Oral Surgery Norwood, MA | Mansfield, MA
Bone loss can occur in the upper and lower jaws for several reasons. Localized bone loss often occurs around diseased teeth due to periodontal (gum) disease, fractured teeth, traumatic injuries, and dental infections. In addition, over a period of time the jawbone associated with missing teeth atrophies (bone resorption/shrinks). This often leaves a condition in which there is poor quality and quantity of bone, unsuitable for placement of dental implants. In the past, patients with significant bone loss were not candidates for placement of dental implants.
With current bone graft techniques, we have the ability to grow bone where needed. Augmentation bone grafts can be accomplished virtually anywhere on the upper and lower jaws. This enables us to offer dental implants as a replacement for missing teeth to almost all patients, even if substantial bone loss has occurred.
Commonly used bone graft materials include autogenous bone (your own bone), cadaver bone (bank bone), bovine bone, and synthetic bone. The selection of graft material and surgical technique is based on the location and severity of the bone loss. In most cases, specially prepared cadaver bone and/or autogenous bone are utilized. Autogenous bone is usually taken from other areas of the upper or lower jaw.
The great majority of bone grafts required for implant placement are minor procedures that can easily be accomplished in the office under local anesthesia or intravenous sedation. Major bone grafts are utilized to repair extremely large defects of the jaws. These major defects usually result from severe traumatic injuries, tumor surgery, and congenital defects. Large defects are always repaired using the patient’s own bone. Since a large amount of bone is needed to repair these extensive defects, the bone must be harvested from areas where there is an abundance of available bone. This bone can be harvested from a number of different sites depending on the size of the defect. The skull (cranium), hip (iliac crest), and lateral knee (tibia), are common donor sites. These procedures are performed in an operating room and require a hospital stay.
Socket Preservation Graft
The socket preservation graft is an extremely simple and important bone graft procedure. This procedure must be accomplished at the time of tooth extraction. It helps to preserve bone at an extraction site in preparation for future implant placement. The area of the jaw bone that holds a tooth in place is called a tooth socket. Preservation of bone volume and architecture (shape) is crucial for implant stability and esthetics. After a tooth has been extracted, the supporting bone (socket) begins to rapidly melt away (bone resorption). Post-extraction bone resorption tends to be particularly severe in sockets with thin walls of bone. A socket preservation graft placed immediately after tooth extraction helps to preserve bone volume and architecture by minimizing post-extraction bone resorption. This procedure diminishes the likelihood that a more complicated bone graft will be necessary prior to implant placement. In many cases, this simple graft is all that is required to provide sufficient bone for implant placement. In some cases, due to severe inflammation at the extraction site, a low maxillary sinus, extensive preexisting bone loss, and/or diseased tissue at the extraction site, it is not possible to provide enough bone volume for implant placement with this procedure alone. In these circumstances, additional bone grafting may be required either at the time of implant placement or as a staged procedure prior to implant placement.
The tooth is extracted with great care leaving as much socket bone intact as possible. After the tooth has been extracted, the socket is gently but thoroughly cleaned and debrided. A specially prepared particulate cadaver bone graft is inserted into the socket and retained in place with a small collagen plug which is sutured over the socket. The collagen plug falls out by itself a week or two later, the sutures dissolve and fall out in two to three weeks. The site is reevaluated for implant placement four months after grafting; if sufficient bone is present the patient is ready to be scheduled for implant surgery.
If you require tooth extraction and you are thinking of replacing the tooth with a dental implant, a consultation visit is strongly recommended prior to the extraction appointment so that Dr. Turesky can determine the best way to proceed and inform you of all treatment options. Please see our information regarding dental implants, tooth extraction, and dental implant video on this website for detailed information concerning these topics.
When severe bone loss has resulted in a ridge that is too narrow to support a dental implant, there are several bone grafting options available:
Guided Bone Regeneration Socket Reconstruction Graft
Particulate cadaver bone grafts have many uses in implant dentistry. They are often utilized in cases where there is sufficient bone to provide initial implant stabilization, but there is inadequate bone volume to fully cover the implant. In these cases, the graft can be placed simultaneously with implant insertion. A small collagen membrane may be required to contain the graft and prevent soft tissue (gum tissue) from interfering with new bone formation. The membrane is broken down and eliminated by the body so removal at a future date is not necessary. This technique is often referred to as guided tissue regeneration or guided bone regeneration.
The simple socket preservation bone graft technique, previously discussed, can be accomplished immediately after tooth extraction with excellent results when there is minor to moderate tooth socket bone loss. However, when there is severe socket bone loss due to infection, traumatic injury, or the extraction process, simple socket preservation is not possible since the socket is no longer intact. Guided bone regeneration can be utilized immediately after tooth extraction to reconstruct the tooth socket when the socket has been largely or completely destroyed. Immediate socket reconstruction with particulate cadaver bone graft and collagen membrane is a fairly simple procedure that can often regenerate sufficient bone volume and satisfactory ridge architecture to permit implant placement four to six months after grafting. This procedure must be accomplished at the time of tooth extraction. A socket reconstruction graft diminishes the likelihood that more complicated bone grafting will be required prior to implant placement.
A ridge split is performed in cases where the ridge is too narrow to place an implant but wide enough to split. There must be sufficient bone height for initial implant stabilization to accomplish this procedure. The crest of the ridge is split along its length between the outer cortex and inner cortex. The ridge is carefully expanded as the implant is inserted. This creates a void in the center of the split ridge which is filled with a specially prepared freeze-dried cadaver bone graft. The implant is buried beneath the gum tissue and allowed to heal for six months. When this procedure is accomplished in the mandible, the procedure must be staged due to the dense non-elastic nature of the mandibular bone. The bone cuts (osteotomies) are accomplished three weeks prior to implant placement. This three week healing period assures excellent blood supply to the expanded bone by allowing the gum tissue to reattach to the bone in the area of the osteotomies before expansion takes place.
Onlay Cortical Bone Graft
An onlay cortical bone graft is performed in cases of moderate to severe bone loss. A small block of bone is harvested from the chin or the mandibular ramus (just posterior to the lower wisdom tooth area). These donor sites are surgically approached from within the mouth. The block of bone is screwed into the recipient site (future implant site) with specially designed tiny surgical bone screws. The area is allowed to heal for 4 to 6 months, at which time the screws are removed and the implant is placed.
Occasionally a deficiency in healthy attached gingiva (gum) necessitates a gingival graft prior to implant placement. If a gingival graft is required after a cortical bone graft has been accomplished, it is performed at the time of screw removal. The implant can be placed approximately three months after gingival grafting.
Sinus Lift Procedure
The maxillary sinuses are located above the roots of the upper posterior teeth and below the eye socket. The maxillary sinuses are positioned behind the cheeks on either side of the nose. Sinuses are like empty rooms that are filled with air. The floor of the maxillary sinus is located just above the roots of the upper molars and second premolar. Frequently, the roots of these teeth extend up into the maxillary sinuses. When these upper teeth are removed, there is often just a thin layer of bone separating the maxillary sinus and the mouth. Dental implants need bone to hold them in place. A thin sinus floor will not provide enough bone to support a dental implant.
The solution to this problem is called a maxillary sinus graft or maxillary sinus lift graft. Dr. Turesky creates a small window in the thin bone on the lateral sinus wall where the maxillary posterior teeth had previously been extracted. The delicate sinus membrane is carefully exposed then lifted upward and a bone graft is inserted beneath the membrane into the floor of the sinus. The bone graft is usually a combination of specially prepared freeze-dried cadaver bone or bovine bone and bone harvested from the patient’s upper or lower jaw. After six months of healing, when the bone becomes solid enough to support an implant, the implants are placed.
The sinus graft makes it possible for many patients to have dental implants when years ago their only option was to wear dentures, partial dentures, or bridges.
In many cases, the bone beneath the sinus floor is slightly deficient but there is sufficient bone height to provide initial implant stabilization. In these situations, sinus grafting and implant placement are performed simultaneously. This remarkably simple bone graft procedure is called a simultaneous internal sinus lift. It is internal because the sinus floor graft site is approached from within the implant preparation site. This is an elegant surgical technique that adds only a few minutes to the implant procedure and reduces the total healing period by approximately six months.
Bone graft and gingival graft procedures can be performed in complete comfort at our office with any one of the following anesthetic options: local anesthesia, intravenous general anesthesia (asleep), intravenous conscious sedation, nitrous oxide gas anesthesia with local anesthesia, oral sedation with local anesthesia. Dr. Turesky will help you to choose the anesthetic technique which best suits your needs during your consultation appointment.