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Insulinlike Growth Factor 1– and 2–Augmented Collagen Gel Repair of Facial Osseous Defects
James S. Toung, BA;
Roy C. Ogle, PhD;
Raymond F. Morgan, DDS, MD;
William H. Lindsey, MD
Arch Otolaryngol Head Neck Surg. 1999;125:451-455.
Background Defects of the facial bone structure are common problems for the facial plastic surgeon. Native type 1 collagen gels (T1CGs) have been shown to mediate repair of facial critical-size defects in rat models.
Objective To evaluate the efficacy of T1CG augmented with insulinlike growth factor (IGF) 1, IGF-2, and a combination of IGF-1 and IGF-2 on the repair of facial critical-size defects in a rodent model.
Methods Twenty-four retired male breeder Sprague-Dawley rats were divided into 4 groups of 6 animals. Facial critical-size defects were created by removing the nasalis bones with a bone-cutting drill. Defects were treated with 300 µg of type 1 collagen gel (T1CG), T1CG augmented with 3 µg of IGF-1, T1CG augmented with 3 µg of IGF-2, or T1CG augmented with a combination of 3 µg of IGF-1 and 3 µg of IGF-2. After 30 days the animals were examined at necropsy with precise planimetry, histological analysis of new bone growth, and radiodensitometric analysis of bone thickness.
Results Radiodensitometric measurements showed that IGF-2 augmentation resulted in greatest osseous healing, with measurements being statistically significant over those of all other groups (P≤.03). Combination IGF-1 and IGF-2 had osseous healing that was intermediate between IGF-1 augmentation and IGF-2 augmentation alone, with measurements being statistically significant over those of unaugmented gels (P<.001) and IGF-1 augmentation (P≤.03). Augmentation with IGF-1 resulted in healing that was significant over that of unaugmented gels (P≤.04).
Conclusion Collagen gels augmented with IGF significantly enhance the osteoconductive repair of nasal critical-size defects in a rodent model, with IGF-2 showing highest efficacy.
From the Departments of Otolaryngology–Head and Neck Surgery (Mr Toung and Dr Lindsey), Plastic Surgery (Drs Ogle and Morgan), and Neurosurgery and Cell Biology (Dr Ogle), University of Virginia Health Sciences Center, Charlottesville.
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