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, many patients are not candidates for placement of dental implants without proper bone grafting (Figure 1).

Figure 1 (Source : Anonym)

There are several areas of the body that are suitable for harvesting 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 or addition, we generally get the best results. In many cases, we can use allograft material to implement bone grafting for dental implants. This bone is prepared from cadavers and used to get the patients own bone to grow into the repair site. It is quite effective and very safe. Synthetic materials can also be sued to stimulate bone formation. We even use factors from patients own blood to accelerate and promote bone formation in graft areas. We now 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 esthetic appearance(Figure 2, 3, 4, 5). Several bone graft procedures are referred to below.

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Ridge-augmentation Ridge Expansion:

In some cases the ridge has been reabsorbed and a bone graft is placed to increase the ridge height and/or width In severe cases, the ridge has been reabsorbed and a bone graft is placed to increase ridge height and/or width (Figure 6, 7, 8). This is a technique used to restore the lost bone 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 the implant.
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Sinus lift procedure:

This procedure involves elevating the sinus membrane and placing the bone graft onto the sinus floor, allowing implants to be placed in the back part of the upper jaw.

The maxillary sinuses are behind the cheeks and on top of the upper teeth. Sinuses are like empty rooms. 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. The sinus membrane is then lifted upward and donor bone is inserted into the floor of the sinus (Figure 9, 10, 11). 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 (Figure 12,13).

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.
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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 to 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 and 2nd premolar, with the above-mentioned secondary condition. Since this procedure is considered a very aggressive approach (there is almost always some postoperative numbness of the lower lip and jaw area, which dissipates only very slowly, if ever), usually other, less aggressive options are considered first.

Typically, ıt will be removed an outer section of the cheek side of the lower jawbone in order to expose the nerve and vessel canal. Then we will isolate the nerve and vessel bundle in that area, and slightly pull it out to the side. At the same time ıt will be placed the implants we’ll be tracking the neuro-vascular bundle. Then the bundle is released and placed back over the implants.
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These procedures:

may be performed separately or together, depending upon the individual's condition. These surgeries are performed in the out-office surgical suite under IV sedation or general anesthesia. After discharge, bed rest is recommended for one day and limited physical activity for one week.

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Figure 2