Board Review DH227
Dental Anatomy
Lisa Mayo, RDH, BSDH
Concorde Career College
Review
• Identify human dentition with terminology
specific to:
▫ # of dentitions
▫ Types of teeth
▫ Terminology not related to man
• Identify component of periodontium
• Be able to relate eruption dates for primary and
permanent teeth to clinical situations
▫ If given a picture of a dentition, identify age of pt.
How Old Is This Patient?
How old is this patient?
How old is this patient?
Review
• Heterodont: man is because have many diff.
types teeth
• Homodont: all teeth the same
• Dispyodont: man: 2 different dentitions
• Monodont: 1 set of teeth
• Polydont: many diff. sets of teeth
Review
• Know key calcification times of teeth to know later
in life what caused certain conditions (fluorosis,
tetracycline staining, hypocalcification, etc…)
• Know how primary roots are in relation to erupting
permanent teeth
▫ Succedaneous teeth: permanent teeth that replace
primary (incisors, canines, premolars)
▫ Resorption
▫ Exfoliation
▫ Non-succedaneous – permanent teeth that do not
replace baby tooth
Primary Teeth
• Also called baby, milk, temporary, deciduous,
primary teeth
• Exfoliation = process of losing tooth
• Resorption = physiological removal of tissue or
body products
Primary Teeth
• Bud = individual tooth buds/cap
• Bell = major amount of enamel and dentin are
laid down
• Root development = begins when CEJ area is
formed at end of the bell
• Root completion = 1-2yrs after eruption
• Ankylosed root = when primary tooth fuses to
alveolar bone and will not exfoliate
Primary Tooth Eruption
ERUPTION
Mand Central (8-12mo)
Mand Lateral (9-13mo)
Max Central (8-12mo)
Max Lateral (9-13mo)
0-1 years
Mand 1st Molar (13-19mo)
Max 1st Molar (13-19mo)
Mand Canine (16-22mo)
Max Canine (16-22mo)
1-2 years
Mand 2nd Molar (25-33mo)
Max 2nd Molars (25-33mo)
2-6 years
Eruption Sequence: central, lateral, 1st molar, canine, 2nd molar
Permanent Tooth Eruption
ERUPTION
ROOT COMPLETION
Permanent Tooth Eruption
Man 1st Molar
Max 1st Molar
Mand Central
Mand Lateral
Max Central
Max Lateral
Mand canine
Mand 1st Premolar
Max 1st Premolar
Mand 1st Premolar
Max 2nd Premolar
Max Canine
6-9 years
9-11 year
9-12 year
12-15 years
Mand 2nd Molar
Max 2nd Molar
12-17 years
14-16 years
Mand 3rd molar
Max 3rd Molar
17-21 years
18-25 years
Primary Teeth vs Permanent
• Enamel is thinner and whiter
• Roots
▫
▫
▫
▫
▫
▫
Same # molar-molar
Mesial root wider
Longer and thinner
More flared
No root trunks
Pulp chambers large, pulp horns close to enamel
• Crown
▫ Shorter
▫ Wider M-D than Occlusal-Gingival
Primary Teeth vs Permanent
•
•
•
•
•
•
Ant smaller than perm
Post wider M-D
More bulbous or bell shaped
Cervical ridges are bulky/prominent
Occlusal tables narrower
Thin dentin layer between pulp and enamel
Review
Know general differences between perm and
primary teeth, know which ones resemble each
other (next slide)
▫
▫
▫
▫
▫
Enamel
Color
Cervical ridges
Size
Flare of roots
Primary vs Perm
PRIMARY
TOOTH
Max 1st Molar
PERM TOOTH
ROOTS
IT RESEMBLES
Max 1st Premolar
3
Max 2nd Molar
Mand 1st Molar
Mand 2nd Molar
Max 1st Molar
Unique crown
Mand 1st Molar
3
2
2
Primary/Permanent
• Mixed Dentition: 6-12 years
• Most common congenitally missing permanent
teeth
▫ Max laterals
▫ 3rd molars
▫ Mand 2nd premolars
Review
Identify key points to teeth
▫
▫
▫
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▫
▫
Angle of a tooth
Types of ridges
# of roots
# of lobes and cusps
Fossas
Grooves
Review
• Know numbering systems
• Relate the size of an embrasure to contact areas of
teeth
• Related the size of interdental papillae to the contact
area between teeth, and to the curvature of the
cervical line
• Know shapes of teeth from F and interprox
• Know what makes certain teeth unique
▫ Ridges
▫ Concavities/Convexities
▫ Furcations
Structures to Review
• Boney alveolar process surrounds each tooth
• Bone socket or alveolus is part of the alveolar
bone in which teeth are set
• Crown – anatomical vs clinical
• Root - anatomical vs clinical
• Enamel: 96% calcified
• Dentin: 70% calcified
• Cementum: 65% calcified
• Cervical line /CEJ/DEJ
Structures to Review
• Pulp: canal, chamber, horns
• Surfaces: mesial, distal, occlusal, incisal,
buccal/labial, lingual
• Anterior teeth, posterior teeth
▫ Know which teeth have occ vs incisal edges
▫ Know which teeth have buccal or labial
▫ Lingual sometimes referred to as palatal for max. post.
• Contact area: where 2 adjacent teeth meet
• Proximal surface: surfaces in-between 2 teeth
• Height of the contour between 2 teeth (gets larger
with age): The line encircling a tooth or other
structure at its greatest bulge or diameter with
respect to a selected path of insertion
Structures to Review
• PDL: attaches tooth to bone
• Gingiva
▫
▫
▫
▫
▫
▫
▫
▫
Gingival line
Free gingiva
Sulcus
Epithelial attachment
Gingival groove
Attached gingiva
Mucogingival junction
Alveolar mucosa
• Fibers
Structures To Review
• Line Angles: Imaginary line formed by the
junction of 2 surfaces
▫ Become more rounded as go from ant to post
• Point Angle: formed by the junction of 3 surfaces
• Cusps: less pointed or steep as go from canine to
molar
Roots
• Named for where they are
• Root termination = apex
• Root usually/typically deflect
towards the distal
• Concavities: 4 key areas (remember all teeth have
M/D concavities!)
▫
▫
▫
▫
Max 1st premolar (M) – Very prominent
Max 1st Molars (L/M/D)
Max Lateral(L)
Mand 1st Premolar (M/D)
▫
▫
▫
▫
Anterior: 1
Premolars: 1, except maxillary 1st premolars (2)
Maxillary molars: 3 (2F, 1L)
Mandibular molars: 2 (M&D)
• Numbers
Roots
Lobe
• Primary division of a tooth
• 4 or 5
• 4- all ant and premolars except for mand molars
that have 2 lingual cusps – these teeth arise from
5 lobes
• Molars develop from 4 lobes except mand first
that have 5 cusps and develop from 5 lobes
• Developmental depressors on labial aspect
separate lobes on ant teeth and buccal of
premolars, not on molars (grooves)
Shapes
•
•
•
•
Trapezoidal:
Triangular:
Ovoid:
Elliptical:
from F and L
Max anterior
Canines
Mand anterior
• Rhomboidal: Mand posterior
• Trapezoidal: Max posterior
Special/Unique Structures
• Max Central
▫ Lingual groove
▫ Lingual pit
▫ Mamelons
• Max Lateral
▫
▫
▫
▫
Linguogingival groove
Lingual pit
Linguogingival fissure
Mamelons
Special/Unique Structures
• Mand Central: smallest teeth in mouth
▫ Mamelons
▫ Root concavity
▫ Longitudinal groove
• Mand Lateral
▫ Mamelons
▫ Root concavity
▫ More prominent cingulum then #24,25 and deeper L fossa
▫ Cingulum: lingual cervical of ant teeth
Special/Unique Structures
• Canines: longest, strongest teeth, most stable
tooth, provides guidance for occlusion
• Max canine
▫
▫
▫
▫
▫
▫
▫
Canine eminence
Mesioincisal/distoincisal cusp ridge/slope
Labial ridge
Linguogingivial groove
Lingual pit
Mesio/distolingual fossa
Lingual ridge
Special/Unique Structures
Mand canine
▫
▫
▫
▫
▫
▫
▫
Canine eminence
Slopes
Labial ridge
Mesio/distolingual fossa
Lingual ridge
Root concavity
Narrower then maxillary
Canine Eminence
Vocabulary
Ridge
▫ Marginal: found at M and D terminations of occlusal
surfaces of post teeth and form the lateral borders of L
surfaces ant teeth
▫ Cusp Ridge: each cusp has 4 extending from its tip
(M,D,B,L)
▫ Triangular: ridge that descends from tips of cusps
toward central area of occlusal surface
▫ Transverse: 2 triangular ridges merging
▫ Oblique: special type of transverse unique to MAX
MOLARS from the ML to DB cusps (ML distal cusp
ridge and DB triangular ridge)
Vocabulary
• Mamelons: small, rounded projections on incisal
edges of newly erupted teeth usually worn away
soon after eruption. Common on adults with
malocclusion (ant open bite)
• Fossa: rounded depression, pit at bottom
• Developmental groove: One of the fine lines found in
the enamel of a tooth that marks the junction of the
lobes of the crown in its development
• Secondary groove: auxiliary groove
Individual Teeth: ANT
• Max incisors
▫
▫
▫
▫
More developed than mand
Fossa and cingulum
Marginal ridges
Incisal edges straight except for mand lateral
twisted
• Max/Mand canines
▫ Max more developed
▫ Lingual ridge forms ML and DL fossa’s
PREMOLARS
Max Premolars General
Max premolars GENERAL
▫ More similar then mand premolars
▫ 2 pointed cusps: B longer than L
▫ M marginal groove, M depression on mid-1/3 of
crown down to root
▫ Single or bifrucated root (B,Palatal) and occurs
apical 1/3 of root
7mm
Max 1st premolar
Max 1st premolars:
▫
▫
▫
▫
▫
▫
Well-developed line angles
Mesial concavity extends onto root
Root bifurcated
Mesial marginal groove
Long central groove
Lingual cusp tip offset to
mesial
Max 2nd premolar
Max 2nd premolar
▫ More rounded line angles
▫ 1 root usually and is larger
than 1st premolar
▫ Central groove shorter with
more supplemental
grooves
▫ M groove absent
Max 2nd premolar
Max 2nd premolar
▫ L cusp larger than L cusp
on Max 1st premolar
▫ B cusp shorter than 1st
premolar and less
pointed
▫ Both cusps near same
length and width
▫ Both 1 and 2 have
transverse ridges
Mand 1st Premolar
Mand 1st premolar
▫ Sharp B cusp
▫ Short nonfunctional L
cusp
▫ Central groove not
always present
▫ M, D fossae with pits
▫ B cusp tip centered
over root
Mand 1st premolar
Mand 1st premolar
▫ Transitional teeth –
more resemblance to
canine as far as
masticatory function
▫ Transverse ridge
▫ ML developmental
groove separates M
marginal ridge from L
cusp
Mand 2nd premolar
Mand 2nd premolar
▫ 2 or 3 cusps, no transverse ridges, more
supplemental grooves than 1st premolar
▫ Larger than 1st premolar
▫ B cusp shorter than 1st premolar
▫ ML cusp is larger than DL
▫ Root wider than 1st premolar with a blunt apex
▫ Y-shape to central and lingual groove
▫ If 2 cusps – can have a U-shape or an H-shape to
central groove
MOLARS
Maxillary 1st Molars
Max 1st Molars
▫ 1st rhomboid occlusal
pattern to cusp tip
alignment
▫ Cusp of carabelli that is
non-functional
▫ Largest tooth in the mouth
in regards to overall bulk/
surface area
▫ Crown is wider F-L than
M-D
▫ Roots trifurcated: 2B, 1
palatal (DB is the
narrowest)
Max 1st molar cusps
Max 2nd Molars
Max 2nd molars
▫ Smaller than the 1st
▫ No 5th cusp
▫ Rhomboid shape to occlusal is more
accentuated
▫ Can have a heart shaped form like 3rd
molar
▫ For both L root is largest then MB
then DB
▫ 2 roots: MB root tip curves distally
Mandibular Molars
First
Second
Third
Mand 1st molar
Mand 1st Molars
▫ 1st pentagon/rectangular wider M-D than B-L
▫ Largest tooth of mand arch
▫ Bifuracted roots: roots twice as long as crown, M
root longer/stronger, root apex of M turns toward
D
Mand 1st molar
Mand 1st Molars
▫ 5 Cusps – D, 2B
grooves, B and DB.
(D smallest. MB
cusp wider than DB
▫ No transverse
ridges
▫ 4 developmental
grooves: Central, B,
DB, L
Central
groove
Mand 2nd molar
Mand 2nd Molars
▫ Rectangle for both distal roots are
straighter, M are widest B-L than D
▫ Roots: shorter than 1st molar, closer
together, M root less broad then on 1st
molars
2 transverse ridges: 1st molar has NONE!
Contact Areas
•
•
•
•
•
Become more cervical as go from ant to post
Distal usually more cervical then mesial
Size ↑ from ant to post
Ant teeth contacts centered F-L
Post teeth contacts slightly B of center
Interprox Space
• Triangular and filled with interdental papillae
• Triangle is formed by proximal surfaces of
adjacent teeth, the apex is the contact of
adjacent teeth and the base is the alveolar bone
• Shape changes ant to post
Embrasures
• Named for location: F, L, Cervical, Occlusal
• For protection and stimulation of the
periodontium
• Form directly related to contact areas:
▫ ie. post teeth the lingual embrasures are
larger than the F because the contact is
to the Facial/Buccal of center
Heights of Contour
• For anterior: height on the labial and lingual is
in the cervical third
• Posterior: the B is in the cervical third
• Posterior: the L is in the middle to occlusal
thirds
• Thirds of crowns and roots: horz and vert thirds
• Cervical lines always steeper on M and D
Comparing ant-post
• Proximal curvature of CEJ flattens
• M/D CEJ curvatures of an individual tooth: M
curvature › D curvature
• Lingual height of contours shift from cervical to
middle 1/3
• Contact areas shift from incisal 1/3 to middle 1/3
Anomalies
• Max Central
1.
2.
3.
4.
Dwarfed root
Hutchinson’s incisors
Talon cusp
Supernumerary
1.
2.
3.
4.
Peg lateral
Cingulum may have tubercle
Congenitally missing (agenesis)
Dens in dente
• Max Lateral
• Mand Central
1. Bifurcated root
• Mand Lateral
1. Bifurcated root
Anomalies
• Max Canine
1. Tubercle on lingual surface
• Mand Canine
1. Bifurcated root
Anomalies
• Max 1st Premolar
1. 3 roots
2. Antrum (root penetrating max. sinus)
• Max 2nd Premolar
1. Absent central groove
2. Antrum
• Mand 1st Premolar
1. ML developmental groove absent
2. Bifurcated root
• Mand 2nd Premolar
1. Congenitally missing
2. Bifurcated root
3. Supernumerary
Anomalies
• Max 1st molar
1. Mulberry molar
2. Root variations (fusion, length)
3. Carabelli
• Max 2nd molar
1. Heart-shaped occlusal
2. Tubercle on B
3. Root fusion
• Max 3rd molar
1. Peg 3rd molar
2. Everything!
Mulberry Molars
Anomalies
• Abnormal #
▫ Adontia: any missing teeth total or partial
▫ Supernumerary: mesodens most common
supernumerary tooth followed by maxillary molar
areas
• Abnormal Size
▫ Macrodontia: true assoc. with gigantism, more
commonly see large teeth
▫ Microdontia
 True: pituitary dwarfs
 False=more common, see Max laterals, peg laterals,
max 3rd molars
Development of two maxilla
together- Genetic Malformation
Anomalies
• Abnormal Shape
▫ Dens in Dente: external structures become
reversed in pulp chamber. “Tooth Within A Tooth”
▫ Dilaceration: linear distortion (bend) in
root/crown from trauma
▫ Flexion: dilaceration root only
▫ Gemination: splitting of single tooth germ single
root but looks like 2 crowns
▫ Fusion: union of 2 tooth buds only involving
crowns
Dens in Dente
Dilaceration
Anomalies
▫ Concrescence: union of 2 teeth at roots
 Molars most common
▫
▫
▫
▫
Segmented roots
Dwarfed roots
Hypercementosis: excessive cementum
Enamel Pearls (Ectopic enamel): on root surface
furcation areas, developmental issue
▫ Hutchinson’s Teeth: prenatal syphilis, incisor may
be screwdriver
▫ Mulberry: notch-shaped in incisal edge and
molars
Enamel Pearl
Anomalies
• Attrition: Mechanical wearing. Abrasive tp, oral
habit, improper tb technique
• Erosion: Chemical wearing. Acid or low-pH,
acidic foods, drinks
HELPFUL LINK
http://dentistry.umkc.edu/Practicing_Communities/asset
/AbnormalitiesofTeeth.pdf
Anomalies
• Abnormal calcification and apposition: Both may be
local, systemic, hereditary factors
▫ Enamel Dysplasia / Hypoplasia
 Disturbance occurs during enamel matrix formation
▫ Dentiogenesis Imperfecta
 Affects mesodermal formation, enamel normal, tooth
opalescent, gray to blue color, obliteration of pulp chambers
and root canals, root shorter
 Genetic
▫ Amelogenesis Imperfecta
 Malfunction of tooth germ
 Enamel appears pitted, aplasia, yellow/dark brown, unusual
wearing, enamel thin, hypocalcification
 Genetic
▫ Hypocalcification
 Later stage during maturation
 Rickets, birth trauma, idiopathic factors, congenital syphilis,
fluoride
What is this?
Answer: Dentiogenesis Imperfecta
What is this?
Answer: Amelogenesis Imperfecta
Amelogenesis Imperfecta
Anomalies
• Abnormal calcification and apposition
▫ Fluorosis: chalky white or brown, mottled teeth
▫ Focal hypomaturation: chalky white, circular, soft
enamel
▫ Turner’s Teeth: injury to follicle during extraction
of baby tooth or from abscess
▫ Tetracycline staining:
oMinocycline: blue/gray
oTetracycline: yellow/brown
▫ Taurodontism: large pulp chamber, location of the
furcation is more apical, elongated crown, Down’s
syndrome, “Bulls tooth”
What Is This?
What Is This?
What is this?
Answer: Taurodontism
Functions
• Incisors
1.
2.
3.
4.
Biting
Cutting
Esthetics
Phonetics
• Canines
1.
2.
3.
4.
5.
Tearing
Piercing
Facial Support
Cosmetics
Phonetics
Functions
• Premolars
1. Grinding
2. Esthetics
3. Phonetics
• Molars
1. Grinding
2. Esthetics
3. Phonetics
A&P: Mand Tooth Innervation
Molars
Premolars
Anterior
Pulp
Inferior Alveolar
Inferior Alveolar
Inferior Alveolar
B/F gingiva
Buccal
Buccal/Mental
Mental
L gingiva
Lingual
Lingual
Lingual
A&P: Max Tooth Innervations
2,3
Molars
1st Molar
Premolar
Canine
Incisors
Pulp
Post
Superior
Alveolar
Post &
Middle
Superior
Alveolar
Middle
Superior
Alveolar
Anterior
Superior
Alveolar
Anterior
Superior
Alveolar
B/F
Gingiva
Post
Superior
Alveolar
Post
Superior
Alveolar
Middle
Superior
Alveolar
Anterior
Superior
Alveolar
Anterior
Superior
Alveolar
Palate
Gingiva
Greater
Palatine
Greater
Palatine
Greater
Palatine
Nasopalatine
Nasopalatine
A&P: Muscles of Mastication
• Innervation: Mandibular Division of the Trigeminal
Nerve (V3)
• Blood Supply: Maxillary Artery (Branch of the
external carotid artery)
• Medial pterygoid & masseter have similar functions
& positions
▫ Medial pterygoid is internal
▫ Masseter external
• Temporalis, medial pterygoid, masseter muscles all
close the mouth (elevate the mandible)
• Lateral pterygoid opens the mouth
A&P: Muscles of Mastication
Temporalis
Masseter
Medial
Pterygoid
Lateral
Pterygoid
Origin
Temporal
fossa
Zygomatic
arch
Medial
surface lateral
pterygoid
plate, max
tuberosity
Lateral
surface lateral
pterygoid
plate,
infratemporal
surface
sphenoid
bone
Insertion
Coronoid
process &
mand post to
3rd molar
Outer surface
of the mand,
angle of the
mandible
Inner surface
angle of the
mandible
TMJ disc,
neck mand
condyle
Function
Retract,
elevate
mandible
Elevate the
mandible
Elevate &
protrude
mandible
Protrude &
depress
mand, lateral
shift of mand
A&P: TMJ Components
• Temporal Bone
▫ Mandibular fossa, glenoid fossa, articular fossa
▫ Articular eminence just ant to the fossa
• Mandible
▫ Condyle
• Articular Disc
▫
▫
▫
▫
▫
Fibrous pad of dense collagen tissue
Prevents bone to bone contact
Divides joint into upper and lower synovial joints
Thickest at the posterior, thinner in center
Moves with condyle under normal function
• Capsule
▫ Thick, fibrous tissue surrounding joint
▫ Reinforced by the temporomandibular ligament
▫ Inner lining secretes synovial fluid
A&P: TMJ Movement
1. Rotation
▫
Condyle rotates in the fossa
2. Translation
▫
▫
Condyle slides forward along the articular fossa
to the articular eminence
Disc moves with condyle in health
3. Trismus
▫
Hypomobility from trauma, disease, bruxism