Correlation of bone density of individual jaw sections according to Hounsfield with the length of the adentiary section in the cone-beam computer tomography program

Abstract

Aim. To study the existence of a relationship between the density of bone tissue and the length of the edentulous part of the tooth row. Materials and methods. Evaluation of the density of the spongy substance of the jaws by the maximum and average value of HU. The density of cancellous bone was evaluated only in the areas available for implant placement. The groups consisted of the localization and extent of the dentition defect. Statistical methods included the estimation of the arithmetic mean (M), standard deviation (σ), error of the mean (m), confidence interval (95 % CI), estimation of the median (Me) and interquartile range ([Q1; Q2]), Student’s test (t criterion). Results. Maximum and average indicators of cancellous bone density in defects of the upper (562.4 [347.1; 777.8] and 301.5 [163.0; 439.9], respectively (р = 0.84) and lower (1379.0 [1116.2; 1641.9] HU and 848.6 [630.6; 1066.6] HU, respectively, p = 0.96) jaws in the areas of molars and premolars with “large” defects are significantly different from the indicators “small” defects (299.7 [176.9; 422.4] and 642.6 [470.4; 814.9], 1061.1 [866.5; 1255.7] and 608.3 [440.5; 776.1, respectively). The average bone density of the alveolar process of the upper jaw is almost the same in defects of different lengths. The average density of the cancellous bone of the alveolar part of the lower jaw in “large” defects has significant differences from “average” ones (p = 0.02) and “small” (p = 0.005) defects. Conclusions. The average density of cancellous bone of the alveolar part of the lower jaw in “large” defects has significant differences from “medium” (p = 0.02) and “small” (p = 0.005) defects, and regardless of the extent of the dentition defect corresponds to class D3 (350–850 HU) according to the Misch classification. The average density of cancellous bone of the alveolar process of the upper jaw in the areas of molars and premolars does not have significant differences depending on the extent of the dentition defect and corresponds to class D4 (150–350 HU) according to the Misch classification. Since one class includes a large range of values, the clinical classification of Misch does not allow taking into account individual bone density indicators that have statistically significant differences in different areas of the dentition.

Keywords

• computer tomography
• bone density
• medical image processing