Palatal Plate-assisted Maxillary Protraction in Early versus Late Mixed Dentition Stages for Class III Orthodontic Patients - A Comparative Study

Abstract Background: Class III malocclusion in orthodontics adversely affects the patient profile, so it needs early intervention to achieve more stable, enhanced skeletal results that are reflected in the patient’s soft tissue profile. Objective: To compare the skeletal, dental, and soft tissue effects of palatal plate–assisted maxillary protraction in early versus late mixed dentition in growing Class III patients. Methods: Thirty-two patients with Class III malocclusion due to maxillary deficiency were included and divided into two equal groups. Group I included 16 early mixed dentition patients (age 7–9 years); Group II included 16 late mixed dentition patients (age 11–13 years). All patients received a palatal miniplate with a face mask. Pre- and post-treatment skeletal, dental, and soft tissue measurements were analysed. Statistical evaluation included paired t-tests, inter-group comparisons, Bonferroni correction, and effect size calculation. Results: Skeletal changes (SNA (angle between S, Nasion and A points), ANB (angle between A, Nasion and B points), angle of convexity, maxillary length) were significantly greater in early mixed dentition. Dental changes were more pronounced in late mixed dentition, especially upper incisor proclination (Upper 1/SN: 7.20° vs. 2.85°). Soft tissue improvements were greater in early mixed dentition, with an H-angle increase of 7.71° vs. 3.90°. Early intervention achieved greater skeletal-driven overjet correction, while late intervention relied more on dental compensation. Conclusion: Timing of palatal plate–assisted maxillary protraction significantly influences treatment outcomes. Early mixed dentition treatment provides maximal skeletal correction, minimal dental compensation, and favourable soft tissue response, supporting the advantage of early orthopaedic management in Class III malocclusion.