IndexIntroductionRelated researchConclusionIntroductionAnatomic variations in the region of the nose and paranasal sinuses are common. Local anatomical variations including deviated nasal septum, Concha bullosa, paradoxical middle turbinate, uncinate deviation, agger nasi, and others may be the source of middle meatus obstruction and subsequent rhinosinusitis. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get Original Essay Related Research Deviated nasal septum Deviated nasal septum or bone spur casus a decrease in the critical area of ​​the OMC which predisposes to obstruction and causes complications. was found 65 out of 100 patients, the maximum anatomical variation in our study was 65% . It was higher than the 14.1% in the study by Dutra and Marchore et al (2) and the 36% reported by Asruddin et al (3) 55.7% by Maru (4 )Concha bullosaThe Concha bullosa (pneumatized middle turbinate) has been implicated as a possible etiological factor in the causation of chronic recurrent sinusitis. This is due to its negative influence on sinus ventilation and mucociliary clearance in the middle meatus region, as cited by Tonai (5). The incidence of concha bullosa was 52%, which is higher than the reported incidence of 42.6% by Maru et al (4), 28% by Asruddin et al (3), and 24% by Llyod ( 6) Uncinate deviation The uncinate process can be deviated or pneumatized. The uncinate deviation prevents sinus ventilation especially in the regions of the anterior ethmoid, frontal recess and infundibulum. Deviated hamate was found in 30% of cases. It was higher than that reported by Bolger et al., (7) 2.5%, Dua et al., (8) 6%, and Asruddin et al., (3) 2% Llyod et al., (6) reported a prevalence of approximately 16% of uncinate process deviation in cases of chronic rhinosinusitis and lower than that reported by Mamtha et al., 65%. (9) Paradoxically Curved Middle Turbinate The middle turbinate may be paradoxically curved (bent in the opposite direction). This can lead to middle meatal impingement and cause sinusitis. Stammberger and Wolf (10) accepted paradoxical curvature of the middle turbinate as an etiological factor of chronic sinusitis because it can cause obliteration or alteration of nasal airflow dynamics. It was found in 15% of patients; the prevalence is similar to that of 12% by Asruddin et al., (3) and 15% by Llyod (6) It is lower than that reported by Bolger et al., (7)Onodi cellsOnodi cells are posterior ethmoid cells that they extend posteriorly, laterally, and sometimes superiorly to the sphenoid sinus, lying medial to the optic nerve. The chances of optic nerve injury increase when the bony nerve canal is dehiscent. The surgeon must pay close attention to the node cell in the preoperative evaluation to avoid potential complications of FESS. It was found in 7% of cases in our study. A similar incidence was found by Arslan in 12/200 patients and higher than the Jones study (11). in 8/200 patients Haller cells are ethmoidal air cells that protrude beyond the limits of the ethmoidal labyrinth into the maxillary sinus. They are considered ethmoid cells that grow in the floor of the orbit and can narrow the adjacent ostium of the maxillary sinus especially if they become infected. The incidence of Haller cells in our study was 3%. It was lower than that reported by Bolger 45.9%,(7) Llyod 15% (6), Maru 36% (4) and Asruddin 28% (3)Agger NasiCellThe Agger nasi cells are located just anterior to the anterosuperior attachment of the turbinate center and frontal recess. These may invade the lacrimal bone or the ascending process of the maxilla. The incidence of Agger nasi cells in our study was 3%..