APPENDIX 2.

Articles Excluded After Full-Text Evaluation Based on Eligibility Criteria

Reference	Reason for Exclusion
Alkumru et al.21	Groups were not divided into anchorage types
Benyahia et al.22	Transpalatal arch (TPA) groups were not specified precisely
Chen et al.23	No control group
Cobo et al.24	Review
Feldmann et al.25	Outcomes not of interest
Lee et al.26	Outcomes not of interest
Stivaros et al.27	Outcomes recorded at alignment phase not retraction
Thiruvenkatachari et al.28	No control group
Thiruvenkatachari et al.29	No control group
Upadhyay et al.30	TPA anchorage group was not specified
Xu et al.31	Anchorage groups were not specified