Craniofacial deformities are among the most common of all birth defects, with 1- 2% of the US population having a deformity severe enough to be disabling or stigmatizing. Surgical procedures continue to be developed to reduce the serious functional and psychosocial effects of these conditions. But most procedures have not been assessed in a systematic way, and for a variety of reasons, many could never be assessed in a randomized clinical trial. Observational studies of the physiologic adaptations post-surgery have indicated that longitudinal assessments are as important. However, the surgeon's ability to assess complex corrective craniofacial procedures has been hampered by the lack of computational and analytical tools for 3D quantitative evaluation of longitudinal data. An image analysis system to register longitudinal Cone-Beam CT scans using the surface of the cranial base is a first step in the process of making 3D scans clinically useful. In this proposal, we are validating and applying a new model to quantify craniofacial deformity surgical outcomes. Using state of the art image analysis methods, regional skeletal changes due to surgical correction and post-surgical remodeling will be quantified. Our multidisciplinary team is well qualified to address these aims. This work will provide preliminary data for future research applications on 3D computer simulation for diagnosis and surgical treatment planning, and for outcome assessments of new treatment procedures. Public Health Relevance: Craniofacial deformities are among the most common of all birth defects, with 1- 2% of the US population having a deformity severe enough to be disabling or stigmatizing. Surgical procedures continue to be developed to reduce the serious functional and psychosocial effects of these conditions. However, the surgeon's ability to assess complex corrective craniofacial procedures has been hampered by the lack of computational and analytical tools for 3D quantitative evaluation of longitudinal data. In this proposal, we are validating and applying a new model to quantify craniofacial deformity surgical outcomes. This work will provide preliminary data for future research applications on 3D computer simulation for diagnosis and surgical treatment planning, and for outcome assessments of new treatment procedures.