USE OF CULTURED MUCOSAL GRAFTS TO COVER DEFECTS CAUSED BY VESTIBULOPLASTY - AN IN-VIVO STUDY

Purpose: In oral and maxillofacial surgery palatal mucosal grafts are routinely used to cover mucosal defects caused by vestibuloplasty. How ever, the quantity of palatal mucosa is a limiting factor in more exte nsive operations. This study investigated whether autologous cultured sheets of mucosa can serve as a dressing for these wounds. Materials a nd Methods: Punch biopsies (diameter, 4 mm) were taken from the hard p alate of eight patients (five men, three women; mean age 43 years). Ep ithelial cells were enzymatically dissociated from these tissue specim ens and grown in vitro in the presence of a fibroblast feeder layer. W ithin 3 weeks, a transplantable epithelial sheet of about 20 cm(2) was obtained. The sheet was detached from the culture flask by enzyme tre atment and fixed to a carrier of Vaseline (Cheeseborough Ponds Inc, Gr eenwich, CT) gauze. Using a split-mouth technique, the sheet was place d on half of a mucosal defect created by vestibuloplasty, while the ot her half of the defect was covered by a conventional split-thickness p alatal graft. Both the cultured and conventional graft were held in pl ace by the patient's relined denture fixed with perimandibular sutures . One week postsurgery, the denture and Vaseline gauze were removed. T hree months after vestibuloplasty, biopsy specimens of each grafted si te were taken and processed for light and transmission electron micros copy (LM, TEM). Results: Three months postsurgery, the grafted mucosa of both sites bore close resemblance to palatal mucosa. Both the cultu red and split-thickness grafts were vascularized, did not evoke a homo graft reaction, and showed a smooth graft/lip mucosal junction and min imal wound contraction. LM and TEM revealed that both types of grafts formed a fully differentiated keratinizing mucosa with a well-develope d basement membrane and rete ridges, comparable with the histology and ultrastructure of palatal mucosa in situ. Conclusion: It was conclude d from this study that cultured mucosa can serve as a proper dressing for mucosal defects after vestibuloplasty.