One-Year Outcome of Implants Strategically Placed in the Retrocanine Bone Triangle

Background: Implant treatment in the partially edentulous maxilla is often challenging because of minimum bone volumes in distal direction. Purpose: The aim of this study was to evaluate, after 1 year of loading, the outcome of three-unit fixed partial dentures supported by two implants in the retrocanine triangle. Materials and Methods: Twenty patients with atrophic posterior maxillae participated in the study. A total of 40 implants were placed in residual bone anterior to the sinus wall and posterior to the canine. Implant angulations and lengths were chosen to match as much as possible boundaries of the available bone. After a 6-month healing period, three-unit, screw-retained, fixed partial dentures were delivered. The patients were clinically and radiographically reexamined after 1 year of loading. Results: All the implants survived at the end of the follow-up. No differences in bone level changes resulted between axial and tilted implants. No biological or mechanical complications were recorded. Conclusions: Within the limitations of this short-term study on relatively few patients, a positive outcome was seen for three-unit fixed partial dentures supported by two implants. Retrocanine placement of implants with carefully planned lengths and angulations might be an alternative to grafting procedures for restoration of atrophic posterior maxillae.