What is a Sinus?
The maxillary sinuses are membrane-lined spaces that lie on both sides of your nose directly above your upper jaw. Sinuses are like empty rooms that typically have nothing but air in them. Some of the roots of the natural upper teeth extend up to the floor of maxillary sinuses and sometimes even penetrate into the sinuses. As we age, the floor of the sinus can pneumatize, which causes the floor of the sinus to slump down and reduce the amount of bone present in the upper jaw. This process may be accelerated with the loss of teeth. A requirement for dental implant placement is adequate bone dimensions. When the sinus floor drops to a point that there is not enough bone present for implant placement, it is impossible to place dental implants in this bone.
There is a solution called a sinus graft, sinus lift, or sinus augmentation. The dental implant surgeon enters the sinus from where the upper teeth used to be. The sinus membrane is then lifted upward and donor bone is inserted into the sinus. In other words, the membrane that lines the sinus, which drops like a bowl, is elevated and shaped into a dome. The space is then filled with bone. After proper healing, the bone becomes incorporated as a part of the patient’s jaw and dental implants can be inserted and stabilized in this new sinus bone.
Sinus augmentations and implant placement can sometimes be performed simultaneously as a single procedure. In certain situations, the sinus augmentation will have to be performed first, then the graft will have to mature, and then implants can be placed.