Periodontium
Definition
[edit]The periodontium is the specialized biological system of tissues that both surround and support the teeth, maintaining them in the maxilla and mandible. The word is derived from the Greek prefix peri- ("around") and -odont ("tooth").
Physiologically, the periodontium serves to attach the tooth to the bone tissue of the jaws and to act as a shock absorber during mastication.
Components
[edit]The periodontium is composed of four main tissues. Two are mineralized (hard) and two are fibrous (soft):
1. Gingiva (Gums)
[edit]The gingiva is the epithelial and connective tissue that covers the alveolar process and surrounds the neck of the teeth. It provides a biological seal that protects the underlying structures from bacterial invasion.
- Free gingiva: The unattached portion surrounding the tooth.
- Attached gingiva: Firmly bound to the underlying alveolar bone.
2. Periodontal Ligament (PDL)
[edit]The periodontal ligament is a dense connective tissue organized into fiber bundles (primarily Type I collagen) that connect the cementum of the tooth to the alveolar bone.
- It transforms the pressure of biting into tension on the bone.
- It contains sensory receptors for proprioception (detecting tooth position and pressure).
3. Cementum
[edit]Cementum is a thin, mineralized layer of tissue covering the tooth root. Its primary function is to provide a medium for the attachment of the PDL fibers to the tooth. It is softer than dentin and enamel.
4. Alveolar Bone
[edit]The alveolar process is the part of the jawbone that contains the tooth sockets (dental alveoli). It undergoes constant remodeling in response to mechanical forces and tooth movement.
Clinical Significance
[edit]The health of the periodontium is the primary focus of the dental specialty known as Periodontology.
- Gingivitis: Inflammation confined to the gingiva.
- Periodontitis: An inflammatory disease that leads to the destruction of the PDL and alveolar bone, potentially resulting in tooth loss.
- Periodontal pocket: Pathological deepening of the gingival sulcus.
Biological Width
[edit]In restorative dentistry, the biological width (or supracrestal attached tissues) refers to the combined height of the connective tissue attachment and the junctional epithelium. Maintaining this width is crucial for the health of the periodontium when placing crowns or fillings.