**1. Introduction**

The art and science of reconstruction of maxillofacial bony defects is a field of interest for most of maxillofacial surgeons due to its importance and prerequisite role for other surgical procedures. Despite significant improvements during last decades in this field, challenge still exists to determine which type of reconstruction techniques and materials is the treatment of choice. Although dental implants are considered as a standard and effective treatment to restore dental defects nowadays, lack of adequate bone quantity is a pitfall for dental implant reconstruction procedures. Grafting techniques have a long history in the literature with different donor sources and technical innovations and improvements. These methods are the most common techniques in bone reconstruction yet, but in the era of bioengineering, new alternative horizons lie ahead.

**Regenerative techniques** for maxillofacial hard tissue reconstruction like other tissue engi‐ neering procedures is based on three principle elements; stem cells, scaffolds, and growth factors. The balanced scenario of bone induction and conduction is a critical issue in every bone regeneration procedure [1].

**Current approaches** used in clinical circumstances to reconstruct bony defects include different bone grafting methods, such as autologous bone grafts, allografts, bone-graft substitutes, distraction osteogenesis, and guided bone regeneration.

**Bone-graft substitutes** have been developed to be used as scaffolds to promote cell migration, proliferation and differentiation for bone regeneration without need to violate other tissue from a donor site [2.[

**Distraction osteogenesis and guided bone regeneration** are brilliant concepts which work basically by modifying normal bone healing process. Soft callous enlarging guidance is the key element in distraction osteogenesis and space maintaining for relatively slow growing hard tissue is the fundamental of guided bone regeneration techniques. This chapter introdu‐ ces methods of bone reconstruction and regeneration in oral and maxillofacial surgery. Indeed the knowledge of exact indications and advantages of each method is invaluable for the surgeon.
