Sinus Bone Graft
What is Sinus Bone Graft
In the back part of the upper jaw, there are 2 hollow cavities called the maxillary sinuses which can enlarge towards the roots of the upper molar teeth. Often, placing implants in the molar region of the upper jaw is compromised due to reduced bone height. In these cases, it is possible to improve bone height by performing a procedure called sinus lift and bone graft.
This procedure involves making a small window of bone in the back part of the upper jaw, the sinus membrane is lifted up, and then bone particles are packed under the membrane to increase the bone height in this region. This procedure is usually performed under day surgery general anaesthesia. It is important that your sinuses are healthy prior to performing the procedure and x-rays and CT scans are often done to assess sinus health.
Risks of sinus grafting
1. Membrane perforation: the membrane is very thin, and sometimes can be perforated as we try and lift it up. Often, this is repairable using a collagen membrane. Rarely, the perforation is severe, and we may decide to abandon and delay the surgery.
2. Sinus infection: if the sinus is uninfected prior to surgery, the risk of infection is uncommon and can usually be effectively treated by antibiotics and nose drops. Rarely, further sinus surgery may be required.
There is usually some swelling and discomfort. It is not advisable to blow your nose for 1 to 2 weeks following surgery. If you wear a denture, you will usually be able to wear this 1 to 2 weeks after surgery.
Source of sinus bone graft
1. Bone morphogenic Protein (BMP)
This is the latest in technology and is a modified protein that stimulates bone formation. It comes as a powder that is mixed with a fluid then soaked in a collagen sponge. This sponge is the carrier of the protein and this is packed into the sinus. The sponge is resorbable and the protein will stimulate cells to transform to bone forming cells and form bone. The advantage is that we do not need to harvest bone from the patient.
2. Bovine Bone (Bio-Oss)
This bovine bone material has been specially prepared to act as a scaffold for the patient’s bone to grow into and eventually will replace the bovine bone with natural bone. This material comes as small particles and packed into the sinus cavity.
3. Autogenous Bone
Bone can be harvested from another part of the jaw for example the chin to be milled in a bone mill. The disadvantage is that there is another part of the mouth that has to undergo an invasive procedure. In sinus graftin procedure, Dr Lydia Lim prefers to use BMP or Bio-Oss to minimize donor site morbidity.