Motor vehicle trauma is a frequent cause of maxillary fractures in cats but any trauma to the head can cause them. Cats can develop non-traumatic fractures of the maxilla when certain disease conditions exist. These fractures, also known as "pathologic fractures" can occur if the cat has severe dental disease leading to destruction of the bone supporting the teeth, has a bone infection (osteomyelitis) or has cancer of the bone.

Symptoms caused by fracture of the maxilla may be relatively subtle, with reluctance of the animal to play or chew on toys or food or more obvious with bloody saliva dripping from the mouth, bloody fluid coming from the nostril, reluctance to close the mouth, or inability to eat at all.

The maxilla is actually a relatively thin and frail bone that forms the outer wall and floor of the nasal cavity (also known as the roof of the mouth or hard palate) and supports the upper canine, premolar and molar teeth on each side of the mouth. Because of the configuration of the maxilla in relation to the rest of the skull, fractures usually are comminuted (multiple pieces) and impacted into the nasal cavity. Sometimes the fractures are not displaced and are relatively well aligned with the remaining bone. Because there is relatively little soft tissue covering the maxilla in the mouth, these fractures are usually "open" (bone exposed). Open fractures have a greater chance of getting infected and may have more complications than closed fractures.

Each case of maxillary fracture needs to be evaluated in its entirety (age of animal, severity of the fracture, experience of the surgeon, and financial concerns of the owner) to determine the most appropriate and best form of treatment.

Inappropriate case management, inadequate surgical stabilization when indicated or poor aftercare can lead to complications such as non-unions (fractures that will not heal), malunions (fractures that heal in an abnormal direction or orientation resulting in malocclusion of the teeth and difficulty chewing or impairment of airflow through the nasal cavity) or osteomyelitis (bone infection).