Abstract:

BACKGROUND: The initial stability of implantable distractor depends on the stress distribution of bone-distractor interface. The understanding of the biomechanical change in initial stage can improve the clinical success ratio of implantable distractor used in alveolar crest.
OBJECTIVE: To evaluate the influence of bone quality on stress distribution and deformation in initial distraction stage.
METHODS: Four three-dimensional models with 10 079-11 456 cells and 17 299-20 101 nodes were prepared by finite element methods (11 mm in length and 3.7-4.1 mm diameter). Implantable distractor was embedded in a segment of mandible. The elastic modulus of cancellous bone and the thickness of cortical bone, stress and deformation of bones and distractor were calculated.
RESULTS AND CONCLUSION: The highest stress in the bone was concentrated in transportable section and the maximum deformation of transportable section was observed at the edge of the cortical bone, both of which were increased with bone quality decreased. The subsidence of distractor was observed with bone quality decreased. Bone quality influenced the initial stability and the result of the implantal distraction. The decrease of bone elastic modulus would increase the failure risk of distraction osteogenisis.