003.biology of periodontal tissues

1. Dr Jaffar Raza Syed Page 1
Biology of Periodontal Tissues
Periodontium is the functional unit of tissues supporting the tooth
including
 gingiva,
 Periodontal ligament
 Cementum
 Alveolar process.
The tooth and periodontium are together called as the
dentoperiodontal unit

2. Dr Jaffar Raza Syed
The Gingiva
Macroscopic Features
The gingiva is that part of the oral mucosa (masticatory mucosa)
that covers the alveolar process of the jaws and surrounds the
necks of the teeth. Anatomically, the gingival is
 marginal
 Attached
 interdental gingival
The gingiva is that part of the oral mucosa (masticatory mucosa)
that covers the alveolar process of the jaws and surrounds the
necks of the teeth. Anatomically, the gingival is divided into
gingival
Page 2
The gingiva is that part of the oral mucosa (masticatory mucosa)
that covers the alveolar process of the jaws and surrounds the
divided into

3. Dr Jaffar Raza Syed
Gingival Sulcus
It is defined as the space or shallow crevice between the tooth
and the free gingiva, which extends apical to the junctional
epithelium. It is V-shaped
periodontal probe. Under normal or
mm (seen only in germ free animals). The so
of a clinically-normal gingival sulcus in humans is
It is defined as the space or shallow crevice between the tooth
and the free gingiva, which extends apical to the junctional
shaped and barely permits the entrance of a
periodontal probe. Under normal or ideal conditions it is about 0
mm (seen only in germ free animals). The so-called probing depth
normal gingival sulcus in humans is 2 to 3 mm
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It is defined as the space or shallow crevice between the tooth
and the free gingiva, which extends apical to the junctional
and barely permits the entrance of a
ideal conditions it is about 0
called probing depth
2 to 3 mm

4. Dr Jaffar Raza Syed
Col
valley-like depression that connects
the facial and lingual papilla. The lateral
borders and tips of the interdental papilla
are formed by continuation of marginal
gingiva and the intervening portion by
the attached gingiva.
In the presence of diastema the
interdental papilla will be absent
like depression that connects
the facial and lingual papilla. The lateral
borders and tips of the interdental papilla
are formed by continuation of marginal
gingiva and the intervening portion by
In the presence of diastema the
interdental papilla will be absent
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5. Dr Jaffar Raza Syed Page 5
Oral sulcular epithelium:
The soft tissue wall of the gingival sulcus is lined coronally with
sulcular epithelium, extending from the gingival margin to the
junctional epithelium.
Junctional epithelium:
Denotes the tissue that joins to the tooth on one side and to the
oral sulcular epithelium and connective tissue on the other. It
forms the base of the sulcus.
Thickness varies from three or four layers in early life and
increases with age up to 15 to 20 layers at the base of the gingival
sulcus, and only 1 or 2 cells at the most apical portion.

6. Dr Jaffar Raza Syed Page 6
The length of the junctional epithelium ranges from 0.25 to 1.35
mm
Three zones in junctional epithelium have been described,
 apical
 coronal
 middle
Apical is for germination, middle is for adhesion and coronal is
permeable.

7. Dr Jaffar Raza Syed Page 7
Supra-alveolar Connective Tissue
The connective tissue supporting the oral epithelium is termed as
the lamina propria and for descriptive purpose it can be divided
into two layers:
a. The superficial papillary layer—associated with the
epithelial ridges.
b. Deeper reticular layer—that lies between the papillary
layer and the underlying structures

8. Dr Jaffar Raza Syed Page 8
The lamina propria consists of cells, fibers, blood vessels
embedded in amorphous ground substances.
I. Cells: Different types of cells present are:
a. Fibroblast
b. Mast cells
c. Macrophages
d. Inflammatory cells.
II. Fibers: The connective tissue fibers are produced by
fibroblasts and can be divided into:
a. Collagen fibers
b. Reticulin fibers
c. Oxytalan fibers
d. Elastin fibers

9. Dr Jaffar Raza Syed Page 9
Gingival Fibers
The principal group fibers are:
1. Dentogingival fibers: They project from the cementum in a fan-
like conformation towards the crest and outer surface of the
marginal gingiva. They provide support to the gingiva by attaching
it to the tooth.
2. Alveolar gingival fibers: They extend from the periosteum of
the alveolar crest coronally into the lamina propria. Their function
is to attach the gingiva to the alveolar bone.
3. Dentoperiosteal fibers: They arise from the cementum near the
cementoenamel junction and insert into the periosteum of the
alveolar bone and protect the periodontal ligament.
4. Circular fibers: They surround the tooth in a cuff or ring like
fashion and course through the connective tissue of the marginal
and attached gingiva.

10. Dr Jaffar Raza Syed Page 10
5. Trans-septal fibers: They are located interproximally, they
extend from cementum of one tooth to the cementum of the
neighboring tooth. Their function is to protect the interproximal
bone and maintain tooth-totooth contact.

11. Dr Jaffar Raza Syed
Fibers of the secondary group
1. Periosteogingival fibers:
They extend from the periosteum of
the alveolar bone to the attached gingiva.
They help to attach the gingiva to the
alveolar bone.
2. Interpapillary fibers:
They are seen in the interdental
gingiva extending in a faciolingua
direction and support the gingival papilla.
3. Transgingival fibers:
These are seen in and around the
teeth with in the attached gingiva.
They maintain the alignment of teeth
in the arch.
Fibers of the secondary group
They extend from the periosteum of
the alveolar bone to the attached gingiva.
They help to attach the gingiva to the
They are seen in the interdental
gingiva extending in a faciolingual
the gingival papilla.
These are seen in and around the
teeth with in the attached gingiva.
alignment of teeth
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12. Dr Jaffar Raza Syed Page 12
4. Intercircular fibers:
They extend from the cementum on distal surface of a tooth splaying buccally
and lingually around the next tooth and are inserted on the mesial surface.
5. Intergingival fibers:
They are seen within the attached gingiva adjacent to the basement
membrane extending mesiodistally. They provide support and contour for the
attached gingiva.
6. Semicircular fibers:
They extend from the mesial surface of a tooth to the distal surface of same
tooth in a half circle.

13. Dr Jaffar Raza Syed Page 13
7. Oxytalan fibers:
They are present in all connective tissue structures of the periodontium. The
function of these fibers is yet unknown.
8. Elastin fibers:
Elastin fibers are only present in connective tissue of the gingiva and
periodontal ligament. They are also seen in the connective tissue of
alveolar mucosa in large numbers.

14. Dr Jaffar Raza Syed
Blood Supply, Lymphatics and Nerves
Three major sources of blood supply
to the gingival has been described:
1. Supraperiosteal arterioles:
Overlying the alveolar bone along the facial
and lingual surfaces, sends branches to
the surrounding tissue.
2. Vessels of the periodontal ligament:
They extend into the gingiva and anastamose
with the capillaries in the sulcus area.
3. Arterioles emerging from the
of the interdental septa.
Blood Supply, Lymphatics and Nerves
Three major sources of blood supply
to the gingival has been described:
1. Supraperiosteal arterioles:
Overlying the alveolar bone along the facial
and lingual surfaces, sends branches to
2. Vessels of the periodontal ligament:
They extend into the gingiva and anastamose
with the capillaries in the sulcus area.
3. Arterioles emerging from the crest
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15. Dr Jaffar Raza Syed Page 15
lymphatic drainage of periodontium.
(i) Mandibular incisors region drains into - Submental lymph nodes
(ii) Buccal gingiva of maxilla, - Submandibular
Buccal and lingual gingiva of mandibular premolar and molar region by
Submandibular lymph nodes
(iii) Third molar region – Jugulodigastric lymph nodes.