HS133 Dental Anatomy

What is dentition? The natural teeth in a jaw.

- a person has 2 dentitions during a lifetime

What are the different types of dentitions?

1. Primary

2. Mixed

3. Permanent

Primary Dentition

aka baby teeth, milk teeth.

• appropriate term deciduous teeth

• 20 in total

• 8 incisors, 4 canine, 8 molars

what type of dentition is this?

primary dentition

Permanent Dentition

aka secondary dentitions “adult teeth”

should have 32 teeth

what is the break down of teeth in permanent dentition?

32 teeth

• 8 incisor

• 4 canine

• 8 premolars

• 12 molars

Mixen dentition

both primary and permeant teeth are present

• is considered a mixed as soon as the first permanent teeth erupts

Approximately at what ages does mixed dentition period begin and end?

begin around age 6 when first premolar erupts, end around age 13 when last primary tooth exfoliates

what does exfoliate mean?

shedding or loosing of primary teeth

define succedaneous

permanent teeth that take place of the deciduous (primary) teeth

define non succedaneous

permanent teeth that do not replace deciduous teeth.

ex: permanent molars, do not replace any primary teeth.

• only found in permanent dentition not found in primary.

Types of teeth

1. incisors

2. canine

3. premolars

4. molars

General functions of teeth

1. eating (cutting, holding and grinding)

2. Communication (speech, phonetics, whistling)

3. protection (hard physical barriers to protect oral structure)

4. aesthetics

What is the function of incisors?

To bite, shear and cut food, due to their triangular proximal form.

How many incisors do human have?

8 total.

-Four maxillary and four mandibular.

- central and lateral

What is the function of canines?

tearing, piercing, holding

- due to their tapered (spear head) shape and prominent cusp.

- longest teeth in the dentition

- best-anchored, most stable due to having the longest root

How many canines do human have?

4 Total

- 2 maxillary, 2 mandibular

Which teeth are only found in the permanent dentition?

Permanent molars.

- not found in primary dentitions

What is the function of premolars? holding, grinding and piercing

- assist molars in grinding food and canines in piercing and tearing.

how many premolars does a permanent dentition have?

8 total

- 4 maxillary, 4 mandibular (2 in each quadrant)

Which teeth have the largest and strongest crowns?

Molars.

What is the function of molars?

chew, grind and crushing

how many molars can a permanent dentition have?

up to 12

what is a alveolus?

cavity/socket in the alveolar process in which the root of the tooth is held

what is the alveolus process?

Part of the bone in the maxillae and audible that forms the socket for each tooth.

- the bone itself that supports and surround the tooth.

what is the difference between alveolus and alveolus process?

alveolus is located in the alveolus process

the alveolus is referring to the socket/cavity itself while the process refers to the bone making this socket

what is each alveolar process of the jaw also considered?

Dental arch

• all teeth in the upper and/or lower jaw forming into a arch shape

what is the term for the upper arch?

Maxillary arch

what is the term for the lower arch?

Mandibular arch

What is the occlusal plane?

An horizontal imaginary curved plane separating the maxilla (upper) and mandible (lower).

• occlusal plane= upper and lower half

What is the midsagittal plane?

An vertical imaginary plane dividing the skull into left and right sides.

• midsagittal = left and right half

• remember as midsagittal = down the midline

Quadrants

occlusal and midsagittal planes are used to divide the jaw, into 4 quadrants

how are the 4 quadrants referred?

Q1 (upper right)- Maxillary right

Q2 (upper Left)- Maxillary left

Q3 (lower left)- Mandibular left

Q4 (lower right)- Mandibular right

What is the quadrant system for primary teeth?

Q1=Q5, Q2=Q6, Q3=Q7, Q4=Q8 . uses Q5-8

D A Q T

Dentition: permanent or primary

Arch: maxillary or mandibular

Quadrant: Left or right

Tooth: central/ lateral incisor, canine, premolars, molars

Midline

Divides each arch into a left and right side

Anterior

front teeth

• closest to the midline

• included incisor and canines

Posterior

away form the midline

• premolars and molars

Sixtants

Divides in 6 segments

• 3 in each arch

how are the segments in sixtants divided

maxillary

Q1, Q2, Q3

mandibular

Q6, Q5, Q4

What are the three main tooth designation systems?

1. FDI (Federation Dentaire Internationale)

2. Universal System (US)

3. Palmer Notation Method

How are permanent teeth numbered in the Universal System?

Consecutively from 1 to 32 clockwise, starting with the upper right third molar.

What does the D-A-Q-T system stand for in tooth description?

Dentition, Arch, Quadrant, Tooth.

According to nomenclature rules, which terms always precede all other terms?

Mesial and distal, with mesial taking precedence.