Objective: This study aimed to compare the effects of Mandibular Protraction Appliance (MPA) and Jasper Jumper (JJ), associated with fixed orthodontic appliances for Class II malocclusion treatment. Materials and Methods: Sample comprised of 71 subjects, divided into 3 groups: Group 1: 24 patients, mean initial age 12.36 years, treated with MPA for 2.74 years; Group 2: 25 patients, mean initial age 12.72 years, treated with JJ for 2.15 years; Control Group: 22 subjects, mean age of 12.67 years,

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... with untreated Class II malocclusion, followed for 2.12 years. Initial and final variables and treatment changes were compared between groups by ANOVA and Tukey tests. Results: JJ group presented greater restriction of growth and maxillary retrusion and MPA showed a greater increase of mandibular effective length. MPA and JJ groups showed improvement of maxillomandibular relationship. Maxillary incisors showed greater retrusion and retroclination in MPA group. MPA presented greater proclination of mandibular incisors and JJ showed greater protrusion. MPA and JJ groups presented a decrease in overbite and overjet. Conclusion: MPA showed a significant increase in mandibular effective length and great dentoalveolar compensation. JJ showed significant restriction of maxillary anterior displacement and also important dentoalveolar compensations. JJ must be indicated mainly in cases with maxillary protrusion, and MPA, especially in cases with mandibular deficiency.