Autogenous bone is harvested from either an intraoral site or extraoral. Intraoral donor sites include the chin bone, the ramal bone, the mandibular body window bone, the mandibular torus bone, the maxillary torus bone, the sinus anterior wall and the maxillary tuberosity bone. The chin bone is the most abundant source among the listed (Figs. 2.2 and 2.3).

Extraoral donor sites include the anterior iliac crest bone, the proximal tibia bone, and the calvarial bone. These sites may suffice any amount of requisite for an alveolar augmentation.

The most intuitive form of autogenous block bone grafting is the onlay or veneer grafting techniques (Fig. 2.4).

These techniques directly replace the resorbed alveolar bone in a vertical or horizontal direction, respectively. Both vertical and horizontal augmentations are possible by the saddle bone graft technique. Khoury demonstrated the method and results of sinus floor augmentation with mandibular block bones where dental implants were installed simultaneously [1]. Cases with severely atrophic alveolar ridge may require additional bone grafting. In the atrophic maxilla, subnasal or subantral block bone graftings are applied in addition of the onlay bone graft for this purpose.

Vertical interpositional bone graft is an alternative to the conventional methods described above, when the bone demand is large. This method has the advantage of preserving the alveolar crest with intact nourished bone. Soft tissue management and flap design is very important and should be done carefully with interpositional bone graft procedures for preserving the vascularity.

Resorption of grafted autogenous bone is always a matter of concern. Cordaro et al. reported that when block bones harvested from the mandibular ramus or symphysis are grafted in an onlay style, mean resorption rates during a graft healing period of 6 months were 23.5 % for lateral grafts and 42 % for verticals [2]. Proussaefs et al. suggested that vertical augmentation of the alveolar ridge with autogenous block bone from the mandibular ramus is a viable treatment option. They reported a vertical resorption rate of 16.34 % from an initial 6.12 mm of augmentation after 4–6 months of healing period [3]. Widmark et al. demonstrated that the horizontal resorption was 25 % after 4 months and 60 % at the time of abutment connection when symphyseal block bone was grafted to the anterior maxilla for single tooth implant installation [4].

In a clinical survey conducted in our department, 76 patients underwent simultaneous autogenous onlay bone graft and installation of total 256 dental implants from 2000 to 2006. The amount of bone augmentation was 5.42 mm in average. After a minimum follow up period of 2 years, average bone resorption at the mesial and distal site of implant collar was 1.48 mm. About 27.3 % of the augmented bone height was resorbed.

Although the autogenous bone is considered as the gold standard of bone grafting for its osteogenic potential, drawbacks exist which limits its application. Donor site morbidity is of the most concern. Bone harvesting procedures may put adjacent anatomical structures at a risk of damage. For instance during chin bone harvesting, the mental nerve may be pulled under undue traction and the incisive nerve may become interrupted when the harvesting depth is inordinate. Ramal bone harvesting can damage the inferior alveolar nerve.

In addition some patients may be reluctant to the harvesting procedures, especially when extraoral donor sites are concerned. General anesthesia is mandatory for these procedures. Gate problem could occur when autogenous bone is harvested from the tibia or the iliac crest.