Orthodontic movement of maxillary incisors through the midpalatal suture area--an experimental study in dogs

Abstract

An experiment, in the beagle dog model, was undertaken to determine whether it is possible to move a maxillary central incisor orthodontically across the midpalatal suture area, and whether this tooth movement will result in displacement of the midpalatal suture, and to describe the histological appearance of this area subsequent to the orthodontic tooth movement. Three dogs were used as test animals, two young and one old, and each of them had a control of the same age. Two left upper incisors (l1, l2) were extracted in each test dog. Orthodontic movement of the first right incisor (1l) across the midpalatal suture area was performed and took 225 days in the old dog and 250 and 450 days, respectively, in the two young dogs. The tooth movement was ended, when the test tooth had been moved bodily across the midline according to both clinical and radiological criteria. The histological analysis revealed that the suture had been dislocated in front of the test tooth in the young dogs. The sutures in the two old dogs were closed and the test tooth had passed the suture area without any impediment. Furthermore, the tooth moved in the old dog exhibited significantly more root resorptions.