Andruch Krzysztof, Płachta Anna
Department of Dental Prosthetics, Medical University of Lodz, Poland.
Adv Clin Exp Med. 2015 Nov-Dec;24(6):1071-7. doi: 10.17219/acem/28113.
During the study the relative bone density thickness in maxilla was evaluated in 20 patients.
The aim of the study was to investigate relative bone density in maxilla by means of voxel value measurements.
The study comprised of 20 patients in whom cone beam computed tomography scans were made for diagnostic purposes. The horizontal scans of the maxilla were used for analysis. The measurements of density of both cortical plates and trabecular bone were taken in interdental spaces. To eliminate negative values a modified grey scale was introduced in which radiological density of the air was determined as "0". For every patient relative bone density was calculated separately for anterior and posterior maxilla.
Mean values of relative radiological density for cortical plates and trabecular bone were 0.849 for palatal cortical plate, 0.8978 for vestibular cortical plate and 0.5988 for trabecular bone in anterior maxilla with standard deviation (SD) 0.0931 - 0.0971 - 0.1091 respectively. In posterior maxilla the mean values were 0.5274 for palatal cortical plate, 0.6047 for vestibular cortical plate and 0.3307 for trabecular bone with SD 0.1635 - 0.1515 - 0.126 respectively. The statistically significant difference (p < 0.001) was found for radiological density of dental alveolus in anterior and posterior maxilla.
The mean of radiological densities of vestibular cortical plate is higher than that of palatal cortical plate. The mean radiological density of trabecular bone is × 2 lower than the mean radiological density of vestibular cortical plate in posterior region and × 1.5 lower in anterior region of the maxilla. The clinical use of CBCT radiological bone density measurement tool with modified grey scale voxel values creates possibility to evaluate the relative bone density of dental alveolus.
在该研究中，对20名患者上颌骨的相对骨密度厚度进行了评估。
本研究的目的是通过体素值测量来研究上颌骨的相对骨密度。
该研究包括20名因诊断目的而进行锥形束计算机断层扫描的患者。上颌骨的水平扫描用于分析。在牙间隙处测量皮质板和小梁骨的密度。为消除负值，引入了一种修改后的灰度，其中将空气的放射密度确定为“0”。对于每位患者，分别计算上颌前部和后部的相对骨密度。
上颌前部皮质板和小梁骨的相对放射密度平均值分别为：腭侧皮质板0.849、前庭侧皮质板0.8978、小梁骨0.5988，标准差（SD）分别为0.0931 - 0.0971 - 0.1091。上颌后部的平均值分别为：腭侧皮质板0.5274、前庭侧皮质板0.6047、小梁骨0.3307，标准差分别为0.1635 - 0.1515 - 0.126。在上颌前部和后部牙槽骨的放射密度方面发现了统计学上的显著差异（p < 0.001）。
前庭侧皮质板的放射密度平均值高于腭侧皮质板。小梁骨的平均放射密度在上颌后部区域比前庭侧皮质板的平均放射密度低2倍，在上颌前部区域低1.5倍。使用具有修改后的灰度体素值的CBCT放射骨密度测量工具进行临床应用，为评估牙槽骨的相对骨密度创造了可能性。
