Faculty Opinions recommendation of Validation of a femoral critical size defect model for orthotopic evaluation of bone healing: a biomechanical, veterinary and trauma surgical perspective.

Tissue engineered constructs should be tested for their efficacy not only in normal but also in osteoporotic bone. The rat is an established animal model for osteoporosis and is used often for bone healing studies. In this study a defined and standardized critical size defect model in the rat suitable for screening new tissue engineered constructs in normal and osteoporotic bone is described and validated. Normal and ovariectomised Wistar rats received a unilateral middiaphyseal 5 mm defect in the femur, which was instrumented with a radiolucent PEEK plate fixed with angular stable titanium screws and left untreated. All animals were euthanized eight weeks after defect surgery and the bone healing was evaluated using radiographs, computed tomography measurements, and histology. The developed fixation system provided good stability, even in osteoporotic bone. The implants and ancillary instruments ensured consistent and facile placement of the PEEK plates. The untreated defects did not heal without intervention making the model a well-defined and standardized critical size defect model highly useful for evaluating tissue engineered solutions in normal and osteoporotic bone.

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Transplantation of human mesenchymal stem cells in a non-autogenous setting for bone regeneration in a rabbit critical-size defect model

Acta Biomaterialia ◽

10.1016/j.actbio.2009.09.007 ◽

2010 ◽

Vol 6 (3) ◽

pp. 900-908 ◽

Cited By ~ 65

Author(s):

P. Niemeyer ◽

K. Szalay ◽

R. Luginbühl ◽

N.P. Südkamp ◽

P. Kasten

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Bone Regeneration ◽

Critical Size ◽

Human Mesenchymal Stem Cells ◽

Defect Model ◽

Critical Size Defect

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Biodegradation Property of Beta-Tricalcium Phosphate-Collagen Composite in Accordance with Bone Formation: A Comparative Study with Bio-Oss Collagen® in a Rat Critical-Size Defect Model

Clinical Implant Dentistry and Related Research ◽

10.1111/j.1708-8208.2012.00467.x ◽

2012 ◽

Vol 16 (2) ◽

pp. 202-211 ◽

Cited By ~ 24

Author(s):

Eiji Kato ◽

Jeffery Lemler ◽

Kaoru Sakurai ◽

Masahiro Yamada

Keyword(s):

Bone Formation ◽

Comparative Study ◽

Tricalcium Phosphate ◽

Critical Size ◽

Defect Model ◽

Critical Size Defect ◽

Beta Tricalcium Phosphate

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Mandible Biomechanics and Continuously Erupting Teeth: A New Defect Model for Studying Load-Bearing Biomaterials

Biomedicines ◽

10.3390/biomedicines9070730 ◽

2021 ◽

Vol 9 (7) ◽

pp. 730

Author(s):

Jonathan Z. Baskin ◽

Brandon M. White ◽

Amit Vasanji ◽

Thomas E. Love ◽

Steven J. Eppell

Keyword(s):

Critical Size ◽

Supporting Evidence ◽

Defect Model ◽

Post Intervention ◽

Critical Size Defect ◽

Load Bearing ◽

Tooth Structure ◽

Incisor Growth ◽

Apparent Relationship ◽

Mandible Defect

Animals with elodont dentition and unfused mandible symphyses are hypothesized to have symmetric incisor morphology. Since these animals maintain their teeth by gnawing, they may provide physiologic feedback on mechanical function when unilateral mandible defects are created that manifest as ipsilateral changes in tooth structure. This defect model would potentially generate important information on the functional/mechanical properties of implants. Rats’ and rabbits’ mandibles and teeth are analyzed with µCT at baseline and post-intervention (n = 8 for each). Baseline incisors were compared. In a unilateral mandible pilot study, defects—ranging from critical size defect to complete ramus osteotomies—were created to assess effect on dentition (rats, n = 7; rabbits, n = 6). Within 90% confidence intervals, animals showed no baseline left/right differences in their incisors. There are apparent dental changes associated with unilateral defect type and location. Thus, at baseline, animals exhibit statistically significant incisor symmetry and there is an apparent relationship between mandible defect and incisor growth. The baseline symmetry proven here sets the stage to study the degree to which hemi-mandible destabilizing procedures result in measurable & reproducible disruption of dental asymmetry. In a validated model, an implant designed to function under load that prevents incisor asymmetry would provide supporting evidence that the implant has clinically useful load-bearing function.

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