Sinus Bone Grafts
SINUS ELEVATION PROCEDURE
A key to implant success is the quantity and quality of the bone where the implant is to be placed. The upper back jaw has traditionally been one of the most difficult areas to successfully place dental implants due to insufficient bone quantity and quality and the close proximity to the sinus. Sinus augmentation can help correct this problem by raising the sinus floor and developing bone for the placement of several implants. Drs. Langer has authored several articles and chapters in books teaching other dentists how to perform this procedure.
BEFORE & AFTER
Before x-ray: Upper right posterior jaw, missing 4 teeth. The sinus has dropped and there is no bone available for the placement of implants. The sinus membrane must be elevated and a bone graft performed prior to placing of implants.
After x-ray: Four implants holding a fixed bridge to replace all the missing teeth. The posterior chewing function has been restored. A 12- year result.
All Teeth Missing
Sometimes all the teeth are missing in the upper jaw and there is an insufficient bone to support dental implants. This problem can often be corrected surgically with the use of Sinus Elevation (Lift) procedures to replace the missing bone. The most commonly used techniques are the Two-staged delayed approach or the Simultaneous bone graft and implant placement technique.
Two Stage Delayed Sinus Bone Graft Technique
In the upper jaw when the posterior (back) teeth are lost, the bone that was supporting them resorbs (disappears) and all that is left are the large air-filled spaces (Sinuses) with no bone inside them.The diagram shows adequate bone on one side (A) for some implants vs insufficient or minimal bone under the Sinus cavity in the upper jaw on the opposite side (B).
In the most challenging cases where there are less than 3 or 4 millimeters of remaining bone in the posterior areas (back of the mouth), the two-stage surgical protocol is preferred. Six to nine months is needed for the new Sinus bone graft to become mature then another 6 months is required for "osseointegration" (bone to bond to the implant) before the implants are ready to support a bridge. In the example below, the x-ray shows minimal bone in the anterior ( front) part of the mouth and large sinuses in the posterior area.
Preoperative CT Scan
reveals 1-3 millimeters of remaining bone on both the right and left sides of the upper jaw. All the teeth are missing and the patient had been wearing a denture for twenty years. She is a well-controlled diabetic.
Before Sinus Graft X-Ray
Axial CT Scan
The Axial CT scans also revealed a severely resorbed anterior ridge which is too narrow for implant placement in the front of the mouth.
For the patient described, Sinus Elevation (Lift) bone grafts were performed on both sides of the mouth using the Two-stage delayed approach.
Nine months later 8 dental implants were placed into the newly regenerated bone and submerged beneath the soft tissue to be allowed to heal undisturbed. After a healing period of 6 months, the implants bonded to the regenerated bone, the tops of the implants were uncovered (exposed) and a full arch bridge was made for the patient by her prosthodontist . The bridge is beautiful, non removable , functions like her original teeth and leaves her palate free.
As of 2015 this patient has been wearing her non-removable bridge for 21 years and comes into the office for dental cleanings twice a year.
Panoramic X-Ray 21 Years Later
There is not enough bone to place implants without a Sinus Bone Graft
Follow-up 21 years after the Sinus Bone Graft and placement of a non-removable bridge. The patient is 83 years old now.
Simultaneous Bone Graft and Implant Placement
In other patient situations when there is more bone available, but not quite enough to cover the whole implant (Fig. 6), a bone graft may be done at the same time as the implant placement. This is called Simultaneous Bone Graft and Implant Placement versus the Two-stage delayed approach.
Contraindications for Sinus Elevation (Lift) procedures
Uncontrolled diabetes mellitus
Intranasal or topical steroid use
Maxillary radiation therapy
Unrepaired oroantral fistula
Active acute sinus disease
Chronic septic sinus disease
Inadequate or excessive interarch distance
Anti-coagulants (blood thinners) that cannot be stopped