“…For IOD treatment, a bar attachment was used in 11 studies [4,5,6,12,13,17,19,21,23,25], and a ball attachment was used in three studies [17,21,23]. For the radiographic method to identify the average rate of PRRR, PAI was used in 10 studies [4][5][6][7]12,13,17,20,23,25], and vertical linear resorption was used in nine studies [10,11,15,16,18,19,21,22,24]. Among studies using the vertical linear resorption measurement, cephalometric radiographs were used in six studies [11,15,18,19,22,24], panoramic radiographs were used in two studies [10,21], and panoramic computed tomography was used in one study [16].…”