A Retrospective Comparison of Implants in the Pterygomaxillary Region: Implant Placement with Two-Stage, Single-Stage, and Guided Surgery Protocols

Purpose: Implants placed into the pterygomaxillary region allow for increased posterior support and a full complement of teeth without the need for distal cantilevers. With advancements in research and technology, implant delivery has evolved from the traditional two-stage procedure to immediate loading freehand and guided surgical template protocols. The purpose of this retrospective study is to determine if there is a significant difference in implant survival rates between these protocols. Materials and Methods: All pterygomaxillary implants placed in a single private practice from September 1985 to July 2011 were categorized into three separate classifications (two-stage freehand, single-stage freehand, or single-stage guided) by retrospective chart review. Life tables were constructed to determine the cumulative survival rates (CSR), and ANOVA was used to identify statistical significance. Results: A total of 981 patients comprising 371 males and 610 females were included in the study. Of all pterygomaxillary implants, 1,460 of 1,608 implants osseointegrated for a CSR of 90.80%. Seven hundred nine of the 825 two-stage, 624 of the 647 single-stage, and 127 of the 136 guided surgery implants osseointegrated for CSRs of 85.94%, 96.45%, and 93.38%, respectively. The comparison between two-stage and single-stage protocols was statistically significant, (P < .05) while the difference between single-stage guided versus freehand protocols was found to be statistically insignificant (P > .05). Conclusion: The results from this retrospective study reinforce that immediate loading of pterygomaxillary implants with a provisional prosthesis is beneficial to both doctor and patient. The lower CSR for the guided surgery protocol compared with the single-stage freehand procedure is statistically insignificant, suggesting guided surgery is still a viable and recommended option for qualified patients.