Evaluation of Inductive effect of palatal connective tissue on alveolar mucosa after subepithelial connective tissue graft: A clinical & histological study

The present clinical & histologic trial was designed to investigate the inductive effect of palatal connective tissue on the alveolar mucosa. 11 subjects 19-49 years of age showing good performance in oral hygiene were selected from Shiraz dental school patients. The test tooth (incisor, canine or premolar) had keratinized gingiva equal of less than 2 mm. This tooth together with the adjacent mesial and distal teeth should be free of gingivitis or periodontitis. The base line clinical measurements were done on the test tooth and mesial and distal adjacent teeth. Surgical phase included a mucosal flap at recipient site (with minimal thickness) at the mucogingival line of the test tooth extending somewhat to buccal of adjacent mesial & distal teeth. The remaining tissue on the bone of the area was removed and the bone was exposed. At the donor site (palate), a mucosal flap was reflected and a piece of connective tissue with thickness of 1-2 mm was removed and sutured at the recipient site & then it was covered by overlying flap. The sutures were removed after 7 days. Maintenance phase was performed by regular follow up visits up to 6 months. Six months postoperatively the base line measurements were repeated. Biopsy specimens were obtained from the grafted area and the adjacent intact alveolar mucosa. The specimens were fixed and sent for histologic examination. Data analysis showed that the keratinized and attached gingiva of test teeth and the adjacent mesial & distal teeth increased significantly clinically the added keratinized gingiva was tightly bound to underlying tissues. The probing depth & gingival recession of test teeth did not increased significantly. The light microscopic histoligic examination showed keratinization in 80% of cases. In 30% of cases dense well organized collagen bundles was seen in lamina propria. This study proved that palatal connective tissue graft can induce nonkeratinized alveolar mucosa into masticatory mucosa.