Treatment outcomes of orthodontic treatment, corticotomy-assisted orthodontic treatment, and anterior segmental osteotomy for bimaxillary dentoalveolar protrusion

Background: The purpose of this study was to compare treatment outcomes of orthodontic treatment, anterior segmental osteotomy, and corticotomy-assisted orthodontic treatment for resolution of bimaxillary dentoalveolar protrusion. Methods: The samples consisted of 65 Korean adult female patients with bimaxillary dentoalveolar protrusion who had achieved a good treatment result and were divided into group 1 (orthodontic treatment), group 2 (corticotomy-assisted orthodontic treatment with skeletal anchorage in the maxilla and anterior segmental osteotomy in the mandible), or group 3 (anterior segmental osteotomy in the maxilla and mandible). The hard- and soft-tissue variables were measured from lateral cephalographic tracings at pretreatment and post-treatment stages. Statistic analyses were performed to compare differences in pretreatment and change from pretreatment to posttreatment. Results: Group 3 showed the largest amount of basal bone retraction and the least amount of upper incisor inclination change and upper alveolar bone bending among the three groups. The amounts of change in the upper lip projection and angulation were greater in group 2 than in group 1. Group 3 showed a decrease of the upper incisal exposure, whereas group 1 showed an increase. Upper central incisor to Frankfurt horizontal plane, upper and lower alveolar ridge angle, Pog-N perpendicular, and anteroposterior discrepancy indicator were selected as significant variables for discriminating the three groups. Conclusions: The results of this study show that orthodontic treatment or corticotomy-assisted orthodontic treatment is indicated for those with severe incisor proclination with normal basal bone position, although corticotomy-assisted orthodontic treatment can be advantageous for adult patients concerned with treatment duration. Anterior segmental osteotomy is recommended for bimaxillary dentoalveolar protrusion patients with a gummy smile, basal bone prognathism, relatively normal incisor inclination, and relatively underdeveloped chin position.