The Journal of Prosthetic Dentistry Manda et al Clinical Implications The addition of cantilevers in cross-arch FPDs in situations of severe bone loss provides better mechanical stress distribution compared with the distal extension abutment design. Statement of problem. Increased technical failure has been reported for cross-arch fixed partial dentures (FPDs), par- ticularly for cantilever units with minimum osseous support. Purpose. The purpose of this study was to investigate the effect of severely reduced bone support on the stress field developed within the connectors for 3 types of cross-arch FPDs. Material and methods. Six digital parametric models were developed, derived from a 3-dimensional (3-D) initial model. The latter simulated a human mandible, dentate bilaterally to second premolars, with normal height of alveo- lar bone. In the initial model, the teeth were prepared and splinted with a cross-arch FPD bilaterally with one of the following: no cantilever, 1-unit cantilever, or 2-unit cantilever. All structures were obtained from computed tomogra- phy (CT)-scan images or constructed in 3-D computer-aided design (CAD) and reverse engineering environments. A 3-D finite element analysis (3-D FEA) was performed. Results. The reduction of the alveolar bone in the no-cantilever FPD model caused a greater increase of stress in the region of connectors among the splinted teeth in comparison to the 1- and 2-unit cantilever FPD model. The stress state within the connectors of the cantilever segment remained constant. The connectors proximal to the retaining abutment demonstrated the highest stress values, independent of the osseous support. The stress values in the region of the same connectors in the 2-unit cantilever restoration were almost double, compared to the 1-unit cantilever model. Decreasing the osseous level in the 1- and 2-unit cantilever FPD models caused milder stress distribution and magnitude in the region of connectors among the splinted teeth. Conclusions. The stress field developed within the connectors of the cantilever segment is independent of the os- seous level. The stress field within the connectors among splinted teeth depends on the osseous support and both the presence and length of the cantilever segment. Furthermore, this study indicates that adding a cantilever segment has a positive effect on the stress behavior of the splinted teeth connectors in situations of reduced osseous support. (J Prosthet Dent 2009;101:54-65) Effect of severely reduced bone support on the stress field developed within the connectors of three types of cross-arch fixed partial dentures Marianthi Manda, DDS, MSc, a Christos Galanis, PhD, b Vasilis Georgiopoulos, PhD, c Christofer Provatidis, MSc, PhD, d and Petros Koidis, DDS, MSc, PhD e School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece; School of Mechanical Engineering, National Technical University of Athens, Athens, Greece The present study was presented at the 31 st Annual Conference of the European Prosthodontic Association, Athens, Greece, October 2007. This article is in partial fulfillment of a Masters degree from the University of Thessaloniki. a PhD student, Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki. b Research Associate, Mechanical Designs and Control Systems Division, School of Mechanical Engineering, National Technical University of Athens. c Research Associate, Mechanical Designs and Control Systems Division, School of Mechanical Engineering, National Technical University of Athens. d Associate Professor, Mechanical Designs and Control Systems Division, School of Mechanical Engineering, National Technical University of Athens. e Professor, Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki.