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

 Thomas J. Balshi, DDS, PhD, FACP, Glenn J. Wolfinger, DMD, FACP,
Robert W. Slauch, BS, Stephen F. Balshi, MBE

Purpose: Implants placed into the pterygomaxillary region allow for increased posterior support and a full complement of teeth without the need of distal cantilevers. With the advancements in research and technology, implant delivery has evolved from the traditional two-stage procedure to immediate loading free hand 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 installed in a single private practice from September 1985 to July 2011 were placed into three separate classifications (two-stage free-hand, single stage free-hand, or single stage guided) by retrospective chart review. Life tables were constructed to determine the cumulative survival rates (CSR), and AVOVA was used to identify statistical significance. Results: a total of 981patients comprising 371 males and 610 females were included in the study. Of all pterygomaxillary implants, 1460 of 1608 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 CSR’s of 85.94%, 96.45%, and 93.38%, respectively. The comparison between two stage and single stage was statistically significant (P<0.05) while single stage guided versus free-hand was found to be statistically insignificant (P>0.05).  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 to the immediate load free-hand procedure is statistically insignificant suggesting guided surgery is still viable and recommended option for qualified patients.

Int J Oral Maxillofacial Implants 2013;28:184-189.

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