Early Intervention For Angle Class II Division 1

This case report represents the early intervention for Angle Class II Division 1 during the stable period of lateral dentition, which highlights the importance of addressing both skeletal and soft tissue discrepancies for long-term stability. A 7-year-4-month-old girl presented with the chief complaint of "protruded and misaligned anterior teeth for over one year." The Facial asymmetry with chin deviation to the left. Convex profile, retruded chin, and hyperactive mentalis muscle were found. Intraoral examination showed that the patient had the mixed dentition period with high palatal vault, tapered maxillary arch, and ovoid mandibular arch. The increased overjet (5mm) with anterior open bite and rotated upper and lower incisors were showed. Atypical swallowing pattern was also found.The cephalometric analysis showed that the patient had posteriorly positioned mandible with normal mandibular length, average growth pattern, proclined upper and lower incisors. 2x4 fixed appliance combined with headgear and facebow were used after maxillary expansion. Myofunctional therapy was conduced. After 8 months of active treatment, a modified Hawley retainer were used for stabilization. The patient achieved Class I molar relationship and improved facial profile with reduced SNA angle. Maxillary orthopedic treatment is effective at CVMS1 and CVMS2 stage. Correct tongue posture and normal swallowing function are critical for the stability of early intervention. Consequently, early intervention prioritizes the harmonization of maxillomandibular development and orofacial muscle function