Retromaxillary Cell: Radiological Analysis and Clinical Significance

Retromaxillary cell (RMC), one of the anatomical variations of the posterior ethmoidal cell and is often overlooked during primary functional endoscopic sinus surgery. The incomplete removal of the disease from RMC leads to need for revision surgery. This study was aimed at analyzing Computed tomography scans of patients' paranasal sinuses for the incidence, types and radiological evaluation of Retromaxillary cell. Incidence of RMC was 74% (74/100 sides). The sex distribution was 31 (62%) males and 19 (38%) females. 34 patients (85%) had bilateral RMC and 6 patients (15%) had unilateral RMC. Lateral extension of RMC ranged from 1.03 to 11.3 mm. Out of 74 sides examined, 20 (27.02) were type I, 36 were type II (48.64%) and 18 (24.32%) were type III. The incidence of maxillary sinus disease on RMC sides and non-RMC sides has no significant difference (p < 0.5). RMC is lateral extension of posterior ethmoidal cell beneath the orbit and posterosuperior to maxillary sinus. The depth of the RMC is highly variable. The risk of residual disease in FESS is high in Type III RMC and one should pay attention to presence or absence of RMC and type of RMC prior to the endoscopic sinus surgery. Radiological study of RMC helps in preoperative planning and therefore intraoperative complete clearance of disease in endoscopic sinus surgery.