Model for Mandibular Condyle Reconstruction

Dodson, Thomas

Abstract

Satisfactory reconstruction of the mandibular condyle continues to challenge reconstructive surgeons. The difficulty in constructing a functional mandibular condyle is illustrated by the multiple autogenous and allogenic materials proposed for joint reconstruction. To our knowledge, autogenous cranial bone has not been evaluated for reconstruction of the condyle in non-human primate models or humans. We propose a pilot study to develop an animal model using Macaca mulatta in order to evaluate reconstruction of the mandibular condyle using autogenous cranial bone grafts. We hypothesize that: l) the cranial bone graft will successfully incorporate into the native mandible resulting in bony union, 2) there will be minimal graft resorption resulting in more predictable joint reconstruction, 3) under function, the graft will remodel producing an anatomic appearing condyle, and 4) the graft will permit acceptable joint function. The purpose of this study is to assess the feasibility of using autogenous cranial bone to reconstruct the mandibular condyle by measuring morphologic, radiographic, and histologic changes in the bone graft and assessing joint function in an animal model comprised of four female adult M. mulatta. To address our research hypotheses, we propose the following specific aims: 1) to determine whether grafted cranial bone is consolidated into the native mandible as manifested by mechanical bony union of the graft to mandible, 2) to observe morphologic changes in the grafted cranial bone assessed by gross visual examination, 3) to measure morphologic changes in volume and linear dimensions of the bone graft, 4) to observe and measure changes in occlusion or facial symmetry following joint reconstruction, 5) to evaluate histologic changes in the grafted bone, and 6) to assess passive joint function as determined by a return toe normal diet and by measuring jaw movement and jaw joint noise. Our long-term research goal is develop an animal model to study condylar reconstruction with transplanted, autogenous cranial bone.