Dental changes in Class II patients treated with Pendex appliance: a prospective study Alterações dentárias em pacientes com Classe II tratados com aparelho Pendex: estudo prospectivo Cambios dentales de los pacientes con Clase II tratados con dispositivo Pendex: estudió prospectivo

The objective of this study was to evaluate the dental changes in the maxilla and the possible facial vertical alterations of patients after using a Pendex appliance for maxillary molar distalization during their orthodontic treatment. A convenience sample of ten patients of both genders (9.3 to 28.8 years old; mean: 15.3 years) with a need of orthodontics treatment was selected for participation in this study at Paulista University Dental School - FOUNIP. Two lateral cephalometric radiographs were obtained for each patient, one at the beginning (T1) and the other after the distalization of the maxillary first molars (T2). The cephalograms were traced and measured by a calibrated operator and the data at T2 and T1 were compared between then for each patient. The following cephalometric measurements were taken: distance from PTV to maxillary first molar (A6PTV), to maxillary first premolar (A4-PTV) and to maxillary incisor (A1-PTV); maxillary first molar tipping (A6.PTV), maxillary first premolar (A4.PTV) and maxillary incisor (A1.PTV) to palatal plane (PP); interincisal angle (A1.B1); lower facial height (LFH); facial axis (FA) and total facial height (TFH). The data were submitted to “t” test for paired samples (5%). The mean and standard deviations obtained for each measurement (T2-T1) were: A6-PTV= -4.9±6.5, A4-PTV=1.2±4.1, A1-PTV= -1.4±7.3, A6.PP=9.4±7.7, A4.PP=-3.6±6.7, A1.PP=9.4±7.7, A1.B1=-4.9±13.7, LFH=1.7±2.1, FA=-1.0±2.4 and TFH=1.0±2.7. Only the A6-PTV (p=0.041); A6.PP (p=0.004) and LFH (p=0.031) angular measurements presented statistic significance (“t” test). It can be concluded that Pendex is an efficient orthodontic appliance for correcting the Class II malocclusion and that its effects were limited to dentoalveolar structures. Descriptors: Malocclusion, Angle Class II; Orthodontics; Cephalometry. Resumen