Basic Dental Anatomy (Preclinic Theory/Dental Anatomy)

Jaws

Maxilla and Mandible

Maxillae

2 paired upper jaw bones

points of reference

maxillary arch, mandibular arch, median line, quadrants, anterior vs posterior, sextants, occlusion, malocclusion

What is the median line?

the midline/vertical line dividing the right and left halves

What are the 4 quadrants in clockwise order?

1: maxillary right, 2: maxillary left, 3: mandibular left, 4: mandibular right

What teeth are anterior?

the incisors and canines (12)

What teeth are posterior?

premolars and molars (20)

What are the sextants?

1: maxillary right posterior, 2: maxillary anterior, 3: maxillary left posterior, 4: mandibular left posterior, 5: mandibular anterior, 6: mandibular right posterior

what is an occlusion?

the relationship of the maxillary and mandibular teeth, where they come together to touch

what is a malocclusion?

abnormal occlusion of the teeth, like an open bite or crossbite

What are the incisors used for?

cutting food

What are the canines (cuspids) used for?

piercing or tearing

What are the premolars (bicuspids) used for?

crushing

What are the molars used for?

crushing, milling and grinding

What teeth are not seen in primary dentition?

the premolars and third molars

What is the enamel?

The hard, calcified tissue that covers the dentin of the crown of the tooth

What is the dentin?

The hard, calcified tissue formed on the inside body of the tooth underneath the enamel and cementum surrounding the pulp

What is the cementum?

very thin layer of calcified tissue covering the root

What is the pulp?

In the center of the tooth, the highly vascular area full of blood vessels and nerves

What is the dentinoenamel junction (DEJ)?

line between the dentin and the enamel

What is the dentinocemental junction (DCJ)?

line between the dentin and cementum

What is the cementoenamel junction (CEJ)?

line between the cementum and enamel, a lot of people have calculus built up around this area, it is horizontal around the tooth and also called the cervical line

What is the crown?

The portion of the tooth covered with enamel

what is the cusp?

the pointed or rounded eminence on or near the occlusal surface

What is the root?

the portion of the tooth embedded in bone and covered with cementum

What is the root apex?

the extremity/very base of the root of the tooth

What is the cervix?

constricted junction of the crown and the root (neck of the tooth), indentation where the CEJ is located

What is a furcation?

a point where the tooth has 2+ root branches

What is bifurcation?

the division of 2 roots (mandibular molars)

What is trifurcation?

the division of 3 roots (maxillary molars)

What is the root trunk?

the area between the cervical line and the furcation on a multirooted tooth

What is dentition?

the kind, size, and arrangement of teeth

how many teeth are in primary dentition?

20

How many teeth in secondary dentition?

28-32, depending on presence of third molars

What is mixed dentition and when is this seen?

dentition containing both primary and secondary teeth in dental arches at the same time, seen around age 6-12

What are teeth functions?

mastication/aid digestion (chewing), facilitate communication (speech), esthetics (appearance)

How is primary dentition useful?

maintenance of space for permanent teeth

act as a guide for erupting teeth

What teeth are in primary dentition?

central and lateral incisors, canines, first and second molars

What are nonsuccedaneous teeth?

permanent molars in the permanent dentition that do not replace primary teeth

What are succedaneous teeth?

permanent teeth that replace primary teeth

Lingual surfaces

surface of the maxillary and mandibular teeth nearest the tongue

Facial surfaces

surfaces next to the face (labial, buccal)

Labial surface

type of facial surface of anterior teeth next to the lips

Buccal surface

type of facial surface of posterior teeth next to the cheeks

proximal surfaces

next to an adjacent tooth in the same arch (mesial, distal)

mesial surfaces

surfaces nearest/toward the midline of the arch

central incisors have mesial sides touching (8/9, 24/25)

distal surfaces

surfaces furthest/away from the midline of the arch

occlusal surfaces

biting surfaces of posterior teeth

incisal surfaces

biting edge of anterior teeth

contact area/point

small spot or area on the mesial or distal surfaces of a tooth which touches or contacts the adjacent tooth in the same arch, usually a space at the top and bottom since they are rounded

embrasure

open space between proximal surface of two teeth where they diverge facially, lingually, or occlusally from the contact area; triangular spaces coming out from the tooth

concavity

depression in a surface

convexity

bulge in a surface

interproximal space

triangular space between adjacent teeth (gingival embrasure)

long axis

imaginary line that divides an object in half lengthwise

cervico-occlusally divided

crown only, horizontal cuts across the tooth into

cervical third, middle third, occlusal/incisal third depending on posterior/anterior

mesiodistally divided

crown or root, only on the facial and lingual

mesial third, middle third, distal third

faciolingually divided

crown or root, vertical cuts only on the proximal/side view

facial third, middle third, lingual third

cervicoapically divided

root

cervical third, middle third and apical third

What are the five tooth surfaces?

facial (buccal, labial), lingual, mesial, distal, occlusal/incisal

What does the green represent?

pulp horns

What does the blue represent?

pulp chamber

What does the pink represent?

pulp canals

What are alveolus?

supporting bone structures (grainy bits)

Types of crown depressions

fossa, grooves, pits

Fossa

rounded depression found on the lingual of anterior teeth and occlusal of posterior teeth

Grooves

lightly depressed lines, marking junction of two loaves

Pits

small pinpoint depression

Types of crown elevations

cusps, cingulum, tubercles, mamelons, ridges

Cusps

mass or elevation on the occlusal surface of a posterior tooth or the incisal surface of a canine

Cingulum

point of calcification forming the lingual lobe and parts of the height of contour

Tubercles

rounded or pointed projections found on the crowns of teeth, atypical

Mamelons

rounded extensions of the labial loads

Ridges

linear and usually convex elevations on the crowns of the teeth named according to their location

Palmer system

quadrant bracket

FDI system

more complicated bracket system naming permanent and primary alongside quadrants

Crown components

96% inorganic, 4% organic

Root components

50% inorganic, 50% organic

Dentin components

70% inorganic, 30% organic

tertiary/reparative

formed in response to trauma

anterior have 8 line angles

mesio labial/lingual/incisal

linguo/labio incisal

disto incisal/lingual/labial

posterior have 8 angles

mesio buccal/lingual/occlusal

disto linguo/bucco occlusal

disto lingual/buccal

point angles

point at which 3 tooth surfaces meet

anterior teeth have 4 point angles:

mesiolabioincisal

mesiolingualincisal

distolabioincisal

distolinguoincisal

posterior teeth have 4 point angles

mesiolinguoocclusal

mesiobuccoocclusal

distolinguoocclusal

distobuccoocclusal

anterior teeth have ___ lobes

4

posterior teeth have __ or __ lobes

4 or 5

lobes are formed by a

separate point of calcification

occlusal curvatures

curve of spee, curve of wilson

curve of spee

begins at the tip of the canines and follows the cusp tips of the premolars and molars, curving upward from anterior to posterior

curve of wilson

medial-lateral curvature of the occlusal plane of posterior teeth complimenting the path of the condyles during movements of the mandible

crown form of facial or lingual aspect is

trapezoidal

crown form of anterior teeth is

triangular

crown form of posterior teeth on the mandible is

rhomboidal

crown form of posterior teeth on the maxilla is

trapezoidal

embrasures function as a

spillway for food and protect the gums

facial line angles are formed by the

junction of two crown surfaces

heights of contour are on the (3) surfaces

facial, lingual, proximal

these are critical to the health of the periodontium

contours

continuity of the central groove of the posterior teeth is for (2)

effective food flow, proper occlusion