Kinds of teeth

There are up to 32 permanent teeth in an adult mouth, 16 in each jaw. Children have 20 primary teeth which are eventually replaced by the permanent teeth. The fundamental function of your teeth is to cutup food into small enough pieces that can be easily swallowed and digested. Since human beings eat both vegetarian and non-vegetarian food, they are termed omnivores. To cope with such diverse requirement, human teeth have 2 basic shapes. The 6 front teeth in each jaw have single knife like edges. The 4 incisors are straight which helps cut food into pieces. The 2 pointed canines are shaped to tear-up food. All these teeth have single root. In the back of the mouth there are ten teeth in each jaw, five on each side, with wide chewing surfaces for grinding food. Besides, these teeth have 2 or more low mounds called cusps, separated by hollows and grooves. Normally 2 premolars appear on each side of the jaw. Premolars are smaller than the molars, and have one or two roots. Upper molars have three roots and lower molars may have two or three. Additional roots are meant to withstand the heavy pressures of chewing. The chewing surfaces of the back teeth are most likely to face decay. This is where adjacent teeth meet.

Mandible

This is the lower jawbone, a single arch-shaped bone. It is the densest and the strongest bone in the skull. It is flexible in childhood and becomes more rigid during adolescence. When the mouth opens and closes, only the mandible moves.

Palatal bones

The bones of the palate are joined together by a thin line of connective tissue called a suture. It becomes stronger and more rigid in adolescence, while it remains flexible and stretchable during infancy and childhood. This change has quite an important significance when considering orthodontic treatment.

Occlusion

Occlusion is a term used for the meeting of the teeth, or bite. For an effective chewing, proper occlusion is necessary. The upper front teeth should overlap the lowers and the biting edges of the lower teeth should lightly touch the inner surfaces of the upper teeth. Also, the back teeth, premolars and molars should meet evenly. The chewing surfaces of the lower teeth should be inside the uppers, so that their outer cusps mesh with the grooves of the uppers. The lower molars and premolars should also be positioned slightly forward of the corresponding upper teeth.

Crown

This is one of the main parts of each tooth. This is the part that protrudes above the gum. It contains the hard biting surfaces. It has an outer layer of Enamel which protects it from wear and decay. Inside these outer layers is the main structure of the tooth, the Denin, containing numerous fine channels called tubules. There are threadlike extensions of living cells called odontoblasts inside the tubules.

Root

This is another vital part of each tooth. The root is located below the gum, resting in the bone of the jaw.

Pulp

At the core of each tooth is a channel that extends from mid-crown to root. It contains soft tissue called pulp. The outer layer of the pulp is made up of the odontoblasts or cells that protrude into the dentin tubules. The rest is composed largely of nerves and blood vessels. The blood vessels carry nourishment to the tooth.

Cementum

It is a material similar to the bone that protects the root of the tooth.

Plaque

This is a thin film that has a tendency to develop naturally on the teeth. It is formed by colonizing bacteria. It must be kept from adhering to your teeth for more than 24 hours to keep plaque from settling down.