The buckle cavity or oral cavity performs two major functions i.e., mastication of food (chewing the food into semisolid paste) and facilitation of swallowing (by mixing food with saliva).

Firstly, food gets mixed with saliva which softens and lubricates the food and cheering process breaks the food into smaller pieces.

In buckle cavity digestion of same food components takes place. Digestion of carbohydrates starts in the buckle cavity. The food is mixed with saliva which contains salivary anylase. This enzyme converts starch into maltose, isomaltose and α-dextrins. 30% of the starch in food is hydorlysed in the buckle cavity.

Starch Maltose + Isomaltose + α-dextrins

The oral cavity has a number of teeth and a muscular tongue. Each tooth is embedded in a socket of jaw bone. This type of attachment is called the phycodont. The human gets two sets of teeth in their lifetime they are temporary teeth and permanent teeth.

Temporary teeth or milk teeth are deciduous and are replaced by permanent teeth. This type of arrangement is called diphyodont. The arrangement of teeth is illustrated below.

There are four types of teeth in human beings – incisors, canines, premolars and molars, denoted as I, C, PM and M respectively.

Arrangement of teeth in each half of the upper and lower jaw in the order I, C, PM, M is represented by a dental formula which in human is

That is two incisors, one canine, two premolars and three molars on each side of jaws. Thus there are 32 teeth in an adult human.

Incisors is for cutting, canine is for tearing, premolars and molars are for grinding and crushing.