Broken Pet Teeth
Broken (fractured) teeth are a very common occurrence in dogs and cats. Pet teeth can break due to trauma (hit by a car, ball, or rock) or due to chewing on hard objects. Any pet tooth can break, however some teeth are more commonly fractured than others, such as the canine (fang) teeth in the dog and the cat, and the upper fourth premolar (large tooth on the upper jaw in the back of the mouth) in dogs.
There are two categories of broken pet teeth: those that directly involve the root canal (termed complicated crown fractures) and those that do not extend deep enough to expose the root canal, but rather only expose the layer beneath the enamel which is called dentin (uncomplicated crown fractures). Both of these types of tooth fracture require therapy, but the treatment can be very different.
Pet teeth with direct root canal exposure are excruciatingly painful to a dog or cat. Unfortunately, only very rarely will animals show discomfort, as they are evolutionarily conditioned to mask pain fairly well, preferring to suffer in silence. This allows owners (and veterinarians) to ignore the problem, as “it doesn’t seem to bother the pet”. But we now know that these animals are suffering with consequences both locally in the mouth as well as systemically throughout the body. This means that in today’s current age of veterinary medicine, it is no longer appropriate or acceptable to ignore broken teeth in our patients. We have had numerous clients who have told us that their pet is not bothered by its broken tooth when it is discovered, that later tell us joyfully that their pet is acting “5 years younger” just two weeks after the problem is fixed.
The reason that a broken pet tooth with direct pulp exposure presents a problem is that after the tooth is fractured, bacteria from the mouth gain access to the root canal and infect the tooth. Eventually, the tooth will die and become a bacterial haven. The bacteria then leak out through the bottom of the tooth, and infect the bone in that area. Eventually, the bacteria cause bone destruction around the tips of the tooth root. Next, the blood vessels in the area pick up the bacteria and spread it to other areas of the body, including the liver & kidneys which filter the blood, and potentially to the heart valves, which damage these vital organs. In fact, infected teeth (and periodontal disease) can so greatly affect the rest of the body and its vital organs that we have had numerous patients with elevated liver and kidney enzymes found on the pre-op blood which then improve or return to normal levels within two weeks of the dental procedure.
Occasionally, the infection at the root tips will get so bad that an abscess will break out through the skin and appear as a wound on the face, often below the eye. This most commonly occurs with a fracture of the upper fourth premolar in dogs, and it is known as a carnasial tooth root abscess. It can also happen secondary to an infected canine as well as most other teeth. In cats, an abscess will usually be due to a fractured canine tooth, but due to the shortness/shape of the nose, this wound will open below the eye as well. Antibiotics will usually resolve the problem for a while, but invariably the problem will continue to reoccur if the offending tooth is not appropriately dealt with.
Treatment Options for Broken Pet Teeth
There are three options for treatment of a fractured tooth with direct pulp expsure, and ignoring it is NOT one of them. This problem can only be solved with either root canal therapy, vital pulp therapy, or extraction.
The first and best option to treat fractured tooth that is otherwise healthy is root canal therapy.
This procedure removes the infected root canal tissue (called the pulp), medicants to help prevent future bacterial contamination. This is most commonly done for canines in dogs and cats, and the upper fourth premolars and lower first molars in dogs. However, any tooth can be saved in this manner. The advantages of root canal therapy over extraction of the tooth include:
- Saving the tooth
- Preserving the strength in the jaw
- Avoiding surgical pain
- Especially for large teeth
- Decreases risk of surgical complications
Vital pulp therapy (VPT) is only recommended in pets under 18 months of age. This is because the teeth are generally not mature enough for root canal therapy until that age. Once the teeth are mature, root canal therapy has a much better prognosis. However, if VPT is to be performed, it should be done as soon as possible
The final option is extraction of the offending tooth. Choosing this treatment option may depend on the tooth involved, degree of fracture, and any other disease issues. Extraction is the least ideal option for the most “strategic” (i.e. useful) teeth which include the canine (fang) tooth, as well as the upper fourth premolar and lower first molar teeth in dogs this is the last option. There are several reasons we prefer to extracting these teeth if possible.
- These are very large teeth with very large roots in animal patients. The root of the canine tooth is twice as long and wider than the crown (the part you can see). Extraction of these teeth requires more invasive oral surgery, i.e. they are not simple extractions.
- The patient loses the function of the tooth, which can be very important for chewing in some cases.
- Orthodontic problems can occur as a result of losing of the tooth.
We try to avoid extraction in cases of otherwise healthy teeth.
Uncomplicated crown fractures are approached with different treatment options. These are also a very common finding on oral exam, particularly in large breed dogs. The most common teeth involved are the carnassials (maxillary fourth premolar and mandibular first molar) as they are the primary chewing teeth. However, any and all teeth can be fractured. These fractures almost always result in exposure of the underlying tooth structure called dentin. This will uncover dentinal tubules which contain what amounts to nerves and creates significant pain for the patient. This is similar to us having a sensitive tooth from a deep cavity. In addition, some of these teeth will die either due to the trauma, inflammation, or direct pulpal invasion via the dentinal tubules. For these reasons, it is recommended that these teeth be radiographed to ensure vitality. If the teeth are dead (evidenced by bone loss at the tips of the teeth) the teeth need to be root canalled or extracted. If the teeth appear to still be alive, the application of a bonded sealant is recommended to decrease sensitivity, block off the pathway for infection, and smooth the tooth to decrease periodontal disease.