The influence of an experimentally-induced malocclusion on vertebral alignment in rats: a controlled pilot study

There is a growing interest in the relationship between occlusion and posture because of a greater incidence of neck and trunk pain in patients with occlusal dysfunction. The study was designed to verify whether an alteration of the spinal column alignment may be experimentally induced in rats as a consequence of altering dental occlusion and also to investigate whether the spinal column underwent any further changes when normal occlusion was then restored. Thirty rats were divided into two groups. Fifteen (15) rats (test group) wore an occlusal bite pad made of composite resin on the maxillary right first molar for a week (T1). The same rats wore a second composite bite pad for another week on the left first molar in order to rebalance dental occlusion (T2). Fifteen rats were included in an untreated control group. All the rats underwent total body radiographs at T0 (before the occlusal pad was placed), at T1 (one week after application of a resin occlusal bite pad on the maxillary left first molar) and at T2 (one week after application of a second resin occlusal bite pad on the maxillary right first molar). A scoliotic curve developed in all the test rats at T1. There were no alterations of spinal position observed in any of the control rats. Additionally, the spinal column returned to normal condition in 83% of the test rats when the balance in occlusal function was restored. The alignment of the spinal column seemed to be influenced by the dental occlusion.