Early Orthopedic and Comprehensive Orthodontic Treatment of a Growing Patient with an Asymmetric, Low-Angle Skeletal Class III Tendency using a Hybrid Rapid Maxillary Expander and Facemask: A Case Report

This case report presents the early orthopedic and comprehensive orthodontic treatment of a growing male patient whose chief complaint was a retruded maxilla. At the start of treatment (age 12 years 7 months), examination revealed an asymmetric facial appearance, a concave profile, a hypodivergent (low-angle) skeletal growth pattern (Jarabak ratio, 68.8%), a borderline skeletal Class I relationship (ANB, 0.6°) with maxillary retrusion (N-A, -2.1 mm; Wits, -4.2 mm), an asymmetric Class III molar relationship, and a negative overjet (-1.5 mm). Model analysis showed a 6.4-mm maxillary arch-length deficiency, no mandibular crowding, bilateral impaction of the maxillary canines and the maxillary left second premolar, and congenital absence of both mandibular second premolars. Treatment consisted of a hybrid-anchorage rapid maxillary expander combined with a protraction facemask, followed by comprehensive fixed appliance therapy, over 2 years 6 months. At the end of treatment (age 15 years), a stable skeletal Class I relationship was achieved (ANB, 3.5°; SNA increased by 4.9°), together with a bilateral Class I molar and canine relationship, a positive overjet and overbite of 2 mm each. This case illustrates that a hybrid RME/facemask protocol followed by fixed appliance therapy can be an effective approach for growing patients with an asymmetric, low-angle skeletal Class III tendency complicated by multiple dental anomalies.