Efecto del retardo prenatal de crecimiento y la subnutrición postnatal en el crecimiento craneofacial / Craneofacial effect of prenatal growth retardation and postnatal undernutrition in craniofacial growth

RESUMEN El objetivo fue analizar en animales con retardo prenatal de crecimiento (RPC) el efecto de la subnutricion proteico-calorica lactacional y postlactacional sobre la morfologia craneofacial, particularizando en el crecimiento de los componentes funcionales neural y facial. Ratas Wistar fueron divididas en los grupos: Control, RPC (inducido por ligamiento parcial de ambas arterias uterinas el dia 15 de gestacion) y Sham-operado (con igual tecnica quirurgica que RPC aunque sin ligamiento de las arterias). A su vez, el grupo RPC se dividio en: (a) crias lactantes de madres con nutricion normal y a partir del destete alimentadas ad-libitum y (b) crias lactantes de madres con restriccion alimentaria del 25% y a partir del destete alimentadas con el 50% de lo consumido por un animal control. Se tomaron radiografias a las edades 1, 21, 42, 63 y 84 y se midieron longitud, ancho y altura de los componentes neural y facial. Se calcularon los indices volumetricos neural y facial y morfometrico neurofacial. Se aplicaron ANOVA y pruebas post-hoc y se calcularon diferencias porcentuales entre medias. Los resultados permitieron concluir que el estres primario ocurrido durante la vida intrauterina resulta critico en lo inmediato y en la vida postnatal, ya que aun mediando normonutricion postnatal el retardo de crecimiento perdura. Ademas, cuando al estres prenatal le continua restriccion nutricional postnatal los efectos adversos son aditivos provocando retardo del crecimiento aun mayor. Finalmente, mientras que el componente neural es mas resistente a las deficiencias nutricionales, el facial presenta mayor plasticidad, hecho que se evidencia en cambios de forma. Palabras clave crecimiento craneofacial; desnutricion pre y postnatal; craneometria funcional  ABSTRACT The aim of the study was to analyze the effect of protein-calorie malnutrition during lactation and post-lactation on craniofacial morphology in intrauterine growth-retarded (IUGR) animals, particularly in the neural and facial functional components. Wistar rats were divided into the following groups: Control, IUGR (induced by partial bending of both uterine vessels at day 15 of gestation), and sham-operated (with the same surgical technique as IUGR, but without vessel bending). The IUGR group was further divided into (a) nursing pups of mothers with normal nutrition and fed ad-libitum at weaning, and (b) nursing pups of mothers with 25% food restriction and fed with 50% of the food ingested by controls at weaning. Radiographs were taken at 1, 21, 42, 63, and 84 days. Neural and facial length, width and height were measured, and neural and facial volumetric and morphometric indices were calculated. ANOVA and post-hoc tests were applied, and percentage differences between means were determined. Results showed that intrauterine stress is critical during early and postnatal life, since even when postnatal nutrition is normal, growth retardation persists. Furthermore, when prenatal stress is followed by postnatal nutritional restriction, adverse effects are additive and cause even greater growth retardation. Finally, while the neural component is more resistant to nutritional deficiencies, the facial component has greater plasticity, as reflected in the shape changes observed. Key words  craniofacial growth; prenatal and postnatal undernutrition; functional craniometry