The maxillary sinus is an air cavity lying over and above the upper back teeth. There are many air cavities in the skull and their function is to allow air to circulate and humidify. The maxillary sinus has no major important biologic function and can increase in size and volume over time. If any of the maxillary teeth are lost, the sinus increases in size to occupy the area of the lost teeth. This means that bone volume is decreased and there may not be enough bone to place implants without intervention. Bone volume increase in this situation is achieved by grafting which lifts the sinus. Success rate for implants placed in the grafted maxillary sinus area is approximately 92%. Antibiotics and anti-inflammatory medication is prescribed before and after the procedure which is carried out under local anaesthetic. There are two methods by which the sinus is lifted.
Osteotome sinus lift
In this procedure, the area to be lifted is relatively small and the sinus anatomy favourable. The graft material is advanced into the sinus by an instrument called an osteotome through a small opening made in the gum at the site of the missing tooth. The implant is often placed at the same time as the grafting procedure or may be done after a period of healing.
Lateral window sinus lift
This technique is used when larger areas require lift. “A window” is made through the bone on the side of the sinus in the area above the missing teeth and graft material is placed directly into the sinus space. After several months of healing, the grafted bone integrates with the surrounding bone so that there is sufficient volume for implant placement.