Craniofacial Biology, Orthodontics, and Implants

The craniofacial skeleton is unique in that it (1) contains different types of joints, including sutures; (2) houses and protects the brain and many other sensory organs; and (3) supports the dentition and their functions. These characteristics result in an amazing integration of tissues arising from many embryonic origins. Unlike postcranial bone, it forms by intramembranous ossification, which gives it some special properties. The craniofacial skeleton is malleable and can be manipulated to move teeth orthodontically and to alter occlusal forces, both of which can alter facial appearance. Because many of the joints are fibrous (sutures) rather than chondral, the biological principles underlying craniofacial adaptation to forces are different than those that apply to bone formed by endochondral processes. The success of dental implants constitutes a major success story in oral biology in part because the integration of bone and implant, which consists of surgical, healing and restoration phases, is well understood. Factors introduced to alveolar bone during the three phases of dental implant treatment include considerations of stress distribution, implant composition, and surface topology; the implant design; and the molecular and cellular events that occur at the bone-implant interface.