You may need a sinus lift in order to have an implant placed in the upper molar region. Most people understand that implants are placed into the jaw bones and you can attach crowns or dentures to them. But what does it mean to have a sinus lift done and why is it necessary? I’ll try to answer that question.
Dental implants are titanium screws that perform the same function as the roots of your natural teeth. In order to place an implant, you must have enough bone to accommodate the implant. If you don’t have enough, the surgeon will have to do something in order to make it work. Some options include adding a block of bone graft under the gum, expanding the jaw bone if it’s too thin, or making more bone where the sinus is present.
When talking about sinus lift, we are talking about the maxillary sinus. A sinus is an air-filled cavity in the skull. The maxillary sinus is the largest air sinus in the body and is located under the eyes. The floor or base of the maxillary sinus is alveolar process or the bone that holds teeth. Roots of the upper back teeth are often right up against the sinus. Sinuses are lined with skin or membrane. The skin lining the maxillary sinus is called the Schneiderian membrane.
Shrinkage and Pneumatization
When a tooth is lost, the bone that holds the tooth resorbs. It’s not needed so the body takes it away. The jaw bone where the tooth used to be shrinks vertically and horizontally. If the tooth that is lost happens to be an upper premolar or molar, pneumatization often occurs. Pneumatization is the process where sinus increases in size in the spot where a tooth root used to be. Combine both and you got bone loss going up from shrinkage and bone loss going down from pneumatization. Sometimes people only have millimeters of bone available in spots where one would like to place an implant.
A sinus lift refers to a procedure where the surgeon “lifts” either the floor or side of the sinus membrane. The membrane or skin on the inside to the sinus can be peeled and lifted off with special tools. This leaves an open space into which the surgeon can place bone graft material. Now that there’s more bone, the surgeon can place the implant into position. This is often done at the same time as the grafting of the sinus lift.
I mentioned that the surgeon “lifts” either the floor of the sinus or the side of the sinus. A lift at the floor is done by fracturing the thin bone at the floor and pushing up. This causes the membrane to lift like a tent. Bone graft material is introduced into the tented area and then an implant can be inserted. After about four to six months you will have converted the graft into your own bone.
If the sinus is large and the available bone is small, the lateral approach is better. The surgeon makes an access hole in the side of the jaw, lifts the membrane away from the sides of the inside of the sinus, and packs it full with bone graft material. Over four to six months the bone graft material converts into real bone. Then implants can be inserted.
If you lost teeth in the upper jaw towards the back, it’s likely you will need a sinus lift in order to have a dental implant placed. The “lift” places additional bone into space created in the maxillary sinus cavity. This procedure is added trauma and you will have a little more discomfort than from just the implant placement.
Molars are made for grinding and serious munching. It’s nice to know that if you’re missing some, there’s a solution to get you back chewing well again.