Virtual Lesion Segmentation and Mandibular Ameloblastoma Radiographic Safety Margin

The specimen with the the mounted Safety Margin Calibration Guide will be sent for histological evaluation. For light microscopic examination, the specimens will be embedded in paraffin wax blocks after being fixed in 10% formalin, neutrally buffered, cleaned, and dehydrated using increasing ethanol concentrations. Tissue sections will be cut to a thickness of 4 μm, and stained with hematoxylin and eosin to be examined under a light microscope.

The specimen will be cut, using the S35 (0.254-mm thickness) microtome blade, at the preoperatively determined margins according to the virtual lesion segmentation from the proximal and distal sides of the lesion. Since the study is limited to segmental mandibular resection, the full lower border of the mandible was resected and their will be no need for assessment of either coronal or apical margins

At the end of the surgical procedure, the Safety margin caliberation guide was mounted on the specimen and fixed using 2 2.0-mm miniscrews. A radiographic MSCT scan for the resected mandible with the Safety margin caliberation guide will be obtained using same preoperative scanning parameters. The DICOM data of the scanned Specimen will be segemented to create an Actual Resected Specimen Model (ARSM). The RSM will be superimposed with the preoperative Virtual Resected Specimen Model (VRSM) using the miniscrews as radiographic markers for superimposition. The postoperative accuracy of the virtually assisted surgery will be conducted using the 3D-analysis software (GOM-Inspect software*) For each of the selected 2D and 3D parameters, the Deviation will be calculated by subtracting the ARSM values from the VRSM. The absolute mean (Δ) for all of the operated patients will be calculated