Insufficient bone is a common problem for many people who seek dental implants, but since it is often invisible, most patients are completely unaware of the issue or its cause. The absence of teeth for a period of time can cause the underlying jawbone to be reabsorbed, leading to the remaining bone being too low in both quality and quantity to support a dental implant.
Fortunately, we can now deal with this problem right here in Miami by not only replacing the missing bone but also promoting fresh bone growth in the area. This allows the implants to be placed as desired to securely anchor the replacement tooth, providing full restoration of both function and appearance.
Major & Minor Bone Grafting
In most cases, Drs. Gallardo and Lamas performs minor bone grafts to repair inadequate bone structure where needed to perform an implant. These sites of inadequate bone are generally due to injury, gum disease, or prior extractions. These grafts can use the patient’s own bone, bone from a tissue bank, or occasionally synthetic alternatives. Special dissolving membranes can also be used under the gum to protect the graft and encourage further regeneration of bone. This is referred to as guided tissue regeneration or guided bone regeneration.
Another grafting procedure called a lift graft or simply a sinus graft is used to permit the replacement of upper teeth that are positioned near a thin sinus wall. The maxillary sinuses are empty pockets positioned behind the cheeks and above the upper teeth. Naturally, the roots of certain upper teeth reach up into these sinuses, and when these are missing, only a thin layer of bone is left to separate the maxillary sinuses and the mouth. Since this sinus wall is very thin, it is often impossible to place dental implants in the area. For years there was no option for missing teeth in the region other than dentures.
Today, the sinus lift graft, which is performed by Dr. Gallardo and Dr. Lamas in addition to our oral surgeon Dr. Arroyo, corrects this situation by augmenting the bone in the area. During this procedure, the sinus membrane is lifted upward, allowing donor bone to be inserted into the bottom of the sinus or roof of the upper jaw. Over the course of a few months, the bone becomes a solid part of the jaw, allowing dental implants to be placed and stabilized in the area.
In some cases, the sinus lift procedure can be performed at the same time as implant placement, but this requires enough bone to be available between the bottom of the sinus and the upper jaw ridge to stabilize the implant adequately during the healing process. If this is not the case, the sinus graft will be performed first and given several months to heal before the implants are placed.
In some cases, particularly those when teeth have been decaying or missing for a longer period of time, much of the bony ridge of the jaw has been reabsorbed, leaving it too thin to place normal implants. In these situations, a bone grafting technique can be used to restore the increase the width of the jaw mechanically and restore the dimension of the jaw ridge. The grafting material for this procedure is generally placed and allowed to mature for several months before the implant procedure is begun.
In a few situations, the inferior alveolar nerve that provides feeling to the chin and lower lip must be moved to allow sufficient room for dental implants in the lower jaw. This is sometimes indicated when the missing teeth are in the area of the lower rear molars or second premolar. This procedure is considered quite aggressive and typically leaves some permanent numbness in the lower lip and jaw, so it is typically considered only after safer options such as blade implants are ruled out.
To perform this procedure, Dr. Gallardo and Dr. Lamas typically removes an outer section of the lower jawbone near the cheek to allow access to the nerve and vessel canal. Once the area is exposed, he isolates the nerve and vessel bundle and pulls it slightly to the side while the implants are placed. Once the implants are in place, the bundle is replaced over the implants, and the area is filled with bone graft material. For best results, this is generally the patient’s own bone, taken from inside the mouth or the hip or tibia.
Bone Grafting FAQs
Grafts from the patient’s own bone are known as autogenous bone grafts, or autografts, and are generally preferred since they are live bone and so contain living cellular elements that will enhance bone growth. However, an autograft requires an additional procedure to harvest bone from the chin, jaw, hip, skull, or lower leg. In cases where it is unwise to put the patient through a second position, alternative sources of bone can be used. This can be either allogenic bone, or bone harvest from a cadaver and then processed with a freeze-dry method to remove water, or xenogenic bone, which is derived from another species like a cow and then processed at high temperatures to avoid potential rejection by the patient’s immune system. In either of these cases, the bone is dead and will not produce new bone by itself, but it serves as a good framework for the surrounding bone to grow over to fill the defect. This generally takes longer and is somewhat less reliable than an autograft.
There are several synthetic options that have been proven safe. One common option is demineralized bone matrix, or DBM, is made from collagen, growth factors, and proteins that have been extracted from allograft bone and is available for use as a powder, putty, chips, or injectable gel. Graft composites consisting of combinations of bone graft materials and various growth factors can also be in some cases, since they combine the benefits of a number of materials, like collagen or bone marrow cells to aid in new growth. In other cases, bone morphogenetic proteins (BMPs) can be used to promote new bone formation and healing.
In most cases, Dr. Arroyo performs these procedures in our out-office surgical suite here in Miami FL using IV sedation or general anesthesia.
In most cases, patients can go home to recover as soon as the procedure is over, although it will be necessary to have a caretaker for the first day or so due to the sedation.
Patients should be prepared for bed rest for the first day following their bone grafting procedure, but normal activities can be gradually resumed after that. Physical activity should be limited for the first week to allow full recovery. You’ll be prescribed medication to deal with any pain, although most patients report only moderate pain along with some swelling for the first few days. Recovery time will also depend on the extent of the procedure.