Transcript Tooth Morphology

Tooth Morphology
Dentition
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Dentition
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Natural teeth in position
in the dental arch.
Arch
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One row of teeth in the
mouth.
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Maxillary
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Upper teeth
Mandibular
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Lower teeth
Numbers of teeth
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Permanent
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32 total
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16 each arch
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20 succedaneous
 Replace baby teeth!
Primary
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20 total
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10 each arch
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NO pre-molars
NO 3rd molars
Quadrants
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Each arch is divided into
R + L.
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Max. R. quadrant
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ULQ
Man. L quadrant
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URQ
Max. L. quadrant
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Midline
LLQ
Man. R quadrant
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LRQ
Sextants
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6 sections of the mouth
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Maxillary
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3 of each arch
Max. R. Post. Sextant
Max. Anterior Sextant
Max. L. Post. Sextant
Mandibular
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Mand. L. Post. Sextant
Mand. Anterior Sextant
Mand. R. Post. Sextant
Tooth surfaces
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Anterior
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Facial / Labial
Lingual
Mesial
Distal
Incisal edge
Posterior
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Facial / Buccal
Lingual
Mesial
Distal
Occlusal
Proximal surfaces?
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Surfaces of adjacent teeth
closest to each other.
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Midline
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Mesial / Distal
Mesial / Mesial
Example
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You floss the proximal surfaces
of a tooth.
Your floss would be
interproximal.
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Between the proximal
surfaces.
Tooth Relationships
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Antagonistic (Antagonists)
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Teeth that work together to
chew
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Same tooth in the opposite
arch.
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#1 and #32
#14 and #19
Adjacent
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Teeth next to each other in the
same arch.
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#17 and #18
Tooth descriptions
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Convex
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Outward curve
Bulge
Rounded projection
Concave
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Inward curve
Recessed area
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Opposite of convex
 convex
Concave
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Tooth Morphology
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Contact point
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Where adjacent teeth
touch each other.
Diastema
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Aka open contact
Naturally occurring ‘gap’
between teeth
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Common #8 #9
Any 2 teeth/arch
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Tooth Morphology
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Embrasure
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Triangular space between
the contact and the
gingiva.
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Cingulum
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Lump of enamel
Lingual surface
@ the gum line.
Maxillary incisors
Tooth Morphology
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Lobes
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Underdeveloped cusps.
Cusp
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Pointed or round mound
of enamel.
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Form the ‘bumps’ on the
chewing surface of molars
and premolars.
“cuspid”!
Tooth Morphology
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Fossa
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Round
Triangular
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“low spot” /
recessed area
On a surface
Between cusps or ridges.
Developmental groove.
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Linear
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“low spot” / recessed area
Usually occlusal surface
Between cusps
Tooth Morphology
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Fissure
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Imperfect union of cusps
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Appears as a small “crack”
Located at the bottom of a
developmental groove
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Pit
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Where fissures cross or
end.
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Sealants are placed in pits
and fissures to prevent
decay.
Tooth Morphology
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Mamelons
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3 small cusps
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Incisal edge
Newly erupted incisors.
Wear down w/ use.
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Cusp of Carabelli
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5th/ additional cusp
Lingual surface
Maxillary 1st molars
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#3 + #14
Tooth Morphology
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Ridges
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Elevated lines of enamel
between cusps.
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Many examples
Marginal ridges
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Form the mesial + distal
borders of the tooth.
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Extend between the buccal
and lingual cusps
Tooth Morphology
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Crown
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Root(s)
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Bottom of the tooth
Covered w/ cementum
Apex
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Top of the tooth
Covered w/ enamel
End of the root
Apical foramen
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Hole @ apex
Tooth Morphology
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Furcation
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Dividing point of roots
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Bifurcation
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Of a multi-rooted tooth
2 roots
Trifurcation
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3 roots
Furcation
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Tooth tissue junctions
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CEJ
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Cementoenamel junction
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Where enamel meets
cementum.
Around the outside of the
tooth.
DEJ
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Dentinoenamel junction
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Where enamel meets the
dentin.
Under the enamel
Permanent Tooth descriptions!
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Max. Cent. Incisors
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Numbers: 8, 9
# of roots: 1
Nerve: ASA
Type of injection:
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Max. Lat. Incisors
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Succedaneous: yes
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Infiltration
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Replaces E and F
Function
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Cut
7, 10
1 roots
ASA
Infiltration
Succedaneous: yes
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Replaces: D, G
Most anomalies.
Function
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Cut
Permanent Tooth Descriptions!
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Max. Cuspid / canine
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6 + 11
1 root (Longest)
“cornerstone” of the mouth
ASA
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Max 1st premolar / bicuspid
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Replace C, H
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Tear / cut
Infiltration
Succedaneous: yes
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Only premolar w/ 2 roots
Removed for ortho
MSA
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Function
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5 + 12
2 roots
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Succedaneous: yes
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Infiltration
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Replace B, I
Function
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Chew
Permanent Tooth Descriptions!
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Max 2nd Premolar
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4 + 13
1 root
MSA
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Succedaneous: yes
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Replace A , J
Chew
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6 year molars
Cusp of carabelli
3 roots
PSA
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Function
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3 + 14
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Max 1st Molars
Infiltration
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MSA MB root
Infiltration
Not Succedaneous
Function
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Grind
Chew
Permanent Tooth Descriptions!
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Max 2nd Molars
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2 + 15
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Grind
Chew
1 + 16
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Infiltration
Not succedaneous
Function
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Max 3rd Molars
(12 year molars)
3 roots
PSA
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3 roots
PSA
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(wisdom teeth)
Infiltration
Not succedaneous
Function
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Grind
Chew
Permanent Tooth descriptions!
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Mandibular Central
Incisors
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24 + 25
1 root
Incisive nerve
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cut
23 + 26
1 root
Incisive nerve
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Replaces O + P
Function
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Mandibular lateral
Incisors
Infiltration
Succedaneous: yes
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Succedaneous: yes
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Infiltration
Replaces N + Q
Function
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cut
Permanent Tooth Descriptions!
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Mandibular Cuspid /
Canine
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22 + 27
1 root
Incisive nerve
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Mandibular 1st Premolar
/ bicuspid
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Infiltration
Replaces M + R
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Function
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Tear / cut
21 + 28
1 root
IA (inferior alveolar)
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Succedaneous: yes
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Succedaneous: yes
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Block injection @?
Mandibular foramen
Replaces L + S
Function
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chew
Permanent Tooth Descriptions!
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Mandibular 2nd Premolar
/ bicuspid
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20 + 29
1 root
IA nerve
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Succedaneous: yes
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Block
Replaces K + T
Function
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Chew
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Mandibular 1st Molars
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19 + 30
2 roots
IA nerve
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Block
Not Succedaneous
Function
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Chew, grind, pulverize
Permanent Tooth descriptions!
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Mandibular 2nd Molars
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18 + 31
2 roots
IA nerve
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Block
Not succedaneous
Function
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Grind, chew, pulverize
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Mandibular 3rd Molars
(wisdom teeth)
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17 + 32
2 roots
IA nerve
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Block
Not succedaneous
Function (if in occlusion)
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Grind, chew, pulverize
Primary Tooth Descriptions
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Aka
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Deciduous
Baby
Milk
Denoted / Labeled
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A–T
ABC’s
Alphabetically
Letters not numbers
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No
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Premolars
3rd molars
Roots
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Max molars
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Mand molars
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3 roots
2 roots
Cuspid / canine and
incisors
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All 1 root.
Naming a Tooth!
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Arch 1st
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Examples
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Right / left
Position
3rd
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Type of tooth 4th
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Molar / premolar /
cuspid / incisor
Max R. 2nd Molar
#21
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Permanent teeth
#2
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Central / Lateral
1st / 2nd / 3rd
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Max or Mand
Side 2nd
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Mand L. 1st Premolar
Primary teeth
#B
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Max R. 1st primary molar
Conclusion
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Knowing your tooth names and numbers is
critical to being a successful dental assistant.
Understanding morphology terminology will
make it easier to communicate with your dentist.
Do you have any questions?