Bone Grafting

Minor Bone Grafting

Over a period of time, the jawbone that once supported missing teeth atrophies (wastes away) or is reabsorbed.  This can affect facial features and caused an aged look.  The poor quality and lack of bone in this situation is unsuitable for placement of dental implants. In these cases, a patient will not likely be a candidate 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 esthetic appearance.

Bone grafting can repair implant sites with inadequate bone structure due to previous extractions, gum disease or injuries. The bone is either obtained from a tissue bank or 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 Grafting

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 on the size of the defect. The skull (cranium), hip (iliac crest), and lateral knee (tibia), are common donor sites. These procedures are routinely performed in an operating room and require a hospital stay.

Platelet Rich Plasma

Platelet Rich Plasma (PRP) is exactly what its name suggests. The substance is a by-product of blood (plasma) that is rich in platelets. Until now, its use has been confined to the hospital setting. This was due mainly to the cost of separating the platelets from the blood (thousands) and the large amount of blood needed (one unit) to produce a suitable quantity of platelets. New technology permits the doctor to harvest and produce a sufficient quantity of platelets from only 55 cc of blood drawn from the patient while they are having outpatient surgery.

Why all the excitement about PRP? PRP permits the body to take advantage of the normal healing pathways at a greatly accelerated rate. During the healing process, the body rushes many cells and cell-types to the wound in order to initiate the healing process. One of those cell types is platelets. Platelets perform many functions, including formation of a blood clot and release of growth factors (GF) into the wound. These GF (platelet derived growth factors PGDF, transforming growth factor beta TGF, and insulin-like growth factor ILGF) function to assist the body in repairing itself by stimulating stem cells to regenerate new tissue. The more growth factors released sequestered into the wound, the more stem cells stimulated to produce new host tissue. Thus, one can easily see that PRP permits the body to heal faster and more efficiently.

A subfamily of TGF, is bone morphogenic  protein (BMP). BMP has been shown to induce the formation of new bone in research studies in animals and humans. This is of great significance to the surgeon who places dental implants. By adding PRP, and thus BMP, to the implant site with bone substitute particles, the implant surgeon can now grow bone more predictably and faster than ever before.

PRP has many clinical applications:

• Bone grafting for dental implants. This includes onlay and inlay grafts, sinus lift procedures, ridge augmentation procedures, and closure of cleft, lip and palate defects.
• Repair of bone defects creating by removal of teeth or small cysts
• Repair of fistulas between the sinus cavity and mouth

PRP also has many advantages:

• Safety: PRP is a by-product of the patient’s own blood; therefore, disease transmission is not an issue.
  
• Convenience: PRP can be generated in the doctor’s office while the patient is undergoing an outpatient surgical procedure, such as placement of dental implants.
  
• Faster healing: The super saturation of the wound with PRP, and thus growth factors, produces an increase of tissue synthesis and thus faster tissue regeneration
• Cost effectiveness: Since PRP harvesting is done with only 55 cc of blood in the doctor’s office, the patient need not incur the expense of the harvesting procedure in hospital or at the blood bank.
• Ease of use: PRP is easy to handle and actually improves the ease of application of bone substitute materials and bone grafting products by making them more gel-like.

Frequently asked questions about PRP:

1. Is PRP safe? Yes. During the outpatient surgical procedure a small amount of your own blood is drawn out via the IV. This blood is then placed in the PRP centrifuge machine and spun down. In less than fifteen minutes, the PRP is formed and ready to use.
2. Should PRP be used in all bone-grafting cases? Not always. In some cases, there is no need for PRP. However, in the majority of cases, application of PRP to the graft will increase the final amount of bone present in addition to making the wound heal faster and more efficiently.
3. Will my insurance cover the costs? Unfortunately not. The cost of the PRP application (approximately $400) is paid by the patient.
4. Can PRP be used alone to stimulate bone formation? No. PRP must be mixed with either the patient’s own bone, a bone substitute material such as demineralized freeze-dried bone, or a synthetic bone product, such as BIO-OSS.
5. Are there any contraindications to PRP?  Very few.  Unfortunately, patients with bleeding disorders or hematologic diseases do not qualify for this in-office procedure. Check with your surgeon and/or primary care physician to determine if PRP is right for you.
   

Sinus Lift Procedure

The maxillary sinuses are behind your cheeks and on top of the upper 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. The dental implant 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 ridge height and/or width. 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.

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 (placement of blade implants, etc.)

Typically, we remove an outer section of the cheek side of the lower jawbone 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.

These procedures may be performed separately or together, depending upon 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 allograft material to implement bone grafting for dental implants. This bone is prepared from cadavers and used to promote the patient’s own bone to grow into the repair site. It is quite effective and very safe. Synthetic materials can also be used to stimulate bone formation. We even use factors from your own blood to accelerate and promote bone formation in graft areas.

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.