Alveolar bone resorption following coronal versus apical approach in a mucoperiosteal flap surgery procedure in the rat mandible

Background: In several publications, we have reported that a distinct resor ptive phase of alveolar bone developed during 3 weeks following elevation o f a mucoperiosteal flap in rats by a coronal surgical approach. In the pres ent study, we compared the alveolar bone loss after mucoperiosteal flap sur gery by a coronal approach (COR) to a surgical approach incising the mucosa close to the tooth apices and separating the mucoperiosteum toward the too th crown (apical approach, AP). Methods: Eighteen Wistar rats were divided into 2 experimental groups; each group consisted of 9 rats. In the first group, COR was performed on both b uccal and lingual aspects on the right side of the rat mandible, while the left side served as a sham-operated control. In the second experimental gro up, AP was performed. Results: In the AP group, the outer aspect (buccal or lingual) of the alveo lar bone was slightly resorbed usually at the level where the mucosa was in cised. In many sections, extensive modeling of new trabecular bone was seen , coronal to the surgical incision. On the contrary, the coronal surgical a pproach revealed an extensive resorptive phase, mainly of the periodontal a spect of the alveolar bone. Conclusions: The results of this study show that periodontal surgery by a c oronal surgical approach stimulates a burst of remodeling of the alveolar b one in a very specific pattern.