About Bone Grafting
Periodontal disease is the leading cause of bone loss in the oral cavity, though there are others such as ill-fitting dentures and facial trauma. The bone grafting procedure is an excellent way to replace lost bone tissue and encourage natural bone growth. Bone grafting is a versatile and predictable procedure which fulfills a wide variety of functions.
Bone grafting is often closely associated with dental restorations such as bridge work and dental implants. In the majority of cases, the success of a restoration procedure can hinge on the height, depth, and width of the jawbone at the implant site. When the jawbone has receded or sustained significant damage, the implant(s) cannot be supported on this unstable foundation and bone grafting is usually recommended for the ensuing restoration.
A bone graft may be required to create a stable base for dental implant placement, to halt the progression of gum disease, or to make the smile appear more aesthetically pleasing.
There are several major factors that affect jaw bone volume:
- Periodontal Disease – Periodontal disease can affect and permanently damage the jaw bone that supports the teeth. Affected areas progressively worsen until the teeth become unstable.
- Tooth Extraction – Studies have shown that patients who have experienced a tooth extraction subsequently lose 40-60% of the bone surrounding the extraction site during the following three years. Loss of bone results in what is called a “bone defect”.
- Injuries and Infections – Dental injuries and other physical injuries resulting from a blow to the jaw can cause the bone to recede. Infections can also cause the jaw bone to recede in a similar way.
Types of Bone Grafts
There are several types of dental bone grafts. The following are the most common:
- Autogenous bone graft – In this type of graft the bone is removed from elsewhere in the body and implanted in the mouth. Common donor sites for bone grafting include the iliac section of the pelvis, the chin and the posterior third molar areas of the jaw. If large amounts of bone need to be harvested, the hip or the shin bone (tibia) is generally used.
- Allograft – Synthetic bone (manmade) can be created in the laboratory and used in the bone grafting procedure. Bone can also be obtained from a bone bank (cadaver bone).
- Xenograft – This is the implantation of bovine (cow) bone. A xenograft is perfectly safe and has been used successfully; ample bone can be obtained, and a secondary donor site is not necessary.
Reasons for Bone Grafts
Bone grafting is a highly successful procedure in most cases. It is also a preferable alternative to having missing teeth, diseased teeth, or tooth deformities. Bone grafting can increase the height or width of the jawbone and fill in voids and defects in the bone.
There are essentially two basic ways in which bone grafting can positively impact the health and stability of the teeth:
- Jaw Stabilization – Bone grafting stabilizes and helps restore the jaw foundation for restorative or implant surgery. Deformities can also be corrected and the restructuring of the bone can provide added support.
- Preservation – Bone grafting can be used to limit or prevent bone recession following a tooth extraction, periodontal disease, or other invasive processes.
- Dental implants – Implants are the preferred replacement method for missing teeth because they restore full functionality to the mouth; however, implants need to be firmly anchored to the jawbone to be effective. If the jawbone lacks the necessary quality or quantity of bone, bone grafting can strengthen and thicken the implant site.
- Sinus lift – A sinus lift entails elevating the sinus membrane and grafting bone onto the sinus floor so that implants can be securely placed.
- Ridge augmentation – Ridges in the bone can occur due to trauma, injury, birth defects, or severe periodontal disease. The bone graft is used to fill in the ridge and make the jawbone a uniform shape.
- Nerve repositioning – If the inferior alveolar nerve requires movement to allow for the placement of implants, a bone grafting procedure may be required. The inferior alveolar nerve allows feeling and sensation in the lower chin and lip.