Tooth anatomy MIDTERM

Parts of the tooth (hardest to softest)

Enamel, dentin, cementum, pulp

Anatomic Crown

Part of tooth that enamel covers & ends at cervical line

Clinical Crown

Part of tooth visible in oral cavity

Anatomical root

part of tooth that has cementum surface

clinical root

part of a tooth which is under the gingiva & is not exposed to the oral cavity

How many lobes in central & lateral incisors

4 lobes (3 facial & 1 lingual cingulum)

How many lobes in canine

4 lobes (3 facial & 1 cingulum)

How many lobes in premolars

3 facial lobe & 1 lobe for each lingual cusp

how many lobes in molars

#of cusps = # of lobes

1st molar= 5 lobes

2nd molar= 4 lobes

3rd molar= 3 or more

Fossa

an irregular depression or concavity

developmental groove

a shallow groove on line between primary parts of a tooth

supplemental groove

less distinct & does not mark junction of primary parts

pits

small pin point depression located at junction of developmental groove

ridge

linear elevation on surface of tooth & is named based on location

triangular ridge

ridges that descend from tip of cusp toward central part of occlusal surface

marginal ridge

rounded borders of enamel which form mesial & distal margins of lingual surface for anterior teeth and margins of occlusal surface for posterior teeth

transverse ridge

when a buccal & lingual ridge join

oblique ridge

 ridge crossing obliquely the occlusal surfaces of maxillary molars. Only found on maxillary molar

tubercle

small cusp-like elevation on crown produced by extra formation of enamel

fissure

narrow, deep cleft on surface of a tooth due to imperfect fusion of enamel lobes

point angle

junction of 3 teeth surface at a point

line angle

junction where 2 tooth surfaces meet

cusp

a round pyramidal elevation w/a peak

furcation

place on multirooted teeth where root trunk divides in separate roots

Cementoenamel junction (CEJ)

part of the tooth where two vital substances that protect the tooth meet on the tooth's surface

Permanent (secondary) dentition

numbers, 32 teeth

Primary (deciduous) dentition

Letters (A-T), no premolars, 20 teeth

Human dentition classification

brachyodont, heterodont, diphyodont

What permanent teeth are the succedaneous teeth for primary molars

Permanent premolars

are permanent molars succadaneous

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

embrasure space

area below contact, caused by gum tissues not completely filling space between teeth

crest of curvature

The shape & extent of the greatest bulge on facial & lingual crown surfaces help determine the direction that food particles are deflected as they get crushed when we chew

mamelons

3 small bulges on incisal edges of newly erupted incisors, gets worn off after tooth comes into functional contact

primary function of teeth

mastication, assisting in development & protection of supporting tissue

secondary function of teeth

aid in production of speech, give form & symmetry to face

incisors function

designed to cut

canine function

designed to grasp & hold food

premolar function

designed to grind & crush food

molar function

designed to grind food

which arch is wider

maxillary arch

where would you find pits

Found deep in the grooves of premolars & molars

How many roots do incisors have

1

How many roots do canines have

1, w/exception for mand canine which can have 2 occasionally

How many roots do premolars have

Max 1st premolar- 2 roots, all other premolars have1 root

How many roots do molars have

Maxillary molars - 3 roots

mandibular molar- 2 roots

bifurcation

2 rooted

trifurcation

3 rooted

what tooth is widest & smallest mesiodistally

central incisors

cusp of carabelli

the 5th cusp found only on maxillary 1st molars

which tooth has the longest root

canines

What does the deciduous maxillary 1^st molar resemble? 

Permanent maxillary 1st premolar 

What does the deciduous maxillary 2^nd molar resemble? 

Permanent maxillary 1st molar

What does the deciduous mandibular 2^nd molar resemble? 

Permanent mandibular 1st molar

What does the deciduous mandibular 1^st molar resemble?  

does not resemble anything in the permanent dentition (fish shaped)

On the deciduous molars, what feature would you find to help determine if it’s a left or right side?

Cervical bulge on MB side of the tooth 

Deciduous teeth root charcteristics

Shorter root trunk, more flared out to make room for the “bigger” succedaneous teeth

When do the first permanent teeth erupt into the oral cavity? Which tooth would that be? 

Mandibular and maxillary first molars erupt at 6-7 years old

When does mixed dentition occur? 

Age 6-12 is usually when teeth are still coming in

Key features between max & mand canine

• maxillary canine have prominent features, a cingulum bulge, looks bulky, has a distal hump

• Mandibular canine appears more slender, no cingulum bulge, mesial marginal ridge appears straighter

deciduous crown characteristics

• enamel & dentin is thinner

• crown smaller

• appears whiter

max vs mand 1st premolar

Max 1st premolar- 2 roots, Deeper M root depression (unique)

Mand 1st premolar- 1 root, resembles a canine due to non-functioning L cusp

Max vs Mand 2nd premolar

Max 2nd Premolar- B & L cusp similar height, deeper d root depression

Mand 2nd premolar- 1-2 L cusp, ML cusp tallest, L crown tilt

Max Vs Mand Molars

Max molar- 5th cusp is cusp of carabelli, 3 roots, oblique ridge

mand molar- 5th cusp is distal, 2 roots, L crown tilt

Pit

oblique ridge

transverse ridge

marginal ridge