Objectives: This retrospective study compared the dental and skeletal effects of two palatal mini-screw- supported methods for maxillary arch mesialization, a Cap Splint appliance and a transpalatal arch (TPA) with NiTi closed-coil springs, in Class III camouflage patients. Materials and Methods: We retrospectively reviewed the records of 142 patients treated for Class III malocclusion at the Department of Orthodontics, Istanbul Okan University, between 2018 and 2025. A total of 26 patients met the inclusion criteria and were enrolled. 11 patients were treated with an acrylic Cap Splint appliance covering complete dentition supported by palatal mini-screws, and 15 were treated with NiTi closed-coil springs placed between a TPA and palatal mini-screws. 11 skeletal and dental parameters were measured on lateral cephalometric radiographs before (T0) and after (T1) treatment, using NemoStudio software (Software Nemotec, Madrid, Spain), and compared within and between the two groups. Significance was set at p<0.05.Results: 5 of the 11 measurements showed statistically significant changes in both groups. SNA increased significantly in the Cap Splint group, where ANB also increased by a mean of 1.55°; in the TPA group, ANB instead declined by 0.87°. The upper molars moved mesially by 1.36 mm in the Cap Splint group and 3.57 mm in the TPA group, avarege amount of movement was 0.17 mm and 0.44 mm per month. The upper incisors also moved labially in both groups (2.31 mm and 1.77 mm), but only the TPA group showed a significant increase in incisor proclination (5.73°), suggesting the incisors tipped labially more in this group. Overjet increased significantly in both groups (1.61 mm and 1 mm), while GoMe-SN, U6-HD, OP-SN, and overbite did not show statistically significant change. Conclusion: Both methods were found effective in the maxillary arch mesialization without major vertical side effects. The Cap Splint moved the whole dentition, while in the TPA method molars moved further mesially but tends to tip the upper incisors labially. Patient’s age, growth stage, and the required type of tooth movement should guide treatment planning.