Gene therapy to enhance condylar growth using rAAV-VEGF

Objective: To test the hypothesis that the introduction of specific vascular growth inducting genes would favorably affect mandibular condylar growth in Sprague-Dawley (SD) rats over a limited experimental period. Therefore, the aim of this study is to examine the effect of gene therapy on condylar growth by means of a morphological assessment. Materials and Methods: Ninety 35-day-old female SD rats were randomly divided into three groups, which received any of the injections of recombinant adeno-associated virus mediated vascular endothelial growth factor (rAAV-VEGF), rAAV mediated enhanced green fluorescence protein (rAAV-eGFP), or phosphate-buffered saline (PBS) into both mandibular condyles. Each group of rats was sacrificed on the following experimental days: 7, 14, 21, 30, and 60. Left halves of the mandibles were isolated and digital pictures were obtained in a standardized manner. Results: The length of condylar process (B-F) as well as mandibular length (A-F) significantly increased on day 30 and continued to increase until the end of the experiment. Moreover, the width of condyle (Q-R) had increased significantly from day 30 and lasted to day 60. Condylar length (C-D) was found to be significantly longer on day 60. Conclusions: Gene therapy with VEGF stimulates condylar growth at will. The rAAV-VEGF is an excellent candidate for future gene therapy to induce mandibular growth.