Evaluation of the impact of postnatal maternal separation stress on enamel formation in an experimental murine model.

BACKGROUND

The adverse effects of postnatal maternal separation (MS) on offspring development are well documented; however, its specific impact on dental enamel formation remains inadequately explored. This study examines the effects of maternal-separation-induced toxic stress on dental enamel formation in a murine model.

METHODS

A total of 24 Wistar rat offspring (Rattus norvegicus) were utilized, divided into a control group (n = 12) and an MS group (n = 12). The MS group underwent 4 h of daily separation from their mothers from postnatal day 2 to day 21, while the control group remained undisturbed with their mothers. Throughout the experimental period, body weight, length, and key developmental milestones (including incisor eruption, eye opening, and ear opening) were monitored. At postnatal day 28, the animals were euthanized, and the incisors were collected for analysis. Incisor photographs were conducted for macroscopic evaluation. Volumetric assessment of the enamel layer was performed using micro-computed tomography (micro-CT) imaging. Microhardness testing quantified enamel resistance, while scanning electron microscopy (SEM) provided insights into the morphology and ultrastructure of incisor enamel. In addition, energy-dispersive X-ray spectroscopy (EDS) was performed to evaluate mineral content and identify possible compositional alterations in dental enamel. Data were statistically analyzed using Student's t-test (α = 0.05).

RESULTS

The findings revealed an increase in body weight within the MS group (p < 0.05), while normal growth and developmental milestones exhibited no significant changes (p > 0.05). No macroscopic alterations were observed in the dental enamel of incisors of MS group. SEM analysis of the incisors indicated that the enamel structure of incisors in the MS group maintained an organized arrangement of enamel rods, characterized by densely packed, elongated structures extending from the underlying dentin to enamel surface. Furthermore, structural integrity, microhardness, and mineral composition remained largely unaffected (p > 0.05).

CONCLUSION

Under the given experimental conditions, postnatal maternal separation does not significantly compromise dental enamel formation in rat offspring.