Study of the dimension change after grafting of bone from the outer mandibular table to different maxillofacial recipient sites.

BACKGROUND

The object of this study was to investigate the dimension change after bone of the outer mandibular table had been grafted to different facial recipient sites.

METHODS

Six cases of hemifacial skeleton dysplasia had accepted therapeutics of onlay bone grafting at both mandibular angle and infraorbital regions of the affected side. Grafted bones had been harvested from the outer mandibular table of the uninjured side. For each patient, computed tomography scans were taken of immediate postoperative and 6 months postoperative results. By a technique based on 3-dimensional spiral computed tomography separated reconstruction and registration, grafted bones both at mandibular angle and infraorbital regions were independent. Volume of the grafted bone was measured, and 3-dimensional analysis was done.

RESULTS

At 6 months after the operation, the volume of the bone that had been grafted to the infraorbital region had a reduction rate of 11.2% ± 2.3%, and for the bone that had been grafted to the mandibular angle region, the volumetric reduction rate was 20.8% ± 7.2%. The difference of grafted bone resorption rate between the 2 recipient areas has statistical significance (<0.05). Three-dimensional analysis of grafted bones shows that the resorption took place mainly at the length-breadth direction and decreased thickness was less. Of the bone that had been grafted to the mandibular angle area, resorption mainly occurred at the inferior and posterior border of mandible.

CONCLUSIONS

As an autogenous bone graft resource for reparation and reconstruction of maxillofacial bone deformity, the outer mandibular table has a different rate of resorption after it had been onlay grafted to various maxillofacial recipient sites, and the difference of the local mechanical environment maybe an influencing factor. Quantization of bone resorption rate could better guide the clinical use of outer mandibular table as an onlay bone graft resource.