Gingiva
The gingiva is the part of the oral mucosa that covers the alveolar processes of the jaws and surrounds the necks of the teeth. It is divided into free gingiva, attached gingiva, and interdental gingiva. The histological structure of the gingiva reveals a keratinized stratified squamous epithelium, which provides protection against mechanical and microbial insults. The underlying connective tissue, known as the lamina propria, contains collagen fibers, fibroblasts, blood vessels, and inflammatory cells.Periodontal Ligament (PDL)
The periodontal ligament is a specialized connective tissue that anchors the tooth to the alveolar bone. It is composed of dense fibrous collagen fibers organized into principal fiber groups such as the alveolar crest, horizontal, oblique, apical, and interradicular fibers. The PDL also contains cells like fibroblasts, cementoblasts, and osteoblasts, as well as nerves and blood vessels. It plays a crucial role in
tooth support, shock absorption, and sensory function.
Cementum
Cementum is a calcified tissue covering the roots of the teeth. It is similar in composition to bone but is avascular. There are two types: acellular cementum, which covers the cervical portion of the root, and cellular cementum, which is found on the apical part of the root and contains cementocytes within lacunae. Cementum serves as an attachment site for the periodontal ligament fibers and helps maintain the integrity of the root surface.Alveolar Bone
The alveolar bone forms the sockets in which the teeth are anchored. Histologically, it is composed of an outer layer of cortical bone and an inner layer of trabecular bone. The alveolar bone proper, also known as the cribriform plate, contains numerous small openings for blood vessels and nerves. It undergoes continuous remodeling in response to occlusal forces and periodontal disease.Clinical Significance
The health of the periodontium is vital for maintaining overall oral health. Conditions such as
gingivitis and
periodontitis can lead to inflammation, destruction of periodontal tissues, and ultimately tooth loss if left untreated. Histological examination of periodontal tissues can aid in the diagnosis and management of these diseases.
