Module 1 - Overview of Dentitions

What is dental anatomy?

The area of dental science dealing with the morphology (or shape/form) of the teeth

Why is this important?

• Patient education

• Fluoride therapy

• Sealants

• Periodontal and tooth assessment

• Instrumentation

Primary Dentition

• Starts with eruption of mandibular incisors at 6 months

• All primary teeth erupted at about 2 ½ years of age

• 20 teeth

  • 8 incisors

  • 4 canines

  • 8 molars

Mixed Dentition

• “Ugly Duckling”

• Occurs between 6 to 12 years of age

• Larger in size

• Darker in color

• Jaw growth

• Crowding

Permanent Dentition

• Begins around age 12

• 32 teeth

  • 8 incisors

  • 4 canines

  • 8 premolars

  • 12 molars

Maxillary Arch

Immovable

Mandibular Arch

Movable

How many quadrants are in the entire oral cavity?

4

Right maxillary

• Quad 1

• Upper Right (UR)

Left maxillary

• Quad 2

• Upper Left (UL)

Left mandibular

• Quad 3

• Lower Left (LL)

Right mandibular

• Quad 4

• Lower Right (LR)

Which one is the anterior teeth?

White

Which one is the posterior teeth?

Yellow

What does the D-A-Q-T System stand for?

• D

  • Dentition

  • Permanent or Primary Tooth?

• A

  • Arch

  • Maxillary or mandibular?

• Q

  • Quadrant

  • Left or right?

• T

  • Tooth type

Parts of the Tooth: Crown - Anatomic

• Part of the tooth covered by enamel

  • 96% mineralized

• Dentin underneath

  • 70% mineralized

• Remains constant even if patient undergoes gingival recession (shrinking)

Clinical

Portion of tooth that is visible in the oral cavity

Parts of the Tooth: Root

• Covered with cementum

  • 50-65% mineralized

• Dentin underneath

Apex

Rounded end of the root

Foramen

Opening at the apex in which blood vessels and nerves enter

Furcation

Area in where the root divides

Root axis line (long axis)

Imaginary line that bisect the root and crown into equal halves

Tissues of the Tooth: Pulp

Innermost noncalcified tissue containing blood vessels, lymphatics, and nerves

1. Pulp canal

2. Pulp chamber

3. Pulp horns

CEJ

• Cementoenamel Junction

• Junction of cementum and enamel

DEJ

• Dentoenamel Junction

• Junction of dentin and enamel

CDJ

• Cementodentin Junction

• Junction of cementum and dentin

Occlusal

Chewing surface of posterior teeth

Incisal

Biting surface of anterior teeth

Cusp

Large, rounded elevated area of enamel

Ridge

Rounded, linear elevation of enamel

Groove

Narrow linear depression

Fossa

Shallow, broad depression

Pit

Sharp, pointed depression generally located at the junction of developmental grooves

Facial

Toward the face

Labial

Toward the lips (facial surfaces of anterior teeth)

Buccal

Toward the cheeks (facial surfaces of posterior teeth)

Lingual/Palatal

Surface toward the tongue/palate

Proximal

Toward adjacent teeth

Mesial

Toward the midline

Distal

Proximal surface farthest from the midline

Contact Area

Area that touches the adjacent tooth in the same arch

Embrasure

The interproximal space between teeth that consist of triangular spaces