[The hiatus semiluminaris, the infundibulum and the ostium of the sinus maxillaris, the anterior attached zone of the concha nasalis and its distance to the landmarks of the outer and inner nose].

The authors described the Infundibulum and Ostium of the maxillary sinus, its width and location and course in the Hiatus semilunaris. There were counted and measured also the accessory Ostia, the Processus uncinatus and Bulla ethmoidalis and distances to landmarks between the outer nose and the Limen nasi to these structures.