Qualitative bone CT as a tool to assess vascularization in irradiated bone: an animal study

Objective The purpose of this paper was to find a correlation between laser doppler flowmetry (LDF) and the bone mineral density quotient (BMDQ) to evaluate irradiated bone quality preoperatively. Materials and methods Premolars and molars were extracted from six minipigs. After a three-month healing period, three animals received irradiation at a total dose of 24Gy. Three months after irradiation, quantitative computed tomography was performed using a calibration bone phantom to determine the 120-position BMDQ in the alveolar bone. A drill template was created to define the exact location for measurement. LDF was then recorded after osteotomy of the residual alveolar ridge. The correlation between the BMDQ and LDF was investigated. Results There was a linear negative correlation between LDF and BMDQ in non-irradiated bone (r=-0.435, P=0.001) and less pronounced also in irradiated bone (r=-0.309, P=0.017). In both non-irradiated and irradiated bone, we found distinct differences between the maxilla and mandible with respect to BMDQ. However, a clear difference in mandibular and maxillary vascularity was only seen in non-irradiated bone. Conclusion In non-irradiated bone, LDF and BMDQ were inversely correlated. In irradiated bone, the BMDQ alone is not an adequate preoperative tool for evaluating bone quality because it was not correlated with bone perfusion