Bone Grafting and Ridge Preservation
Bone grafting is often required to support implants. The success of a restoration (crown, bridge or implant supported denture) depends on the height, depth, and width of bone available at the implant site. Various processes including tooth removal, periodontal disease and trauma allow the jaw bone that once surrounded the teeth to atrophy (shrink), leaving inadequate support for a dental implant.
What Does Bone Grafting Involve?
There are several types of bone grafts. Dr. Young will help you to determine the best type for your particular condition.
Autogenous Bone Graft - Harvested from your own body
Allograft Bone Graft – From a cadaver (human donor)
Xenograft – From another species e.g. cow bone
Alloplastic – Using artificial or synthetic bone
As an Oral and Maxillofacial Surgeon Dr. Young is often able to replace or even grow bone where needed. The procedures are referred to as:
Sinus Lifts - The maxillary sinuses are behind your cheeks and over (superior to) the upper teeth. They are air filled spaces that limit the length of upper implants. If the bone below the sinuses is very thin a “sinus lift” may be required. Dr. Young 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.
If enough bone between the upper jaw ridge and the bottom of the sinus is available to stabilize the implant, sinus augmentations and implant placement can sometimes be performed at the same time. 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. Once the graft has matured, the implants can be placed.
Ridge-augmentation / Block Bone grafting - Used when the ridge has been reabsorbed and a “block” of bone is fixed into place on the native bone to increase the ridge height and/or width. Usually your own bone is the best choice for this.
Ridge Expansion - in severe cases, the bone has been reabsorbed and is too thin to allow implant placement. Using ridge expansion the bone of the jaw is “expanded” or “split” by mechanical means. Bone graft material can be placed and allowed to mature for a few months before placing the implant, or the implant may be placed at the time of the initial surgery.
Nerve-repositioning - Involves moving the inferior alveolar nerve (which gives feeling to the lower lip and chin) in order to make room for dental implants in the lower jaw. This procedure is considered to be aggressive: 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.
BMP – Bone Morphogenic Protein is an exciting product whereby chemical “messengers” are placed onto native bone to “grow” bone. This is a very new area in dental implantology but one that has tremendous potential.
These procedures may be performed separately or together, depending upon the individual's condition. There are several areas which are suitable donor sites for a bone graft. They can be taken from inside the mouth: from the chin or from the wisdom tooth regions. In more extensive situations, a greater quantity of bone can be obtained from the skull (calvarium), hip (anterior or posterior iliac crest), lower leg below the knee (tibia) and rib.
These surgeries are typically performed in our outpatient surgical suite under an I.V. sedation or general anesthesia. Occasionally Dr. Young may take you to the hospital for the surgery. If major bone grafting is done (e.g. from the lower leg or hip) you will need to avoid strenuous activity for a period of time.
Please also see our sections on dental implants.