The aim of this study was to comparatively evaluate the effects of an activator-headgear (FIG) combination to a Jasper Jumper (JJ) plus occipital HG, which was incorporated into removable upper and lower plates. The study group consisted of 60 subjects with mandibular deficiency and a vertical growth pattern. Of these, 20 were treated with JJ appliance-HG incorporated to removable upper and lower plates, 20 were treated with an activator-HG combination. Another 20 subjects who refused orthodontic treatment served as controls. Pre- and postreatment lateral cephalograms and hand-wrist films were gathered for all 60 subjects. Lateral cephalograms were manually traced before being transferred to RMO JOE software by a digitizer. Measurements that are not included in the software were measured manually. Thirty-five dental and skeletal parameters were used in the study. The collected data were subjected to statistical analysis using SPSS packet software. Wilcoxon paired t-test was used for intragroup comparisons. Differences between groups were evaluated by analysis of variance and Bonferroni tests. Results suggest that ANB angle was decreased significantly in both treatment groups compared with the controls. Increase in total facial height was greater in the activator group than in the JJ group. Vertical growth inhibition of lower incisors was greater in the JJ group. The activator-HG appliance was more effective on the mandible, whereas the JJ appliance was mainly active on the maxilla. Thus, ideal cases for JJ-splinted appliance should be high-angle cases, particularly with maxillary excess and some mandibular deficiency.