Retained (Persistent) Deciduous Teeth in Cats

Retained (Persistent) Deciduous Teeth in Cats

Cats are a wonderful and cherished companion for many people. Consistent evaluation of their oral cavity throughout their life is important as are vaccinations and choosing an appropriate diet/nutrition. And this is especially key during the development from kitten to adult. 

Cats use their mouth not only for eating, but also for grooming, play, and hunting. A feline’s quality of life will begin to decrease if the oral cavity is not healthy. The oral cavity is the first part of the digestive tract. If it is not in good health, then additional components of the gastrointestinal tract will begin to suffer. 


Understanding Your Cat’s Dentition

Cats, as are most domesticated animals, and man are diphyodont. Diphyodont is a classification of tooth development in which there are two sets of teeth, primary and permanent. The first teeth that erupt during kittenhood are called primary teeth, or deciduous teeth. Deciduous teeth are very sharp. Most of us have felt those sharp little needle teeth when kittens attack toes or fingers during interactive play! 

Cats have 26 deciduous teeth and 30 permanent teeth. Deciduous teeth begin erupting around 3-4 weeks of age. These baby teeth are eventually replaced by permanent teeth. Their permanent teeth begin erupting at 4 months of age. 

Tooth eruption will often have ceased by 7 months of age. Eruption times are variable with size, breed, and individuals. ​It is important for the oral cavity to be thoroughly evaluated at every kitten visit to identify any deviations from the normal eruption pattern. The first year of life is the most important for determining tooth and jaw position. 


What Are Retained Deciduous Teeth?

Normal tooth eruption involves the deciduous tooth falling out once the permanent tooth begins to erupt. Retained deciduous teeth are teeth that do not exfoliate (fall out) once the permanent tooth erupts. 

This condition is seen most often in small-breed dogs, but can also occur in medium to large-breed dogs, and in cats. No specific cat breed has been noted to have a genetic predisposition for retained deciduous canine teeth. 

The most common retained deciduous tooth in felines is the upper canine tooth, followed by the lower canine tooth. Incisors are the third most common retained teeth. Occasionally, premolar deciduous teeth can fail to exfoliate or fall out.


Why Do Primary Teeth Not Fall Out?

Exfoliation of deciduous dentition is a complex process and not fully understood. It is believed that as the permanent tooth root begins development, the crown makes contact with the deciduous tooth root structure. The pressure of the permanent tooth crown on the deciduous tooth root will stimulate a resorptive process of the deciduous tooth root and the crown is lost or shed. 

Additional causes for failure of deciduous tooth exfoliation include lack of a permanent successor, ankylosis or fusion of the tooth to the tooth socket, or hormonal influences. 

A change in the term ‘retained’ pertaining to a deciduous tooth should be noted. The terminology has shifted from the term retained deciduous canine teeth to persistent canine teeth. 

On the website for the American Veterinary Dentistry College (AVDC), a persistent deciduous tooth is defined as follows: A deciduous tooth that is present when it should have been exfoliated.


Why Are These Teeth an Issue?

Persistent deciduous teeth can cause multiple problems for the growing cat. With a persistent maxillary (upper jaw) canine tooth, the permanent tooth typically erupts very closely in front of the deciduous tooth. Subsequently, tartar accumulates between the two teeth leading to periodontal disease and eventual loss of the permanent tooth. 

In the mandible (lower jaw), the permanent canine tooth will erupt inside of the deciduous tooth toward the hard palate. Having a tooth pressing up into the roof of the mouth can be very painful! Sharp teeth pressing into the roof of the mouth can make even the sweetest kitten cranky. 

Persistent incisor and premolar teeth will lead to tooth crowding, tartar accumulation, and subsequent periodontal disease. 

Additionally, when teeth do not follow the normal eruption pattern, it can lead to jaw malformation due to an adverse interlock. This adverse interlock will affect the maxilla and mandibles from growing properly and may affect the pet’s ability to eat in a traditional manner. 

When the mouth does not close together properly in the normal scissor bite, it is called a malocclusion

Our pets are oftentimes much more tolerant of oral pain than we would be in a similar situation. If a persistent deciduous tooth is removed early, the permanent tooth has a greater chance of erupting in a normal pattern. 


Treating Persistent Deciduous Teeth

Once a retained (persistent) deciduous tooth has been identified, it should be extracted. There is a “Rule of Permanent Succession.” This means that no two teeth should be in the same location at the same time. 

A complete oral exam and dental radiographs need to be obtained under anesthesia to address the tooth or teeth. Extraction of persistent deciduous teeth is the most common treatment performed.  

The retained tooth should always be removed in its entirety as broken roots can be quite painful and lead to infection. Some veterinarians may believe that the deciduous tooth root will undergo resorption even if it is not removed in its entirety. This is erroneous. When the tooth is broken, it will most likely never resorb as it is dead. The remaining tooth root will stay, often for the life of the pet, serving as a nidus for future infection. 

In rare cases, the remaining root tip may resorb, but this slight probability should not be a reason to leave a fragmented tooth root behind. 


Impacted Teeth

Occasionally there can be a deciduous tooth present without a permanent successor. If a kitten is 7 months or older and only a deciduous tooth is present without a visually apparent permanent tooth, dental imaging should be completed to determine that tooth impaction of their permanent tooth is not occurring. 

An anesthetized exam with full mouth dental imaging should be completed in all the permeant teeth that have not erupted in the anticipated timeline. Dental imaging can be in the form of dental radiographs or cone-beam CT imaging. 

Tooth impaction occurs with the permanent tooth’s tooth eruption mechanism has failed and it has a physical barrier (gingiva, bone) surrounding it. Teeth that are impacted can cause problems by forming cysts, which often are expansile and destruction to the surrounding bone. These are often referred to as dentigerous cysts. 


Should You See a Board-Certified Vet Dentist?

Extraction of deciduous teeth can provide a challenge for some veterinarians. The roots are very long, thin, and prone to fracture during extraction therapy. Extraction of deciduous teeth should be completed by a veterinarian who has experience in veterinary dentistry, or ideally by your local veterinary dentist.

In many cases, impacted teeth should also be treated by a veterinary dentist as surgical removal of impacted teeth can be challenging. The most common teeth that may be impacted in the cat are the maxillary and mandibular canine teeth. 


Veterinary Dentists in Colorado Springs

Kittens should have their teeth evaluated closely at every visit to ensure the normal tooth eruption pattern is occurring. Daily tooth brushing of your pet’s mouth during the growing period is a great way to institute a consistent oral home care routine as well as identify any abnormalities. A healthy mouth contributes to a healthy and happy pet. 

If you have any questions about your cat’s oral health or would like to schedule an evaluation, please contact us at (719) 536-9949.


Photo by Erik-Jan Leusink on Unsplash