introduction to dental anatomy

3mmar’s dental anatomy 01063970030 m.3mmar9428@yahoo.com 2015
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Chapter 1
Introduction to dental anatomy & physiology & occlusion

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Chapter (1)
introduction to dental anatomy
(1) Dental nomenclature
 Teeth
1arrangement of the teeth in oral cavity.
2 identify the position , distribution of the teeth.
3types & forms of the teeth.
4-tooth identification systems.
5-morphological feature (external morphology or macro-anatomy )
or micro-anatomy).6 structural feature (internal composition
7 the appearance of the oral cavity.
8 tooth surfaces.
9 division into third.
10 line & point angles.
11 anatomical landmarks of the crown.
12 functions of the tooth.
 Periodontium
1-gengiva.
3-cementum.
2-periodontal ligament.
4-alveolar bone.
(2) Human dentition
1 primary dentition.
2 mixed dentition.
3 permanent dentition.
Dental formula.
.
(3) terms
1- shedding
3- socket
5- self cleansable surface.
2-eruption.
4-crypt.
6-calcification.

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Chapter 1
introduction to dental anatomy
(1) teeth
1-arrangement of the teeth: teeth are arranged in the oral cavity in the form
of horse-shoe shaped dental arches; one upper , one lower.
the upper dental arch is attached to upper jaw (maxilla) so the teeth in
the upper dental arch is called upper teeth or maxillary teeth.
the lower dental arch is attached to lower jaw (mandible) so the teeth in
the lower dental arch is called lower teeth or mandibular teeth.
N.B1: maxillary jaw is fixed to the bones of skull
while
mandibular jaw is movable , articulate with the skull by tempro-mandibular ligament
Maxillary
teeth
Mandibular
teeth
mandible
maxilla
1-Dental nomenclature
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2-identify the position & distribution of the teeth in dental arches:
to identify the position of the teeth in dental arch two imaginary lines can be drawn.
the midline: is imaginary vertical plane that divide the arches into
two equal right , left segments.
occlusal plane: is imaginary horizontal plane that divide the arches into
two equal upper , lower segments
as result of this two lines the oral cavity is divided into four quadrants which are:-
1-maxillary right quadrant.
3-mandibular right quadrant.
2-maxillary left quadrant.
4-mandibular left quadrant.
 the total number of primary dentition is 20 teeth & permanent dentition is 32 teeth.
 The teeth of both deciduous , permanent dentition are equally distributed between
the maxillary , mandibular arches & each arch contains half the total number of teeth
which equally distributed in four quadrants.
Maxillary right quadrant Maxillary left quadrant
mandibular right quadrant mandibular left quadrant
N.B: add word (primary) in primary dentition & add word (permanent) in permanent dentition
N.B: the first arch is maxillary right quadrant then follow clock-wise
4 3
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Quadrant 1
primary maxillary right
quadrant
Quadrant 2
primary maxillary left
quadrant
Quadrant 3
primary mandibular left
quadrant
Quadrant 4
primary mandibular right
quadrant
Quadrant 1
permanent maxillary
right
Quadrant2
permanent maxillary left
quadrant
Quadrant 4
permanent mandibular
right
quadrant
Quadrant 3
permanent mandibular
left
quadrant
right left
Primary teeth
right left
note: the number of primary teeth in each quadrent is 5 teeth so the total number is 20 teeth.
Permanentteeth
note: the number of permanent teeth in each quadrent is 8 teeth so the total number is 32 teeth.
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3 types & forms of the teeth:
According to form , function; teeth are classified into:
1- Incisors: they are 8 in number (4 in each arch) i.e. 2 in each quadrant ;
central incisor , lateral incisor.
1 central incisor: is the first tooth centralized next to midline.
2 lateral incisor: is the second , its lateral to central incisor.
Function: incising , cutting of the food.
2- canines: they are 4 in number (2 in each arch) i.e. 1 in each quadrant;
it’s the third tooth from the midline.
Function: cutting , tearing of the food
3- pre-molars: they are 8 in number (4 in each arch) i.e. 2 in each quadrant;
first premolar & second premolar.
1 first pre-molar: the fourth tooth from the midline.
2 second pre-molar: the fifth tooth from the midline.
Function: tearing , grinding of the food.
4- molars: they are 12 in number (6 in each arch) i.e. 3 in each quadrant;
first molar & second molar & third molar.
1 first molar: the sixth tooth from the midline.
2 second molar: the seventh tooth from the midline.
3 third molar: the eighth tooth from the midline, its called wisdom tooth.
Function: grinding of the food.
the 4 incisors & 2 canines present in dental arch are called anterior teeth.
while
the pre-molars & molars are called posterior teeth.
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Third molar (8)
second molar (7)
first molar (6)
Second premolar(5)
first premolar (4)
Canines (3)
lateral incisors (2)
central incisors (1)
1 2 3
4 5
6 7 8
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4-tooth identification systems ( tooth numbering or coding systems ) :
many systems are designed to identify the exact position of the tooth in dental arch.
1-palmer notation system:
o These system utilizes a symbol that represented with bracket
having a vertical , horizontal lines, which meet at right angle.
- vertical line: separate right from left teeth.
-horizontal line: separate maxillary (upper) from mandibular (lower) teeth.
.
-the bracket open toward the quadrant at which the identified tooth is located.
oThe permanent teeth are numbered from 1 to 8 in each quadrant ,
starting the numbering from midline
so: 1 is central incisor , 4 is first premolar , 8 is thirdmolar.
Ex.: is upper right permanent central incisor.
oThe deciduous teeth are numbered from A to E in each quadrant ,
starting the numbering from midline
so: A is central incisor , C is canine , D is first molar , E is secondmolar.
Ex.: is lower left deciduous first molar.
U.L
L.LL.R
1
U.R
2
34
Upper Right
lower Right
.
8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 Upper left
8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 lower left
1
Upper Right deciduous Upper left deciduous
lower Right deciduous lower left deciduous
E D C B A
E D C B A
A B C D E
A B C D E
D
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2-two digit system (the international numbering system) :
o Its bi-numberical system used for tooth identification.
o The tooth to be identified are defined by two digit.
the first digit: indicate the number of the quadrant , written to the left.
 The digit from 1 to 4 is used for permanent teeth starting from the
upper right quadrant , directed clockwise manner.
.
 The digit from 5 to 8 is used for deciduous teeth by the same rule.
1
4 3
2 Permanent
teeth
78
65 Deciduous
teeth
18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28
48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38
55 54 53 52 51 61 62 63 64 65
85 84 83 82 81 71 72 73 74 75
the second digit: indicate the number of the tooth in the quadrant ,
written to the right.
 The digit from 1 to 8 is used for permanent teeth starting from the
midline in each quadrant , directed distally.
 The digit from 1 to 5 is used for deciduous teeth by the same rule.
The two digit must be pronounced separately.
so upper right permanent canine is 13 (one-three)
Permanent
teeth
Deciduous
teeth
Ex.: 44 is lower right permanent first premolar & 65 is upper left deciduous second molar.
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3-the universal numbering system(the American numbering system) :
For the permanent teeth: the numbers from1 to 32 are used.
starting from the maxillary right 3rd molar as #1
to end at the mandibular right 3rd molar as #32.
* the number is preceded by the sign # to designate this system from two-digit system
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
24 23 22 21 20 19 18 1732 31 30 29 28 27 26 25
Ex.: #3 is upper right permanent firs molar & #9 is upper left permanent central incisor.
Ex: #27 is lower right permanent canine & #20 is lower left permanent second premolar
For the deciduous teeth:
1-the numbers from 1 to 20 are used , the letter d is added as a suffix to
each number to designate the deciduous teeth from the permanent teeth.
1d 2 d 3 d 4 d 5 d 6 d 7 d 8 d 9 d 10 d
15 d 14 d 13 d 12 d 11 d20 d 19 d 18 d 17 d 16 d
Ex: #7d is upper left deciduous lateral incisor
2-the alphabet from A to T are another system for deciduous teeth.
A B C D E F G H I J
T S R Q P O N M L K
Ex: #S is lower right deciduous first molar.
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5- morphological feature of th tooth ( external morphology or macro-anatomy):
each tooth has three anatomical parts: crown & root(s) & neck.
 crown:
-its coronal part of the tooth covered by enamel.
-its variably seen in the mouth according to its extent of eruption.
-there is difference between the part of the crown exposed in the mouth at
certain time and the actual size of the crown.
anatomical crown: its part of the tooth which covered with enamel &
ends at cervical line.
clinical crown: its part of the tooth which visible in oral cavity (crown or root).
crown
neck
root
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 root:
-its part of the tooth covered with cementum.
-its variably embedded , surrounded & supporting with alveolar bone of the jaw.
anatomical root: its part of the tooth which covered with cementum.
clinical root: its part of the tooth which invisible in oral cavity (crown or root).
-according to the number of the roots; teeth may be:
1-single rootedteeth:
-incisors , canines.
-premolars ( except maxillary first pre-molar).
2 double rootedteeth:
root trunk divides at bi-furcation area into 2 roots as:
-maxillary first pre-molar.
-mandibular molars.
3 triple rooted teeth:
root trunk divides at tri-furcation area into 3 roots as:
-maxillary molars.
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root trunk: its undivided portion of the root
or
it’s the distance from cervical line to furcation area.
or
it’s the single root part of multi-rooted teeth.
furcation area: it’s the area where the root branching occurs.
in double rooted teeth; its called bi-furcation area.
in triple rooted teeth; its called tri-furcation area.
root apex: its free termination of the root.
 neck (cervical line ) or ( CEJ):
anatomical crown meets the anatomical root at a line known as cervical line.
Single
rooted
teeth
triple
rooted
teeth
double
rooted
teeth
7
76
64
1 2
3
5
54321
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6-structural feature (internal composion or micro A)
each tooth composed of four structures;
three hard (dentin , enamel&cementum )
& one soft (pulp).
 Dentin:
- its represent the main bulk of the tooth.
-crown dentin is covered by enamel.
-root dentin is covered by cementum.
-there are dention-enamel junction (DEJ)
& dentino-cemental junction (DCJ).
 Enamel:
-its cover the anatomical crown.
- it’s the hardest tissue in the body.
 cementum:
-its cover the anatomical root.
-its provide a medium for attachment of PDL.
-its meet enamel at cement-enamel junction (CEJ).
 Pulp cavity:
-its cavity in central part of dentin.
-its conform the external outline of the tooth.
-it’s the only soft tissue supplying the tooth with blood vessels ,nerves.
-its consist of:-
1 pulp chamber: it’s the part of the pulp cavity housed
in the crown (coronal pulp).
2 pulp horns: horns-like extensions at the roof of pulp chamber
3 pulp orifice: opening in the floor of pulp chamber that
connect it by radicular canal.
4 root canal:the part of the pulp located at the root (radicular C).
5 apical foramen: it’s the opening of the root canal at theapex;
through which the vessels , nerves enter the pulp.
6-sometimes; root canal send some branches which open on lateral surface of the root
called lateral canals or (accessory canals)
1
3
4
5
enamel
dentin
pulp
Cemen
-tum
6
2
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wein’s classification of root canal morphology:-
type 1: one orifice & one foramen.
type 2: two orifice & one foramen.
type 3: two orifice & two orifice.
type 4: one orifice & two foramina.
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7- the appearance of the oral cavity ( surface form of the oral cavity ) :
3-gengiva (gum)
6-floor of themouth
upon looking into the oral cavity you can see:
1-lips ( upper , lower ) 2-cheek ( buccal)
4-teeth 5-tongue (lingual)
7- palate (roof of mouth) 8-oral cavity proper. 9-vestibule ( labial , buccal)
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gengiva
Upperlip
Cheek
( buccal)
teeth
vestibule
Tongue(
lingual)
palate
Oral
cavity
proper
lowerlip
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8- teeth surfaces: the crown of the teeth has five surfaces , like a boxwith
four sides and roof & the surfaces are Identified by
The Relationship to other oro-facial structures.
The five tooth surfaces
1-Facial 2- lingual
lower teeth
3&4- proximal 5- masticatory
labial
(ant.)
buccal
(post.)
Mesial
towardthe
midline
Distal
awayfrom
midline
incisal
(ant.)
occlusal
(post.)
palatal
upperteeth
&
The crown of anterior teeth has fivesurfaces:-
1-mesial: toward the midline. 2-distal: away from the midline
3-labial (facial): toward the lip. 5-incisal: the incising , biting edge.
5- a. lingual: toward the tongue. (lower teeth)
b. palatal: toward the palate. (upper teeth)
The crown of posterior teeth has fivesurfaces:-
1-mesial: toward the midline. 2-distal: away from the midline
3-buccal (facial): toward the cheek. 5-occlusal: masticating surface.
5- a. lingual: toward the tongue. (lower teeth)
b. palatal: toward the palate. (upper teeth)
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7- division intothirds:
- for purpose of description of the surface regions of the tooth;
the crown & root could be divided into thirds.
- each third are named according to the adjacent area to it.
- the crown & root can be divided from any aspect horizontally or vertically.
1 horizontally: ( inciso-cervical & occluso-
cervical for the crown ) and ( apico-cervical for the
root ).
Crown: incisal third or ( occlusal third ) & middle third & cervical third.
 root: cervical third & middle third & apical third.
.
2 vertically: the crow only can divide vertically either mesio-distally or
labio-lingually ( bucco-lingually ).
& distal third.
 Mesio-distally:
crown: mesial third & middle third
 Labio-lingually (bucco-lingually):
crown: labial third ( buccal third ) & middle third & lingual third.
N.B: in vertical direction; the root divide into half ( M.D half ) or ( labial , lingual half )
MD Lab ling
middle
cervical
cervical
middle
incisal
apical
labial
middle
lingual
middle
mesial
distal
distalhalf
Mesialhalf
Labialhalf
Lingualhalf
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9- line & point angles:
1-lineangle
 Its angle that’s formed by the union of two surface.
 Its name is derived from these two surfaces.
2-point angle
 Its angle that’s formed by the union of three surface.
 Its name is derived from these three surfaces.
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10- anatomical landmarks of the crown: in order to study the surface
anatomy of the teeth; its important to know the basic anatomical landmarks;
there are in the form of elevations & depressions
Anatomical landmarks of the crown
Crownelevations Crowndepressions
lobe tubercle ridges
mamelon
cinglum
cusp
Ridges present
on facialaspect
Ridges present
on ling. aspect
Ridges present
on occ. aspect
LabialR
buccalR
cervicalR
lingualR
marginal R
( M & D)
cusp R (
M & D )
triangularR
lingualR
obliqueR
transverseR
marginal R
( M & D)
cusp R (
M & D )
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- by age; the mamelons wear down into a flat edge due
to the force of biting & the pulp horns obliterated
due to formation of secondary dentin.
N.B: the pulp chamber of incisors has 3 pulp horns that
corresponding to this 3 mamelons
1-crown elevations
(1)lobe:
- its one of primary center of calcification & growth that
fuse together to form the crown during
the tooth development
- each tooth develops from four lobes in most cases.
 The anterior teeth: develop from four lobes ( three labial & one lingual ).
 The Premolars: develop from four lobes (three buccal & one lingual ) however
lower 5 may formed from five lobes (three buccal & two lingual ).
 The Molars: develop from four lobes (two buccal & two lingual ) however
lower 6 may formed from five lobes (three buccal & two lingual )
N.B1: the teeth which have more than four lobes are lower 5 & lower 6.
N.B2: maxillary lateral incisor & maxillary second , third molars may have three lobes such as
( peg-shaped max. lateral incisor & heart shaped molars )
N.B3: some supernumerary teeth have less than three lobes.
- the mature form of lobes can be presented as mamelons & cinglum & cusp.
1-mamelons:
- they are three small rounded projections present in
the incisal third of newly erupted incisors.
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2-cinglum:
- its smooth rounded prominence;
making the lingual bulk at the cervical third
of the lingual surface of anterior teeth
( incisors + canine ).
3-cusp
- its pyramidal projection present on
the incisal third of the canine &
occlusal third of pre-molars , molars.
(2) tubercle:
- it’s a small elevation on the crown resulting from
excessive localized formation of enamel only.
- its present on the palatal aspect of max. E & 6
and sometimes on lingual aspect of incisors.
N.B: cusp must be formed of enamel & dentin & pulp horn.
N.B: tubercle differ from cusp as its formed of enamel only.
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(3)ridge:
- it’s a linear elevation present on the different surfaces of the crown , its named
according to their location or shape.
1. ridges on the facial surface
1-labial ridge (LR):
- its vertical linear elevation.
- its present on the labial
surface of the canine.
- its result from greater
development of middle labial lobe.
2-buccal ridge (BR):
- its vertical linear elevation.
- its present on the buccal
surface of the premolars.
- its result from greater
development of middle buccal
lobe.
3-cervical ridge (CR):
- its horizontal linear elevation.
- its present at cervical third
on the facial surface
of the all teeth.
- its well developed in D & E .
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.
2. ridges on the lingual surface
1-incisal ridge (IR):
- it’s a linear elevation present on lingual aspect
in newly erupted incisors.
- by time; it’s will transformed into edge
as attration removes some of incisal enamel.
2-linguall ridge (LR):
- its vertical linear elevation extend
from the cinglum to cusp tip.
.
- its present on the lingual surface
of the canine.
.
.
3-cusp ridges (MCR & DCR):
- they are two sloped linear elevations (mesial , distal )
. which meet to form an angle at the cusp tip.
- they may also be called cusp slopes ( M,D slopes) or cusp arms.
-they can be seen from lingual or labial aspect of the canine.
4-marginal ridges (MMR & DMR):
- they are two linear elevations present on
mesial & distal margins of the lingual aspect
of anterior teeth.
N.B: cusp ridges present also on the occlusal aspect of posterior teeth
N.B: marginal ridges present also on the occlusal aspect of posterior teeth
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3. ridges on the occlusal surface
1-cusp ridges (MCR & DCR)
they are two sloped linear elevations (mesial , distal ) which meet to form an
angle at the cusp tip.
- they may also be called cusp slopes or cusp arms.
- hey can be seen from occlusal or lingual or buccal aspect of posterior teeth.
2-marginal ridges (MMR & DMR):
- they are two linear elevations present on
mesial & distal margins of the occlusal aspect
of posterior teeth.
3-triangular ridge ( R)(:
- Its a linear elevation
descend from the cusp tip
to the center of occlusal aspect
of posterior teeth.
-its formed as two occ. sides of
the cusp meets together to form
a line angle
N.B: cusp ridges present also on the lingual or labial aspect of the canine.
N.B: marginal ridges present also on the lingual aspect of anterior teeth
LTR
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4-transverse ridge:
- Its a linear elevation result from union of
two triangular ridge opposing to each other.
-its transverse the occlusal surface in
bucco-lingual direction.
-its present in lower pre-molars.
5-oblique ridge:
- Its a linear elevation result from union of
two triangular ridge not opposing to each other.
-its cross the occlusal surface in
bucco-lingual direction obliquely.
e.g. mesio-lingual & disto-buccal cusps.
-its present in maxillary molars.
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Crownelevations Crowndepressions
Linear depression sulcus Circumscribed depression
grooves
developmental
fossa pit
lingual
triangular
fissure
Central (circular)
true
Anatomical landmarks of the crown
fault
D
s
supplemental
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2-crown dpressions
(1) linear depressions:
1-developmental groove:
-its shallow , narrow & sharply defined linear depression.
-its denoting to the line of fusion of the primary lobes.
-its present on the labial aspect of anterior teeth &
on the occlusal aspect of posterior teeth , may extend
buccaly or lingually.
2-supplemental grooves:
- they are irregular auxiliary grooves
- they are branched from developmental grooves.
- they don’t denoting to line of fusion of lobes
-they present on occlusal surface of posterior teeth
( 8 followed by 7 have large number of this grooves).
.
3-fissure:
-its a linear depression present in
the bottom of developmental groove.
-its result from incomplete fusion of the primary lobes.
-its defect in enamel so dental caries
often begins in a deep fissure.
D
s
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(2) circumscribed depressions:
1.fossa:
- its small concavity depression present on the occlusal surface of posterior teeth
& on the lingual aspect of anterior teeth.
- its named according to its location or shape.
1-lingual fossa (LF):
- Its present on the lingual aspect of anterior teeth.
.
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2 mesial & distal triangular fossa :
-they are present on occlusal surface of
posterior teeth distal , mesial to marginal ridges.
.
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3 central (circular) fossa :
- its present on the occlusal surface of molars
& lower five 3-cusp type.
- its formed by the convergence of
the triangular ridges as they approach
the center of occlusal aspect.
‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬‫ـــ‬‫ــــــــــــ‬
N.B: in canine; LF divide by ling. ridge into two lingual fossa
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2
2.pit:
- this is a pinpointed depression
present at the junction or at the ends
of developmental grooves.
- its may be true pit or fault pit.
1-true pit:
-it’s a pinpointed depression
-present at the bottom of central fossa ( central pit )
or at the bottom of the mesial , distal
triangular fossa ( mesial , distal pits ).
2-fault pit:
- it’s a pinpointed depression
- present at the end of the
deve. grooves of the molars
- its result from incomplete formation of enamel.
‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬‫ـــ‬‫ــــــــــــ‬
(3) sulcus:
- its tent or valley shape or U-shape.
- its inclines from the cusp tips & meet in developmental grooves.
- its present on the occlusal surface of posterior teeth
Fault
pit
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2
10-functions of the teeth:
1-mastication: it’s the most important function of the teeth. The teeth are designed
in specific form related to the function.
- incisors: have chisel like suitable for incising , cutting of food.
- canines: have wedge shape suitable for cutting , tearing of food.
- premolas: have two cusps suitable for tearing , grinding of food.
- molars: have multiple cusps suitable for grinding of food.
.
2-appearance (esthetic):
- well arranged clean teeth with proper alignment give nice appearance to the face.
- teeth give support to facial expression.
3-speech:
- the teeth are importance for clear pronounciation of certain words
& production of sound.
- teeth , lips & tongue are essential for speech
.
4 growth of jaws:
- the teeth play a role in the growth of the jaw by
formation of alveolar process due to their eruption.
- the teeth maintain the jaw bones.
‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬‫ـــ‬‫ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬
(2) the periodontium
o Its investing , supporting ,
attachment & covering system.
o Its consist of: four tissues
1two hard tissues: cementum
& alveolar bone.
2 two soft tissues : peri-odontal ligament
( P.D.L ) & gengiva
‫ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬
gengiva
P.D.L
cementum
Alveolar
bone
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- Human is di-phyodont since he has two sets of teeth; the
preceding set is primary dentition during childhood while the
succeeding set is the secondary dentition during the adult
hood.
-each dentition predominates for certain time however the replacement of primary
dentition by secondary dentition doesn’t occurs for all primary teeth at the same time
so there are transitional dentition when some of both primary , secondary dentition
are present in the oral cavity at the same time which is called mixed dentition.
1-primary dentition:
( temporary or deciduous or predecessor or milky or baby dentition )
- They are 20 teeth; 10 maxillary & 10 mandibular ( 5 teeth in each quadrant ).
- they are present as follow: 2 incisors & 1 canine & 2 molars.
- this dentition begins at 6 monthes & completed at 2 years & end at 6 years.
its begins by eruption of deciduous lower central incisor at 6 monthes.
its completed at 2 years by eruption of maxillary second deciduous molar.
its end at 6 years by beginning of mixed dentition due to eruption of
permanent 1st
molar which is the permanent tooth erupt in the oral cavity.
2-Human dentition
Centralincisor
Lateral incisor
canine
Firstmolar
Second molar
Deciduous dentition
Second molar
First molar
canine
Lateral incisor
Centralincisor
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2-mixed dentition: (ugly duckling stage)
-Its a transitional dentition when some of both deciduous , permanent dentition
are present in the oral cavity at the same time.
-its begins at 6 years with eruption of permanent 1st
molar & end at 12 years with
shedding of the last deciduous teeth (usually the upper canine )
3-secondary dentition: ( permanent or succedanuous or adult dentition )
- They are 32 teeth; 16 maxillary & 16 mandibular ( 8 teeth in each quadrant ).
- they are present as follow; 2 incisors & 1 canine & 2 premolars & 3 molars.
- its begins at 12 years by shedding of the last deciduous teeth in the oral cavity
& persist for the whole life span of the teeth.
N.B: clinically ; this period is called ugly duckling stage due to
1.diffrence in size , color of the teeth (the deciduous teeth is smaller , whiter than the permanrnt teeth ).
2.presence of edentulous area. 3.inflamation of the gengiva
N.B: not all the permanent teeth replace the deciduous ones , since the permanent molars are
group of teeth which are not preceded with deciduous teeth .
there for the permanent dentition can be classified into
1 succedenuous teeth: include a group of permanent teeth (incisors
& canine & premolars) that replace the deciduous teeth ( incisors
& canine & molars)
2 non-succedanuous teeth: include a group of permanent
teeth (permanent molars) that don’t replace any deciduous
teeth.
They have no deciduous predecessors.
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2
N.B: no premolars in deciduous dentition.
N.B: deciduous molars are replaced by premolars .
N.B: permanent molars have no predecessors .
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2
 dental formula :
 it indicates the dentitions of only one side ( upper , lower ) of the mouth.
‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬‫ـــ‬‫ـــــــــــــــــــــــــــــــــــــــــــــ‬
1-shedding (exfoliation) : its process of physiologic loss of deciduous teeth
to be replaced by their successors .
2-eruption: its process of physiologic axial movement of the tooth toward
the occlusal plane (process of appearance of the tooth into the oral cavity).
In permanent dentition In deciduous dentition
2 1 2 3
I C PM M =16
2 1 2 3
2 1 2
I C M =10
2 1 2
It reads as follow:
-incisors; 2 maxillary & 2 mandibular.
-canines; 1 max. & 1 mand.
-premolars; 2max. & 2 mand.
-molars; 3 max. & 3 mand.
Equal 16 teeth in one side
It reads as follow:
-incisors; 2 maxillary & 2
mandibular.
-canines; 1 max. & 1 mand.
-molars; 2max. & 2 mand.
Equal 10 teeth in one side
3-terms
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2
3 - socket : its bony space in the alveolar
containing the root of
the erupted tooth .
3- crypt : its bony space in the alveolar containing the
developing un-erupted teeth .
4- self cleansable surface : Those surfaces of the teeth that are smooth , convex ,
lubricated by saliva & cleaned by the normal functional
action of the tongue, lips, cheeks .
5- calcification : The organic framework of a tooth becomes hard by apposition
of calcium and phosphate salts brought in by small blood vessels.
‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬‫ـــ‬‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬
 contact area : ???
 maximum of convexity = high of contour = crest of curvature : ???!!!!!
‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬‫ـــ‬‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬
38Page Chapter1

introduction to dental anatomy

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