There are many reasons why a patient may need a bone graft. When a tooth is lost the supporting bone is resorbed over several years due to lack of function. If a patient subsequently desires a dental implant, often this bone must be recreated through a grafting procedure. Common terms for grafting in the mouth are socket preservation, guided bone regeneration, block graft, and sinus lift.
In this procedure a bone graft is placed in an extraction socket after a tooth is removed. This ensures maximal regeneration of bone during healing. As mentioned previously, when a tooth is removed the surrounding bone tends to resorb due to lack of function. Bone is a living tissue and responds to mechanical forces. In the absence of mechanical forces from chewing, bone can atrophy. Socket preservation is frequently used if a patient desires an implant after and extraction and is not a candidate for immediate implant placement at the time of extraction.
Guided Bone Regeneration:
GBR is a bone grafting technique where a bone graft is placed at a deficient site and covered with a membrane to separate bone from overlying soft tissue. The graft is allowed to heal for 5-6 months before the site is re-evaluated. Membranes can be resorbable (collagen) or non-resorbable (titanium, plastic).
A block graft takes a square or rectangle of bone from another area on the jaw or body and fixates it to the recipient site. If a small graft is needed it can be harvested from other sites on the jaw. If a large graft is needed the hip (Iliac Crest) is commonly used.
A sinus lift can be direct/lateral approach or indirect/crestal approach. The direct/lateral approach makes a small window into the maxillary sinus, whereupon the lining of the sinus is lifted and bone graft placed underneath. In an indirect/crestal approach the graft is inserted through the hole made to place the implant. Generally, the direct/lateral approach is used for large sinus grafts and the indirect/crestal approach is used for small sinus grafts.
Patients may also lose bone as a result of trauma, infection, or treatment of a jaw tumor. In these cases a larger graft is needed. These larger grafts are typically taken from the hip (iliac crest), knee (tibia), or rib (costochondral). Drs. Poyourow, Chandra, and Pham have extensive training in all bone grafting procedures from major to minor.
SOURCES OF A BONE GRAFT
There are 4 possible sources of a bone graft: synthetic (man made), animal (coral, cow, horse), cadaveric (human tissue bank), and the patient’s own bone. The choice depends on patient preference, surgeon’s preference, size of the bone defect, location of the graft, and final goal.