[ prevalence of frontal sinus aplasia in Mashhad, northeast of Iran]

ABSTRACT

There are various reports of the prevalence of frontal sinus aplasia in different geographical areas and ethnic origins. The size and shape of frontal sinus is different among various populations. This study used CT scan images to investigate the frequency of absence of frontal sinuses in adults of northeastern Iran. The present study was performed retrospectively on the axial and coronal CT scans of the paranasal sinuses from a series of 588 patients who had referred to CT scan ward of Mashhad Imam Reza hospital without any other sinus pathology. The mean age of patients was 44.39 +/- 19.44 years. Unilateral and bilateral aplasia of frontal sinuses was seen in 36 and 51 patients, respectively. The dominant sinus was in the left side in 68.24% of cases. The lower incidence of frontal sinus aplasia in this particular ethnic and geographical area relative to other populations emphasizes the effect of environmental and genetic factors on the development of frontal sinuses