Upper and Lower Jaw Fractures in Cats

Both upper and lower jaw fractures are very painful for the cat and they require immediate treatment. The lower jaw is more susceptible to fractures as it is made up of of two bones that have fused together, a process called symphysis. Often, because jaw fractures are linked with major trauma, the cat will be suffering from other, more serious injuries such as bruising of the lungs, punctured lungs, a diaphragmatic hernia, additional bone fractures and/or internal bleeding. A jaw fracture in itself may be life threatening, as most cats will refuse to eat due to significant mouth pain.

Upper and lower jaw fractures generally happen when a cat’s jaw is subjected to blunt force trauma. This can cause the fragile mandible (lower jaw) or the more sturdy maxilla (upper jaw) to fracture. Any type of break is classified as a fracture. It can be as small as a hairline crack or as devastating as a severe comminution (a bone shatter). Your cat may only have subtle swelling, or its entire mouth may hang open.

The following list shows many of the possible symptoms for both upper and lower jaw fractures. Please note that while some fractures are visibly obvious, others can be harder to recognize, especially in maxilla (upper jaw) fractures. All fractures need immediate veterinary care.

• Reluctance or refusal to eat
• Swelling around the mouth
• Bleeding from the mouth
• Wounds in or around the mouth
• Excessive drooling
• Jaw misalignment
• A mouth that hangs open or can not close at all
• Other trauma on body (from original blunt force that has caused the jaw fracture)

Types

Jaw fractures in cats are generally classified as either favorable or unfavorable, depending on the severity of the fracture and the general healing success associated with it.

Favorable

If the fracture has not caused the jaw to move out of place, it is referred to as a favorable fracture. Fractures of the maxilla (upper jaw) are often favorable.

Unfavorable 

If the fracture has caused jaw displacement, it is referred to as an unfavorable fracture. This includes situations where the fracture is exacerbated by the mouth muscles, and when the fracture runs perpendicular to the mandible (lower jaw). Mandible fractures are generally unfavorable.

Upper and lower jaw fractures are very common occurrences in cats. Jaw fractures are most commonly the outcome of impact injuries. These include but are not limited to:

• Being hit by an automobile
• Attacks from other animals (especially large dogs)
• Falls from great heights

When injury is not the cause, the cause is generally one of the following:

• Tooth decay
• Metabolic disease
• Cancer (or cancerous tumors)
• Tooth extraction complications

It is important to note that these issues are seen much more often in older cats than in younger cats.

All fractures need professional care to ensure that quality of life is restored as best as possible for the cat. Once at the veterinary clinic, your vet will most likely take the following steps:

Immediate Pain Relief 

Most jaw fractures are extremely painful, and are often paired with other, very serious, injuries. Generally, before any tests are run your vet will sedate or anesthetize your cat to give it some relief while also providing the best conditions for assessment.

Visual Assessment

The vet will then look for any and all external wounds or swelling to locate the main fractures. Often, because the jaw has such little flesh, the bone may be protruding from the skin.

Injury Severity Assessment 

Before any tests can be done, the vet has to ensure that your cat's condition is stable. This is especially true when the cat is suffering from multiple injuries, or there is significant blood loss.

Diagnostic Imaging 

The vet will take either X-ray (radiography) images or complete a CT (computer tomography) scan. They serve the same purpose, however a CT scan combines X-ray images with computer technology to provide the most detailed view of the affected area. It does take more time and it is generally more expensive. CT scans are preferred when the injury or complication is severe.

Once your vet has collected all of this information, they will be able to diagnose which type of fracture has occurred and plan the next steps of action.

The treatment needed for jaw fractures in cats is very dependent on what type of fracture is present. The most common procedures are listed below:

External Immobilization

The affected bones are aligned properly and then secured by a muzzle. The muzzle is administered using either a commercially produced mouth muzzle or medical tape. In less complicated fractures, this is sometimes all that is needed.

External Skeletal Fixation 

Pins are threaded through the skin into the bone while all being connected to an external rod or bumper bar which holds the jaw in place. It is a less invasive surgery in which all implants can be removed after healing has occurred. There is some postoperative care involved to remove the pins. This method is very effective in treating open mandibular body fractures.

Internal Reduction 

Bone plates and screws are placed surgically to secure bone pieces. They stay in the animal upon recovery. There is minimal postoperative care involved. This procedure is often used in repairing temporomandibular joint luxations (complete joint dislocation).

Interosseous or Interfragmentary Wiring 

A long, slender wire is inserted through the lower jaw but remains under the tongue and then protrudes back through to the underside of the jaw. It is then bent properly to prevent snagging.Postoperative care is required to remove the wire. This works to join two pieces of broken bone back together, especially in mandible symphysis breaks.

Interarcade Wiring 

The jaw is essentially wired shut to prevent movement and encourage proper alignment. The cat can only consume liquids and pureed foods throughout the healing process. A postoperative visit is required to remove the wire so the mouth can function again. This treatment is often used to correct a simple mandibular body fracture.

Interdental Wiring 

The wire is secured around the cat’s teeth to stabilize the realignment of the jaw. Wires will be removed at a later vet visit once the jaw has healed. This treatment is noninvasive.

Partial or Full Mandibulectomy

If the jaw is shattered beyond repair, or there is a tumour, mandibulectomy (amputation of the jaw) may be offered as a last resort attempt to save your cat's life. It is important to note that some cats will permanently refuse to eat after having this surgery, and the morbidity rates are high.

Feeding tubes may be used for a time with all of the above treatments.

Your cat should resume eating soft foods in one or two  days after being released from vet care. Pain medication is often prescribed to help your pet get through the recovery period. Non-steroidal anti-inflammatories are also given to help reduce swelling and general inflammation in the fracture area. Your vet may want to prescribe antibiotics, especially if there are any signs of infection after injury or surgery. You will need to limit your cat’s activity and discourage play throughout the time of recovery. If the cat has any external wiring, you will have to clean it and ensure no food remains attached to it to prevent dermatitis. If there are bandages, they may need to be changed. It is common to feel sadness or guilt over your cat’s injuries, especially if they are due to severe trauma that could have been prevented.

Certain complications can occur after your pet is discharged. They are:

• Malocclusion (imperfect positioning) of teeth, which can discourage your cat from eating
• Jaw dysfunction
• Incomplete/delay/failure of bone healing
• Tooth root injury
• Osteomyelitis (inflammation of the bone)
• Periodontal disease
• Infection

Overall the prognosis is generally good, with most cats healing completely within 4-6 weeks. The cause of the fracture paired with the impact at which it happened usually determines the overall healing success.