Odontoclasts Gone Wild: Feline Resorptive Lesions in the Shelter
By Heather Inzalaco, Dane County Humane Society Animal Medical Services Intern
What are Feline Odontoclastic Resorptive Lesions (FORLs)?
Feline tooth resorption is a condition in cats characterized by resorption of the tooth by odontoclasts. Tooth resorptions involve the activation of these odontoclastic cells (cells that are responsible for the normal remodeling of tooth structure) which eat away normal bone cells of the teeth. The result is a hole in the tooth that looks like a red dot at the base. Typically these lesions are hard to see as they can be covered with dental tarter or the gum tissue has grown over the lesion in an attempt to protect the area. It is one of the most common diseases of domestic cats, affecting up to two-thirds of the population. It is also seen in dogs and other animals, but is less common. It is a progressive disease that tends to occur at or just below the gum line, however they may affect only the root structure. The teeth most commonly affected are the premolars, followed by the molars and finally the canines. The majority of the lesions are on the on the outside of the tooth, against the cheek while some can be seen on the inside. |
How are they diagnosed?
In most cases FORLs are found on a routine physical exam. Most often however they aren't apparent unless the cat is already anesthetized for a dental exam and cleaning. Dental radiography is considered the gold standard of care for accurate diagnosis and treatment of this disease |
What are the causes?
Several theories have and are being investigated about the cause of tooth resorption, but unfortunately there are no definitive answers at this time. What researchers and doctors do know is that inflammation caused by dental disease is often a factor. Tooth resorptions are the most common dental problem in cats and purebred cats seem to be at a greater risk for developing them. Regular dental care (dental cleaning under anesthesia, brushing teeth, dental diet, dental treats, etc.) may be useful in preventing this disease, so it is important for adopters to discuss at home dental care with their regular veterinarian. |
Are FORL’s painful?
Yes! FORLs are incredibly painful. In fact, when a dental probe is gently placed on the lesion, cats typically "chatter" or vibrate their jaws which is an obvious sign of pain. The cat may also show signs of discomfort when the lesions are touched during oral examination. Some cats may show decreased appetite, pawing at the mouth, drooling or weight loss. |
How can tooth resorption be treated?
According to the Academy of Veterinary Dentistry, there are three types of tooth resorptions. Type 1 lesions have resorption of the root. Type 2 lesions have replacement resorption, when there is resorption of the root canal and periodontal ligament. In advanced type 2 lesions, the cat's tooth will basically end up with nothing left as it has been taken over by bone. Type 3 lesions are essentially a combination of Types 1 and 2. Treatment for most Type 1 and Type 2 at this time is extraction of any affected teeth. If not extracted, the tooth will continue to erode and be a constant source of pain for the cat. In some cases, restorative procedures can be performed to save a tooth that is in an early stage of the disease. Advanced Type 2 and Type 3 can be treated with a newer procedure called crown amputation. During a crown amputation, the tooth is cut at the crown, after which the remaining bone is smoothed and then closed over with a gum flap. This approach is less invasive for the cat and healing time is also faster. |