Anatomy & Histology Of The Gingiva

To understand the pathologic changes that occur during a disease process, one must first understand the normal anatomy, histology and clinical appearance of the gingiva. With this prerequisite knowledge dental professionals can accurately assess a patient's periodontal health.

The gingiva functions to cover the alveolar bone and surround the teeth.1 In addition, the gingiva is the only clinically visible component of the periodontium inside the mouth.2 Healthy gingiva will appear coral pink in color (with the exception of normal pigmentation seen in dark-skinned individuals) indicating a lack of inflammation (inflammation would indicate unhealthy gingiva).
Fig 2
Healthy gingiva will also have a snug, firm attachment to the underlying supporting structures. The gingival margin follows a scalloped-like course across the dentition due to the interdental papillae, which fill the interdental spaces beneath the tooth contacts.1 (Fig. 2)
Fig 3

Two portions of the gingiva can be identified:1 (Fig. 1)

  • Free gingiva
  • Attached gingiva
Interdental papillae are the extensions of gingiva filling the spaces between neighboring teeth. Depending on the size of the tooth, the mass of the interdental papilla varies. For instance, a large molar tooth will have a correspondingly larger mass of interdental papillary tissue. Conversely, a smaller incisor will have a significantly smaller interdental papilla (Fig. 3)
The free gingiva surrounds the tooth and creates a cuff or collar of gingiva measured from the margin of the attached gingiva extending coronally about 1.5mm.2 The inner surface of the free gingiva (next to the tooth) forms the gingival wall of the sulcus.3 The healthy patient will present with a sulcus measuring approximately 1-3mm in depth. The precise millimeter measurement of sulcus depth is obtained using an instrument known as a periodontal probe (Fig. 4). A sulcus measuring >3 mm indicates an unhealthy periodontium.
Fig 4
The attached gingiva extends apically from the free gingiva to eventually merge with the alveolar mucosa. The attached gingiva is firmly bound to the underlying cementum and bone with collagen fibers of the connective tissue.1