Unit 2 - Tooth Morphology (Chapter 12)

Morphology

study of the size, shape, structure and surface of teeth

How many teeth in anterior permanent dentition?

12 (includes incisors & canines)

What incisors erupt first

(lower) Central incisors

Which teeth are the longest in permanent dentition?

canines

which teeth are the smallest in permanent dentition?

mandibular central incisors

pegged laterals

incisors with a pointed or tapered shape

diastema

space or gap between teeth in same arch

how many teeth in posterior permanent teeth?

20 (includes premolars & molars)

which tooth is referred to as wisdom tooth?

3rd molars

How many teeth in primary dentition?

20

what method of identification is used in universal/national system for primary teeth

alphabetical (letters A-T)

what teeth are not included in primary dentition?

premolars

what teeth are non-succedaneous?

molars

characteristics of primary teeth

• very white enamel

• narrow & long roots

• large pulp chamber

• thin enamel

• no mamelons

Why are primary teeth important?

• important for function and development of permanent teeth

• assist in speech

• give shape to the face

3 main parts to tooth

1. enamel

2. dentin

3. pulp cavity

what feature do newly erupted central & lateral incisors have on incisal ridges?

mamelons

pinpoint depression where two or more grooves meet

pit

Non-succedaneous

tooth that does not replace a primary tooth

Cusp of Carabelli

5th cusp found of the maxillary 1st molar

which primary tooth has an H-shaped groove pattern on its occlusal surface?

Mandibular molar

Which primary tooth in the largest?

Molar

which molar is the largest & which is the smallest?

Largest: 1st molar

Smallest: 3rd molar

what canines usually erupt first?

mandibular

Cingulum

raised, rounded area on cervial third of the lingual surface

margional ridge

rounded, raised boarder on the mesial & distal portions of the lingual surfaces of anterior teeth and occlusal table of posterior teeth

Fossa

wide, shallow depression on the lingual surfaces of teeth

Incisal edge

ridge on permanent incisors that appears flattened on labial, lingual, or incisal view after tooth eruption

canine eminence

external verticle bony ridge on the labial surface on canines

cusp

major elevation on the masticatory (includes occlusal) surface of canines & posterior teeth (includes canines, premolars, and molars)

Imbrication lines

slight ridges that run mesiodistally in the cervial third of the teeth (includes incisors and canines)

inclined cuspal plane

sloping area between cusp ridge

central groove

most prominent developmental groove on posterior teeth

margional groove

developmental groove that crosses marginal ridges, serves as a spillway for food

triangular groove

developmental groove that separates a marginal ridge from the triangular ridge of a cusp

furcation

area between (two or more) root (branches)

bifurcated

divided into two

trifurcated

dividied into three

bifurcation

area/space between two roots

trifurcation

area between three roots

bicanineate

two-cusp type of mandibular second premolar

tricanineate

three-cusp type of mandibular second premolar

root numbers of maxillarry teeth

Incisors: 1

Canines: 1

1st premolars: 2

2nd premolars: 1

All molars: 3

root numbers of mandibular teeth?

Incisors: 1

Canines: 1

1st premolars: 1

2nd premolars: 1

All molars: 2

cusps on maxilary teeth

Canines: 1

1st premolar: 2

2nd premolar: 2

1st Molar: 4

2nd Molar: 4

3rd Molar: varies (3-5)

1-2-2-4-4-variable

cusps on mandibular teeth

Canine: 1

1st premolar: 2

2nd premolar: 3

1st Molar: 5

2nd Molar: 4

3rd: varies (4-5)

1-2-3-5-4-variable