An engineering model of maxillary single anterior implants was developed to calculate the force-moment systems resulting from occlusal contacts. Analysis of a clinical example showed that flattening the incisal guidance and/or placing the implant in a more upright position reduced the moment and the labial component of the force but increased the intrusive component. The calculations are applicable to the design of implants and may help in the long-term evaluation of clinical success. Keywords: biomechanics, dental implants, implant failure, prosthodontics