* Tears and grind the food, breaking it down into smaller fragments. * By the age of 21, two sets of teeth have been formed.
Deciduous teeth (baby teeth or milk teeth)
* Begins to erupt around 6 months , and a baby has a full set of (20 teeth) by the age of 2 years. Permanent Teeth
* Enlarge and develop, the roots of the milk are reabsorbed, and between the ages of 6 and 12 they loosen and fall out. * The teeth are classified according to shape and function as incisors, canines, premolars, and molars. * Incisors (chisel-shaped)- are adapted for cutting.
* Canines (fanglike)- are for
Tearing and piercing.
* Premolars and molars
(bicuspids)- Have broad
crowns with rounded cusps
(tips) and are best suited for
* A tooth consists of two major regions, the crown and the root. * The enamel-covered crown is the exposed part of the tooth above the gingiva or gum.
Enamel- Is the hardest substance in the body and is fairly brittle because it is heavily mineralized with calcium and salts. * The outer surface of the root is covered by a substance called cementum, attaches the tooth to the periodontal membrane (ligament)
Dentin- a bonelike material, underlies the enamel and forms the bulk of the tooth. Pulp Cavity- Contains a number of structures (connective tissue, blood
vessels, and nerve fibers) collectively called pulp.
Root Canal- Provides a route for blood vessels, nerves, and other pulp structures to enter the pulp cavity of the tooth.
* Three pairs of salivary glands empty their secretions into the mouth. Parotid glands- lie anterior to the ears.
Mumps- a common childhood disease, is an inflammation of the parotid glands. * Submandibular glands and Sublingual glands empty their secretion into the floor of the mouth through tiny ducts. * Saliva is a mixture of mucus and serous fluids. The mucus moistens and helps to bind food together into a mass called...