The marginal gingiva is the terminal edge of gingiva surrounding the teeth in collar like fashion. In about half of individuals, it is demarcated from the adjacent, attached gingiva by a shallow linear depression, the free gingival groove. This slight depression on the outer surface of the gingiva does not correspond to the depth of the gingival sulcus but instead to the apical border of the junctional epithelium. This outer groove varies in depth according to the area of the oral cavity; the groove is very prominent on mandibular anteriors and premolars.
The marginal gingiva varies in width from 0.5 to 2.0 mm from the free gingival crest to the attached gingiva. The marginal gingiva follows the scalloped pattern established by the contour of the cementoenamel junction (CEJ) of the teeth. The marginal gingiva has amore translucent appearance than the attached gingiva, yet has a simi- lar clinical appearance, including pinkness, dullness, and firmness. In contrast, the marginal gingiva lacks the presence of stippling, and the tissue is mobile or free from the underlying tooth surface, as can be demonstrated with a periodontal probe. The marginal gingiva is stabilized by the gingival fibers that have no bony support. The gingival margin, or free gingival crest, at the most superficial part of the marginal gingiva, is also easily seen clinically, and its location should be recorded on a patient's chart.