Long-term stability of a Class III malocclusion with severe anterior open bite and bilateral posterior crossbite in a hyperdivergent patient.

Anterior open bite malocclusion is generally associated with several causes. This case report describes the 2-phase treatment of a 13-year-old boy with a Class III malocclusion, severe anterior open bite, and bilateral posterior crossbite treated without surgical intervention. An orthopedic approach was performed in phase 1 with a hyrax-type palatal expander, followed by maxillary protraction with a facemask for a 10-month period to promote the correction of transverse and sagittal deviations. In phase 2, a comprehensive orthodontic approach using fixed preadjusted appliances associated with intermaxillary elastics was performed. These approaches, combined with good patient compliance, established a functional and esthetic occlusal relationship, normal overjet and overbite, and a well-balanced facial appearance. The 4.5-year follow-up indicated that treatment results were stable.