The periodontium is a very important structure as it provides the teeth with the support needed for them to function. The structures of the different components of the periodontium, which are: the gingiva, periodontal ligament, cementum, and the alveolar bone, are related to each other and any damage to any component may affect the other components as well.
The gingiva, normally covers the alveolar bone with the underlying root and extends just above the cementoenamel junction.
It consists of:
- Marginal gingiva.
- Attached gingiva.
- Interdental gingiva.
Marginal Gingiva is also called unattached gingiva, is the edge or border of the gingiva that surrounds the teeth in a collar-like fashion. A shallow linear…show more content… The interdental gingiva can be pyramidal in shape (tip of one papilla located immediately apical to contact point) or col shaped (valley-like depression forms connection between facial and lingual papillae and conforms to the shape of the space). Recession of gingiva affects the shape of the interdental gingiva and cause more exposure of tooth surface. If tooth is missing, the gingiva will firmly bind to the interdental bone and forms smooth rounded surface with no papillae.
Microscopic features of gingiva:
Under microscopic examination, the findings reveal that the gingiva is composed of stratified squamous epithelium and underlying central core of connective tissue which is less cellular and composed of mainly collagen fibers and ground substance.
Many types of cells exist in the gingival epithelium, such as the keratinocyte or the principle cell and the nonkeratinocyte or the clear cell. Proliferation and differentiation of keratinocytes provide the main function of the gingival epithelium which is protection of deep structures while allowing selective interchange with oral environment.
Other cells includes:
- melanocytes (dendritic cells in basal and spinous layers, synthesize melanin),
- Langerhans cells (dendritic cells in suprabasal levels, role in immune reaction as antigen-presenting cells for…show more content… This cementum is formed before the tooth reaches the occlusal plane, and its thickness ranges from 30-230um. Sharpey's fibers comprise most of the structure of acellular cementum, which has a principal role in supporting the tooth. Most fibers are inserted at approximately right angles into the root surface and penetrate deep into the cementum, but others enter from several different directions. Their size, number, and distribution increase with functions' Sharpey's fibers are completely calcified, with the mineral crystals oriented parallel to the fibrils as in dentin and bone, except in a 10- to 50-gm-wide zone near the cementodentinal junction, where they are only partially calcified. The peripheral portions of Sharpey's fibers in actively mineralizing cementum tend to be more calcified than the interior regions, according to evidence obtained by scanning electron microscopy. Acellular cementum also contains intrinsic collagen fibrils that are calcified and irregularly arranged or parallel to the