ANATOMY OF
TEETH
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1 Introduction
Types and Classification of
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Teeth
3 Parts of tooth
Topics covered Identification of tooth
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surfaces
5 Dental tissues
6 Landmarks
7 blood and nerve supply 2
Introduction
The teeth form part of the masticatory apparatus and are fixed to
the jaw.
Dental anatomy - The study of the development , morphology ,
function and identity of each teeth in the human dentitions , as well
as the way in which the teeth relate in shape , form , structure,
colour, and function to other teeth in the same dental arch and to
the teeth in the opposing arch.
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Deciduous teeth Permanent teeth
The 1st set of dentition (milk 2nd set of teeth.
teeth) These are 32 in number.
20 in number. In each half of jaw , there are
In each half of jaw , there are 2 incisors
2 incisors 1 canine (cuspid)
1 canine 2 premolars (bicuspid)
2 molars. 3 molars.
Erruptes by age of 6 and Erruptes by age of 12 years.
complete primary dentition by Molars by early 20s.
age of 3 years. ICPM = 2123
ICM =212 2123
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212
Classification of teeth
Incisor - function as cutting or
shearing instruments for food.
Canine - possess the longest roots of
all teeth and arelocated at the corners
of the dental arch.
Premolar - act like the canines in the
tearing of food and are similar to
molars in the grinding of food
Molar - are located nearest the
temporomandibular joint (TMJ),
which serves as the fulcrum during
function. 6
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Parts of tooth
Crown
Projecting above or
below the gum and
clinically visible.
Root
Embeded within
alaveolar socket of
jaw.
Neck
Between the crown
and root and
surrounded by the 8
gum.
Parts of tooth
Neck
Crown Root
Also called the
Visible portion of cementoenamel junction Tooth's larger
tooth above the neck (CEJ) or cervical line portion extending
and extending out of Allows for attachment of from neck to apex.
the gum tissue gingivae (gums) Secures to a socket
Think "crown = top" This is where the crown's (alveolar process) in
Covered in a hard enamel layer meets the mandible or maxilla
layer of enamel cementum layer of root. (jawbones).
Line often curves and is
irregular around tooth.
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ROOTS
Single
Multiple
Maxillary & mandibular Anteriors - One root
Mand 1,2 &Max 2 PM - One root
Max 1 PM- two roots = buccal &Lingual Maxillary molars - 3 roots - MB,DB &P
Mandibular Molars - 2 roots - M&D
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Identification of Tooth surfaces
• Apical: Pertaining to the apex or root of the
tooth.
• Labial: Pertaining to the lip; describes the
front surface of anterior teeth.
• Lingual: Pertaining to the tongue; describes
the back (interior) surface of all teeth.
• Distal: The surface of the tooth that is away
from the median line.
• Mesial: The surface of the tooth that is
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toward the median line.
Dental tissues
Enamel
Dentin
Odontoblast layer
Pulp chamber
Gingiva
Periodontal ligament
Cementum
Alveolar bone
Pulp canals
Apical foramen
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Structure of tooth (Dental tissues)
Enamel - It is the external structure
layer which covers the upper part of the
dentine over the crown.
The hardened outer layer of the crown
It has no vessels, nerves, cells
Made of dense minerals (96%) such as
hydroxyapatite
Keyhole-shaped prism rods run in
waves perpendicular to tooth's surface
or sometimes parallel near the tooth's
neck
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Dentin - It is the major portion of the
tooth which surrounds the pulp cavity.
It is a hard , avascular calcified tissue
containing minute dental tubules
having innervation of pulpal nerve
endings which act as sensory receptors.
It is extremely sensitive to cold , heat ,
acid and drilling.
Hard tissue that's deep to enamel or
cementum layer
Formed and maintained by cells called
odontoblasts
Most of tooth's mass
Made of 70% minerals; harder than
cementum/bone but softer than ename
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Pulp cavity - It occupies the centre of the tooth extending from root the crown. It
communicates outside by an apical foramen through which various nerves , blood vessels
and lymphatics enter the pulp cavity. the cavity is filled by pulp containing loose
connective tissue.
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Cementum - It is a outer
covering of root which covers
the dentine in the root of the
tooth.
It seperates the sensitive
dentine from periodontal and
body tissue.
It has no vascular or nerve
supply.
-The periodontal ligament
surrounds and attaches to the
cementum, anchoring it to the
alveolar process (bone) in the
maxilla or
mandible (jawbones). 16
Periodontol ligament - It attaches the root of the tooth with the bony alveolar socket.
It is a modified periosteum of alveolar bone which holds the tooth in position against
pressure on its occlusal surface and act as shock absorber against mastication.
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Landmarks
Cusp Oblique Ridge
Tubercle Fossa
Cingulum Sulcus
Ridge Developmental Groove
Marginal Ridge Supplemental Groove
Triangular Ridge Pit
Transverse ridge Lobe
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Cusp -
A cusp is an elevation or
mound on the crown portion of
tooth making up
a divisional part of the occlusal
surface.
Cingulum - A cingulum is the lingual
lobe of an anterior tooth. It makes the
bulk of the cervical third of the
lingual surface. Its convexity
mesiodistally resembles a girdle
encircling the lingual surface at the
cervical third
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Ridge - A ridge is any linear
elevation on the surface of tooth
and is named according to
location :
Buccal ridge
Lingual ridge
Incisal Ridge
Marginal Ridge
Marginal ridges - Marginal ridges are
those rounded borders of the enamel
that form the
Mesial & distal margins of
occlusalsurfaces of Premolars &
Molars
Mesial & distal margins of lingual
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surfaces of Incisors & Canines
Oblique ridge - Oblique ridge
is the ridge crossing obliquely
the occlusal surfaces of the
maxillary molars.
It is formed by union of
triangular ridges of
Distobuccal cusp
Mesiolingual cusp
Transverse ridge - When a buccal & lingual triangular ridge join, they
form a transverse ridge.
Union of two triangular ridges - transverse ridge = posterior tooth
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Triangular ridges - Triangular
ridges descend from the tips
of cusps of molars &
premolars toward the central
part of the occlusal surfaces.
Fossa - A fossa is an irregular
depression or concavity"
Types:
Lingual fossa - Lingual
surface of incisors
Central fossa - Occlusal
surface of molars
Triangular Fossa - Occlusal
surface of M & PM mesial/
distal to marginal ridges 22
Sulcus - A sulcus is a long
depression or valley in the
surface of tooth between ridges
and cusps, the inclines of which
meet at an angle.
Groove
Developmental groove - Shallow
groove /line between the primary
parts of crown and root.
Supplemental Groove - Shallow
linear groove on the surface of
tooth.
Buccal & lingual Grooves -
Developmental grooves on
buccal /lingual side. 23
Pits - Pits are small pin
point depressions located
at the junction of
developmental grooves.
Lobe - A lobe is one of the primary
sections of the formation in the
development of the crown
Cusps
Mamellons
A mamellon is any one of the 3
rounded protuberances found on
the incisal ridges of the newly
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erupted incisor teeth.
Blood supply
3 superior alveolar arteries
Inferior alveolar artery
Lymphatic drainage
The dental pulps and the gingivae drain into deep
cervical nodes.
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Nerve supply
Upper teeth - maxillary division of trigeminal nerve.
Posterior superior alveolar nerves - molars
Middle superior alveolar nerves - premolars
Anterior superior alveolar nerves - incisors and canines.
Lower teeth - inferior alveolar branch of mandibular division
of trigeminal nerve.
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ANATOMY OF
GINGIVA
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Introduction
Gums or gingiva is a fold of dense vascular fibrous tisssue , covered by
mucous membrane being lined by lightly keratinised squamous epithelium ,
which is continuous with the mucous of cheek.
The gingiva is the part of the oral mucosa that covers the alveolar processes
of the jaws and surrounds the necks of the teeth.
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Classification
1. Marginal
2. Attached
3. Interdental
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Marginal Gingiva
The marginal, or unattached, gingiva is the terminal edge or border of
the gingiva surrounding the teeth in collar like fashion.
Free gingival groove
Shallow linear depression that demarcates marginal gingiva from the adjacent attached
gingiva.
about 50% of cases.
Usually about 1mm wide, the marginal gingiva forms the soft tissue wall of the gingival
sulcus.
The most apical point of the marginal gingival scallop is called the
gingival zenith.
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Attached Gingiva
Continous with the marginal gingiva.
Firm, resilient, and tightly bound to the underlying periosteum of alveolar bone
Facial aspect of the attached gingiva extends to the relatively loose and movable
alveolar mucosa
Demarcated by the mucogingival junction
The width of the attached gingiva is the distance between the mucogingival junction
and the projection on the external surface of the bottom of the gingival sulcus or the
periodontal pocket
width of the keratinized gingiva also includes the marginal gingiva
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Interdental Gingiva
The interdental gingiva occupies the gingival embrasure, which is the interproximal
space.
beneath the area of tooth contact The interdental gingiva can be pyramidal or can
have a "col" shaped.
In the pyramidal the tip of one papilla is located immediately beneath the contact
point.
The Col presents a valley like depression that connects a facial and lingual papilla
and conforms to the shape of the interproximal contact.
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Gingival sulcus
It is the shallow crevice or space around the teeth bounded by the surface of the tooth on
one side and the epithelium lining the free margin of the gingiva on the other side.
It is v shaped and barely allow the entrance of a periodontal probe.
Under absolute normal or ideal conditons the depth of the gingival sulcus is Omm or
close to Omm
The probing depth is not necessarily exactly equal to the histologic depth of the sulcus.
The so-called probing depth of a clinically normal gingival sulcus in humans is about 2-
3m
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Microscopic features
Microscopic examination reveals that gingiva is composed of the overlying stratified
squamous epithelium and the underlying central core of connective tissue
I. Epithelium - cellular in nature.
II. Connective tissue - less cellular and composed primarily of collagen fibers a ground
subtance.
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Blood supply
Alveolar arteries and veins
Periodontal arteries and veins
Supra periosteal arteries and veins
Lymphatic drainage
Submandibular lymph nodes - gums of lower central incisors.
Sub mental lymph nodes -rest of the lower gums and upper gums.
Deep cervical lymph nodes
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Nerve supply
Upper jaw (maxilla)
Infra orbital nerve
Greater palatine nerve
Posterior superior alveolar nerves
Lower jaw (mandible)
Inferior alveolar nerve
Lingual nerve
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Thank you for
your attention
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