88 THE SURGICAL ANATOMY OF THE HORSE 



inferior part of the hard palate, whilst its anterior surface forms part of 

 the floor of the nasal chamber. Its inner edge is opposed to the corre- 

 sponding edge of the opposite plate. Its outer edge forms the inner 

 boundary of the interval in the mascerated skull known as the naso- 

 palatine cleft. 



In the mature animal the inner surfaces of the bodies of the two 

 pre-maxillary bones become firmly ossified to one another. 



In the young animal fracture frequently occurs along the pre- 

 maxillary suture due to the animal fiilling and striking the antero-lateral 

 aspect of the muzzle, or both pre-maxillary bones may be displaced 

 downwardly, and cause fracture of small portions of the nasal bones 

 near the upper extremity of the nasal processes. In the adult animal 

 from a similar cause both bones may be fractured transversely across 

 the line of continuity between the nasal processes and the bodies. The 

 walls of the incisor alveoli may be broken in. Frequently the body 

 of the premaxilla is broken into a number oi irregular pieces and 

 we have a comminuted fracture. 



Treatment depends upon the nature of the injury. Detached pieces 

 of bone should be removed. In cases of fracture through the symphysis 

 and downward displacement of one pre-maxilla only, the body of this 

 bone may frequently be elevated to its proper position by the insertion 

 of a mouth gag, which must be opened very gradually. The bone 

 may be maintained in position by twisting wire round both pre- 

 maxillary bodies, the wire being passed between the incisor teeth. 

 Wire so applied may also be utilised to keep large fractured pieces 

 of one pre-maxillary body in position after reduction. 



Some operators, after reduction of the displaced bones, maintain 

 them in position by the application of a padded, wooden or metal 

 splint to the palate, upon which the splint is moulded. This splint 

 is held in position by two straps carried round one on either side 

 to near the peak of the nasal bones, where they are attached to a 

 strap whicli descends the face from the brow-band. 



