A special form of vertical bone structure in the upper jaw is the sinus lift. Sinus lift (often called sinus floor augmentation / elevation) is a surgical procedure that involves inserting bone into the posterior (molars and anterior molars) of the maxilla to enlarge it. A sinus lift is often performed as part of an implant restoration.
Bone graft material is stored in the maxillary sinus floor in order to anchor the implants safely.
There are basically two methods: internal / internal / closed and external / external / open sinus lift.
In the internal procedure, bone graft material is introduced over the graft that has been drilled for the graft.
In the outer sinus lift, a bone window is prepared for the maxillary sinus.