Clinical Anatomy of the Healthy Gingival Unit

It is important to understand normal anatomy, histology, and clinical characteristics of the gingival unit in order to accurately assess a patient’s periodontal health status. Once a basic understanding has been established, the hygienist then has the tools needed to understand the pathologic changes that occur during the process of disease.

The gingival tissue in the oral cavity is the most important tissue of the oro-facial region for dental professionals to know and understand.² The gingiva forms a protective covering over the other components of the periodontium and is well adapted to protect against mechanical insults.³ The color of the gingiva is normally salmon pink (except for normal pigmentation in patients with various ethnic backgrounds).³ The pink color of gingiva indicates a lack of inflammation; inflammation of the gingiva is an indicator of gingival disease. Healthy gingival epithelium is firmly attached to the underlying cementum and connective tissue covering the alveolar process.³. The space between the free gingiva and the tooth is the gingival sulcus and is measured using a periodontal probe; a healthy gingival sulcus is 3 mm or less in depth and does not bleed when probed or brushed.¹. Free gingiva is the portion of the gingiva that is unattached and is continuous with the attached gingiva. In health, the marginal gingiva follows the scalloped pattern established by the contour of the cementoenamel junction (CEJ) of the teeth.². The part of the gingival tissue that fills in the triangular-shaped spaces between the teeth is the interdental papilla. Interdental papilla is shaped differently depending on the size of the tooth. Posterior teeth are wider buccolingually than anterior teeth, making the interdental papilla of an anterior tooth significantly smaller. Apical to the contact area, interdental papilla assumes a concave shape between the facial and lingual gingival surfaces, forming the gingival col.².

Figure 3. Gingiva.

Figure 3. Gingiva.

Attached gingiva is continuous with the free gingiva and is not movable, as it is bound to the bone and cementum by connective tissue fibers.³

The alveolar mucosa is movable and is separated from the attached gingiva by the mucogingival junction. This tissue is darker in color, thin, soft, and loosely attached to underlying bone.¹.