Pharyngeal Airway Changes After Mandibular Advancement with Clear Aligners in Growing Patients with Class II Malocclusion Due to Mandibular Retrusion: A Retrospective Controlled Pilot Study

Clear aligner mandibular advancement is increasingly used for Class II correction in growing patients, but its effect on pharyngeal airway morphology remains unclear. This retrospective controlled pilot study evaluated pharyngeal airway, soft-palate, adenoidal, and hyoid bone changes after clear aligner mandibular advancement in growing Class II patients with mandibular retrusion. Treated patients were selected from orthodontic records, while untreated controls were selected from the AAOF Craniofacial Growth Legacy Collection. Inclusion required ANB1 > 4°, SNB1 ≤ 78°, and CVMS 1–4 at T1. The final sample included 40 subjects: 20 treated patients and 20 untreated controls. Lateral cephalograms were analyzed at T1 and T2. Airway dimensions, adenoidal measurements, soft-palate morphology, and hyoid bone position were assessed. T2–T1 changes were compared within and between groups. Baseline demographic, skeletal screening, and airway-related variables were comparable between groups. In the treated group, significant within-group increases were observed for LP and PNS–AD2, while controls showed significant changes in H–Cv2 and H–Cv3. Between-group comparison of T2–T1 changes showed a nominally significant difference only for Cv2′–MPW, with a greater increase in the treated group (p = 0.039). No significant between-group differences were observed for the remaining variables. Clear aligner mandibular advancement was associated with a localized increase in the middle pharyngeal airway dimension in growing Class II patients with mandibular retrusion. However, these findings do not support generalized airway enlargement or functional respiratory improvement and should not be interpreted as evidence of pediatric obstructive sleep apnea treatment.