On the Drainage of the Normal Frontal Sinus of Man

The conveyance of secretion in the frontal sinus system of man follows an “open circular course”, in which secretion is conveyed from the medial wall of the ductus frontalis via the ostium internum, the septum interfrontale with the adjacent parts of the anterior and posterior wall, and then in an archlike direction laterally. From above and laterally it reaches the bottom of the frontal sinus and then travels by way of the lateral part of the ostium internum again into the ductus. There, part of it is conveyed via the hiatus semilunaris into the middle nasal duct, whilst the other part, by way of a dimple in the ductus, again arrives at the medial wall, along which it is once more conveyed upwards and through the frontal sinus. The passages of conveyance of secretion, where important anatomical variants are concerned—as a defect in the septum interfrontale, large extrusions in the ductus frontalis, accessory ostia to adjacent cells, conveyance in frontal ethmoidal cells in case of frontal sinus aplasy—and many more things will be discussed as well.