Department / Institution Mori Orthodontic Office
Classification Research report
Materials and Methods: Two groups were compared and examined with lateral roentgenographic cephalograms which were taken before and after their treatments. First group, which is called the enmasse group, is 17 cases with the extraction of maxillary first premolar and mandibular first premolar or second premolar by the enmasse orthodontic treatment. Second one, which is called the control group, is 17 cases with distal movement of central and lateral incisor after distal movement of cuspid.
Results: These comparisons and examinations resulted as follows. In all angle and distance measurement items, the statistical significance was not recognized in the changing positions of maxillary first molar.
Conclusion: This follows that no difference between the en masse group and the control one is recognized in the mesial movement of maxillary first molars, in the quantity of lingual slant of maxillary central incisors. It is thought that the strong power is necessary because the transseptal fibers between lateral incisor and cuspid are pulled in the distal movement of cuspid and therefore it causes the mesial movement of molars. It is considered that the simultaneous distal movement of central, lateral incisor, and cuspid is more effective with no necessary to pull the transseptal fibers and then with weak power. Therefore it is verified that the en masse orthodontic treatment is useful.
Mesial Movement of Maxillary First Molar in En Masse Orthodontic Treatment with Extraction of Premolar