Tài liệu Báo cáo y học: "Aplasia and Agenesis of the Frontal Sinus in Turkish Individuals: A Retrospective St

The frontal sinus is contained within the frontal bone and is situated behind the supercilliary arch [1,2].The two irregularly shaped frontal sinuses are separated completely by a bone septum, which is approximately located in the midline [2-4]. The frontal sinus is vulnerable because of its close relationship to other anatomical structures, such as the anterior skull base or the orbit [5]. The frontal sinuses arise from one of several outgrowths that originate in the region of the frontal recess of the nose, and their site of origin can be identified on the mucosa as early as 3 to 4 months in utero. Less commonly, the frontal sinus develops from anterior ethmoid cells of the infundibulum [68]. The frontal sinuses are essentially the only paranasal sinuses that are absent at birth, because, on average, these sinuses do not reach up into the frontal bone until about the age of 6 years.