Tooth Terminology

Anatomy of the Tooth

  • Outer protective layer of the tooth is enamel, which is extremely hard.
  • Middle layer is dentin.
  • Pulp is composed of nerves and blood vessels that exit the tooth via the apices.
  • The root connects to alveolar bone via the periodontal ligament.

Adult Dentition

Permanent teeth begin to erupt around age 6 years and are all present by 21 years of age. Some adults had their third molars (wisdom teeth) or premolars extracted to relieve crowding, or they may not have erupted, so there may be only 24 to 28 teeth in intact-appearing dentition.

However, most adults have 32 teeth, which include:

  • 8 incisors
  • 4 canines
  • 8 premolars
  • 12 molars
AAFP Home Study Program
AAFP Home Study Program