Gingiva: Types, Histology And Clinical Aspects
Clinical and Microscopic Features of Normal Gingiva
The color of attached gingiva and marginal gingiva is generally described as coral pink and is produced by the vascular supply, the thickness and degree of keratinization of the epithelium and presence of pigment-containing cells. The color varies among different persons and appears to be correlated with the cutaneous pigmentation. It is lighter in blond individuals with fair complexion than in dark-haired individuals. The attached gingiva is demarcated from the adjacent alveolar mucosa on the buccal aspect by the clearly defied mucogingival line. The alveolar mucosa is red, smooth, and shiny rather than pink and stippled. Comparison of the microscopic structure of the attached gingiva with that of the alveolar mucosa provides an explanation for the difference in appearance. The epithelium of the alveolar mucosa is thinner, nonkeratinized, and contains no rete pegs. The connective tissue of the alveolar mucosa is loosely arranged, and the blood vessels are more numerous.
Gingiva Size
Size of gingiva corresponds with the sum total of the bulk of cellular and intercellular elements and their vascular supply. Alteration in size is a common feature of gingival disease.
Gingiva Contour
Contour or shape of the gingiva varies considerably and depends on the shape of the teeth and their alignment in the arch, the location and size of the area of proximal contact, and the dimensions of the facial and lingual gingival embrasures. The marginal gingiva envelops the teeth in collar-like fashion and follows a scalloped outline on the facial and lingual surfaces. It forms a straight line along teeth with relatively flat surfaces. On teeth with pronounced mesiodistal convexity (e.g. maxillary canines) or teeth in labial version, the normal arcuate contour is accentuated, and the gingiva is located farther apically. On teeth in lingual version, the gingiva is horizontal and thickened.
Gingiva Shape
Shape of the inter-dental gingiva is governed by the contour of the proximal tooth surfaces and the location and shape of gingival embrasures. When the proximal surfaces of the crowns are relatively flat faciolingually, the roots are close together, the inter-dental bone is thin mesiodistally, and the gingival embrasures and inter-dental gingiva are narrow mesiodistally. Conversely, with proximal surfaces that flare away from the area of contact, the mesiodistal diameter of the interdental gingiva is broad. The height of the inter-dental gingiva varies with the location of the proximal contact. Thus, in the anterior region of the dentition, the inter-dental papilla is pyramidal in form, whereas the papilla is more flattened in a buccolingual direction in the molar region.
Gingiva Consistancy
Gingiva is firm and resilient and with the exception of the movable-free margin, tightly bound to the underlying bone. The collagenous nature of the lamina propria and its contiguity with the mucoperiosteum of the alveolar bone determine the firmness of the attached gingiva. The gingival fibers contribute to the firmness of the gingival margin.
Gingiva Surface Texture
- Gingiva presents a textured surface similar to an orange peel and is referred to as being stippling. Stippling is best viewed by drying the gingiva. The attached gingiva is stippled; the marginal gingiva is not. The central portion of the interdental papillae is usually stippled, but the marginal borders are smooth. The pattern and extent of stippling vary among individuals and diffrent areas of the same mouth. Stippling is less prominent on lingual than facial surfaces and may be absent in some persons.
- Microscopically, stippling is produced by alternate rounded protuberances and depressions in the gingival surface. The papillary layer of the connective tissue projects into the elevations, and the elevated and depressed areas are covered by stratified squamous epithelium. The degree of keratinization and the prominence of stippling appear to be related. Scanning electron microscopy has shown considerable variation in shape, but a relatively constant depth of stippling. At low magnification, a rippled surface is seen interrupted by irregular depressions 50µm in diameter.
- The surface texture of the gingiva is also related to the presence and degree of epithelial keratinization. Keratinization is considered a protective adaptation function. It increases when the gingiva is stimulated by tooth brushing.
Gingiva Position
The position of the gingiva refers to the level at which the gingival margin is attached to the tooth. When the tooth erupts into the oral cavity, the margin and sulcus are at the tip of the crown; as eruption progresses, they are seen closer to the root. During this eruption process the junctional epithelium, oral epithelium, and reduced enamel epithelium undergo extensive alterations and remodeling while maintaining the shallow physiologic depth of the sulcus. Without this remodeling of the epithelia, an abnormal anatomic relationship between the gingiva and the tooth would result.
Role of attached Gingiva in Oral Heath
- Attached gingiva is continuous with the marginal gingiva. It is firm, resilient and tightly bound to the underlying periosteum of alveolar bone. The facial aspect of the attached gingiva extends to the relatively loose and movable alveolar mucosa and is demarcated by the mucogingival junction. The width of the attached gingiva is another important clinical parameter. It 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. It should not be confused with the width of the keratinized gingiva because the latter also includes the marginal gingiva. The width of the attached gingiva on the facial aspect differs in different areas of the mouth. It is generally greatest in the incisor region (3.5–4.5 mm in maxilla, 3.3–3.9 mm in mandible), and narrower in the posterior segments (1.9 mm in maxillary and 1.8 mm in mandibular first premolars).
- Because the mucogingival junction remains stationary throughout adult life, changes in the width of the attached gingiva are caused by modifications in the position of its coronal portion. The width of the attached gingiva increases with age and in supraerupted teeth. On the lingual aspect of the mandible, the attached gingiva terminates at the junction of the lingual alveolar mucosa, which is continuous with the mucous membrane lining the floor of the mouth. The palatal surface of the attached gingiva in the maxilla blends imperceptibly with the equally firm and resilient palatal mucosa.
Gingiva In Health And Disease
Discuss clinical features of gingiva in health and disease.
Answer.
Leave a Reply