The implant site 59

lomas, cysts, or odontogenic tumors. In older per-sons mainly, calcified bodies called cementicles may be present in the periodontal ligament, separate from or fused with the cementum. They may originate from degenerated epithelial cells.

Gingiva

Around the necks of the teeth and extending over the alveolar process is a portion of the oral mucous membrane, the gingiva. This tissue, when healthy, is pink, firm, and resilient. That part over-lying the alveolar process is normally heavily stippled, looking when dried like an orange peel. If the stippling is lost, gingival disease should be suspected.

The gingiva is divided into three zones: marginal, attached, and intradental. The marginal gingiva is that part which lies above the alveolar crest and forms a collar around the tooth (Fig. 3-10). Its inner surface extends down to the gingival sulcus and its labial limit is marked by a V-shaped fold, the free gingival groove. This groove, which is generally level with the gingival sulcus, is sometimes difficult to see clinically, but it is usually distinct

in histologic cross sections (Fig. 3-11). The groove is probably caused by a continual folding back of the free marginal gingiva during mastication.

Below the marginal gingiva extends the attached gingiva. This is firmly bound to the underlying cementum and alveolar bone by fibers. This is the area in which high connective tissue papillae elevate the surface epithelium, producing the stippled effect.

The attached gingiva continues labially to the alveolar mucosa and lingually to the mucous membrane lining the sublingual sulcus in the floor of the mouth. Both labial and lingual junctions are easy to see because the tissue changes markedly in appearance. Whereas the attached gingiva is firm, tightly bound, stippled, and pink, the alveolar and sublingual mucosae are loose, unstippled, and red with numerous distinct blood vessels.

The interdental gingiva forms pyramids of tissue, called papillae, between the teeth on the buccal and lingual surfaces of the jaw (Fig. 3-12). The mesial and distal surfaces of each pyramid are slightly concave, while the outer surface is tapered

Hard palate

Palatine

mucosa

Gingiva

Fig. 3-10. Upper premolar showing various zones of gingiva. The marginal gingiva lies coronal to the bone and is continuous with the attached gingiva of the alveolar palatine mucosa. (From Sicher, H., editor: Orban's oral histology and embryology, ed. 6, St. Louis, 1966, The C. V. Mosby Co.)