Development and characterization of a rabbit alveolar bone nonhealing defect model

Abstract

The aim of this study was to develop an easily accessible and reproducible, nonhealing alveolar bone defect in the rabbit mandible. Twenty-four adult male New Zealand white rabbits underwent unilateral mandibular defect surgery. Two types of defect in the premolar/molar region were compared: (1) a 10-mm "full thickness" cylindrical defect removing both cortical plates and the intervening trabecular bone and tooth roots; (2) a 10-mm "partial thickness" cylindrical defect removing only the lateral bony cortex, trabecular bone, and tooth roots. Both types of defect were examined at 0, 8, and 16 weeks using histology and/or microcomputed tomography to determine the quality and quantity of bone formation. The partial thickness defect displayed significant bone fill at 8 weeks (86.9% +/- 10.8%), and complete regeneration of bony contours and bridging by 16 weeks. In contrast, the full thickness defect was never able to bridge itself and displayed no significant difference in bone regeneration between the 8-week (61.5% +/- 3.7%) and 16-week (55.1% +/- 18.5%) time points. These results indicate that a nonhealing defect can be created with a 10-mm bicortical cylindrical ostectomy placed in the premolar/molar region of the rabbit mandible, demonstrating the potential of this animal model as a test bed for mandibular biomaterials and tissue-engineering constructs.

Evaluation of Soft Tissue Coverage over Porous Polymethylmethacrylate Space Maintainers Within Nonhealing Alveolar Bone Defects

“…The animal model was based on a previously developed rabbit mandibular defect 42 that was modified to allow contamination of the wound through an opening into the oral cavity. This conferred several advantages.…”

“…31 All surgical procedures followed protocols approved by the Institutional Animal Care and Use Committees at both Rice University and the University of Texas Health Science Center at Houston. Eighteen healthy male adult New Zealand white rabbits (n ¼ 6 per group) at least 6 months old and weighing 3.5-4 kg were purchased from Myrtle's Rabbitry (Thompson Station, TN).…”

Microcomputed Tomography Characterization of Neovascularization in Bone Tissue Engineering Applications

“…Indeed, both long bone segmental defect52,58,59 and cranial cavitational defect60–63 models are commonly performed in small rodents to test bone regeneration materials. However, to provide a reproducible and challenging test bed for potential bone tissue engineering constructs in the unique healing environment of the oral cavity, a rabbit alveolar bone nonhealing defect model has recently been developed 64. Both histological characterization of wound healing and micro-CT quantification of bone repair within this rabbit model have been performed at 8 and 16 weeks 64.…”

“…However, to provide a reproducible and challenging test bed for potential bone tissue engineering constructs in the unique healing environment of the oral cavity, a rabbit alveolar bone nonhealing defect model has recently been developed 64. Both histological characterization of wound healing and micro-CT quantification of bone repair within this rabbit model have been performed at 8 and 16 weeks 64. Thus, by introducing a 3D method for quantifying neovascularization in this defect model, investigators would have the expanded ability to quantitatively assess both the angiogenic and osteogenic potential of an implanted biomaterial in a clinically relevant environment.…”

Chitosan Membrane with Surface-bonded Growth Factor in Guided Tissue Regeneration Applications

“…Eighteen New Zealand white male rabbits (2.5-3.0 kg) were anesthetized by ketamine (25 mg/kg) and local administration of lidocaine (0.5%). After the operation site was shaved and sterilized, a 10 mm long bone defect, 2.5 cm from the radiocarpal joint, was surgically created in both radii of each rabbit, according to the critical-size defect (CSD) model [30,31]. A total of 36 bone defects were created and divided into three groups: 12 defects were wrapped with 2 cm 2 of the chitosan surface-bonded rhBMP-2 membrane (surface concentration of rhBMP-2: 43.56 AE 1.75 ng/cm 2 ); 12 defects were wrapped with 2 cm 2 native chitosan membrane; 12 defects were not treated and served as a control group.…”