Long-term alveolar ossification of connective tissue graft placed around natural teeth: a report of five cases

Connective tissue graft (CTG) surgery has been performed since the 1980s with the principal aim of root coverage. Various types of CTG surgery have been reported, not only for root coverage but also as a preprosthetic treatment for the prevention of gingival recession and to alleviate gingival discoloration. Although there have been numerous reports on the prognosis of such treatment, few observational case reports of 10 years or more have been published. The present article reports on five patients who were monitored from between 13 to 23 years after CTG surgery through the use of intraoral findings, CBCT, and histologic evaluation. The hypothesis of the present authors is that growth factors are released gradually from connective tissue placed either above or below the periosteum. Furthermore, stimulated by the optimal occlusion of the natural teeth, osteoblasts present on the periosteum and/or alveolar bone surrounding the teeth are stimulated. Similarly, the connective tissue itself ensures that the soft tissue has a certain biologic width. At the same time, it acts as a scaffold, resulting in the tissue being replaced by bone.