Feline dentition – cats' teeth

 

Dental disease is a very common problem in both young and old cats.

It is thought that as many as 85% of cats aged three years and older have some sort of dental disease.

Why do cats have teeth?

Although domestic cats can potentially live without teeth, if fed the right diet, teeth are important (especially in wild cats) for a number of reasons including:

  • Prehension – Grasping and holding food
  • Mastication – Chewing food (this is a cutting rather than grinding action in cats, their sharp teeth cutting through meat and bone)
  • Weapons – Teeth are used both for killing prey, and also for self defence!

Tooth anatomy

Each tooth sits in a socket in the bone (called an alveolar socket) held firmly in place by ligaments, cementum (bony like substance) soft tissue and bone.

The tooth itself can divided into the crown visible above the gum line) and the root. The point at which the crown and the root meet is termed the neck of the tooth.

The tooth is made up of three substances:

  • Pulp – this lies within the centre of the tooth (called the pulp cavity). Pulp enters this cavity at the tip of the root and contains cells nerves and blood vessels. Because of this, damage or inflammation of the pulp is extremely painful.
  • Dentine – this covers the pulp and is the main bulk of the root as well as providing a middle layer between the pulp and the enamel on the crown of the tooth. Dentine is hard and mineralised but is very sensitive making root exposure or enamel damage very painful.
  • Enamel this is a very hard, mineralised substance, which contains no nerves and is insensitive. Enamel covers the crown of the tooth protecting the tooth and the underlying dentine, and therefore prevents sensitivity when the animal is eating. However, cat dental enamel is thin, measuring only around 0.2mm thick compared with around 0.5mm in dogs. Damage to the enamel exposes the underlying dentine and will result in a very sensitive tooth, which is also susceptible to infection.

Types of teeth

A cat has thirty teeth in total, and each tooth plays an important role. The different types of teeth are:

Incisors (I)

These are the very small teeth at the front of the mouth. Incisors have minimal use but are used to help hold prey in the mouth. They only have one root and when diseased are often quite unstable, making extraction easy. A cat should have twelve incisor teeth in total (six at the top and six at the bottom) but quite often some of these teeth will be lost as a cat gets older, or sometimes one or more incisors may not even develop in the first place.

Canines (C)

The cat is a true carnivore, hunting and killing prey (mainly rodents and birds) in the wild. The canines are the teeth responsible for killing and shredding prey. They are long teeth and only have a single (long) root, supported by strong ligaments and deeply embedded in the bone. Cats should have four canines (one on each side at both the top and the bottom).

Pre-molars (PM)

Cats should have six pre-molars in the upper jaw (UPM - three on each side), and four in the lower jaw (LPM - two on each side). The two lower pre-molars are labelled as PM2 and PM3. The pre-molars are used for chewing prey (cutting through the meat and bone) and have various roots:

  • UPM1 … one root
  • UPM2, LPM2, LPM3 … two roots
  • UPM 3 … three roots

The presence of more than one root makes it more difficult to remove these teeth when they are diseased. It is important to know how many roots there are, and where they are, so that they can all be removed properly. If roots are left behind when teeth are extracted this can lead to problems.

Molars (M)

Cats should have two upper molars (UM - one on each side) and two lower molars (LM - one each side). Molars are also used for chewing food (cutting through meat and bone) but upper and lower molars have different root systems:

  • UM1 … one root
  • LM1 … two roots

When diseased, upper molars are usually easier to remove as they have a single quite short root. Lower molars are more difficult to remove as these have one thick root and one small root with bone and ligament attachment.