A Modified Surgery-first Approach for Mandibular Prognathism with Proclined Maxillary Incisor and Mandibular 86 Spacing

A Modified Surgery-first Approach for Mandibular Prognathism with Proclined Maxillary Incisor and Mandibular 86 Spacing

This case report describes the management of an adult patient presenting with a skeletal Class III malocclusion, mandibular protrusion, upper incisor proclination and mandibular arch spacing by a modified surgery-first approach. A 26-year-old man had skeletal Class III and dental Class III malocclusion with concave facial profile, midface deficiency and mandibular prognathism with chin deviation to left. His dental manifestation presented anterior crossbite, upper incisors proclination and spacing in his mandibular arch. Treatment was performed with a modified surgery-first approach, which included a short presurgical alignment phase. In the maxilla, the significant maxillary crowding was relieved by 14 and 24 extractions while partially retracting the maxillary incisors to reduce the incisal proclination. Then, the upper incisors inclination was furtherly corrected more by a 2-pieces LeFort I osteotomy and closure of the 14, 24 residual dental space during surgery. In the mandible, the lower dental spacing was caused by general tooth size/ jaw bone discrepancy with relative upright incisal inclination. The presurgical preparation included consolidation the dental space distal to the bilateral mandibular canines. The bilateral sagittal split osteotomies were conducted for mandible setback and asymmetry correction. Additionally, the subapical osteotomy with Köle procedure was applied to close the dental space in the mandibular arch while keeping the anterior teeth in relative normal inclination. The excessive chin prominence caused by the Köle procedure was reduced by reduction genioplasty and surface contouring. Post-operative orthodontic treatment included overbite control and detailing of the occlusion. After treatment, the maxillary incisors proclination was corrected and all the dental spaces were closed. Patient's profile was dramatically improved with well teeth alignment, angulation and interdigitation. The 2-pieces LeFort I and Köle osteotomy are the surgical procedures to address the correction in the dentoalveolar portion for efficiently control the inclination of the anterior teeth. Moreover, it also provides benefits for patients who require large amount of jaw setback with minimal effect at the posterior airway space. The treatment goals of the dentoalveolar portion and facial proportion should be contemplated for the staged procedures to improve the efficiency and effectiveness of the treatment outcome.