Fig.1

In the schematic drawing, one can see the lumen of the maxillary sinus including the facial wall, the main nasal chamber with the inferior nasal meatus, the cheek bone with the crista zygomaticoalveolaris and the alveolar process with a significant reduction of the ridge height.

Fig.2

Access is carried out by a trepanation of the bony wall of the maxillary sinus, with a diameter of approximately 5 mm, directly anterobasal of the crista zygomaticoalveolaris. Starting from the bony trepanation, the mucosa of the maxillary sinus is detached in the area of the alveolar recessus.

Fig.3

By widening the tunnel up to the back wall of the maxillary sinus, the subantral area is created by shifting the mucosa of the maxillary sinus cranially. The subantral area is thoroughly examined endoscopically with regard to its dimension and the condition of the detached mucosa of the maxillary sinus.

Fig.4

Then, the implant cavities get prepared before the augmentation. Their location in the subantral area is checked endoscopically.

Fig.5

For the step-by-step augmentation, the distal part of the subantral area gets augmented first and is controlled endoscopically. After inserting the distal implant, the locations of augmentation and implant are checked once again.

Fig.6

After that, the mesial part of the subantral area gets augmented and an implant is inserted in this area. Here, the result is controlled endoscopically as well.

Fig.7

The middle part gets augmented last. The third implant is inserted near the point of trepanation in this area.