title: Critical-size defect ossification:  effect of leporid age in a cranioplasty model.
abstract: The ability of the human cranium to ossify full-thickness defects depends on the size of the area and the age of the patient. An adult leporid cranioplasty model is commonly used to study inlay cranioplasty materials; the influence of age on ossification is unknown in this model. The purpose of this study was to determine the effect of age on healing of a rabbit critical-size defect. Nineteen rabbits were divided into 4 groups: group 1 (n = 5) aged 4 months, group 2 (n = 4) aged 8 months, group 3 (n = 5) aged 12 months, and group 4 (n = 5) aged 16 months. A 17 × 17-mm defect was created in the parietal bones with preservation of the underlying dura. Animals underwent micro-computed tomography 4 months postoperatively to determine ossification of the defect. Group 1 defects healed by 28.5% (SD, 12.5%), group 2 defects ossified by 37.2% (SD, 5.7%), group 3 defects closed by 28.2% (SD, 11.9%), and group 4 defects healed by 39.4% (SD, 11.0%). No difference in ossification was found between groups (P = 0.31).Leporids as young as 4 months do not close a 17 × 17-mm defect; ossification is similar to animals as old as 16 months. Rabbits 4 months or older are suitable for a calvarial critical-size defect model.
authors: Department of Plastic and Oral Surgery, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors: Aladdin H
authors: AH
authors: Hassanein
authors: Rafael A
authors: RA
authors: Couto
authors: Arthur
authors: A
authors: Nedder
authors: Elizabeth R
authors: ER
authors: Zielins
authors: Arin K
authors: AK
authors: Greene
mesh_terms: D000367:Age Factors; D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D023421:Models, Animal; D010294:Parietal Bone / Q000000981:diagnostic imaging / Q000601:surgery*; D011817:Rabbits; D019651:Plastic Surgery Procedures; D018709:Statistics, Nonparametric; D014945:Wound Healing / Q000502:physiology; D055114:X-Ray Microtomography