Dietary consistency and the midline sutures in growing pigs

Abstract

The purpose of this study was to investigate the effects of reduced masticatory function on midline suture growth and morphology in growing pigs. The sample was 20 pigs separated into two dietary groups and raised at the Department of Anthropology, Harvard University. Midline suture specimens were analyzed at the Department of Orthodontics, University of Washington. Ten farm pigs and 10 minipigs, all male, were randomly assigned to hard (n = 9) and soft-diet (n = 11) groups. Fluorochromic mineral labels were administered to document bone apposition, and the animals were killed after 12 weeks. Undecalcified sections of the interfrontal, interparietal, internasal, and intermaxillary sutures were evaluated for bone quantity and sutural thickness, interdigitation ratio and growth rate. Soft-diet pigs were characterized by a slower rate of weight gain and less bone than their hard-diet counterparts. Even after correction for weight gain, soft-diet pigs had reduced suture growth rate and thickness. However, no difference in interdigitation ratio was detected between dietary groups. Restriction to a soft diet reduces midline suture growth and bone apposition in the growing pig.