed from production because of fracture-associated complications, but decreased milk yield occurred in 2 cows. Tooth abnormalities developed in 6 cows, but function of the mandible was not altered.

Mandible fractures involving the molar teeth carry a good prognosis for return to normal function. Radiographic follow-up is necessary to detect bone sequestration.