This document discusses the anatomy, measurement, and clinical significance of the attached gingiva. It notes that the attached gingiva extends from the base of the gingival sulcus to the mucogingival junction. The normal width is 3-4.5mm in the maxillary anterior region but narrower in other areas. Inadequate width can facilitate subgingival plaque formation. Methods to measure width and increase width through surgery are described. The importance of keratinized, attached tissue for resisting mechanical irritation and stabilizing the gingival margin is emphasized.