Three dimensional evaluation of dentofacial changes due to corticotomy assisted rapıd maxıllary expansıon with computed tomograpy

Transverse maxillary deficiency is the skeletal discrepancy which is seen frequently in the adult individuals who seek orthodontic treatment. Corticotomy assisted rapid palatal expansion is indicated in the skeletally matured individuals with transverse maxillary deficiency whose maxilla can not be corrected with conventional rapid palatal expansion.More recently, the use of computed tomography (CT) has come to be considered a reliable method of evaluating the changes in maxillary dimensions after corticotmy assisted rapid maxillary expansion. The images produced by the CT method allow better localization of the anatomical structures than conventional 2-dimensional (2D) radiographs, which are often geometrically distorted and plagued by bilateral structural superimpositionsThe purpose of this study is to assess transversal maxillary deficiency in adults after corticotomy assisted rapid maxillary expansion, using CT to evaluate dentofacial changes.The research material were composed of skeletally matured 24 patients whose age was 18 years 8 mounts at the beginning of the treatment period, divided into 3 groups who had Skeletal Class 1, 2 and 3 malocclusion due to unilateral or bilateral transverse maxillary deficiency. Without lateral cephalograms and hand-wrist radiographies only CT was taken at the start and end of the treatment.Statistical evaluation was made by using the parametric and nonparametric test according to compatibility results.The dental measurements on cast models and 3D measurements on 3D models derived from computed tomography (CT) data were compared statistically. No significant differences were found between those two measurements.At the end of rapid maxillary expansion, it was found that the mean expansion was obtained at the interdental widths across the first molars, premolars and canines. After corticotomy assisted RPE treatment: SNA angle increased, the mandible rotated downward and backward, the ANB increased and the anterior facial height increased significantly and the widths of the maxilla and nasal cavity increased significantly. Also Pd is reduced by the lowering of the palatal shelves of the maxilla during RME.