ABSTRACT
PURPOSE: This study tested the use of a dentate transport segment for the reconstruction of a large U-shaped defect in the anterior segment of the canine mandible using a novel curved reconstruction plate. The quality and quantity of bone regenerate formed by dentate versus edentulous transport segments were compared. MATERIALS AND METHODS: In 5 adult foxhound dogs, a defect of 70 to 75 mm was created in the canine mandible by excising the mandible anterior to the right and left fourth premolars. Reconstruction was performed by trifocal distraction osteogenesis using a bone transport reconstruction plate (BTRP-02), with 2 transport units being activated simultaneously, one on either side of the defect, 1 dentate and 1 edentulous. Bilateral distraction proceeded at a rate of 1 mm/day until the segments docked against each other in the midline. After 39 to 44 days of consolidation, the animals were euthanized. The quantity and quality of bone regeneration on the 2 sides were compared using micro-computed tomography. RESULTS: The defect reconstruction was successful. The amount and quality of bone formed by the transport segments were similar on the 2 sides. There were no major differences in the bone volume fraction and density of the regenerate bone formed by the 2 transport segments. The bone volume fraction and density of the regenerate bone were considerably lower than those of the host bone in the distal segments, likely owing to the short consolidation period. CONCLUSIONS: Bone transport remains a viable option in reconstructing anterior segmental defects in the mandible. The use of dentate or edentulous transport segments for reconstruction provides options for the surgeon in often highly compromised patients requiring these surgeries.
Subject(s)
Mandibular Diseases/surgery , Osteogenesis, Distraction/methods , Plastic Surgery Procedures/methods , Animals , Biocompatible Materials/chemistry , Bone Density/physiology , Bone Plates , Bone Regeneration/physiology , Cone-Beam Computed Tomography/methods , Dental Arch/surgery , Dentition , Dogs , Equipment Design , Feasibility Studies , Granulation Tissue/pathology , Imaging, Three-Dimensional/methods , Jaw, Edentulous/surgery , Male , Mandible/surgery , Organ Size , Osteogenesis, Distraction/instrumentation , Plastic Surgery Procedures/instrumentation , Titanium/chemistry , X-Ray Microtomography/methodsABSTRACT
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 8 control animals, the defect was stabilized with a reconstruction plate without further reconstruction and the animals were killed 2 to 3 months after surgery. The remaining 5 animals were reconstructed with a bone transport reconstruction plate, comprising a reconstruction plate with attached intraoral transport unit, and were killed after 1 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.
