“…The data available from the existing literature revealed the following acquisition modalities: CT scans [26,29,31,36,39,41,43,46,54,60,67,71], MRIs, CBCTs (for maxillary obturators) [22,24], structured light scanners [19][20][21]23,58], laser scanners [37,49,51,56,57,[62][63][64]68,70], light intensity scanners [30], facial scanners, intraoral scanners (IOSs) [3,18,25,27,32,44,53], desktop scanners [34,66], 3D photogrammetry [28,40,52,55,59,69], the monoscopic photogrammetry technique with a mobile phone [15] or two (or more) of the following combined registration modalities: CT and a facial scanner [61], CT an...…”