Objectives-Reconstruction of mandibular segmental bone defects is a challenging task. This study tests a new device used for reconstructing mandibular defects based on the principle of bone transport distraction osteogenesis.Methods-Thirteen beagle dogs were divided into control and experimental groups. In all animals, a 3 cm defect was created on one side of the mandible. In eight control animals, the defect was stabilized with a reconstruction plate without further reconstruction and the animals were sacrificed two to three months after surgery. The remaining five animals were reconstructed with a bone transport reconstruction plate (BTRP), comprising a reconstruction plate with attached intraoral transport unit, and were sacrificed after one month of consolidation.Results-Clinical evaluation, cone-beam CT densitometry, three-dimensional histomorphometry, and docking site histology revealed significant new bone formation within the defect in the distracted group.Conclusion-The physical dimensions and architectural parameters of the new bone were comparable to the contralateral normal bone. Bone union at the docking site remains a problem.