Craniofacial/maxillofacial surgical procedures are used to correct congenital defects and abnormalities caused by ablative cancer surgery or traumatic injury. Since these surgeries are complex and invasive, patients often require initial care in an intensive care unit and lengthy post- operative hospitalization. Advances in videoendoscopy, real-time radiologic imaging, and distraction osteogenesis have led to less invasive procedures; however, the mechanical saws and drills currently in use are poorly suited to endoscopic procedures. The development of a high-power Er:YAG laser with fiber-optic delivery for bone cutting and recontouring would represent a significant step towards the development of endoscopic maxillofacial procedures. On the proposed Phase I effort, we will build a 20-W Er:YAG laser and interface it to a novel contact-tip fiber-optic delivery system. The bone ablation characteristics of the laser system will be evaluated by in vitro and in vivo experiments. PROPOSED COMMERCIAL APPLICATION: The minimally invasive laser-based bone cutting and recontouring system developed on this project would lead to improved maxillofacial procedures that would require shorter hospital stays compared to current techniques.