Bone dynamics in the upward direction after a maxillary sinus floor elevation procedure: Serial segmentation using synchrotron radiation micro-computed tomography

Objective: Maxillary sinus floor augmentation has been shown to be the most predictable surgical technique for enhancing the bone volume in the posterior area of the maxilla. The purpose of this study was to analyze the serial slice image segmentation of newly formed bone and bone substitutes after sinus floor elevation using synchrotron radiation X-ray micro-computed tomography (SR-µCT). Materials and methods: Bone biopsy specimens were collected after 6 months of sinus floor augmentation. From the six bone biopsy specimens, the cross-sectional images at every 8 µm along the apical direction from the inferior border using serial segmentation from threedimensional reconstructed X-ray images were analyzed. The amount of new bone and bone substitutes were measured at each slicing image (300–430 images per specimen). Results: The bone dynamics between the new bone and bone substitutes along the inferior– superior direction in humans after maxillary sinus floor elevation (MSFE) were analyzed using the whole sample region. Although these observations suggest that the specimens are structurally inhomogeneous, sinus floor elevation was confirmed to be a reliable surgical procedure for increasing the amount of bone. Conclusion: SR-µCT is highly effective for obtaining high-resolution images. An analysis of biological specimens using SR-µCT is quite reliable and this technique will be an important tool in the wide field of tissue engineering.