Clinical, histological and histomorphometric evaluation of the healing of mandibular ramus bone block grafts for alveolar ridge augmentation before implant placement

J Craniomaxillofac Surg. 2010 Apr;38(3):222-30. doi: 10.1016/j.jcms.2009.07.004. Epub 2009 Aug 3.

Abstract

Background: Localized bone defects in the maxilla are commonly reconstructed with autologous mono-cortical bone blocks prior to the placement of dental implants. This study presents a clinical, histological and histomorphometric analysis on the use of mandibular ramus block grafts for ridge augmentation.

Materials and methods: mono-cortical bone blocks from the mandibular ramus were grafted in 15 patients. The bone grafts were left to heal for period varying from 3 to 9 months. Afterwards, 30 implants were inserted and bone samples were removed for subsequent histological analysis.

Results: All the bone grafts were successful and resorption was minimal. There were no implant failures. At graft placement, mean lateral augmentation was 4.6+/-0.73mm, which, later, at the time of implant insertion, reduced to 4+/-0.77mm. Histological evaluation indicated signs of active remodelling in all specimens. However, the grafted bone contained substantial amounts of non-vital bone (NVB) and generally weak neo-vascularization regardless of the time of biopsies.

Conclusions: The outcome of the study suggests that the larger part of osteocytes in mono-cortical bone do not survive grafting and neo-vascularization of non-vital grafted bone is difficult because of the slow remodelling process into new vital.

MeSH terms

  • Adult
  • Aged
  • Alveolar Bone Loss / surgery
  • Alveolar Ridge Augmentation / methods*
  • Bone Remodeling
  • Bone Transplantation / methods
  • Bone Transplantation / physiology*
  • Cell Death
  • Dental Implantation, Endosseous
  • Female
  • Graft Survival / physiology*
  • Humans
  • Least-Squares Analysis
  • Male
  • Mandible / blood supply
  • Mandible / surgery*
  • Maxilla / blood supply
  • Maxilla / surgery*
  • Maxillary Diseases / surgery
  • Middle Aged
  • Neovascularization, Physiologic
  • Osteocytes / cytology
  • Tissue and Organ Harvesting / methods
  • Wound Healing
  • Young Adult