Flapless cortical bone damage has no effect on medullary bone mesial to teeth being moved.

INTRODUCTION: In this study, we evaluated the effects of bone awl-induced damage to bone surrounding a tooth that was moved. METHODS: A randomized split-mouth design with 7 foxhounds was performed to evaluate protraction of the mandibular third premolars for 56 days with 200 g of orthodontic force. Before initiating tooth movements, a bone awl was used on the experimental side to create 60 buccal and lingual microfracture injuries to the cortical bone without a periosteal flap. Tooth movements were performed on the control and experimental sides. Microcomputed tomography and histology were used to assess bone morphology and modeling. Radiographic and caliper measures were used to assess tooth movements. RESULTS: The awl-induced injuries produced significant damage and microfractures (95 mm(3)). Buccal and lingual cortical bone volume fractions and densities were significantly less and cortical modeling was significantly greater on the experimental sides than on the control sides. Bone volume fractions and densities mesial to the third premolars were the same on the experimental and control sides. Experimental side tooth movements (1.40 +/- 0.25 mm) were statistically the same as the control side tooth movements (1.57 +/- 0.45 mm). CONCLUSIONS: The effects of flapless, bone awl-induced damage were limited to the cortical bone. Because there was no effect on the medullary bone mesial to the tooth being moved, no differences in tooth movements were produced.