Avaliação cefalométrica em telerradiografias póstero-anteriores das dimensões transversais de indivíduos submetidos à expansão rápida da maxila

Abstract

A maloclusão caracterizada pela mordida cruzada pode ser definida como sendo a falha dos arcos dentários superior e inferior ocasionada por problemas localizados corno posição dentária ou crescimento alveolar, ou uma grave discrepância transversa antra maxila e mandíbula. Pode envolver um ou mais dentes e pode ser unilateral ou bilateral. Tais problemas transversos que, em geral, se manifestam como mordida cruzada posterior, com o arco superior estreito, são relativamente comuns. Podem existir muitas causas para esta alteração no desenvolvimento normal da face e da oclusão, como habito de sucção, interposição lingual, padrão respiratório, retenção prolongada de dentes decíduos, apinhamentos, perda prematura de dentes decíduos, fenda palatina, deficiências nos arcos entre outros.

The posterior cross bite is a kind of malocclusion that should be corrected earlier. One in the ways of accomplishing this correction is through the rapid maxillary expansion when the problem is due to the narrow upper arch. The effects generated by this procedure in the facial structures have been discussed thoroughly in the literature. In this work they were appraised the individuals' traverse dimensions submitted to the rapid maxillary expansion through posteroanterior cephalometric analysis, with the objective of analyzing the dental and skeletal results reached with this treatment type, pointing the alterations that the rapid maxillary expansion propitiates in the result of the clinical treatment and using the posteroanterior cephalometric to analyze the effects of this procedure. Twelve individuals were analyzed with some degree of posterior cross bite, six male and six female, with ages varying between 5 years and 6 months to 16 years and 11 months, in three different times: in the beginning of the treatment, fifteen days after the beginning, in the moment of stabilization of the appliance and three months after the stabilization. Posteroanterior cephalometric analysis was accomplished on these three times and then appraised being used measures of the width of the nasal cavity, maxillary width, distance between crowns and roots of the upper central incisor and first upper molars. The election appliance was the Haas expander maxillary. The cephalometric measures facilitated the verification of the traverse alterations that happen during the procedure. The rapid maxillary expansion was shown effective for the correction of the posterior cross bite and for the increase of the volume of the nasal cavity. The separation of the medium palatine suture and the alterations that happened in the upper central incisor were fleeting and reversible. The alveolar bony remodelação denotes the occurrence of the expansion of the upper molars registering a gain in the distance between them. The result of the procedure was good for most of the analyzed individuals. The rapid maxillary expansion was shown effective for the correction of the posterior crossed bite, being a fast procedure, of easy execution and with little painful.