the canine teeth are sharp and large for tearing the flesh. Chewing process is mainly caused by chewing reflex. The presence of bolus in mouth first initiates reflex inhibition of the muscles of mastication, which causes the lower jaw to drop. The drop of lower jaw initiate a stretch reflex of the jaw muscle that in turn initiate rebound contraction, which automatically raise the jaw upward to closure of the teeth. But again bolus compress against the lining of mouth, which inhibit the jaw muscles once again, allowing the jaw to drop again and rebound another time; this is repeated again and again.

Chewing is important for proper digestion of any king of food (except liquid food) but it is most important of fruits and raw vegetables because there indigestible cellulose membrane around the nutrients causes hindrance for digestion. Chewing also increase the surface area of food so that enzymes can act properly and increase the rate of digestion.

Deglutition or swallowing: Swallowing is a complicated process because pharynx is involved both in respiration and swallowing. The pharynx is converted into food tract only for few seconds at a time without compromising respiration.

Swallowing can be divided into three stages:

1. Voluntary stage: initiation of swallowing process.
2. Pharyngeal stage: involuntary movement of food from pharynx to esophagus.
3. Esophageal stage: involuntary movement of food from esophagus to stomach.