3-dimensional analysis of nasal soft tissue alterations following maxillary Lefort I advancement with and without impaction using 3D photogrammetry scanner

Purpose This study was designed to investigate the changes in nasal soft tissue following maxillary Lefort I advancement with and without impaction in subjects presenting a skeletal class III malocclusion, using a 3D photogrammetry scanner. Materials and methods Patients with class III malocclusion undergoing Lefort I advancement with and without impaction and bilateral sagittal split osteotomy with the standard technique were included in this study. Patients were divided into two groups: maxillary Lefort I advancement alone (group 1) and combined with impaction (group 2). Facial soft tissue landmarks of the nose including nasal height (NH), nasal length (NL), nasal tip projection (NTP), alar width (AW), alar base width (ABW), subalar width (Sbal), nasolabial angle (NLA), nasofrontal angle (NFA), and columella inclination (CI) before and at least 4 months after surgery were obtained by a 3D scanner. Results Twenty-one patients were included in this study (Group 1: 11 and Group 2: 10). NH, NTP, and NL decreased significantly in both groups following surgery. In addition, Sbal decreased only in group 2. On the other hand, NLA and CI increased significantly in group 2. The inter-group comparison revealed a statistically significant difference in the alterations in NH, NL, and CI between the two groups. Conclusion Changes in the nose soft tissue occurred after both surgeries, but their type and extent were different. Actions taken to reduce unwanted changes need to be further investigated. To evaluate the changes, 3D photogrammetry scan is a feasible imaging technique that can be used, providing numerous benefits.