Resumo

GONZALEZ, T. et al. Estudio morfométrico de las malformaciones craneofaciales experimentales inducidas por ácido retinoico. Rev Esp Cirug Oral y Maxilofac [online]. 2003, vol.25, n.5, pp.288-293. ISSN 2173-9161.

Objective: Retinoic acid is an active metabolite of Vitamin A that is teratogenic when present in excess during mammalian embriogenesis. We have investigated the effects of early exposure of rat embryos to retinoic acid on craniofacial structures. Design: Treatment of 45 pregnant Sprague-Dawley rats with 125mg./Kg all-trans-retinoic acid on pregnancy day 10 was performed. Twenty controls were treated only with oil. The fetuses were recovered the day before term, and both morphologic and morphometric analyses of the craniofacial structures were performed. Results: None of the control fetuses had malformations. Craniofacial defects were observed in 100% of the retinoic embryos including facial clefts, proptosis, abnormalities and inferior placement of the pinnae, skin tags, and nasal anomalies. Morphometric analyses revealed an increased distance between nasal pores (p<0,01) and between both eyes (p<0,05) in retinoic embryos. A reduced distance of the maxilla (p<0,01) and the mandible (p<0,01) were also noted. Conclusions: Morphologic and morphometric studies confirm the hypothesis that retinoic acid disturbs normal craniofacial development when administered during a critical period. Hindrance of migration of the cranial neural crest cells may be a main reason to explain these events.

Palavras-chave : Retinoic acid; Sprague-Dawley rats; Embriopathy; Neural crest; Craniofacial malformations; Morphometric analysis.

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