Notes on the Mechanism of Attachment of the Dentogingival Junction

Notes on the Mechanism of Attachment of the Dentogingival Junction

Electron microscopic findings revealed that the strong union between the soft gingival tissues, namely junctional epithelium and the tooth surface, namely enamel and/or cementum, are dependent on the presence of a basal lamina and hemidesmosomes.

Junctional epithelium is associated with two basal laminae;

i. One is present between the junctional epithelium and the tooth surface which is referred to as internal basal lamina.

ii. The other is present between the junctional epithelium and the underlying connective tissue of the lamina propria, and it is called as external basal lamina.

iii. Both basal laminae consist of a lamina lucida (clear layer) and lamina densa (dense layer).

iv. Though both basal laminae are morphologically similar, their biochemical structure is different.

v. The basal lamina between the junctional epithelium and the tooth surface appears to lack collagen types IV and VII.

vi. These collagen fibers are present at the basal laminae at the epithelial/connective tissue interfaces.

Age and Inflammation Changes of the Junctional Epithelium

The level of the junctional epithelium relative to the tooth surface shifts apically with increasing age, and it is believed that inflammation is an important factor that contributes to this apical migration.

This apical shift is gradual and if it is accelerated, this pathological condition is referred to as gingival recession.

The underlying connective tissue is believed to play a significant role in determining the formation of the junctional epithelium.

When connective tissue is destroyed during the periodontal disease, junctional epithelium migrates apically until it reaches intact connective tissue that provides the signal to stop its migration, forming long junctional epithelium.