a. Classification and anatomic distribution of gingival fibers:
The collagen fibers of the gingiva are subdivided into 8 principal fiber groups, as shown in Fig. 32.
Fig. 32: Diagrammatic representation of the principal fibers
of the gingiva. These are largely composed of collagenous fibers. The dentogingival
fibers (A) insert into the supracrestal root cementum and fan out into the adjacent
connective tissue. 
The dentoperiosteal fibers (B) insert into the
supracrestal root cementum and blend with the periosteal covering of the adjacent alveolar
process. The alveologingival fibers (C) insert into the alveolar crest and fan out
into the adjacent gingival connective tissue. The circumferential fibers
(D) follow a circular course around individual dental units. The semicircular
fibers (E) insert on the approximal surfaces of a tooth and follow a semicircular
course to insert on the opposite side of the same tooth. The transgingival fibers
(F) insert into the approximal surface of a tooth and fan out toward the oral or
vestibular surface. The intergingival (G) fibers course along the
oral or vestibular surfaces of the dental arch. The transseptal fibers (H)
course from one approximal tooth surface to the approximal surface of the adjacent tooth.
