The "osteomeatal complex" of the middle meatus, is a group of anatomical structures that contribute the final common drainage pathway of maxillary, anterior ethmoidal and frontal sinuses. Knowledge of inconsistent location of principle maxillary sinus ostium is essential for surgical intervention of the maxillary sinus as there are important structures like superiorly orbit and medially nasolacrimal duct lying adjacent to medial wall of maxillary sinus. The principle maxillary sinus ostium is

more »

... ened in the Hiatus semiluneris and it is located on the highest part of medial wall of maxillary sinus. This study was carried out in the department of Anatomy, Government Medical College, Surat and Surat Municipal Institute of Medical Education and Research (SMIMER) where 54 cadaveric heads were cut in midsagital section into 108 half heads and then incidence and location of maxillary ostium was studied. In the present study, the ostium of the maxillary sinus was more commonly open into the posterior third of the infundibulum in 78 (84.24%) half head while it opened into the middle third in 26 (28.08%) half heads, anterior third in 4 (4.32%) half heads. Among 108 half heads, accessory maxillary ostium was found in 20 (18.5%) half heads. The endoscopic sinus surgeons must have a detailed knowledge of inconsistent situation of principle maxillary sinus ostium (PMO) and accessory maxillary sinus ostium as it is extremely beneficial for surgical intervention of the functional endoscopic sinus surgery which is designed to remove the blockage of maxillary sinus ostium and to restore normal sinus ventilation and mucociliary function.