Dental Anatomy

purpose of teeth

1. mastication

2. esthetics

3. speech

4. reserve space

5. support

purpose of teeth: mastication

Chewing

Normal tooth form and alignment can produce maximum chewing efficiency and helps in digestion.

purpose of teeth: Esthetics

Proper form and alignment of teeth will improve appearance

purpose of teeth: Speech

Proper alignment helps in making different sounds

purpose of teeth: Reserve space

primary teeth has a job to hold space for permanent teeth

purpose of teeth: Support

anterior tooth support lips

parts of the tooth

1. root

2. crown

   a. anatomic crown

   b. clinical crown

crown

enamel → dentin → pulp

anatomic crown

portion of the tooth covered with enamel

clinical crown

the portion of the tooth that is visible in the mouth.

root

cementum → dentin → root canal

teeth arches

frontal plane

parallel to face

horizontal plane

parallel to floor

sagittal plane

parallel to sides of head

perpendicular to frontal and horizontal planes

which plane divides each arch in half?

mid-saggital plane

what planes divide the maxillary and mandibular planes?

horizontal plane

teeth sextants

anterior teeth = canine to canine

posterior teeth = 1st molar to 3rd molar

types of dentition

Primary/Deciduous: first set of teeth (20 teeth)

Permanent dentition: Adults (32 teeth)

Mixed dentition: primary and permanent teeth

dentition stages

** variations can occur

adult teeth vs primary teeth

mixed dentition

between 6 and 12 years of age.

Both primary and permanent teeth are present during this transitional period.
this period begins with the eruption of the first permanent tooth,
which is a permanent mandibular first molar.
this period ends with shedding of the last primary tooth.

Permanent Dentition

the final or adult dentition.
this period begins with shedding of the last primary tooth. (Usually 14 years of age)
Growth of the jawbones slows and eventually stops.

Succedaneous teeth are
the permanent teeth
that replace the
primary/deciduous
teeth.
Permanent molars are
not succedaneous
teeth because they do
not replace any
primary teeth.
Permanent x Primary Dentition
Terminology and Overview of Dental Anatomy

permanent teeth that replace the primary/deciduous teeth.

Permanent molars are not succedaneous teeth because they do not replace any primary teeth!!

1st + 2nd primary molars are replaced by 1st + 2nd premolars NOT molars

Types of teeth
Incisors: central and lateral
Canines
Premolars: first and second
Molars: first, second and third

Incisors: central and lateral

Canines
Premolars: first and second
Molars: first, second and third

incisors

single-rooted teeth with a relatively sharp and thin edge

Located at the front of the mouth (front 4 teeth)

designed to cut food without the application of heavy forces.

the lingual surface, is shaped like a shovel to aid in guiding the food into the mouth.

Canines

Located at the “corner” of the arch.
Designed for cutting and tearing foods.
Are the longest teeth in the human dentition.
They have the longest root and are usually the last teeth to be lost.

Premolars

four maxillary and four mandibular premolars.

cross between canines and molars.

not as long as canines + a broader surface for chewing food.

The pointed buccal cusps hold the food while the lingual cusps grind it.

molars

six maxillary and six mandibular molars.

larger than premolars.

have more cusps than the other teeth, 4/5 on the occlusal (biting) surface of each molar, depending on its location.

Maxillary and mandibular molars differ greatly from each other in
shape, size, number of cusps, and roots.

all molars chew or grind up food

anterior

Refers to direction towards the front plane of the body.
(Incisors and Canines)

Posterior

Refers to direction towards the back plane of the body.
(Premolars and Molars)

midline

An imaginary line dividing the maxillary and mandibular arches into
two equal halves.

tooth surfaces

mesial surface

toward midline

distal

away from midline

incisal

only anterior teeth (incisors + canines)

occlusal

only posterior teeth (premolars + molar)

lingual

tounge side

buccal

cheek side for posterior teeth

labial/facial

anterior lip side

abbriviations for surfaces

tooth divisions

convexities

bulge outward

Concavities

form hollows or depressions (“caves”)

cusps

elevated projections on canines and posteriors only
Molars have 3 to 5 cusps.
Premolars have 2 to 3 cusps (usually 2).
Canines have only 1 cusp.
Cusp tips are the most occlusal or incisal portion of the cusps.

contact points

Occurs between 2 contacting teeth

Usually at the Height of Contour (HOC)

HOC is responsible for contacting the adjacent tooth

Ridges

linear elevations on the surface of a tooth usually named by location

marginal ridges

linear elevations found at the mesial and distal terminations of posterior teeth.
Also found on anterior teeth but are usually less prominent, forming the lateral margins of the lingual surface.

fossa/fossae

an singular irregular concavity or depression

It is often large and shallow and found on the surface of the tooth.

pit

deepest point of fossa

formed by the junction of 2+ grooves

sulcus/sulci

A broad depression on the occlusal surfaces of posterior teeth between the facial and lingual cusps

the inclines of which meet in a developmental groove and extend outward to the cusp tips.

Usually v-shaped in cross-section.

Developmental (primary) groove

located at the bottom of a sulcus and the sides of inclined planes
and triangular ridges.

usually denote junction of 2 primary lobes of the tooth

Supplemental (secondary) groove

branch from developmental grooves.

grooves and pits

line angle

formed by the junction of two surfaces and is named from the combination of the two joined surfaces

point angle

formed by the junction of three surfaces at one point and is named from the combination of surfaces that form them.

line + point angle naming

When combining the names of the surfaces, the last two letters of the first and/or second surface are dropped, and replaced by letter ‘o’.

embrasures

A V-shaped space formed by the curved proximal surfaces of adjacent teeth.

anterior teeth embrasures

gingival, incisal, labial and lingual

posterior teeth embrasures

gingival, occlusal, buccal and lingual

identifying specific teeth

1. Set or dentition (permanent or primary)
2. Arch (maxillary or mandibular)
3. Quadrant (right or left and 1st, 2nd or 3rd)
4. Specific tooth name

Permanent maxillary right second premolar

universal dental numbering (ADA)

Permanent dentition numbered 1-32
Primary dentition uses letters A-T
Starts at the patient’s top right, follows across the maxillary arch, drops to lower left then across the mandibular arch

palmer-zsigmondy

use symbols below to identify which quadrant

FDI system