title: A Comparison of Vascularity, Bone Mineral Density Distribution, and Histomorphometrics in an Isogenic Versus an Outbred Murine Model of Mandibular Distraction Osteogenesis.
abstract: OBJECTIVE
  The vascularity, bone mineral density distribution, and histomorphometric data between the inbred, isogenic Lewis rat and the outbred, nonisogenic Sprague Dawley rat within mandibular distraction osteogenesis (MDO) were evaluated to allow future researchers to compare the results generated from these 2 animals. We hypothesized that little difference would be found between the 2 strains within these metrics.
  
  
  METHODS
  We implemented a comparative study between the Lewis and Sprague Dawley rat strains within MDO. The sample was composed of 17 male Lewis and 17 male Sprague Dawley rats that underwent surgical external fixation and distraction. The rats' hemimandibles were distracted to a total distance of 5.1 mm. After 28 days of consolidation, 9 rats from each group underwent bone mineral density distribution analysis. The remaining rats from each group were analyzed for the vascular and histologic metrics. Descriptive and bivariate statistics were computed, and the P value was set at .05.
  
  
  RESULTS
  We demonstrated successful MDO in all the rats, with no significant difference found in the histologic or bone mineral density distribution metrics. No significant differences were found in any of the vascular metrics, with the exception of vascular separation, which was not normalized to the mandibular volume (P = .048).
  
  
  CONCLUSIONS
  The results of the present study have demonstrated that little dissimilarity exists between the isogenic Lewis and outbred Sprague Dawley models of MDO. Thus, researchers can confidently compare the gross results between the 2 strains, with consideration of the very small differences between the 2 models. For studies that require an isogenic strain, the Lewis rat is an apt surrogate for the Sprague Dawley strain.
authors.affiliation: Medical Student, Craniofacial Research Laboratory, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI.
authors.forename: Edward G
authors.initials: EG
authors.lastname: Carey
authors.affiliation: Medical Student, Craniofacial Research Laboratory, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI.
authors.forename: Sagar S
authors.initials: SS
authors.lastname: Deshpande
authors.affiliation: Medical Student, Craniofacial Research Laboratory, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Zheutlin
authors.affiliation: Research Fellow, Craniofacial Research Laboratory, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI.
authors.forename: Noah S
authors.initials: NS
authors.lastname: Nelson
authors.affiliation: Research Fellow, Craniofacial Research Laboratory, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI.
authors.forename: Alexis
authors.initials: A
authors.lastname: Donneys
authors.affiliation: Assistant Professor, Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, OH.
authors.forename: Stephen Y
authors.initials: SY
authors.lastname: Kang
authors.affiliation: Assistant Professor, Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Waco, TX.
authors.forename: Kathleen K
authors.initials: KK
authors.lastname: Gallagher
authors.affiliation: Resident, Plastic Surgery and Aesthetics Center, University of Florida, Gainesville, FL.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Felice
authors.affiliation: Research Fellow, Department of Dermatology, University of California Davis, Sacramento, CA.
authors.forename: Catherine N
authors.initials: CN
authors.lastname: Tchanque-Fossuo
authors.affiliation: Chair, Pediatric Plastic Surgery, Craniofacial Research Laboratory, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI. Electronic address: sbuchman@med.umich.edu.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Buchman
mesh_terms: D000818:Animals; D015519:Bone Density; D004195:Disease Models, Animal; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D051379:Mice; D019857:Osteogenesis, Distraction / Q000379:methods*; D010027:Osteotomy / Q000379:methods; D011917:Rats, Inbred Lew; D017207:Rats, Sprague-Dawley; D055114:X-Ray Microtomography