Bone mineral density

Abstract

Objective: To verify whether bone mineral density (BMD) of cortical bone, trabecular bone, and total bone influence the primary stability of orthodontic miniscrews and to verify whether there is a correlation between the measurement of BMD by cone-beam computed tomography (CBCT) and central dual-energy x-ray absorptiometry (DEXA). Materials and Methods: Twenty bovine bone sections were extracted from the pubic and iliac bones from regions with cortical thicknesses of approximately 1 mm. The BMD of the total bone block was evaluated using two methods: CBCT and DEXA. The BMD of cortical, trabecular, and total bone in the region of interest (ROI) were also evaluated by CBCT. After scanning the bone blocks, 20 self-drilling miniscrews (INPH) 1.4 mm in diameter and 6 mm long were inserted into them. The peak implant insertion torque (IT) was registered. After this, the pull-out test (PS) was performed and the maximum force registered. The Pearson correlation test was applied to verify the correlations between variables. Results: The BMD of the total bone block verified by CBCT and DEXA showed a positive and strong correlation (r 5 0.866, P 5 .000). The BMD of the ROI for cortical bone influenced the IT (r 5 0.518, P 5 .40) and the PS of miniscrews (r 5 0.713, P 5 .001, Table 2). However, the total bone BMD (verified by CBCT and DEXA) and trabecular bone BMD presented weak and not statistically significant correlations with primary stability. Conclusions: There was a positive correlation between total bone block BMD measured by DEXA and CBCT. The cortical BMD influenced the IT and PS. (Angle Orthod. 2012;82:62-66.)

Evaluation of osteoporosis in jaw bones using cone beam CT and dual-energy X-ray absorptiometry

“…In a study by Marquezan et al, although no relationship was detected between BMD and cortical bone CT value, a correlation was noted between BMD value and the total bone CT values (38).…”

Hounsfield Units: A new indicator showing maxillary resistance in rapid maxillary expansion cases?

“…12 Several comparative studies confirmed the reliability and high accuracy of 3D CT for quantitative and qualitative analyses [13][14][15] and concluded that CT is a valuable diagnostic supplement to subjective bone density evaluation. [16][17][18] Cone beam computed tomography (CBCT) is preferred in dentistry as a result of the lower radiation dose it affords compared to that required in standard CT. However, standardization between CBCT machines is low, 7 which causes Hounsfield scale variability.…”

Is trabecular bone related to primary stability of miniscrews?

“…The mini-implants were placed by a single operator with the use of a manual key connected to a digital torque meter (Lutron TQ-8800; Lutron, Taipei, Taiwan). To guarantee perpendicular insertion of the miniscrews into the bone, the torque meter and the bone blocks were adapted to a mechanical device 16 ( Figure 1). The peak insertion torque (IT) values were recorded in Newton centimeters (Ncm).…”