Clinical, tomographic, and histological assessment of periosteal guided bone regeneration with cortical perforations in advanced human critical size defects

Background: Large osseous defects that fail to heal spontaneously require ridge augmentation prior to implant placement. The periosteum can act as an effective barrier membrane. Little is known about the influence of bone decortication in enhancing guided bone regeneration outcomes. Purpose: The aim of the present study was a clinical, tomographic, and histological evaluation of bone healing in large defect sites treated with cortical perforations without the use of other membranes but the periosteum. Material and Methods: Ten consecutive patients undergoing ridge augmentation on the pre-maxilla due to severe bone loss were followed for an average of 35 months. Recipient sites were cortico-perforated and augmented using a combination of autogenous particulate and block grafts. The periosteal membrane was preserved and it fully covered the autografts. Histological analysis was performed in four sites from a trephine core taken at the time of implant osteotomy preparation. Tomographic assessment (computed tomography [CT] scan) at baseline and post-augmentation evaluated graft volume maintenance. Results: Recipient sites were re-entered for implant placement showing good incorporation of the grafts with minimal volume loss. Biopsy specimens showed viable bone rich in osteoblast-like cells with little or no inflammatory cells. Clinical exam revealed absence of implant transparency, mucosal recession, mobility, bleeding on probing, or suppuration at follow-up. CT scan evaluation showed an average increased bucco-lingual width at the recipient site of 8.1mm\ub10.9 (2.5 fold) versus a 3.2\ub10.9 at baseline (p<.0001; CI 95%: 4.04-5.71mm), maintaining on average 98% of the augmented width at 2.9 years. Conclusions: Periosteal preservation seems to be sufficient as a barrier membrane to protect particulate or block osseous grafts provided that good primary closure is achieved. Bone decortication may enhance clinical and histological outcomes. Graft viability (biopsy specimens) and volume maintenance (CT evaluation) remained stable 35 months post-augmentation. \ua9 2010 Wiley Periodicals, Inc