Paranasal sinuses: Anatomy of the ostiomeatal complex

Panel A shows a coronal view of the ostiomeatal complex (OMC). Arrows indicate the direction of mucociliary flow, and circles mark areas that can become obstructed. Panel B, in which the middle turbinate has been removed, shows the remaining structures that comprise the OMC: the uncinate process, hiatus semilunaris, ethmoid bulla, and ostium of the maxillary sinus.