M. Stoilova, G. Stoilov

Medical University – Plovdiv, Faculty of Dental Medicine, Department of Orthodontics

Hyrax – type orthodontic appliance fixed with bands on the first premolars and molars result in rapid maxillary expansion. When non-extraction treatment of class II-2 patients is needed, it is necessary to evaluate if the use of this type of appliance can help correction of the discrepancy.

Aim: The aim of the presented clinical case of a patient with permanent dentition, was to evaluate the transversal changes after rapid maxillary arch expansion with rapid expander (RME) during the initial phase of the orthodontic treatment.

Material and methods: An 14-year-old female patient with permanent dentition was examined in the Department of Orthodontics of the Faculty of Dental Medicine in Plovdiv. Biometric analysis of orthodontic models indicated transversal discrepancy measuring maxillary interpremolar and molar widths, maxillary retrusion, conical lateral incisor (21) , deep and distal bite. For correction of the skeletal and dentoalveolar deviations is used rapid maxillary expander. Changes in transversal parameters are measured by Pont’s method analysis. In this study we used norm values established by Linder and Hart.

Results: Using rapid palatal expander we achieved opening of the midpalatal suture and transversal increase of maxillary arch width simultaneously in interpremolar and molar region and intercanine distance expansion, obtaining additional gap between the central incisors( diastema).

Conclusion: Based on the results , it can be concluded that the use of bonded RME in upper dental arch achieves expansion in tranversal dimention. This correction provides the proper conditions for accurate dental alignment of the present teeth in the maxilla.

Keywords: Rapid maxillary expander, rapid expansion, transversal correction of upper dental arch