Bone loss to the jaw is one of the most serious consequences of missing teeth. It begins as soon as a tooth is lost, when the natural stimulation for bone growth created by the force of teeth chewing can no longer occur. The result can be dramatic—the width of the bone can reduce by 25% in the first year alone after tooth loss.
Progressive bone loss can affect your mouth in a number of ways, such as a decrease in gum tissue. It can also limit your choices for tooth replacement. Losing more and more teeth (and bone along with them) could alter your facial appearance if the distance between the nose and chin noticeably shortens as the years go by.
Fortunately, excessive bone loss isn’t inevitable if you lose a tooth. Dentists can perform bone grafting procedures with materials that stimulate new bone growth at the missing tooth site. And, if placed immediately after a tooth extraction, grafting can prevent excessive bone loss and allow for future dental implants to be placed.
Bone grafts are derived from one of four possible sources: the patient, another human being, an animal or synthetic materials. The source used will depend on whichever the dentist believes will work best in the patient’s situation. Donor tissue from another person or animal is thoroughly disinfected and safe for grafting.
The graft itself acts more as a platform for nearby bone to grow upon; the new bone growth will eventually replace the graft material, which is made up of the minerals calcium, phosphorous and hydroxyapatite. The dentist may also cover the graft with collagen membranes to guide the regeneration, or synthetic material that acts with other biologically active molecules in the body to promote healing. These materials are eventually absorbed by the body.
Not all grafting procedures are alike—the particular approach taken will depend on the location in the mouth, the degree of bone loss, and whether the grafting takes place immediately after removing a tooth (extraction) or if some time has passed since tooth loss.
In the case of tooth extraction, one option would be for the dentist to fill the site with bone-grafting materials after removing the tooth and before suturing the gum in place. Immediate grafting can limit bone loss during gum healing and facilitate a future dental implant procedure. If the tooth has been missing for some time and the remaining bone is insufficient, the dentist will make an incision in the gum tissue to expose the bone, place and secure the graft along with any planned membranes or growth factors, and then suture the incision closed. Procedures like this are usually performed with local anesthesia.
In cases involving the back of the upper jaw, where bone is insufficient vertically, a surgeon may also utilize the sinus cavity just above it as a grafting site. This sinus can be accessed through the future implant site or laterally through the cheek-side wall of the sinus. There are many more types of bone grafting procedures, from saving teeth threatened by periodontal (gum) disease to repair of traumatic injuries, all of which have similar post operative needs.
After a grafting procedure, patients may experience only mild discomfort for a few days, usually managed with anti-inflammatory, non-steroidal medications like ibuprofen. As a precaution against infection, an antibiotic may also be prescribed.
Besides halting a patient’s accelerated bone loss, bone grafting could also make possible the best tooth replacement choice available in cosmetic dentistry—dental implants. Since their introduction over three decades ago, dental implants have increased in popularity among both patients and dentists for their lifelike appearance, durability and applicability with a number of other tooth replacement options.
But implants require a minimum amount of bone at the site for proper anchorage, and adequate bone ensures the implant’s eventual crown placement will function properly and appear natural. Bone regeneration through grafting can improve the bone mass at a missing tooth site to the point that a dental implant becomes indistinguishable from a natural tooth.
The implant’s unique composition also holds an added benefit for bone health: The titanium post inserted into the jawbone becomes fused with bone tissue, encouraging continued bone growth in the area
The success rate for bone grafts in the jaws for the purpose of placing dental implants is very high. However, there is always a chance that the bone graft will fail, even if your own bone was used. Bone grafts are not rejected like organ transplants. Dentists don’t know why some bone grafts fail. They do know that certain people—such as those who smoke and those with certain medical conditions—have higher risks of graft failure than others do.
A failed graft will be removed. Once the area has healed, your dentist may choose to place a second graft
A nerve called the inferior alveolar nerve runs through the lower jaw. This nerve gives feeling to the lower lip and chin. In patients who have lost significant amounts of lower jawbone, it may not be possible to place implants without damaging this nerve. To address this problem, an oral surgeon can drill a small window in the bone and move the nerve to one side. The implants then can be placed through the bony canal previously filled by the nerve. This technique is not used very often because it is possible to damage the nerve just by moving it.