Nakayama T, et al. - Researchers identified the associations between residual frontal recess cells and primary endoscopic sinus surgery (ESS) failure in the frontal sinus. They retrospectively analyzed clinical data and computed tomography (CT) images before and 3 months after surgery to identify risk factors. Findings suggested that for postoperative opacification of the frontal sinus, independent risk factors were residual frontal recess cells, especially suprabullar cells (SBCs) and suprabullar frontal cells (SBFCs). Surgical outcomes could be improved by complete surgical excision of frontal recess cells.