title: Effects of collagen membrane application and cortical bone perforation on de novo bone formation in periosteal distraction: an experimental study in a rabbit calvaria.
abstract: OBJECTIVE
  The aim of the present study was to assess the impact of collagen membrane application and cortical bone perforations in periosteal distraction osteogenesis.
  
  
  METHODS
  A total of 32 New Zealand rabbits were randomized into four experimental groups, considering two treatment modalities. Calvarial bone was perforated or left intact (P+/-). In half the animals, the distraction mesh was covered with a collagen membrane (M+/-). All animals were subjected to a 7-day latency period and a 10-day distraction period. The samples were harvested after 4-week and 8-week consolidation periods and analyzed histologically and by means of micro-computed tomography.
  
  
  RESULTS
  Primary, woven bone observed at the 4-week consolidation period was gradually replaced by lamellar bone at the 8-week consolidation period. Significant increase in bone volume was found in all groups (P < .001) and in bone mineral density in groups I (P-/M-; P < .001), III (P+/M-; P < .001), and IV (P+/M+; P = .013). Group III (P+/M-) showed significantly more new bone at the 8-week consolidation period compared with the other three groups (P = .001), with no differences observed in bone mineral density between groups at a given time-point.
  
  
  CONCLUSIONS
  In the present model, cortical bone perforations have more impact on the osteogenic process compared with the application of a collagen membrane.
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Faculty of Medicine, University of Bern, Bern, Switzerland; Advanced Research Center, The Nippon Dental University School of Life Dentistry at Niigata, Niigata, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Nakahara
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Faculty of Medicine, University of Bern, Bern, Switzerland; Department of Histology, The Nippon Dental University School of Life Dentistry at Niigata, Niigata, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Haga-Tsujimura
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Faculty of Medicine, University of Bern, Bern, Switzerland; Advanced Research Center, The Nippon Dental University School of Life Dentistry at Niigata, Niigata, Japan.
authors.forename: Kosaku
authors.initials: K
authors.lastname: Sawada
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Faculty of Medicine, University of Bern, Bern, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Mottini
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Faculty of Medicine, University of Bern, Bern, Switzerland.
authors.forename: Benoit
authors.initials: B
authors.lastname: Schaller
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Faculty of Medicine, University of Bern, Bern, Switzerland. Electronic address: Nikola.saulacic@insel.ch.
authors.forename: Nikola
authors.initials: N
authors.lastname: Saulacic
mesh_terms: D000818:Animals; D003094:Collagen / Q000494:pharmacology*; D005260:Female; D008567:Membranes, Artificial; D010012:Osteogenesis / Q000502:physiology*; D019857:Osteogenesis, Distraction / Q000379:methods*; D011446:Prospective Studies; D011817:Rabbits; D011897:Random Allocation; D012886:Skull / Q000000981:diagnostic imaging / Q000502:physiology*; D013524:Surgical Flaps; D013526:Surgical Mesh; D055114:X-Ray Microtomography
chemical_list: D008567:Membranes, Artificial; D003094:Collagen