Quantitative assessment of contouring for fibro-osseous lesions in the orbital area using navigation system 3D (Three dimensions) resection rate

Background : Bone contouring is currently the best treatment for fibro-osseous lesions after bone growth arrest. Navigation systems available for this surgery allow intra-operative visualization. However, assessment after contouring surgery with the navigation system has rarely been reported. Method : To assess the utility of this surgery we used a 3D (three dimensions) resection rate. This is defined as real contoured volume measured with postoperative CT data divided by planned volume to contour preoperatively. Result : We used this method to contour fibro-osseous lesions in five patients. 3D resection volume was 8114.9mm3 (3109mmM9779mm3) in average. 3D resection rate was 63.9% (50.6%-87.7%) in average. These data present reasonable resection rate compared with other reports. All patients achieved acceptable facial contour line and improvement in symptoms. Conclusions : 3D resection rate is a new quantitative method measuring the rate of resected area for a targeted bulging bone. This rate presents a simple and easy assessment for surgical contouring of the orbital fi-bro-osseous lesions.