Wh. Lindsey et al., A NASAL CRITICAL-SIZE DEFECT - AN EXPERIMENTAL-MODEL FOR THE EVALUATION OF FACIAL OSSEOUS REPAIR TECHNIQUES, Archives of otolaryngology, head & neck surgery, 124(8), 1998, pp. 912-915
Objective: To create a standardized nonhealing defect of craniofacial,
minimal load-bearing, endochondral type bone with geometric propertie
s that are amenable to quantitative and biomechanical testing that can
be used to develop new osteoconductive and osteoinductive engineering
repair techniques. Design: Before-and-after randomized trial of an an
atomical description. Subjects: Twenty-four retired male breeder Sprag
ue-Dawley rats. Methods: A standardized osseous defect was created by
removing the nasal bones with a cutting burr to the level of the nasal
mucosal membranes. The defects were not repaired, and groups of 8 ani
mals were examined using planimetry, computed tomographic scanning, an
d histological analysis at 1, 3, and 6 months following surgery to qua
ntify defect repair. Results: Mean repair rate by surface area measure
ments at 1, 3, and 6 months was 5.75%, 4.89%, and 7.09%, respectively.
Results from histological analysis revealed that the defects were fil
led with fibrous tissue. Computed tomographic scans showed the bone de
fect without repair. Conclusion: This nasal osseous defect fulfills cr
iteria to be considered as a critical-size defect that can be used to
investigate new techniques for bone reconstruction.