Elevation of a Full-Thickness Mucoperiosteal Flap Alone Accelerates Orthodontic Tooth Movement

Abstract

Introduction: The purpose of this study was to evaluate if elevation of a full-thickness mucoperiosteal flap alone decreases the amount of bone around teeth and accelerates mesial tooth movements. Methods: Seven beagle dogs were fitted with orthodontic appliances to protract the mandibular third premolars. Both mandibular second premolars were extracted. Then, using a randomized split-mouth design, one side of the mandible had a full-thickness mucoperiosteal flap elevated on the buccal aspect of the bone extending from the distal of the third premolar to the mesial of the first premolar; the other side of the mandible did not receive flap surgery. Tooth movements were analyzed over an eight-week period with calipers and radiographs. The amount and density of bone were analyzed using μCT; bone remodeling was evaluated with histologic sections. Results: Experimental tooth movements measured intraorally were significantly greater (25%) than control tooth movements (3.86 mm versus 3.09 mm). A similar 31% increase in tooth movement on the experimental side was seen radiographically. Medullary bone mesial to the third premolar showed a significantly lower (8%) bone volume fraction and apparent density on the experimental side than on the control side. Histologic sections of the bone showed no distinct differences in the number of osteoclasts or osteoblasts when comparing the experimental and control medullary bone. Conclusions: Elevation of a full-thickness mucoperiosteal flap alone resulted in a decrease in medullary bone and accelerated tooth movement.