Radiographic healing patterns after tooth-borne distraction in canine model

The osteogenesis distraction technique applied to the craniofacial skeleton is an alternative treatment for dentofacial deformities. Despite the advantages of tooth-borne distractors, few studies have evaluated their clinical implementation in sagittal dentoskeletal deformities. This study aimed provide a radiographic assessment of the effect of two different activations of tooth-borne distraction in the lengthening of the mandible in canines.Ten male beagle dogs, approximately one year old, were used for this experimental study. Three remained as a control group and seven underwent a mandibular tooth-borne distraction protocol with single daily activation in one hemimandible and two daily activations in the other, during ten days. The consolidation period took 12 weeks. Occlusal radiographs were performed immediately pre- and postoperatively.After the distraction period, the host bone margins presented very well-defined outlines with regular contours. Concerning the consolidation period, between the second and fourth weeks, all hemimandibles showed small rectangular radiopaque regions with parallel orientation to the distraction axis. At the twelfth week, all hemimandibles presented an entire mineralization of the distraction gap with no axial deviations of the anterior and posterior host bone, nine of which with both margins showing corticalization.Radiographic analysis showed bone regeneration in order to achieve the original bone architecture, especially in the group of multiple distraction. Tooth-borne distraction allowed successful sagittal lengthening of the mandible in a canine model. Key words:Orthodontics, osteogenesis, distraction, mandibular advancement, orthodontic appliance design.