Long-term changes of anterior alveolar bone after treatment with mandibular molar distalization, evaluated with cone-beam computed tomography

This case report update describes a camouflage treatment in a 24-year-old male with moderate crowding, Class III skeletal and dental relationships, and normovergent facial pattern. To establish Class I molar relationships and create space for mandibular incisor alignment, mandibular posterior teeth were distalized first before brackets were bonded on the mandibular anterior teeth. During treatment, mandibular incisors were extruded along with the counterclockwise rotation of the mandibular occlusal plane caused by the moments created from the distalization forces applied from brackets to the retromolar mini-implants. Posttreatment cone-beam computed tomography showed that the distal root of the mandibular second molars contacted the lingual cortex of the mylohyoid ridge and submandibular fossa and the extrusion of the mandibular incisors with thinning of the alveolar bone. This thinned alveolar bone was not recovered during 9 years of retention. Therefore, prevention of the extrusion of mandibular incisors during Class III camouflage treatment is recommended.