In addition, YAP mRNA levels on Day 7 (1.72-fold, P < 0.05) and Day 14 (1.42-fold, P < 0.001) were significantly greater in the OI group than in the NC group (Fig. 5B), which indicates that YAP activation is a characteristic event during TMJ ankylosis development. This evidence concerns the gene YAP1 and osteogenesis imperfecta.