The objective of this study was to assess the possibility of developing a clinical minimally invasive and standardized method to evaluate the relationship between the microstructure of the jaw bone and systemic bone turnover. For this purpose, we performed standardized bone biopsy of the alveolar bone, and compared the 3D bone microstructure using micro-computed tomography (micro-CT) with bone mineral density (BMD) of the lumbar spine and biochemical markers of bone turnover. We evaluated a total of 9 samples taken from 6 patients by standardized biopsy using a trephine bur. BMD was evaluated using dual energy X-ray absorptiometry (DXA). Regarding the biochemical markers of bone turnover, serum bone-specific alkaline phosphatase (BAP) and serum osteocalcin (OC) were used as bone formation markers, and urinary cross-linked N-telopeptides of type I collagen (NTx) and urinary deoxypyridinoline (DPD) were selected as bone resorption markers. We scanned micro-CT images of these samples. Bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular spacing (Tb.Spac), fractal dimension, trabecular bone pattern factor (TBPf) and node-strut (Nd.Nd/TV, TSL/TV) were measured. Regarding the correlations between the parameters of bone microstructures, TB/TV, Tb.N, fractal dimension, and node-strut seemed to be positively correlated and Tb.Spac and TBPf seemed to be negatively correlated with each other, but Tb.Th seemed to have a low correlation with other parameters. OC and/or BAP showed a significantly high correlation with many structural parameters (p<0.05%). In conclusion, some microstructural parameters may change according to the systemic bone turnover.

Concerning the bone structures of the mandible reconstructed by particular cellular bone and marrow (PCBM), platelet rich plasma (PRP) and tray, we have examined the possibility of implant insertion by clarifying the morphological conditions in each compact and cancellous bone on computed tomography (CT), and by observing the differences in their CT values.Using the computer software program Sim Plant (Materialize Dental, Leuven, Belgium), we morphologically observed 6 cases of implant inserted area after mandibular reconstruction and 11 cases of native bone, and examined the differences in their CT values. The osseointegration rate of each inserted implant was also evaluated.Compared with the native bone group, the PCBM reconstruction group had generally thin compact bone. In the over-3cm-length PCBM reconstruction group, the average CT value was 259.7 ± 94.4 HU (n = 3) in the cancellous bone, whereas in the native bone group, the average CT value was 528.9 ± 140.1 HU (n = 10). Therefore, the PCBM reconstruction group showed significantly lower CT value than the native bone group. However, in the under-3cm-length group, the PCBM reconstruction group showed no significant difference compared with the native bone group. The osseointegration rate of the inserted implants almost 6 months after insertion was 100% in the PCBM reconstruction group and 94.1% in the native bone group.Although the PCBM reconstructed bone had thinner cortical bone and showed lower CT value compared with the native bone, implant insertion was possible.