Fracture of the Maxilla in Cats
Overview of Feline Maxilla Fractures
Fractures of the maxilla (upper jaw) are usually the result of major trauma, but can be caused by disease of the bone itself or dental disease.
Fractures of the maxilla are often segmental involving a short region of the upper dental arcade. The fractures can be impacted (pushed inward) resulting in disruption of the adjacent nasal cavity. Maxillary fractures infrequently result in instability. These fractures are usually “open” (bone exposed) and “comminuted” (multiple bone fragments). Depending on the nature of the fracture and the age of the animal, different methods of management may be indicated for each situation. Maxillary fractures can have serious complications if repair is indicated but not performed or if the repair fails.
What to Watch For
- Bloody fluid coming from the nostril
- Difficulty breathing through the nose
- Inability to close the mouth
- Pain when attempting to eat
Diagnosis of Maxilla Fractures in Cats
Thorough physical examination including examination of the oral cavity is initially performed. No laboratory tests are required to make the diagnosis, but several additional tests may be needed, including:
- Chest X-rays
- Complete orthopedic examination
- Complete neurological examination
- Radiographs or computed tomography (CT scan) of the skull
Treatment of Maxilla Fractures in Cats
Emergency care for concurrent problems caused by the trauma is initially performed prior to specific treatment for the maxillary fracture. After stabilization, additional treatment may include:
- Some fractures of the maxilla can be managed without surgery simply by resting the cat and preventing further injury to the mouth by feeding soft foods and not allowing the animal to chew on toys or other objects.
- Some maxillary fractures require anesthesia and surgical stabilization of the bone fragments for the best results.
- If dental disease is suspected as the cause for the fracture, a full dental cleaning with extractions of some teeth may be required.
- Injectable analgesics (pain medications) are given to the animal while being treated in the hospital and may be continued orally once discharged from the hospital.
- Antibiotics are commonly given to minimize the chance for systemic infection from bacteria in the mouth.
Home Care and Prevention
With conservative management or after surgical repair of the fracture, the cat will be kept restricted from activity for several weeks and will be fed only a soft gruel that does not require chewing.
Recheck appointment with the veterinarian will occur in several weeks to evaluate how the bone is healing (possibly with new radiographs), to monitor the animal’s progress, and to make sure it is safe to return the animal to his regular diet.
Many traumatic events are true accidents and thus unavoidable. Dental hygiene and routine cleaning by the veterinarian may prevent severe dental disease that could lead to maxillary fractures.
In-depth Information on Maxilla Fractures in Cats
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).
A thorough physical examination is very important to make sure your pet is not showing signs of hypovolemic shock secondary to the trauma or blood loss. It is also important to make certain that there are no other injuries present. No laboratory tests are required to make the diagnosis. After stabilization, additional tests may include:
- Examination of the oral cavity and palpation of the skull. Commonly found abnormal findings include broken teeth, disruption of the palate or gum line, hemorrhage from the gum line, palpation of instability of the entire nose in relation to the rest of the skull, crepitation (abnormal “crunchy” feeling with motion), swelling, and pain along the side of the face, or malocclusion (misalignment of the upper and lower teeth). Also, a finding of blood tinged fluid or decreased airflow from one or both nostrils may indicate fracture of the maxillary bones.
- Thoracic radiographs (chest X-rays). Chest trauma, in the form of pulmonary contusions (bruising) or pneumothorax (collapsed lung lobes secondary to free air within the chest cavity), must be ruled-out with chest radiographs prior to anesthesia to repair the jaw.
- Complete orthopedic examination. A complete orthopedic examination must be performed to look for other possible injuries in other bones or joints caused by the trauma. Examination involves palpation of all of the bones and joints of each leg for signs of pain or abnormal motion within a bone or joint as well as an assessment of the neurological status of each leg. The thorough orthopedic examination is especially important for an animal that is unable or unwilling to get up and move.
- A complete neurological examination. This is extremely important for an animal that has suffered trauma to the head. Damage to the brain and other important nerves in the head may result in temporary or permanent deficits that may need to be treated quickly and must be considered when planning a course of treatment for other injuries, such as a maxillary fractures.
- Radiographs of the jaw. Several radiographic view of the animal’s skull are used to confirm the diagnosis of maxillary fracture. In order to get useful information from the radiographs, general anesthesia is usually necessary to take the X-rays. Because of the location of the maxilla in the skull, normal radiographs often are not the best method for identifying these fractures. Computed tomography (CT scan) of the skull is a much better way of determining the extent of the fractures and their impingement on the nasal cavity. The CT scan also requires general anesthesia.
Based on the location and severity of the fractures, a more informed discussion with the owner can occur regarding potential treatments, prognosis, and costs.
Emergency care for concurrent problems is paramount. Shock is a frequent result of major trauma and must be treated quickly. Treatment for shock involves intravenous fluid administration to maintain blood pressure and adequate oxygen delivery to the body. Injury to the lungs and chest cavity are also commonly seen after major trauma and may require supplemental oxygenation or removal of free air (pneumothorax) from around the lungs. After stabilization, other treatments may include:
- Soft-tissue injuries must be addressed in order to minimize the chance for the development of wound infections. Lacerations and other open wounds or open fractures must be cleaned of debris and covered or closed to minimize infections.
- In the interim between treating the emergency patient and surgical repair of the maxillary fracture, all of the orthopedic injuries that have been found should be addressed with splints and/or pain medications to keep the animal comfortable until they can be properly addressed.
- Depending on the specific fracture type, location, and age of the animal, maxillary fractures may be repaired in many different ways. Many fractures require no surgical intervention at all. Fractures in which the entire nose is unstable, airflow through the nasal cavity is impaired, or (occasionally) for cosmetic reasons, surgical stabilization of the fractured bones may be necessary. Most commonly, the fractures are stabilized with small wires placed in the bone or around the teeth. In some cases miniature bone plates and screws can be used to reconstruct the shape of the face.
- Maxillary fractures, as well as any other traumatic injuries that the animal might have, are painful and the animal will be given analgesics before and after surgery.
- Open fractures of the mandible are susceptible to infection from bacteria and other debris in the animal’s mouth and antibiotic therapy may be given while the animal is in the hospital and continued at home to prevent systemic infection.
Follow-up Care for Cats with Maxilla Fractures
After discharge from the hospital, the cat must be restricted from activity for several weeks to allow the fracture time to properly heal. The duration will vary depending on the severity of the injury and any concurrent injuries the animal may have. Restricted activity means that the cat should be kept confined to a carrier, crate, or small room whenever he cannot be supervised. Play and rough-housing should be avoided, even if the cat appears to be feeling well. It is especially important that cats with maxillary fractures not be allowed to chew on toys or other objects and be fed only soft food or blenderized gruel.
Fractures that are repaired with internal fixation (wires or bone plates and screws) will have a skin incision on the face that needs to be monitored daily for signs of excessive swelling or discharge. These can indicate problems with the incision or possibly infection.
Analgesics (pain medications) or anti-inflammatory medication should be given as directed by the veterinarian. Analgesics, such as butorphanol (Torbugesic®) can cause sedation, and anti-inflammatory drugs, such as aspirin can cause stomach upset. Your veterinarian should be informed if any adverse side effects do occur.
If at any point prior to the follow-up evaluation the cat stops eating after some improvement following surgery, or if a bad odor begins coming from the mouth, there could be a problem.
Several weeks after surgery a follow-up appointment will be needed. The skull occasionally may need to be X-rayed again to make sure the bone is healing properly. If healing has occurred as expected wires placed around the teeth will be removed and the animal’s activity level and diet will be allowed to return to normal.
In general, any other implants that were used in the repair under the skin will be left in place unless they cause a problem at some point in the future. Potential problems can include migration (movement) or infection of the implants.