mucogingivaljunction

The mucogingival junction (MGJ) is the anatomical boundary between the keratinized, attached gingiva and the nonkeratinized alveolar mucosa. It marks the transition from the firm, tightly bound gingival tissue to the movable, nonkeratinized mucosa that covers the alveolar bone and the root surfaces in exposed areas. The MGJ is most easily identified on the facial aspects of the teeth, where the attached gingiva is pink and stippled, and the alveolar mucosa beyond it appears redder, looser, and more flexible. In some individuals the junction may be difficult to visualize due to limited keratinization, inflammation, or anatomical variation.

Clinical significance centers on the width of attached gingiva, which is measured as the distance from the MGJ to the gingival margin. The attached gingiva provides resistance to mechanical trauma, aids in stabilization of the gingival margin, and supports effective plaque control. A narrow or absent zone of attached gingiva—often described as a mucogingival defect—can be associated with gingival recession, root sensitivity, and challenges in maintaining periodontal health, particularly during tooth movement or restorative procedures.

Assessment and treatment considerations: assessment involves locating the MGJ and measuring the attached gingiva. When mucogingival defects affect function or aesthetics, periodontal plastic procedures may be considered to augment the width of attached gingiva. Techniques include free gingival grafts, connective tissue grafts, and various flap methods designed to increase keratinized tissue or relieve frenum or muscle pull.