A human has eight incisors; four on top and four on the bottom. They are used for cutting foods. We have four canines; two on the top and two on the bottom These are used for tearing apart foods and are sometimes called cuspids. We also have eight premolars in total and 12 molars in total. Molars are used for grinding up foods. Premolars are similar to molars but smaller. They are sometimes called "bicuspids. The major jaw muscles used in the human mouth are the masseter and pterygoids. The pterygoideus muscles function for the opening of the jaw and to protract the jaw. The masseter is used to apply force to chewing, thus its most efficient function is unilateral chewing.
A dog has two canines; one on each side and six incisors; three on each side. They are very sharp and therefore bite, cut and tear chunks of flesh. They also have eight premolars; four on each side, and four molars; two on each side. They are sharp and jaggered which grind and shear flesh. The dog has two carnassials, which only carnivores have. They are used for slicing food. Carnivores do not have molars (flat, back teeth) which vegetarians need for grinding their food. The dog has an up and down motion of chewing. The major jaw muscle of the dog is the temporalis, which is used for biting. It acts to elevate the jaw and clench the teeth. The jaw motion is minimal, shearing and they can only move it up and down like most carnivores.
The cow has a top dental pad below their top lip instead of top front teeth. The cow has a huge gap between the dental pad (also known as a horny pad) and the back teeth. This dental arrangement helps the cow gather great quantities of grass and fibrous plants. The cow has 24 special molar teeth. They use a side to side motion to grind their food. The cow has no sharp teeth. Foods must be chewed well and thoroughly mixed with ptyalin in order to be broken down. The cow has a side to side motion to grind their food. The major jaw muscle used in a cows mouth is the masseter, which is used for chewing.