Page 248 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.6 The hea d 223

VetBooks.ir 1.6 The head

FRACTURES OF THE ROSTRAL SKULL bone, resulting in avulsion of the incisor(s). Some
cases will involve fracture of only the tooth, poten-
Definition/overview tially exposing sensitive pulp tissue (Fig. 1.415).
Fractures of this region are not uncommon, with Mandibular fractures within the interdental space
the mandible being the most frequently fractured are often bilateral. Many displaced fractures of
bone in the head. Many rostral skull injuries ini- the rostral mandible and premaxilla are open and
tially appear dramatic, with profuse haemorrhage heavily contaminated and are usually presented with
and distortion of the bones, but most carry a good an organising haematoma within the fracture gap
prognosis for full recovery. (Fig. 1.416). However, the high vascularity of the
region and relative ease of attaining fracture stabil-
Aetiology/pathophysiology ity aid rapid healing in most cases. The horizontal
Fractures may result from kicks by companion horses and vertical rami of the mandible and the maxilla
or from self-induced trauma when the horse tries to appear to be fractured less frequently, possibly due
free itself after trapping its muzzle in a feeder, gate to protection from the overlying masseter muscles
or related object. Collisions or falls can also cause and being in a position less likely to become trauma-
similar fractures. tised or trapped. Neurological deficits are unusual
The mandible and maxilla are relatively narrow with rostral skull fractures.
bones, with thin cortices and little soft-tissue cover-
ing. The most common site of fracture is the rostral Clinical presentation
mandible, where the bone narrows at the interdental Clinical signs of mandibular fractures vary with
space and flares rostrally to accommodate the apices severity of injury and whether both mandibles are
of the incisors, thus predisposing this area to becom- affected. Horses with small fractures of the incisive
ing trapped in external devices. In some cases the portion of the mandible may be able to prehend and
osseous trauma will be confined to the labial alveolar masticate normally and show few or no signs, while

1.415 1.416

Fig. 1.415 A traumatic fracture of a 301 tooth Fig. 1.416 An avulsion fracture of the 401 and 402
with exposure of the pulp tissues, but no evidence teeth, with contamination and a large haematoma
of collateral damage to the adjacent teeth or the within in the fracture gap.
mandibular bone.