Evaluation of the dentoalveolar inclination and upper arch dimensions in posterior cross bite treated with removable and fixed expander appliances

Ary dos SANTOS-PINTO, Talita Cristina ROSSI, Luiz Gonzaga GANDINI JR., Gustavo Mattos BARRETO

Aim: to evaluate the differences of arch dimension and arch form obtained by treating the posterior cross-bite with the fixed expander appliance Hyrax and with the removable expander type Hawley plate with centralized screw. Methods: initial and final study models of thirty-one children in the mixed dentition phase, of both genders and same ethnic origin treated in the Araraquara School of Dentistry, UNESP, São Paulo, Brazil – undergraduate and graduation Orthodontic courses. Fifteen children were treated with a removable expander appliance and sixteen with the fixed expander appliance, rapid palatal expansion. Measurements of inter canine and inter molar distances, palatal and dental inclination, were taken using the images of the upper arch and the palatal contour with the aid of an adjustable template and Radiocef analyzing program. Results and Conclusion: the results indicated a significant increase in the inter canines and inter molars distances in both groups, significant inclination of teeth and alveolar process toward buccal direction in the group treated with the fixed expander appliance. The expansion obtained when using the fixed expander appliance was about the double of the expansion obtained with the removable expander appliance.

Keywords: Palatal expansion. Occlusion development. Orthodontics.

Sunday, April 28, 2024 01:51