title: Relative contributions of osteogenic tissues to new bone formation in periosteal distraction osteogenesis: histological and histomorphometrical evaluation in a rat calvaria.
abstract: BACKGROUND
  The relative contributions of different, potential factors to new bone formation in periosteal distraction osteogenesis are unknown.
  
  
  OBJECTIVE
  The aim of the present study was to assess the influence of original bone and periosteum on bone formation during periosteal distraction osteogenesis in a rat calvarial model by means of histology and histomorphometry.
  
  
  METHODS
  A total of 48 rats were used for the experiment. The contribution of the periosteum was assessed by either intact or incised periosteum or an occlusive versus a perforated distraction plate. The cortical bone was either left intact or perforated. Animals were divided in eight experimental groups considering the three possible treatment modalities. All animals were subjected to a 7-day latency period, a 10-day distraction period and a 7-day consolidation period. The newly formed bone was analyzed histologically and histomorphometrically.
  
  
  RESULTS
  New, mainly woven bone was found in all groups. Differences in the maximum height of new bone were observed and depended on location. Under the distraction plate, statistically significant differences in maximum bone height were found between the group with perforations in both cortical bone and distraction plate and the group without such perforations.
  
  
  CONCLUSIONS
  If the marrow cavities were not opened, the contribution to new bone formation was dominant from the periosteum. If the bone perforations opened the marrow cavities, a significant contribution to new bone formation originated from the native bone.
authors.affiliation: Research assistant, Department of Cranio-Maxillofacial Surgery, University Hospital, Bern, Switzerland; research assistant, Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland; postgraduate student, Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland; associate professor, Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland; research assistant, Department of Cranio-Maxillofacial Surgery, University Hospital, Bern, Switzerland; professor and chairman, Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland; research assistant, Second Department of Oral and Maxillofacial Surgery, Osaka Dental University, Osaka, Japan; professor and chairman, Department of Cranio-Maxillofacial Surgery, University Hospital, Bern, Switzerland.
authors.forename: Nikola
authors.initials: N
authors.lastname: Saulacic
authors.forename: Cladius
authors.initials: C
authors.lastname: Hug
authors.forename: Dieter D
authors.initials: DD
authors.lastname: Bosshardt
authors.forename: Benoit
authors.initials: B
authors.lastname: Schaller
authors.forename: Daniel
authors.initials: D
authors.lastname: Buser
authors.forename: Hideya
authors.initials: H
authors.lastname: Haeniwa
authors.forename: Tateyuki
authors.initials: T
authors.lastname: Iizuka
mesh_terms: D000818:Animals; D001846:Bone Development; D008297:Male; D019857:Osteogenesis, Distraction; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000473:pathology*