Apical migration of oral epithelium in experimental dehiscence wounds

The purpose of the present investigation was to determine if the placement of free mucosal grafts would delay the apical migration of oral epithelium into surgically created dehiscence wounds. Dehiscence wounds, measuring 8 x 6 mm, were surgically created on the mandibular canines of 5 beagle dogs. The exposed root surface was then curetted and horizontal grooves were made, one at a point just below the gingival sulcus and the other at the apical border of the dehiscence. Experimental teeth received free alveolar mucosal grafts while the contralateral teeth served as controls. The grafts were placed with the epithelial side against the tooth surface to bridge the dehiscence at the level of the coronal notch and were sutured in place. The flaps were then repositioned (over the mucosal grafts) and sutured. Apical migration of the oral epithelium, after 10 days, was assessed histologically using the coronal and apical grooves as points of reference. The oral epithelium was detected in the coronal one half of the dehiscence, in both the control and experimental teeth. There were no significant differences observed between the two, suggesting that the placement of a mucosal graft, as described here, provides little benefit in delaying apical migration of oral epithelium. The fact that the epithelium failed to reach the apical half of the dehiscence may indicate that features of this wound model may help our understanding of epithelial cellular kinetics operative in periodontal wound healing.