Jaw fractures in pets, resulting from trauma, require specialised care. Veterinary dentistry provides a considered approach to these cases, sparing function and anatomy.
Due to the high vascularity of the oral cavity, most oral fractures will repair no matter which technique is used, providing fixation is reasonable. Repair and adequate healing of the fracture unfortunately does not guarantee return to function. Returning the animal to a normal functional occlusion as soon as possible post-operatively should be the objective of any treatment performed.
Causes of Jaw Fractures:
- Traumatic events, such as falls or accidents, and unfortunately inter dog aggression.
- Dental extractions, particularly in aged animals.
- External forces leading to unforeseen damage.
Challenges in Repair
Oral fractures pose challenges due to bacterial contamination, difficult access, and the influence of periodontal disease. Repair is not just aimed at having the bone repair, but repairing in such a way that we preserve the functionality of the mouth, the teeth as much as possible and importantly the occlusion of the teeth.
Initial Evaluation
Immediate relief involves temporary stabilisation, usually with a muzzle. A comprehensive clinical assessment follows to determine the extent of the damage. This will always require xrays (dental, and sometimes skull) and often will require CT for a full evaluation.
Anaesthesia and Medical Considerations
Specialised care is crucial for animals with complex health conditions affecting anaesthesia risks. As many of the patients presenting with jaw fractures have experienced other trauma, particularly in other parts of their head, their care is not necessarily straightforward. Some patients require other more impactful injuries to at least be stabilised before jaw fracture repair can be attempted.
Types of Jaw Fractures and Repair Techniques
Maxillary Fractures:
Usually less frequent; conservative treatment is possible. If the maxillary fractures are not particularly distracted, the other tissues present can often stabilise these fragments well. Surgical closure of any soft tissue injuries will stabilise things a great deal. Severe cases may involve interdental wires and acrylic splints.
Mandibular fractures:
These are some of the most frequent fractures seen in companion animals.
Several points to consider in selection of the method of repair:
- the dental arcade is the tension side of the fracture
- the final occlusion is the most important factor in fixation
- mandibular tooth roots go virtually to the ventral border of the mandible and are unlikely to be missed with fixation devices
- any damage to the teeth during repair will cause long-term complications
- the maxillary teeth occlude to the outside of the mandibular teeth
The most successful repair techniques involve the use of interdental wiring combined with acrylic splints. Variations will occur depending on the fracture type and position.
Cerclage wiring for symphyseal separation
Symphyseal separation is common in the cat and may be associated with TMJ luxation or caudal mandibular fractures. Cerclage material placed behind the canine teeth is the best technique for uncomplicated separations. This has traditionally been performed with wire, however modern synthetic sutures are suitable and in many cases superior than wire. Complete, firm stabilisation is not necessary.
Figure of 8 wires around the canine is not suitable for use in the cat as the canines are forced into a more vertical position and will interfere with normal occlusion. Complicated, unstable separations are best treated with inter-canine bonding techniques.
Interosseous wiring
Wires can be placed to stabilise the fracture providing care is taken to avoid dental damage. Radiographs are taken with markers in place to ensure that tooth roots are avoided and small holes are made with drills or small pins for the wire placement.
Interdental wiring
This involves placing wires around adjacent or multiple teeth in order to stabilize the fracture. The wires are placed below the enamel bulge of the tooth (at the gum margin) in order to prevent them slipping off. If this is unsuccessful, a small amount of composite resin is placed to hold the wire or a small notch can be made in the tooth.
There are several wiring techniques but they all involve tightening a series loops around the teeth which then acts as a fixation device. An acrylic splint is often used over this wire to increase the effect.Â
Inter-canine bonding
This is a very useful technique for multiple unstable fractures especially those involving the caudal mandible of cats.
Post-operative Care
Oral hygiene is important in the post operative period. The mouth is an area that accumulates a high bacterial load very quickly. So, when combined with intra-oral appliances, infection of the damaged tissue is a possibility. Generally rinsing the mouth regularly and using foods that leave minimal residue is very helpful.
The vast majority of patients who suffer from jaw fractures will go on and lead a very normal life after they have healed. The repair and healing period can be difficult for some, but generally within 6 weeks of the fracture, patients are back to normal, interacting with their family and eating and drinking normally.