Long-Term Effect of Diet Consistency on Mandibular Growth within Three Generations: A Longitudinal Cephalometric Study in Rats

SIMPLE SUMMARY: Craniofacial growth has been shown to be affected by different factors, including environment. It is thought that environmental changes could possibly affect the growth of the mandible. The question of how diet consistency affects mandibular growth within one generation of rats has been answered to some extent by various studies, according to which diet consistency may result in different masticatory forces that affect mandibular growth. There is no study so far that examined possible quantitative and qualitative growth changes in the mandible within different generations. The present experiment evaluated the impact of different food consistencies on mandibular growth within three generations. The results of this study indicate that a soft diet could be responsible for less mandibular growth, and this information might be passing through generations. ABSTRACT: Background: This study investigated the effect of diet consistency on mandibular growth of Wistar rats through three generations. Methods: A total breeding sample of 60 female and 8 male Wistar rats were used in this study. Measurements took place only on female animals. Twenty female Wistar rats at 30 days old and four male rats at 30 days old comprised the primary breeding sample of the first generation, and from these animals two different generations were reproduced. Lateral cephalometric X-rays were taken from all female rats at the age of 100 days. A total of 7 craniofacial landmarks were selected for the linear measurements, and 12 curves and 90 landmarks were selected for geometric morphometric analysis of the lateral X-rays. Bonferroni test and a permutation test were performed for the statistical analysis. Results: Means of measurements of all soft diet groups compared to hard diet groups were significantly smaller. According to linear measurements, there was a significant difference only between the first-generation soft diet with the third-generation soft diet group. According to geometric morphometric analysis, the statistical differences appeared on the condylar process and the angle of the mandible. Conclusions: The soft diet could be responsible for less mandibular growth, and this information might be passing through generations.