New Assessment of Trabecular Bone Mechanical Properties by Intraoral

本研究的目的是开发一种新的方法，定量评估颌骨小梁骨的力学性能的口内x线片。方法：选取2只成年猴下颌骨无牙区4块（20*15 mm）骨块进行解剖。在60 kV和6.4 ma下对这些块体进行口内x线片拍摄。测定骨小梁结构参数如下；小梁面积（T.Ar），小梁表面长度（TSL），小梁数(Tb。N)、结点数（N. nd）、末端数（N. trn）和分形维数（FD）。4块骨块经微ct连续扫描，切片厚度为0.08 mm。利用微ct图像建立三维有限元模型，并计算其力学性能的弹性模量。用弹性模量对4块骨块共16个区域的骨小梁结构参数进行比较。结果TAr、nd与弹性模量呈显著正相关。(P < 0.05)。结核感染率呈显著负相关。N、N. tm、FD和弹性模量（P<0.05）。然而，TSL与弹性模量之间没有显著的相关性。多元回归分析显示，弹性模量可由t.r ar和FD解释[弹性模量=0.07 * t.r ar -5.08 * FD + 6.85] （R方= 0.91，P<0.000 1）。结论：我们的研究结果表明，颌骨小梁骨的力学特性可以通过口内x线片定量评估。

The purpose of this study was to develop a new method which quantitatively assesses mechanical properties of trabecular bone of the jaws by intraoral radiographs. Methods: 4 bone blocks (20*15 mm) were dissected from mandibular edentulous area obtained from two adult monkeys. Intraoral radiographs of these blocks were taken with 60 kV and 6.4 mAs. Parameters of trabecular bone structure were determined as follows; trabecular area (T.Ar), trabecular surface length (TSL), trabecular number (Tb.N), number of node (N.Nd), number of terminus (N.Trn), and fractal dimension (FD). 4 bone blocks were serially scanned by micro-CT with slice thickness of 0.08 mm. A three-dimensional finite element model was created from micro-CT images and elastic modulus of mechanical properties was also calculated. Parameters of trabecular bone structure in a total of 16 regions obtained from 4 bone blocks were compared with elastic modulus. Results Significant positive correlations were found among TAr, N.Nd and elastic modulus. (P<0.05). Significant negative correlations were found among Tb.N, N.Tm, FD and elastic modulus (P<0.05). However, there was no significant correlation between TSL and elastic modulus. Multiple regression analysis revealed that elastic modulus was explained by T.Ar and FD [elastic modulus=0.07 * T.Ar -5.08 * FD + 6.85] (R square = 0.91, P<0.000 1).Conclusion: Our results suggest that mechanical properties of trabecular bone of the jaws may be quantitatively assessed by intraoral radiographs.