Pet Jaw Fracture Repair
There are many causes of jaw fractures in dogs and cats, but by far the most common is trauma. More specifically, hit by cars, falls, and fights. These patients typically present with other signs of trauma as well. Therefore, stabilization of the patient is often required prior to fixing the jaw. However, there are instances when the jaw breaks due to being weakened by a disease which is called a “pathologic fracture”.
There are numerous techniques for the fixation of jaw fractures. The type of fixation selected depends on the type of fracture as well as surgeons preference. This listing is a brief summary of techniques and is not complete or exhaustive. Here at SCVDS&OS prefer to use non-invasive techniques whenever possible. In our experience the vast majority of jaw fractues can be performed without painful and potentially damaging techniques which place metal directly in the bone. These techniques include: bone plates, pins, screws, and (intrabony) wires.
By far the most common technique we use is an acrylic splint. Dr. Niemiec published this technique over 10 years ago and has been performing it successfully on a regular basis ever since.
An acrylic splint uses the patient’s own teeth as the connection points between the broken pieces of jaw. The jaw is placed in alignment (reduced) and then the teeth are coved with an acrylic resin (actually used for temporary crowns and bridges). Once set (which only takes a few minutes), the splint is smoothed and the occlusion (bite) is checked. No holes are drilled in the bone, which is great as these holes can easily damage tooth roots, nerves, and blood vessels. Another significant advantage of an acrylic splint is that no surgery is required to remove the fixation after healing has occurred. Following radiographic confirmation of healing (anesthesia is required for this), the splint is cut and removed from the teeth. The patient has immediate return to function.
There are a few fractures, however, which do not respond well to acrylic splint fixation. Where possible, we still attempt to not further damage the bone with invasive techniques. These instances are detailed along with their ideal fixation methods below.
Mandibular symphaseal separations are the most common type of “fracture” in a cat. It is not a true fracture because a bone is not broken, rather a “joint” is dislocated. The easiest way to fix this is by a procedure called circummandibular wiring. This is done by placing a wire around the lower jaw just behind the canines and tightening under the skin below the chin. This will be removed after healing, but again, the bone is not further traumatized by the fixation method (or its removal).
Fractures of the temporomandibular joint (TMJ) or ones that are very far back (behind the teeth) will not be able to be treated with an acrylic splint. In addition, any type of direct fixation is often impossible. Therefore, they are often treated with what is known as interarch bonding. This is very similar to “wiring the mouth shut”. This technique relies on the large jaw muscles in the back of the mouth holding the fracture in position. The jaws are placed in proper alignment and the canines bonded together. After healing this is removed and the patient can eat normally.
Occasionally, fractures are too severe to be treated with non-invasive means. These cases can be caused by severe trauma with numerous small fragments (like a gunshot wound), or more commonly when a diseased tooth must be extracted from the fracture area. This typically occurs in pathologic fractures (below). When a tooth (or root) is extracted, it leaves a large void in the bone which must be bridged and stabilized. In these cases, intrabony wires are added to the splint to aid stabilization. We use wires as opposed to other so called rigid fixation methods because it is easier to avoid sensitive structures like tooth roots, nerves, and blood vessels due to their small size and flexibility in placement. These wires are generally removed following healing.
If a plate, pin, or external fixator has been recommended for your pets jaw fracture, please contact us or your nearest veterinary dentist for an opinion prior to surgery.