Perfect adaptation to life as a predator differentiates the cat's physiology very dramatically from other animals.
The cat's shortened skull, which accentuates eyesight rather than the sense of smell, provides only limited space for teeth - sixteen in the upper jaw and fourteen in the lower jaw. The four canine teeth, positioned in the front corners of the upper and lower jaws, are tools for seizing and killing prey. Their spacing directly relates to the type of prey each species of cat is most adapted to hunt because, in most cats, the canines are used to penetrate between the neck vertebra of the prey forcing them apart and thereby severing the spinal cord.
The flattened, pointed molars, or carnassial teeth function like shears which cut the prey into manageable bits to swallow. This action is supported by the hinging of the lower jaw which can only be moved up and down and possesses no ability for a lateral grinding motion. The cat does not chew her food. The tiny incisor teeth, arranged in a straight line between both upper and lower canines, aid in maintaining a grip on prey, plucking feather or fur as well as, scraping meat off larger, inedible bones. Cat teeth are sensitive to pressure and cats avoid contact with, or gnawing on, hard bones in order to prevent possible shattering of their teeth, especially the canines.
Today, domestic cats often suffer from dental disease, primarily build-up of calculi. Consequently, Veterinarians urge cat owners to feed their cats solely a dry, commercial cat food. The theory is that the crunching of a dry food, and the friction created on the teeth when biting on pellet like feed, will reduce plaque and inhibit tartar build-up. And, a theory it is because in real life, dry cat food has proven to have marginal tartar fighting properties. Since cats purposely avoid biting on hard bits, dry food pellets are subsequently swallowed whole. The grain based make-up of dry cat food gives a hard baked, cracker nature, which, if actually crunched to bits and moistened with saliva, will more likely clog the dentition, as well as leaving a starchy coating which encourages plaque growth. Carbohydrate based feed like dry cat foods lead to an unnatural alkaline body environment which in turn, can cause mineral deposits in soft tissue within the body (kidney stones and urinary crystals) as well as increased tartar build-up.

Nature combats dental disease with a proper diet. An all prey based, high protein diet will keep the cat's body acidic and prevent mineral deposits. The absence of carbohydrates, which are broken down by enzymes in the saliva to sugars, inhibit plaque causing bacteria growth. Any plaque that may naturally accumulate is wiped away by the biting and shearing through fur and flesh. The largest bones of a mouse or bird snap like dry spaghetti and offer minimal friction on the cat's teeth, especially when surrounded by flesh and when considering that it takes the cat only a few seconds to "wolf down" her catch. This fact completely invalidates the common belief that the teeth of wild cats are kept clean by crunching bones!