Tooth Anatomy

Each tooth consists of three main parts – the crown, the neck and root.The crown is the visible part of the tooth; it is the portion that lies above the gum tissue. A protective layer called enamel covers the crown. The neck is the area of the tooth between the crown and the root. The root is the portion of the tooth that extends through the gum and into the bone of the jaw.

Every tooth consists of hard and soft tissues. The hard tissues are enamel, dentin, cementum. The soft tissue is the pulp. Enamel is the hardest material in your body and makes up the outside of your teeth, above the gum line. Dentin is the tissue that makes up the core of each tooth. Pulp is the living part of the tooth, located inside the dentin. It contains the nerve tissue and blood vessels that supply nutrients to the tooth. Cementum is located at the root of the tooth.

Enamel

Enamel is the substance that covers the crown of the tooth. It is very hard and quite resistant to mechanical and chemical attack. The enamel is made up of microscopic enamel rods. Each enamel rod is attached to the dentin underneath it.

Dentin

Dentin is the hard, yellow bone-like material that underlies the enamel and surrounds the entire nerve. It composes the bulk of the tooth, and is sensitive to touch and other stimuli. Dentine consists of dentinal tubules. The dental pulp (the nerve of the tooth) is the soft center of the tooth. Pulp is composed of connective tissue, blood vessels, and nerves; it nourishes the dentin. A root canal is actually only a part of the dental pulp. Blood

vessels and nerves enter through a hole at the tip of each root. The tip of the root is called the apex, and the hole that allows the nerve tissue, with its blood vessels to enter the tooth is called the apical foramen. The apical foramen is simply the hole in the tip of the root where the nerve and all its accompanying blood vessels must enter the tooth.

The pulp has several functions, such as:

Sensory function - pain from trauma to the dentin and/or pulp, differences in temperature, and pressure are caused by stimulation of the pulp.

Formation of dentin - the pulp is responsible for the formation of dentin. In response to trauma, the pulp forms secondary dentin, also known as reparative dentin.

Nourishment - the pulp contains blood vessels that help to prevent the tooth from becoming brittle by keeping it moisturized and nourished.

Cementum is a layer of tough, yellowish, bone-like tissue that covers the root of a tooth. It helps hold the tooth in the socket. The cementum contains the periodontal membrane.

Cementum is to the root of a tooth as enamel is to the crown. Its main function is to act as an attachment layer for the periodontal ligament which is a soft tissue sheath that acts as a cushion between the bony socket and the tooth itself.

Ex.9. Translate the following word-combinations into English:

Видима частина зуба, над яснами, захисний шар, серцевина зуба, постачати поживні речовини, стійкий до механічних та хімічних пошкоджень, подразники, живити дентин, проходити через отвір, кінчик кореня, покривати корінь, утримувати зуб в ясеневій кишені.

Ex.10. Answer the following questions:

1. What main parts does each tooth consist of? 2. What is the crown? 3. What is enamel? 4. Where is the neck located? 5. What is the root? 6. What is the hardest material in your body? 7. What is located inside the dentin? 8. What does the pulp contain? 9. Where is cementum located? 10. What is the enamel made up of? 11. What does dentine consist of? 12. What is apex? 13. what is apical foramen? 14. What is the main function of cementum?

Ex.11. Read the definitions, then label the tooth below:

Bone - the hard supportive tissue in which the tooth's root is anchored. Crown - the visible part of a tooth. Dentin - the hard but porous tissue located under both the enamel (and cementum) of the tooth. Dentin is harder than bone. Enamel - the tough, shiny, white outer surface of the tooth. Gum - the soft tissue that surrounds the base of the teeth. Nerves and Blood Vessels - nerves transmit signals, and blood vessels carry nutrients to the tooth - they run through the tooth's root within the pulp. Pulp - the soft center of the tooth. The pulp contains blood vessels and nerves; it nourishes the dentin. Root - the anchor of a tooth that extends into the bone of the jaw. The number of human tooth roots ranges from one to four.

Ex.12. Familiarize yourself with the following data. Mind the pronunciation of the following words:

Incisor [In'saIzq], canine ['keInaIn], cuspid ['kAspId], bicuspid ["baI'kAspId], premolar ["pri:'mqVlq], molar ['mqulq].

What Are the Different Types of Teeth? Every tooth has a specific job or function: Incisors— the sharp, chisel-shaped front teeth (four upper, four lower) used for cutting food. Canines— sometimes called cuspids, these teeth are shaped like points (cusps) and are used for tearing food. Premolars— these teeth have two pointed cusps on their biting surface and are sometimes referred to as bicuspids. Premolars have a more flat chewing surface because they're meant for crushing food. Molars are the last teeth towards the back of your mouth. Molars are much bigger than the premolars and have bigger, flatter chewing surfaces because their job is to chew and grind the food into smaller pieces. Molars have several cusps on the biting surface.