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Bone Grafting

Major & Minor Bone Grafting

Over a period of time, the jawbone associated with missing teeth atrophies or is reabsorbed. This often leaves a condition in which there is poor quality and quantity of bone suitable for placement of dental implants. In these situations, most patients are not candidates for placement of dental implants.

Today, we have the ability to grow bone where needed. This not only gives us the opportunity to place implants of proper length and width, it also gives us a chance to restore functionality and aesthetic appearance.

Socket Preservation

Socket preservation will often be recommended to be completed at the time teeth are removed. This technique helps to preserve the original bony anatomy of the tooth extraction site. This is very helpful for areas where dental implants are planned and may be recommended for individuals having multiple extractions when dentures are planned. The technique involves careful, atraumatic removal of the tooth/teeth with preservation of as much bone as possible. This is often done by using a thin instrument (periotome) and gently tapping to loosen the tooth. The socket is cleansed of any infection and a bone substance is inserted and covered by a thin collagen barrier to protect the site along with dissolving sutures. The bone substance used is usually bovine-derived and completely inorganic, i.e. free from residues of protein or DNA and this substance simply acts like a scaffold to encourage your bone to fill in to the site. Synthetic and other materials are available if patients would prefer this for personal reasons. Although socket preservation cannot restore bone where it has already been lost, if restoration of more bone is required later, socket preservation can minimize or eliminate the need for future bone grafting.

Major Bone Grafting

Bone grafting can repair implant sites with inadequate bone structure due to previous extractions, gum disease or injuries. Your own bone is taken from the jaw, hip or tibia (below the knee). Sinus bone grafts are also performed to replace bone in the posterior upper jaw. In addition, special membranes may be utilized that dissolve under the gum and protect the bone graft and encourage bone regeneration. This is called guided bone regeneration or guided tissue regeneration.

Major bone grafts are typically performed to repair defects of the jaws. These defects may arise as a result of traumatic injuries, tumor surgery, or congenital defects. Large defects are repaired using the patient’s own bone. This bone is harvested from a number of different sites depending of the size of the defect. The jaw, hip (iliac crest), and lateral knee (tibia), are common donor sites. These procedures are routinely performed in an office or hospital operating room and may require a hospital stay depending on the nature of the surgery.

Sinus Lift Procedure

The maxillary sinuses are air-filled chambers in your upper jaw connecting to your nose and just above the roots of the upper back teeth. Sinuses are like empty rooms that have nothing in them. Some of the roots of the natural upper teeth extend up into the maxillary sinuses. When these upper teeth are removed, there is often just a thin wall of bone separating the maxillary sinus and the mouth. Dental implants need bone to hold them in place. When the sinus wall is very thin, it is impossible to place dental implants in this bone.

There is a solution and it’s called a sinus graft or sinus lift graft. Your surgeon enters the sinus from where the upper teeth used to be. The sinus membrane is then lifted upward and donor bone is inserted into the floor of the sinus. Keep in mind that the floor of the sinus is the roof of the upper jaw. After several months of healing, the bone becomes part of the patient’s jaw and dental implants can be inserted and stabilized in this new sinus bone.

The sinus graft makes it possible for many patients to have dental implants when years ago there was no other option other than wearing loose dentures.

If enough bone between the upper jaw ridge and the bottom of the sinus is available to stabilize the implant well, sinus augmentations and implant placement can sometimes be performed as a single procedure. If not enough bone is available, the sinus augmentation will have to be performed first, then the graft will have to mature for several months, depending upon the type of graft material used. Once the graft has matured, the implants can be placed.

Ridge Expansion

In severe cases, the ridge has been reabsorbed and a bone graft is placed to increase the ridge height and/or width. This is a technique used to restore the lost bone of dimension when the jaw ridge gets too thin to place conventional implants. In this procedure, the bony ridge of the jaw is literally expanded by mechanical means. Bone graft material can be placed and matured for a few months before placing in the implant.

Nerve Repositioning

The inferior alveolar nerve, which gives feeling to the lower lip and chin, may need to be moved in order to make room for placement of dental implants in the lower jaw. This procedure is limited to the lower jaw and indicated when teeth are missing in the area of the two back molars and/or second premolar, with the above-mentioned secondary condition. This procedure is considered a last approach (there is almost always some postoperative numbness of the lower lip and jaw area, which dissipates very slowly).

Typically, an outer section of the cheek side of the lower jawbone is removed in order to expose the nerve and vessel canal. Then we isolate the nerve and vessel bundle in that area and slightly pull it out to the side. At the same time, we will place the implants. Then the bundle is released and placed back over the implants. The surgical access is refilled with bone graft material of the surgeon’s choice and the area is closed.

Summary – Bone Grafting

These procedures may be performed separately or together, depending on the individual’s condition. As stated earlier, there are several areas of the body that are suitable for attaining bone grafts. In the maxillofacial region, bone grafts can be taken from inside the mouth, in the area of the chin or third molar region, or in the upper jaw behind the last tooth. In more extensive situations, a greater quantity of bone can be attained from the hip or the outer aspect of the tibia at the knee. When we use the patient’s own bone for repairs, we generally get the best results.

In many cases, we can use xenograft material to implement bone grafting for dental implants. The bone is sourced from a bovine-derived bone material used to promote the patient’s own bone to grow into the site. In some cases, we use an allograft material which is derived from a human source. Synthetic materials can also be used to simulate bone formation. In addition to bone grafting, sometimes you will need restoration of healthy soft tissue with gum grafting. Grafting procedures, the type of graft and the source of the grafting material will be discussed in great detail before any intervention with grafting is done.

These surgeries are performed in the office surgical suite under IV sedation or general anaesthesia. In some cases, the procedures are done in the hospital for proper performance of the surgery. After discharge, bed rest is recommended for a day or two and limited physical activity for about a week and sometimes more.