Bone augmentation is a term for a variety of procedures that are used to “build” bone. These procedures typically involve grafting (adding) bone or bonelike materials to the jaw, and waiting for the grafted material to fuse with the existing bone over several months. Bone grafting is often associated with dental restorations such as bridge work and dental implants, procedures that depend on the jawbone having sufficient bone volume to support the bridge or implant.
Major factors that negatively affect jaw bone volume include:
- Periodontal Disease – Periodontal disease can permanently damage the jaw bone that supports the teeth. Damage is progressive and eventually the teeth become unstable.
- Tooth Extraction – Studies have shown in the three years following a tooth extraction, patients lose 40-60% of the bone surrounding the extraction site. Bone loss results in what is called a “bone defect”.
- Injuries and Infections – Dental injuries and other physical trauma to the jaw can cause the bone to recede. Infections can also cause a similar recession of the bone.
Reasons for bone grafts
In most cases, bone grafting is a highly successful procedure and certainly a preferable alternative to having missing teeth, diseased teeth, or tooth deformities.
There are essentially two basic ways in which bone grafting benefits 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 improve support.
Preservation – Bone recession resulting from tooth extraction, periodontal disease, or other invasive processes can be prevented or limited by grafting.
Where does the bone come from?
Bone grafts are categorized according to the source of the graft material:
autogenous – bone taken from one area of the patient and transplanted to another area
allograft – either synthetic bone or bone from a bone bank (cadaver bone)
xenograft – bovine/cow bone
Usually, the best material for a bone graft is your own bone, which most likely will come from your chin or ramus (the back part of your lower jaw).Your surgeon will discuss your options for graft materials, and help you weigh their risks and benefits, before any procedures are done.
What does bone grafting involve?
Initially, your surgeon will do a thorough examination to assess the general condition of the teeth and gums. If periodontal disease is present or teeth are in poor condition, these factors will be addressed before bone grafting begins. To assess the depth, width and condition of the existing bone, your surgeon will recommend panoramic X-rays and in some cases, a CAT scan as well. Depending on these results, the surgeon may also anesthetize the area and explore into the gum in order to determine what kind and how much bone is required.
The bone grafting procedure can often take several months to complete. Bone is typically harvested from your own body (or less frequently from one of the other sources mentioned above) and added to the affected site. This bone will fuse with the existing bone and the migration of cells will cause firm adhesion and cell growth.
During the surgery, a local anesthetic will be used to numb the grafting and extraction sites. A small incision will be made to prepare the site for the new bone and it will be anchored into place. On occasion, a synthetic membrane is used to cover the new bone. This membrane prevents soft tissue and bacterial invasions, and encourages new bone growth. Bone grafting is primarily done in the office, and you will return home with instructions for your post-operative care. Your surgeon will prescribe medications to help manage infection, discomfort and swelling.