Perbedaan ketinggian dan ketebalan tulang alveolar regio simfisis paska perawatan ortodonti cekat pada maloklusi Kelas I Bimaxillary Protrusion dan Hiperdivergen (studi sefalometri) = Differences in alveolar bone height and thickness at the symphysis region after fixed orthodontic treatment in Class I Hyperdivergent with Bimaxillary Dental Protrusion (a cephalometric study)