Effect of prenatal stress on craniofacial growth pattern in rat offspring

Abstract

Gestational stress is an environmental factor which induces physical and behavioral alterations in offspring. It is still unclear whether prenatal stress can induce any modification in craniofacial bony structure. To test this possibility, the effects of continued restraint stress in pregnant rats were investigated in the skeletal properties of the craniofacial structure in the male offspring. Objectives: The aim of this study was to investigate whether craniofacial bony structure and growth pattern of rat offspring can be affected by experiencing prenatal maternal stress. Study design: 40 pregnant Wistar rats were divided into 2 groups. Those in the experimental group were exposed to restraint stress from the first day of pregnancy to the parturition day. The control group did not receive the stress protocol. Offspring of both prenatally stressed (PSG) and control (CG) groups were kept in a similar standard environment and were killed in 50 days of age. Then cone beam computed tomography scans (CBCT) of craniofacial region and conventional lateral radiography of left hemi-mandibles were obtained and 31 linear and angular measures were assessed. Results: In PSG, anterior cranial base length, total skull length and viscerocranium measures increased significantly compared to CG whereas cranial width, mandibular dimensions, posterior cranial height and length remained unchanged. Furthermore, PSG showed backward rotation of midface and decreased flattening of the cranial vault. Conclusions: Prenatal restraint stress can induce some alterations in craniofacial pattern by encouraging endochondral growth in cranial base and nasal septum.