Determination of the radioanatomical factors related to the position of facial nerve in accessing jugular foramen and carotid artery in temporal bone.

Introduction: Preservation of the facial nerve is of great importance in temporal bone surgeries. We intend to investigate the measurements of the radioanatomical factors related to the position of the facial nerve in accessing jugular foramen and internal carotid artery (ICA) in temporal bone of patients who were candidates for temporal high resolution computed tomography (HRCT) scan. Methods: In this correlation cross-sectional study, samples were selected from patients referred to Amir Alam Hospital who were previously candidates for temporal HRCT. Radioanatomic factors were evaluated in three axial, coronal and sagittal views. Analyzes were performed using descriptive statistics, correlation analysis and factor analysis. Results: A total of 173 samples were investigated. The most reliable radioanatomical factor based on coefficient of variation (CV) was the distance of the 7th nerve to the temporomandibular joint (TMJ) in the inferior to the cochlea in the sagittal view (variable name S2) (CV = 8.1%) and then the distance from the 7th nerve to the TMJ in the inferior section of the cochlea in the axial view (variable name AI3) (CV = 8.4%). Based on correlation analysis and then confirmatory factor analysis, three common latent factors were identified (overall R2 = 0.999). Conclusion: The results of this study can be used for two purposes. First, the direct use of the estimated measures in surgical operations, and the second is more advanced modeling to choose the approach in the surgical operation and how to implement that approach. For the first aim, the two factors AI3 and S2 were the most reliable radioanatomical factors in different people. For the second aim, the three-dimensional understanding of the obtained measurements and the further identification of the anatomical nature of the latent factors can help in choosing the approach in surgery.

An ecological modeling on the adjusted effects of socioeconomic determinants and HLA-DRB1 alleles in fatality of COVID-19 during the early phase of epidemics in a group of countries.

INTRODUCTION: Socioeconomic determinants along with genetic status may affect fatality rate of COVID-19. We intend to investigate the adjusted effects of the HLA-DRB1 alleles and socioeconomic determinants including gross domestic product per capita (GDP cap) and health expenditure per capita (HE cap) in fatality of COVID-19 during the early phase of epidemic in a group of countries. METHODS: As an ecological study, early exposure to epidemics was defined as having more than 5000 confirmed cases of COVID-19 from 1 March 2020 to 1 April 2020. Poisson regression was used to report adjusted incidence rate ratio (IRR) for case fatality rate in this constant time period. RESULTS: Fourteen countries were eligible. Among the alleles, DR7 showed the strongest risk factor (IRR=112.535, P<0.001). Having GDP cap more than 40000$ or having HE cap more than 3000$ was a protecting factor (IRR=0.899, P<0.001, adjusted with allele DR7). Having GDP cap more than 40000$ along with having HE cap more than 3000$ was a protecting factor (IRR=0.471, P<0.001, adjusted with allele DR7). CONCLUSION: Socioeconomic status of the countries may compensate the probable harmful effect of some HLA-DRB1 alleles. This conclusion was limited to a period that all the selected countries had almost similar governmental intervention.