Mandibulectomy in Dogs
Dr. Nicholas Trout
Mandibulectomy is a surgical procedure in which a portion of the lower jaw is removed. This can involve both sides of the jaw or just one side. Up to three-quarters of the entire lower jaw can be removed. Mandibulectomy may be discussed as a potential treatment option for an oral mass.
Mandibulectomy is most commonly undertaken for the treatment of benign or malignant tumors affecting the lower jaw. Occasionally, mandibulectomy may be selected as the best option for animals with certain types of jaw fracture, jaw bone infection, or fractures that have failed to heal properly.
Most animals with oral tumors are older, and certain breeds of dog more commonly get certain types of tumor, for example dogs with black pigment in their mouths have a higher incidence of malignant melanoma.
Dogs are more likely to undergo mandibulectomy than cats since they tolerate the surgery so much better.
Osteomyelitis (infection and inflammation in the bone) in the jaw most commonly occurs secondary to dental disease, more frequently seen in small and toy breeds of dog.
What to Expect
Your pet may receive a biopsy to confirm the mass is a tumor and then this area may be radiographed or imaged using a CT scan to assess the likelihood of complete surgical excision.
Your vet may show you pictures of dogs or cats that have undergone mandibulectomy. Because we as humans physically look down to our pets, mandibular surgery often produces only minor cosmetic changes in your pet's appearance.
Dogs have plenty of loose skin around their mouth to allow reconstruction of the defect produced when part of the mandible is removed. Cats have less loose skin making mandibulectomy in cats more challenging.
It is important to remember that animals are not concerned with their own cosmetic appearance. They do not look in mirrors to assess their own beauty. Their primary concern is to be free of pain or discomfort associated with an oral tumor, and to be able to eat, drink and breathe normally.
The bone is removed using a saw, a drill, a wire or a bone chisel (osteotome). Teeth are usually removed with the bone. Local nerves supplying the jaw can be blocked with local anesthetics. Pain is carefully prevented and controlled by the judicious use of morphine derivative compounds. These medications can ensure that your pet is comfortable throughout the procedure and during the recovery phase.
Your animal will be hospitalized until he/she is comfortable and beginning to eat and drink.
Some animals may need nutritional support in the form of a feeding tube into the stomach since their desire to eat and drink may take longer. This type of feeding ensures adequate nutrition as the surgical site heals.
What You Can Do
Be prepared to experiment with soft foods, like boiled chicken, boiled ground beef and hot dogs, for example, in order to get your pet eating again. Hand feeding and watering can be essential in the early recovery.
Following mandibulectomy, your dog's tongue may stick out to one side, or flop forward. Most animals will learn to adapt their tongue and eventually "sling" it back into a more normal position. Until this occurs make sure it is kept moist.
In many mandibulectomy procedures the two halves of the lower jaw are no longer fused. The result can be a "drift" of the jaw as it slides from side to side. This may look strange but most pets adapt to this variation in function quite quickly.
If there is a surgical incision through the skin it can be checked daily for swelling, redness or discharge. Skin sutures need to be removed 10-14 days following the procedure.
It is usually best not to stretch the mouth open to inspect oral sutures. Just note your pet's water when drinking for signs of bleeding into the water. Contact your veterinarian if this occurs.
Despite the mouth being a "dirty," bacteria-laden site, infection is not common following mandibulectomy because it has such a great blood supply. In most cases, antibiotics will be given at the time of surgery and not be required after that time.
Preventing a mandibulectomy may not be feasible for certain types of oral tumor. However, daily dental care and regular inspection of the mouth will help you notice abnormal lumps or bumps when they are smaller and more easily removed, and also help control dental disease which may predispose bone to infection and fracture.