The periodontium includes the gingiva, periodontal ligament, root cementum, and alveolar bone. The gingiva is divided into the marginal gingiva, interdental gingiva, and attached gingiva. The gingiva provides protection and forms a connection with the tooth. Histologically, the gingiva contains keratinized oral epithelium, non-keratinized sulcular and junctional epithelium. The periodontal ligament contains collagen fiber bundles that connect the cementum and alveolar bone. Cementum is deposited on the root surface and provides attachment for collagen fibers. The periodontium receives blood supply from the periodontal ligament, alveolar

1. Periodontium: anatomy, histology,
blood supply and innervation
Speaker: Shao-Wei Chao 07/03/2023

2. 1 Anatomy
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3. Anatomy
01
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The tissues that surround
and support the teeth are
known as the periodontium.
 It includes:
1- The gingiva.
2- The periodontal ligament.
3- The root cementum.
4- The alveolar bone.
The periodontium

4. Anatomy
01
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The gingiva is that part of the
oral mucosa which surrounds the
tooth and covers the alveolar
ridge.
It forms a connection with the
tooth and protects the underlying
tissues of the periodontium
(bone & periodontal ligament)
from the oral environment.
The Gingiva
AM, alveolar mucosa
G, gingiva
MGJ, mucogingival junction

5. Anatomy
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 Divided into 3 classes:
The marginal ( free) gingiva
The interdental gingiva
The attached gingiva
The Gingiva

6. Anatomy
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 The marginal gingiva forms a cuff 1-2 mm
wide around the neck of the tooth and it is
the external wall of the gingival crevice.
 The marginal gingiva can be separated
from the tooth by a blunt probe.
 The surface of marginal gingiva is
smooth in contrast to the attached gingiva
which is stippled.
 The marginal gingiva is demarcated from
the attached gingiva by a shallow, v-
shaped or an indentation called the free
gingival groove .
1.The marginal ( free, unattached) gingiva

7. Anatomy
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It is defined as the space or
shallow crevice between the tooth
and the free gingiva.
It is V-shaped and barely permits
the entrance of a periodontal probe.
Under normal or ideal conditions it
is about 2 to 3 mm.
The gingival sulcus is probing
depth of a clinically-normal
gingival. It provides good
resistance to mechanical forces.
Gingival sulcus

8. Anatomy
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The interdental gingiva occupies the space in the interdental
embrasure apical to the contact point.
There are three parts of interdental gingiva:
Facial papilla Lingual papilla Col region
2.The interdental gingiva

9. Anatomy
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It extends from the free gingival groove to the
mucogingival junction where it meets the
alveolar mucosa.
The attached gingiva is tightly bound to the
underlying alveolar bone.
Function of attached gingiva:
It provides gingival tissue that can withstand the
mechanical forces of mastication, brushing and
tension applied on mucosa.
Prevent free gingiva from being pulled away
from the tooth when tension is applied to the
alveolar mucosa.
3.The attached gingiva

10. Anatomy
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The surface of the attached gingiva is stippled like orange peel.
The width of the attached gingiva can vary from zero to 9 mm. Attached gingiva is
greatest in incisor region ( 3.5-4.5 in maxilla, 3.3-3.9 in mandible) . Least in canine and
premolar area ( 1.9 mm in maxilla, 1.8 in mandible) .
3.The attached gingiva

11. 2 Histology
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Gingival Epithelium
Three zones of gingival epithelium:
1.Oral (outer) epithelium which is
keratinized (from the mucogingival
junction to the gingival margin).
2.Sulcular epithelium which are
non- keratinized (lines the gingival
crevice).
3.Junctional epithelium which are
non- keratinized (lies at the base of the
gingival crevice).
Histology
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1.Oral (outer) epithelium
Keratinized or parakeratinized consist of four layers:
1.Basal or formative cells layers of columnar cells (The
deepest cells:CT); it is characterized by active mitosis
(stratum basal or stratum grrminativum:SB).
2.Prickle or spinous cell layer of polygonal cells (stratum
spinosum:SS).
3.Granular cell layer in which the cells are flatter and contain
many particles of keratohyaline (stratum granulosum:SG).
4.Cornified or keratinous cell layer in which cells have become
flat, shrunken and keratinized (stratum corneum:SC).
Histology
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2.Sulcular epithelium
It lines the gingival sulcus
facing the tooth similar to
oral epithelium except the
2nd layer (it lacks granular
cell layer)
It acts as semipermeable
membrane allows bacteria to
pass into gingiva.
Histology
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GS, gingival sulcus
ICS, intercellular spaces
PKC, parakeratinized epithelium

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3.Junctional epithelium
Lies at the base of the crevice, it mediate the
connection of the gingiva with the tooth.
In health the junctional epithelium lies against
enamel and extends to the cemento-enamel
junction without wavy course at the junction
between the epithelium and connective tissue.
Histology
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Fibers
The fiber bundles are
classified into:
1)Alveolar crest fibers
2)Oblique fibers
3)Transseptal fibers
4)Horizontal fibers
5)Interradicular fibers
6)Apical fibers
Histology
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Principal periodontal ligament fiber groups:
(1) alveolar crest fibers; (2)oblique fibers;
(3) transseptal fibers; (4) horizontal fibers; (5)
interradicular fibers; (6) apical fibers.

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Cementum
There are two sources of collagen fibers in cementum:
1.The extrinsic fibers (Sharpey’s fibers) which are the
embedded portion of the principal fibers of the
periodontal ligament, arranged at right angle to the root
surface and are synthesized by fibroblasts of the
periodontal ligament.
2.The intrinsic fibers which belong to the matrix of
cementum forming irregular mesh work and they are
synthesized by cementoblasts.
Histology
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Alveolar Bone
The alveolar process is that part of the jaw bone
which supports the teeth. It is partly tooth
dependent and after tooth extraction some bone
resorption follows.
Alveolar bone:
1- Alveolar bone proper
( lamina dura in radiographs)
2-Trabecular bone
3-Compact bone
Histology
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19. 3Blood supply and Innervation
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Blood supply
 The gingiva has a rich blood
supply derived from three
sources:
1.periodontal ligament vessels
2.alveolar vessels
3.supraperiosteal vessels
These links in the gingiva to form
capillary loops in the connective tissue
papilla between epithelial peds.
Blood supply and Innervation
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Gingival blood supply
A, vascular plexus adjacent to junctional epithelium
B, vascular plexus adjacent to oral epithelium
1, blood supply from periodontal ligament
2, blood supply from alveolar process
3, supraperiosteal blood supply

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Innervation
 The nerve supply is derived from
branches of:
The trigeminal nerve
 A number of nerve endings have
been identified in the gingival
connective tissue as tactile
corpuscles and temperature and
pain receptors.
Blood supply and Innervation
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22. Thanks for your participation
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