Fate of monocortical bone blocks grafted in the human maxilla: a histological and histomorphometric study

• Published in: Clinical oral implants research 2003-12, Vol.14 (6), p.759-766
• Main Authors: Zerbo, Ilara R., De lange, Gert L., Joldersma, Manon, Bronckers, Antonius L.J.J., Burger, Elisabeth H.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Alveolar Bone Loss - etiology; Alveolar Bone Loss - pathology; Alveolar Bone Loss - surgery; Alveolar Ridge Augmentation; Biopsy; Bone Transplantation; Cell Survival - physiology; Dental Implantation, Endosseous - methods; Dentistry; Female; Follow-Up Studies; Graft Survival - physiology; histology; histomorphometry; Humans; Male; mandibular symphysis; Maxilla - pathology; Maxilla - surgery; maxillary defects; Maxillary Diseases - complications; Maxillary Diseases - pathology; Maxillary Diseases - surgery; Middle Aged; monocortical bone graft; Osteocytes - cytology
• ISSN: 0905-7161; 1600-0501
• DOI: 10.1046/j.0905-7161.2003.00967.x

: Local bone defects in the anterior maxilla are commonly grafted with monocortical blocks of autologous bone in order to restore the defect site prior to the placement of dental implants. Increasing evidence suggests that osteocytes are involved in the control of bone remodelling and thus may be important for optimalisation of bone structure around implants, and thus for implant osseointegration. However, it is not well known whether osteocytes will survive when bone blocks are grafted into defects. We grafted 19 patients with monocortical bone blocks derived from the symphysis, to the defect site in the maxillary alveolar process. The bone grafts were left to heal for times varying from 2.5 to 7 months. During implant installation, bone biopsies were removed using a trephine burr, and processed for hard tissue histology. Bone histology and histomorphometry were then carried out in order to gain insight into the density, viability and remodelling of the graft. Clinically, all the bone grafts were successful, with no implant failures, and little resorption was seen. Histologically, bone volume expressed as percentage of tissue volume at the implant site varied from 27% to 57% with an overall average of 41%. Bone fields with empty osteocyte lacunae were observed and measured. The amount of this so‐called nonvital bone (NVB) varied between 1% and 34% of the total tissue volume. The amount of NVB decreased significantly with the time of healing. The data suggest that the majority of the osteocytes of the monocortical bone do not survive grafting. The results indicate that the NVB is progressively remodelled into new vital bone 7 months after grafting. Résumé Les lésions osseuses locales dans le maxillaire antérieur sont souvent greffées avec des blocs monocorticaux d'os autogène afin de restaurer le site avant le placement d'implants. Il semble de plus en plus évident que les ostéocytes sont induits dans le contrôle du remodelage osseux et pourraient donc être importants pour optimiser la structure osseuse autour des implants et donc l'ostéoïntégration implantaire. Cependant le taux de survie des ostéocytes lorsque les blocs osseux sont greffés dans les lésions n'est pas suffisament connu. Dix‐neuf patients ont été greffés avec des blocs osseux monocorticaux provenant de la symphyse dans le site de la lésion au niveau des alvéoles maxillaires. Les greffons osseux sont restés in situ durant des périodes de 2,5 à 7 mois. Pendant l'insertion des implants des bio