Anatomy of Teeth

Overview

• Teeth are not considered bones.
• Consist of three major parts:
  • Crown
  • Neck
  • Root

Major Parts of a Tooth

Crown

• Visible portion above the neck.
• Covered in enamel.
• Encloses dentin and pulp chamber.

Neck

• Also known as cemento-enamel junction (CEJ) or cervical line.
• Allows attachment of gums (gingiva) to teeth.
• Transition area between enamel and cementum.

Root

• Extends from neck (CEJ) to root apex.
• Secured to alveolar bone socket in mandible or maxilla.
• Covered in cementum which encloses dentin and root canal.
• May have one or more roots (incisors vs. molars).

Major Tissue Types

Enamel

• Hard outer layer of crown.
• Composed mostly of minerals like hydroxyapatite.
• No living tissue.
• Susceptible to acid erosion leading to cavities.

Cementum

• Covers the root of the tooth.
• Formed by cementoblasts.
• Softer and less mineralized than enamel and dentin.
• Light yellow appearance.
• Part of periodontium along with gums, periodontal ligament, and alveolar bone.

Dentin

• Located beneath enamel and cementum.
• Formed by odontoblasts.
• Accounts for most of tooth's mass.
• Contains dentin tubules that transfer nutrients from pulp.
• Harder than cementum and bone, softer than enamel.
• Dentino-enamel junction (DEJ): Border with enamel.
• Dentino-cemental junction (DCJ): Border with cementum.

Pulp

• Soft tissue within pulp cavity.
• Composed of odontoblasts, vessels, nerves.
• Provides nutrition, sensation, immune defense.
• Pulp cavity divided into:
  • Root canal (narrow, in roots)
  • Pulp chamber (larger, in crown)
• Apical foramen: Opening at root apex.

Types of Teeth

• Incisors
• Canines (cuspids)
• Premolars (bicuspids)
• Molars

Additional Resources

• Free quiz available on RegisteredNurseRN.com.
• More anatomy videos in the playlist.

Note: Understanding the structure and composition of teeth helps in maintaining dental health and addressing sensitivity and cavity issues.