Surgical-Orthodontic Treatment of a Severe Hyperdivergent Skeletal Class III Malocclusion With Dento-Alveolar Compensations: A Case Report

Skeletal Class III malocclusion resulting from maxillary retrognathism is associated with maxillary endognathia, dento-alveolar compensations, and an anterior crossbite and may be complicated by hyperdivergent facial growth patterns. We report the case of a 16-year-old male patient who presented with skeletal Class III malocclusion secondary to maxillary retrognathism and maxillary endognathia, associated with maxillary proalveolia, mandibular retroalveolia, an anterior open bite tendency, vertical hyperdivergence, and a Class III molar and canine relationship bilaterally. The previous extraction of mandibular second premolars significantly complicated space management and pre-surgical decompensation. Cephalometric analysis showed a skeletal discrepancy (ANB = -3°, AoBo = -8 mm, FMA = 47°), and a difficulty index calculation placed the case in the severe category. Treatment combined pre-surgical orthodontic decompensation, extraction of 14, 25, 18, and 38, maxillary expansion, and combined orthognathic surgery consisting of a Le Fort I osteotomy with advancement and posterior impaction of the maxilla, together with a bilateral sagittal split osteotomy (BSSO) (Obwegeser-Dalpont technique) for mandibular setback, followed by post-surgical orthodontic finishing, allowing the achievement of a satisfactory Class I occlusion at the completion of treatment. This case demonstrates the importance of comprehensive cephalometric and dento-alveolar assessment in planning combined surgical-orthodontic treatment.