chapter 4 - dental anatomy

Anatomic crown

The portion of the tooth covered with enamel. Remains the same size throughout the life of the tooth, regardless of the position of the gingiva

Clinical Crown

The portion of the tooth that is visible in the mouth. The length varies during life cycle of the tooth, depending on the level of the gingiva

Cementum

The root is the portion of the tooth that is normally embedded in the alveolar process and is covered with

Bifurcation

Means division into two roots

Trifurcation

Means division into three roots

Apex

The tapered (reduce in thickness toward one end) end of the root tip is known as the

Apical

Anything that is located at the apex is referred to as

Periapical

Anything that is surrounding the apex is said to be

Cementoenamel junction, CEJ

Formed by the enamel of the crown and the cementum of the root

Enamel

Makes up the anatomic crown and is the hardest material of the body, thus forming a protective covering for the underlying dentin

Enamel prisms, also known as enamel rods

Enamel is composed of millions of calcified

Dentin

Makes up the primary portion of the tooth and extends almost the entire length of the tooth

Dentinal tubules

Although hard, dentin is a very porous tissue made up of microscopic canals called

Dentinal fiber

Each dentinal tubules contains a

Pulp

The inner aspect of the dentin forms the boundaries of the

Cementum

Protects the tooth but is not as hard has either enamel or dentin

CEJ (cementoenamel junction)

The cementum joins the enamel at the

Periodontium

Supports the teeth in the alveolar bone

Periodontal ligaments

Dense connective tissue organized into groups of fibers that connect the cementum covering the root of the tooth with the alveolar bone of the socket wall

Maxillary and the mandibular arches (upper and lower jaw)

What are the two dental arches called?

Quadrants

The two arches, each divided in to halves, create four sections, which are called

8 (permanent), 5 (primary)

How many teeth does each quadrant contain?

Incisors

Teeth with relatively sharp and thin edges that are designed to cut food without heavy force

Canines

Teeth with thick crown and one well-developed pointed cusp. Designed for cutting and tearing of food that requires the application for force

Canines/Cuspids (because of their long roots)

What teeth are the most stable and usually the last teeth to be lost?

Premolars

Similar to canines in that they have points and cusps but have broader chewing surface. Designed for grasping and tearing and have a broad surface for chewing

Molars

Have more cusps than the other teeth. The shorter, blunder cusps provide a chewing surface. Designed for chewing and grinding solid masses of food that require the application of heavy forces

Incisors and canines

The anterior teeth includes

Premolars and molars

The posterior teeth includes

Facial/Buccal/Labial, Lingual, Masticatory/Incisal/ Occlusal, Mesial and Distal. (class 5, near the gumline)

What are the 5 tooth surfaces?

Contours

Curved surfaces of teeth. Can be concave or convex. That the crown narrows toward the cervical line is an example of this

Contact point (or contact or contact area)

The exact spot at which the teeth actually touch each other

1. Prevents food from being trapped between teeth

2. Stabilizes the dental arches

3. Protects the inter-proximal gingival tissue from trauma during mastication

The crown of each tooth in the dental arches should be in contact with its adjacent tooth or teeth. A proper contact relationship between adjacent teeth serves the following three purposes:

Embrasures

The triangular space near the gingiva between the proximal surfaces of two adjoining teeth. Continuous with

Occlusion

The contact between the maxillary and mandibular teeth

Cusps (raised areas) and fossae (indentations or groves)

The occlusal surfaces consist of

Mixed dentition

During the transition from primary to permanent dentition

Exfoliation

The normal process by which primary teeth are shed

Permanent dentition

Begins when the last primary tooth is shed, after approximately 12 years of age

Universal National System

What tooth numbering system is approved by the American Dental Association and used through the United States?

International Standards Organization System based on the Federation Dentaire Internationale System

What tooth numbering system is used in most countries?

Palmer Notation System

The teeth in all four quadrants are numbered 1-8. A bracket is used around its number to indicate its position. A shorthand diagram of the teeth as if the patients teeth are viewed from the outside.

Left side and vice versa. This layout stimulates looking into the patiens mouth

The diagrams used for dental charting have the teeth in the right quadrant arranged on the