METHODS: Five sectioned maxilla of adult Dorper male sheep were scanned using a CBCT system with a resolution of 76 μm3 (Kodak 9000). The CBCT images were reconstructed using different reconstruction parameters and analysed. The effect of reconstruction voxel size (76, 100 and 200 μm3) and threshold values (±15% from the global threshold value) on trabecular bone microstructure measurement was assessed using image analysis software (CT analyser version 1.15).
RESULTS: There was no significant difference in trabecular bone microstructure measurement between the reconstruction voxel sizes, but a significant difference (Tb.N = 0.03, Tb.Sp = 0.04, Tb.Th = 0.01, BV/TV = 0.00) was apparent when the global threshold value was decreased by 15%.
CONCLUSIONS: Trabecular bone microstructure measurements are not compromised by changing the CBCT reconstruction voxel size. However, measurements can be affected when applying a threshold value of less than 15% of the recommended global value.
METHODS: On the basis of a series of bone milling experiments with commercial artificial bones, an artificial neural network force model is developed to estimate the milling force of different bone densities as a function of the milling feed rate and spindle speed. The model estimations are used to identify the bone density at the cutting zone by comparing the actual milling force with the estimated one.
RESULTS: The verification experiments indicate the ability of the proposed method to distinguish between one cortical and two cancellous bone densities.
CONCLUSIONS: The significance of the proposed method is that it can be used to discriminate a set of different bone density layers for a range of the milling feed rate and spindle speed.
METHODS: This study enrolled 147 SLE patients from the Asia Pacific Lupus Collaboration (APLC) cohort, who had BMD and TBS assessed from January 2018 until December 2018. Twenty-eight patients sustaining VF and risk factors associated with increased fracture occurrence were evaluated. Independent risk factors and diagnostic accuracy of VF were analyzed by logistic regression and ROC curve, respectively.
RESULT: The prevalence of vertebral fracture among SLE patients was 19%. BMD, T-score, TBS, and TBS T-score were significantly lower in the vertebral fracture group. TBS exhibited higher positive predictive value and negative predictive value than L spine and left femur BMD for vertebral fractures. Moreover, TBS had a higher diagnostic accuracy than densitometric measurements (area under curve, 0.811 vs. 0.737 and 0.605).
CONCLUSION: Degraded microarchitecture by TBS was associated with prevalent vertebral fractures in SLE patients. Our result suggests that TBS can be a complementary tool for assessing vertebral fracture prevalence in this population.
Materials and Methods: This study was carried out in ten cases of biopsy-proven GCTs: five males and five females, in the age group between 18 and 39 years. All patients were given three doses of zoledronic acid, one pre-operative and two post-operative. Extended curettage was done three weeks after the pre-operative dose of zoledronate. The cavity was left empty in all the cases. Fibular struts were used to support the cavity from collapse. Patients were followed-up for post-operative local recurrence. The functional status of the patients was assessed during each visit using the Musculoskeletal Tumour Society (MSTS) score.
Results: There were no recurrences at a follow-up of two years. All patients had a stable knee and were able to bear weight fully. The average knee flexion was 75º. The average MSTS score of the study was 92%.
Conclusion: Extended curettage using hydrogen peroxide, systemic zoledronic acid adjuvant and leaving the cavity empty without using cancellous bone graft did not lead to a recurrence of GCT. Non-vascularised fibular strut provided adequate support while the cavity left empty after curettage did not collapse and there was good knee function.
Methods: Eighteen male Dorper sheep were randomly distributed into three groups (n = 6 each group): group 1, RME with corticotomy on the buccal and palatal sides; group 2, conventional RME treatment; and group 3, no treatment. Post-RME, trabecular bone microstructure and new bone formation were evaluated by using microcomputed tomography (microCT) and histomorphometry after a 4- or 12-week retention period. Intergroup differences in bone quality and bone remodeling were analyzed by using two-way analysis of variance with Bonferroni post-hoc test.
Results: The bone volume fraction (bone volume [BV]/total volume [TV]) values relative to the control in groups 1 and 2 were 54.40% to 69.88% after the 4-week retention period and returned to approximately 80% after the 12-week retention period. The pooled BV/TV values of the banded teeth in groups 1 and 2 were significantly lower than those of the control after the 4-week retention period (p < 0.05). However, after the 12-week retention period, the pooled BV/TV values in group 2 were significantly lower than those in groups 1 and 3 (p < 0.05). Histomorphological analysis showed that the new bone formation area in group 1 was approximately two to three times of those in group 2 and control.
Conclusions: Corticotomy significantly enhanced the restoration of bone quality after the retention periods for banded teeth. This benefit might result from the increased new bone formation after corticotomy.