Marcelo Parra; Héctor Torres; Víctor Ravelo; Sergio Olate

The present study aimed to evaluate the use of X-Ray microtomography for three-dimensional analysis of critical bone defects in rabbit hip filled with a biphasic synthetic graft (B-TCP/HA) or particulate autogenous bone, and morphological characterization of the temporomandibular joint (TMJ) in the same experimental model. Five adult female rabbits were used, in which 5-mm defects were created bilaterally; the right side was filled with the synthetic graft and the left side with autograft. After three weeks, hip and TMJ specimens were harvested, fixed in 70% ethanol and scanned with micro-CT, generating multiplanar visualizations and three-dimensional reconstructions for qualitative and volumetric analysis. In defects treated with the synthetic graft, micro-CT revealed a well-defined hyperdense mass completely occupying the defect, with a sharp interface between biomaterial and host bone and predominantly peripheral trabeculae. In defects treated with autograft, the filling showed a density similar to the surrounding trabecular bone, a more gradual morphological transition and greater trabecular continuity across the defect, consistent with a relatively more advanced degree of bone integration at the time point studied. In the TMJ, orthogonal slices and 3D reconstructions allowed precise localization of the condyle, definition of volumes of interest and description of condylar trabecular architecture. Taking all aspects into account, the findings indicate that micro-CT is a suitable tool to differentiate between synthetic graft, autograft and host bone, and to demonstrate differences in the pattern of bone integration and joint morphology, supporting its use as a central method in experimental studies of bone regeneration and three-dimensional anatomy.

KEY WORDS: X-Ray Microtomography; Bone; Morphology.

PARRA, M.; TORRES, H.; RAVELO, V. & OLATE, S. Use of X-ray microtomography for three-dimensional morphological analysis of bone tissue. Int. J. Morphol., 44(2):669-676, 2026.