title: Brånemark system implant lengths in the pterygomaxillary region: a retrospective comparison.
abstract: OBJECTIVE
  Implants that engage the cortical bone of the pterygomaxillary region help restore dentition to the posterior maxilla. However, proper implant length is required. The purpose of this study was to determine if there is a statistically significant difference in the survival rates between different sized implants placed in the pterygomaxillary region.
  
  
  METHODS
  All Brånemark System 4.0-mm-diameter implants delivered into the pterygomaxillary region in a single private practice were separated into 7- to 13-mm and 15- to 18-mm groups by retrospective patient chart review. Cumulative survival rates (CSR) were calculated.
  
  
  RESULTS
  Of all implants delivered, 930 of the 992 osseointegrated for a CSR of 93.75%. Fifty-nine of the 67 implants in the 7- to 13-mm grouping and 871 of the 925 implants in the 15- to 18-mm grouping osseointegrated for CSRs of 88.06% and 94.16%, respectively. The results were statistically significant (P < 0.05).
  
  
  CONCLUSIONS
  The results suggest that increased implant length in the pterygomaxillary region may result in higher osseointegration rates. The implant apex better engages the cortical bone between the medial and lateral pterygoid plates and therefore increases primary and secondary stability.
authors.affiliation: *Founder and Prosthodontist, PI Dental Center, Institute for Facial Esthetics, Fort Washington, PA. †Prosthodontist, PI Dental Center, Institute for Facial Esthetics, Fort Washington, PA. ‡Research Associate, Pi Dental Center, Institute for Facial Esthetics, Fort Washington, PA; Dental Student, University of Maryland Baltimore, College of Dental Surgery, Baltimore, MD. §Director of Research, PI Dental Center, Institute for Facial Esthetics, Fort Washington, PA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Balshi
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Wolfinger
authors.forename: Robert W
authors.initials: RW
authors.lastname: Slauch
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Balshi
mesh_terms: D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants / Q000592:standards / Q000706:statistics & numerical data; D017268:Dental Prosthesis Retention / Q000706:statistics & numerical data; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D006801:Humans; D008437:Maxilla / Q000601:surgery*; D016348:Osseointegration; D012189:Retrospective Studies
chemical_list: D015921:Dental Implants