For patients with an atrophic mandible who require implants, augmentation of the mandible can increase bone height and width sufficiently to allow placement of implants. According to a publication of the American Association of Oral and Maxillofacial Surgeons, if a patient's general health would not allow bone graft harvesting from the iliac crest, that patient's mandible should not be augmented. If the patient is healthy enough for a bone graft harvest procedure, bone augmentation of the anterior mandible is indicated if the patient has less than 8 mm of bone height. Most clinicians use iliac crest corticocancellous blocks for augmentation of the anterior mandible. It is the clinician's decision whether or not to place implants at the time of bone graft placement. Advantages of immediate implant placement include a reduction in restoration time, the graft can be secured to the mandible with threaded implants, and graft resorption may be prevented due to the shorter time to functional loading. Disadvantages of placing implants at the time of bone graft placement include the possibility of partial resorption of the graft and exposed portions of the implants, implant malposition because of improper angulation at placement, and the potential for lack of integration secondary to poor graft remodeling.
(Source: AAOMS Surgical Update, Vol. 19, Issue 1, 2004)