Analysis of gonial angle related to age in Surabaya population, Indonesia*

Background: Natural disasters potentially cause large numbers of death and a lot of them are yet identified due to the highly destroyed bodies of the victims. Therefore, an immediate identification should be required. The identification can be done age identification. Panoramic radiographs can be used to assess age by measuring the mandible from the gonial angle. Purpose: To analyze the significance of age determination using gonial angle as parameter from panoramic radiographs. Methods: A gonial angle was measured using panoramic radiographs from 251 samples with the RadiAnt DICOM Viewer 4.6.5 software. Result: The measurements of the gonial angle were divided into five groups. One Sample Kolmogorov Test showed p-value (0.001) <0.05, which means the data were not normally distributed. In this case, a Box-Cox power transformation might help make the data normal. Independent t-test showed significant value of 0.989 > 0.05 on gender, showing the gonial angle was not affected by gender, while the significant value of 0.006 <0.05 showed the opposite result. Moreover, one-way ANOVA test showed significant value achieved by group A (4-12 years) of 125.68º and followed by group E (41-62 years) of 124.85º, group D (31-40 years) of 123.63º, group B (13-20 years) of 122.86º and group C (21-30 years) of 122.04º. Conclusion: The gonial angle was influenced by age, and samples with younger age had greater angle than the older ones. The highest average value resulted in the following order: age group A, group E, group D, group B and group C.