title: Corticocancellous fresh-frozen allograft bone blocks for augmenting atrophied posterior mandibles in humans.
abstract: BACKGROUND
  Allograft fresh-frozen bone (FFB) is an alternative to autogenous bone for oral implantation due to bone quantity availability and lower morbidity for patients. Few specific studies about the use of FFB for reconstructing the posterior mandibular alveolar crest have been conducted.
  
  
  OBJECTIVE
  The objective of this study was to evaluate histological, histomorphometrical, and volumetric aspects of FFB allografts used to augment atrophied posterior mandible bone ridges.
  
  
  METHODS
  Sixteen hemi-mandibles of twelve patients presenting with critical alveolar atrophy were three-dimensionally reconstructed using corticocancellous FFB. Thirty blocks were fixed with titanium screws and covered with particulate bovine bone mineral and collagen membrane. Volumetric data were obtained by cone beam computed tomography analysis after 6 months, implants were inserted, and bone biopsies were harvested and sent for histological and histomorphometric analyses.
  
  
  RESULTS
  The blocks were distributed between nine female and three male patients (mean age, 50.9 ± 8.3 years). Thirty implants were installed, and the implant survival rate was 96.66%. Histology demonstrated newly formed vital bone contacting residual acellular allograft bone and connective tissue. The histomorphometric analysis showed 18.9 ± 8.1% newly formed bone and 32.5 ± 14.8% allograft residual bone. Graft absorption was 45% for height and volume, and both measures were significantly different (P < 0.001).
  
  
  CONCLUSIONS
  Fresh-frozen allografts are a viable alternative for reconstructing an atrophied mandible in the posterior region, allowing for new bone formation, installation of implants, and prosthetic loading.
authors.affiliation: Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirão Preto Dental School, University of São Paulo, São Paulo, Brazil.
authors.forename: Rafael R
authors.identifier: http://orcid.org/0000-0002-0813-4252
authors.initials: RR
authors.lastname: Dias
authors.affiliation: Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirão Preto Dental School, University of São Paulo, São Paulo, Brazil.
authors.forename: Felipe P
authors.initials: FP
authors.lastname: Sehn
authors.affiliation: Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirão Preto Dental School, University of São Paulo, São Paulo, Brazil.
authors.forename: Thiago
authors.initials: T
authors.lastname: de Santana Santos
authors.affiliation: Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirão Preto Dental School, University of São Paulo, São Paulo, Brazil.
authors.forename: Erick R
authors.initials: ER
authors.lastname: Silva
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Tel Aviv University, Tel Aviv, Israel.|Department of Oral and Maxillofacial Surgery, Rabin Medical Center, Petah Tikva, Israel.
authors.forename: Gavriel
authors.initials: G
authors.lastname: Chaushu
authors.affiliation: Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirão Preto Dental School, University of São Paulo, São Paulo, Brazil.
authors.forename: Samuel P
authors.initials: SP
authors.lastname: Xavier
mesh_terms: D064591:Allografts; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000818:Animals; D001863:Bone Screws; D016025:Bone Transplantation / Q000379:methods*; D002417:Cattle; D003094:Collagen / Q000627:therapeutic use; D054893:Cone-Beam Computed Tomography; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000601:surgery*; D008875:Middle Aged; D008903:Minerals / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: C106416:Bio-Gide; C077540:Bio-Oss; D015921:Dental Implants; D008903:Minerals; D003094:Collagen
keywords: atrophic mandible; fresh-frozen bone allograft; histological analysis; histomorphometry; implants; volumetric