Gingiva Or Gums- Microscopic & Clinical Features, Parts | ScienceMonk

Gingiva is the scientific term for our Gums. Yes, the pinkish transparent tissues in our oral cavity hold onto the tooth.

Definition- The Gingiva is the part of the oral mucosa that covers the alveolar processes of the jaws and surrounds the necks of the teeth.

Colour- The colour of the Gingiva is usually coral Pink in colour. The colour varies among different individuals.

Size- The size of the Gingiva corresponds to the total of the bulk cellular and intercellular elements.

Contour- It depends upon the shape of teeth and their alignment in the arch.

Consistency– The Gingiva is firm and resilient and tightly bound to the underlying bone.

Surface Texture- The texture is similar to that of an orange peel appearance in a healthy individual.

 

Clinical features of Gingiva-

In an adult, the normal Gingiva covers the alveolar bone and tooth root to a level just coronal to the cementoenamel junction. The Gingiva is divided anatomically into marginal, attached, and Interdental areas. Although each type of Gingiva exhibits considerable variation in differentiation, histology, and thickness according to its functional demands. Each type is specifically structured to function appropriately against Mechanical and Microbial demands.

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Parts of the Gingiva

The Marginal Gingiva

  • The marginal Gingiva or unattached Gingiva is the terminal edge or border of the Gingiva that surrounds the teeth in a collar-like fashion.
  • The marginal Gingiva is usually about 1-mm wide, and it forms a soft tissue wall of the gingival sulcus.
  • It may be separated from the tooth surface with a periodontal probe.
  • The most apical part of the marginal gingival scallop is called the Gingival Zenith.

Gingival Sulcus

  • The gingival sulcus is the shallow crevice or space around the tooth surrounded 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, and it barely permits the entry of a periodontal probe.
  • The clinical evaluation used to determine the depth of the sulcus involves the introduction of a metallic instrument (i.e., periodontal probe) and the estimation of distance it penetrates (i.e., the probing depth).
  • The penetration of the probe depends on several factors such as probe diameter, probing force and the level of inflammation
  • The probing depth in a clinically normal gingival sulcus in humans is 2-3 mm

Gingiva

Attached Gingiva

  • The attached Gingiva is continuous with the marginal Gingiva.
  • It is firm, resilient, and tightly bound to the underlying periosteum of the alveolar bone.
  • The facial aspect of the attached Gingiva extends to relatively loose and movable alveolar mucosa.
  • It is demarcated by the Mucogingival Junction.
  • Because the mucogingival junction remains stationary throughout adult life, changes in the with of the attached Gingiva are caused by modifications in the positions of its coronal portion.
  • The width of attached gingiva increases by the age of 4 years and in the supra erupted teeth.

Interdental Gingiva

  • The interdental Gingiva occupies the gingival embrasure, which is the interproximal space beneath the area of the tooth contact.
  • The interdental Gingiva can be pyramidal, or it can have a “COL” shape.
  • The shape of the Gingiva in a given interdental space depends on the presence or absence of a contact point between the adjacent teeth, the distance between the contact point and the osseous crest and the presence or absence of some degree of recession depicts the variations in normal interdental Gingiva.
  • The facial and lingual surfaces are tapered towards the interproximal contact area, whereas the mesial and distal surfaces are slightly concave.

Microscopic Features of Gingiva

  • The microscopic features reveal that the Gingiva is composed of the overlying stratifies squamous epithelium and the underlying central core of connective tissue.
  • The epithelium is predominantly cellular in nature, the connective tissue is less cellular and composed primarily of collagen fibres and ground substance.
  • These two tissues are considered separately.

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The Gingival Epithelium

  • The gingival epithelium consists of a continuous lining of stratified squamous epithelium.
  • There are three different areas that can be defined from a morphologic and functional point of view: the oral or outer epithelium, the sulcular epithelium, and the junctional epithelium.
  • The Principal Cell Type- of the gingival epithelium as well as of other stratifies squamous epithelium is the Keratinocyte.
  • The other cells found in the epithelium are the Clear Cells or Non-Keratinocytes, which include the Langerhans Cells, The Merkel Cells, and the Melanocytes.
  • The keratinocyte receives its name because it can synthesize keratin. It constitutes about more than 90% of the cell population.
  • The primary function of the gingival epithelium is to protect the deep structures while allowing for a selective interchange with the oral environment.
  • This is achieved via the proliferation and differentiation of the keratinocytes.
  • The proliferation takes place via the mitosis in the basal layer and less frequently in the suprabasal layers.

Process of Keratinization

  • Keratinization

A complete keratinization process leads to the production of an ortho-keratinized superficial horny layer similar to that of the skin, with no nuclei in the stratum corneum and a well-defined stratum granulosim. Only some areas of the outer gingival epithelium are orthokeratinized.

  • Parakeratinization

It is considered to be an intermediate stage of keratinization and is the most prevalent surface area of the gingival epithelium. These areas can progress to maturity or differentiate under different physiologic or pathologic conditions.

In para keratinization epithelia the stratum corneum retains pyknotic nuclei, and the keratohyalin granules are parsed rather than giving rise to a stratum granulosum.

  • Non-keratinization

the non-keratinized epithelium (although the cytokeratins are the major component as in all epithelia) has neither granulosum nor corneum strata, whereas superficial cells have viable nuclei.

  • Immunohistochemistry

gel electrophoresis and immunoblot techniques have made the identification of the characteristic patterns of cytokeratins possible in each epithelial type.
The keratin proteins are composed of different polypeptide subunits characterized by their isoelectric points and molecular weight.

Functions and features of Gingival Epithelium

Gingiva

  • Functions mechanical, chemical, water, microbial barrier, and signalling functions.
  • Architectural Integritycell- cell attachments, basal lamina, keratin cytoskeleton.
  • Major cell type –keratinocyte
  • Other cell types– Langerhans cells, Melanocytes, Merkel cells.
  • Constant renewal– replacement of damaged cells
  • Cell-cell attachments- desmosomes, adherens junctions, tight junctions, gap junctions
  • Cell – Basal lamina- synthesis of basal lamina components, hemidesmosomes.

The gingival fibres are namely

  • Gingivodental fibres
  • Circular fibres
  • Transeptal fibres.

 

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