Fig. (2a) Scanning electron micrographs of rat embryos treated with 0.05% DMSO (A), 20 µM 13-cis-RA (B), 100 µM FA (C) and pre-treatment of 100 µM FA, followed by 20 µM 13-cis-RA (FA-RA) (D) in vitro. (A) and (C) showed normal midfacial formation (score=6). (B) showed teratogenic effect of 13-cis-RA induced atrophic of midfacial processes (score=2) presenting the lowest score of developing midfacial processes. (D) showed the protective effects of FA on RA induced malformation resulting in increased midfacial process score (score=5), Scale bar = 200 µm. (b): By scoring system assessment, there were no significant differences in midfacial morphogenesis score between DMSO-treated (n=19) and FA-treated embryo (n=18). The midfacial morphgenesis score of 13-cis-RA treated group significantly decreased compared to that of the DMSO-treated group. The FA-RA treated embryos showed significantly increased in midfacial morphgenesis scores compared to 13-cis-RA-treated group (RA). *p < 0.05 vs. DMSO and FA; **p < 0.05 vs. RA.