microscopic feature of gingiva with presentation

microscopic feature of gingiva with presentation General aspects of gingival epithelium biology:-

* The main function of the gingival epithelium is to protect the deep structures while allowing a selective interchange with the oral environment.
This is achieved by proliferation and differentiation of the keratinocytes - which comprise about 90% of the total cell population.

* Keratinocytes are characterised by their ability to produce cytoplasmic keratin filaments (tonofilaments).
* Proliferation – takes place by mitosis in the basal layer and less frequently in the suprabasal layers; where a small proportion of cells remain as a proliferative compartment while a larger number begin to migrate to the surface.��* Differentiation – involves the process of keratinization which consists of progression of biochemical and morphologic events that occur in the cell as they migrate from the basal layer.
1. Progressive flattening of the cell and increasing prevalence of tonofilaments.��2. Intercellular junctions coupled to the production of kerato-hyaline granules.��3. Disappearance of nucleus.��4. Cells lose the ability to multiply by mitotic division.��5. Cells lose the cytoplasmic organelles responsible for protein synthesis and energy production.
6. Cells eventually degenerate into a cornified layer due to the process of intracellular keratinization.��7. Cells are ultimately sloughed away from the epithelial surface and into the oral cavity as the cell-cell attachment mechanisms (i.e. desmosome and gap junctions) finally disintegrate.* The keratinized stratified squamous epithelium can be divided into the following cell layers on the basis of the degree to which the keratin-producing cells are differentiated :-��A) Progenitor population� - Basal layer = stratum basale or stratum germinativum��B) Maturing population� - Prickle cell layer = stratum spinosum� - Granular cell layer = stratum granulosum� - Keratinized cell layer = stratum corneum* The keratinized stratified squamous epithelium can be divided into the following cell layers on the basis of the degree to which the keratin-producing cells are differentiated :-��A) Progenitor population� - Basal layer = stratum basale or stratum germinativum��B) Maturing population� - Prickle cell layer = stratum spinosum� - Granular cell layer = stratum granulosum� - Keratinized cell layer = stratum corneum* The keratinized stratified squamous epithelium can be divided into the following cell layers on the basis of the degree to which the keratin-producing cells are differentiated :-��A) Progenitor population� - Basal layer = stratum basale or stratum germinativum��B) Maturing population� - Prickle cell layer = stratum spinosum� - Granular cell layer = stratum granulosum� - Keratinized cell layer = stratum corneum* The keratinized stratified squamous epithelium can be divided into the following cell layers on the basis of the degree to which the keratin-pro

2. CONTENTS

3. Microscopic features
Structural and metabolic characteristics of gingival
epithelium
Formation of dentogingival junction
Defense mechanisms of gingiva
Renewal of gingival epithelium Cuticular structures on
teeth
References

4. Introduction

5. Collectively all the soft tissues of
the mouth are known as oral
mucosa.
Oral mucosa – 3 zones :-
1) Masticatory mucosa = Gingiva +
covering of hard palate
2) Specialized mucosa = Dorsum of
tongue + taste buds
3) Lining or reflecting mucosa = oral
mucous membrane lining the
remainder of oral cavity
(lip,cheek,vestibular fornix,alveolar
mucosa,floor of mouth,soft palate)

6. Definitions :-
- It is the part of oral mucosa that covers the
alveolar process of the jaws and surrounds the
necks of the teeth. (Carranza 2003)
Anatomically it consists of three types of
gingiva
•Marginal gingiva
•Attached gingiva
•Interdental gingiva
GINGIVA

52. They lack desmosomes and
tonofilaments but possess
long dendritic processes
that inoculate the
melanosomes into the
cytoplasm of adjacent
keratinocytes.
(Oral Histology-Ten Cate)

67. Palat
e-
Mo
st
Ke
rat
ini
zed
G
i
n
g
i
v
a
Ton
g
u
e
Cheek
(Least
Keratin
ized)

100. Hypoglycemia and nutritional deficiencies
decrease the mitotic rate.
(Manson,Eley 4
th
edition)