Referral & Clinical

Oral Trauma to Jaws

Jaw trauma is common in dogs and cats . Fractures to the jaws comprise 6% of all skeletal trauma surgery. New dental techniques, combined with standard surgical techniques, are often available to provide fracture repair without the need for invasive surgery.

With any jaw fracture it is absolutely essential to support the fracture site with a tape muzzle or soft Mikki muzzle as soon as possible. We frequently see cases where support has not been provided. As a result the weight of the fractured jaw pulls on the tissues and blood vessels making subsequent healing difficult if not impossible.

Normal orthopaedic techniques are tolerated very poorly by the jaws. There are a number of reasons for this. Firstly, most pins or plates are likely to damage the tooth roots and contribute to further pain and instability. Secondly, it is much more important to provide normal dental occlusion in order to allow the mouth to shut and return to normal function than it is to align the fragments accurately. Thirdly, these problems are often see in animals that already have significant dental disease.

Inter-dental wiring combined with composite resin or dental acrylics can be used to splint extensive fractures. Additionally, cats and small dogs lend themselves well to the bonding together of upper and lower canines to provide a stable environment for healing with the cat still being able to lap soft foods through the gap. Feeding tubes may be placed for initial nutritional support but can often be removed in 2-3 days.

The case series shown below shows Phoebe the cat that presented with multiple head trauma. The referring practice had attempted to stabilise the jaws with wires. The effect of the wires being too tight was to destabilise the fractures further and leave sharp wires in the mouth damaging the soft tissues further.

The radiograph shows that, apart from the symphysis separation, there is no other significant fracture. Note, however, the deviation and shortening of the mandibles. This is common in cats once the powerful masticatory muscles re-align themselves following symphyisis separation. The red arrows show the condylar processes on the mandibles. Note the symmetry proving no TMJ luxation.

The jaws very often re-align under GA without difficulty. They just won't stay there! Our solution is to place a bonding agent between the upper and lower canine teeth using a cut-down drinking straw as a retainer. If there is a cerclage wire round the symphysis the cut end below the chin can be grasped with forceps to guide the jaws and hold them there while the material sets.

If the jaws stay aligned for 2-4 weeks the material can be removed. The result with Phoebe was excellent.

One word of advice when selecting wire for interdental wiring techniques or cerclage wires in feline symphysis separation. Many texts and journal articles advise the use of 20 SWG wire for cats. This is not necessary - 24SWG is far easier to use and plenty strong enough. Also, NEVER leave the cut ends in the mouth or exposed under the chin. Cat s love to rub their chins and a jagged end of a wire will cause unnecessary trauma.

The radiograph below shows an ellipse round a caudal mandible fracture in Harry The Cat - see photo above. Inter-canine bonding worked very well in this case with full healing in 4 weeks.

Many dogs with periodontal disease of the teeth suffer from pathological fractures of the mandible from minimal trauma. Lack of teeth can be a challenge but occlusion as a primary objective, with rapid return to function as a close secondary objective is still necessary. Flo (French Bulldog)was kicked by a horse and fractured her right mandible. The site was open and infected. This healed well with twin cerclage wires once the compromised teeth and infected tissue was removed. The radiographs below show her before and after surgery and the photograph is of her right mandible 6 weeks following wiring.

TMJ conditions are also common in trauma cases – particularly in high rise syndrome in cats. Luxation of the condyle is easily resolved but fractures of the condyle or zygomatic process of the temporal bone can be challenging to diagnose and resolve. CT scanning provides excellent imaging in these cases