Gingival fibers, primarily composed of collagen, are the fibers of connective tissue that are found in the tissue of the gums and that work to hold the gum tissue securely against the teeth. Whereas the periodontal ligament attaches the teeth to the alveolar bone, the gingival fibers hold the teeth to the gums themselves. Specifically, gingival fibers at no point attach to or insert into alveolar bone. In addition to holding the gums to the teeth, the gingival fibers support the marginal gingiva, which is the gum tissue that’s at the coronal edge of the gums, providing this tissue with the rigidity that’s necessary to withstand the forces of chewing. The gingival fibers also help stabilize the tissue of the marginal gingiva and affix this marginal gingival tissue to the attached gingiva and to the cementum of the teeth. The gingival fibers do not regenerate when they are damaged, and, if they do undergo damage and their connection to the teeth is loosened, the gingival sulcus can widen and increase in depth. This increases the risk of debris and bacteria entering and becoming trapped in gingival sulcus, which is the small crevice of gum tissue around each tooth. The accumulation of bacteria and debris in the gingival sulcus can lead to periodontitis and to the eventual damage of the alveolar bone and the roots of the teeth and, in a gingival sulcus that has been compromised, the depth of the sulcus may make cleaning more challenging; a sulcular depth of 3mm or fewer has been determined to be most conducive to effective cleaning with traditional mechanical devices used in home hygiene, like toothbrushes.
Gingival fibers are generally grouped into three different classifications. These classifications are the dentogingival group, the circular group, and the transseptal group. The three types of fibers in the dentogingival group extend toward the coronal edge of the gingiva, laterally to the outside surface of the gingiva, and outward past the alveolar crest and then apically along the alveolar bone. The circular fibers exist only within the gingiva and are not connected with the teeth. The transseptal fibers are embedded in the gum tissue between the teeth and immediately around the teeth. Within the classification of transseptal gingival fibers are two additional subtypes: semicircular fibers and transgingival fibers. Semicircular fibers run through the gingiva on both the facial and lingual sides around each individual tooth and attach to the interproximal surfaces of the same tooth. Transgingival fibers run between teeth that are not adjacent. These fibers are embedded in the cementum of the surfaces closest to them, passing around the tooth between the two teeth that they attach.