Abstract
In orthognathic surgery, it is important for treatment planning to predict postoperative changes from preoperative facial appearance. These changes can be estimated by superimposing two-dimensional lateral cephalograms and lateral facial photographs or by using X-ray CT images; however, radiation exposure and soft tissue reproducibility must also be considered. Three-dimensional （3D） imaging techniques, such as 3D photographic images, can accurately record and reproduce soft tissue in 3D without exposing patients to radiation. In this study, we compared soft tissue changes in preoperative and postoperative 3D photographic images with the amount of jawbone movement and investigated whether there was a correlation between the two.
Twenty patients, diagnosed with skeletal prognathism and who underwent orthognathic surgery, were included in the study and divided into two groups: the symmetry and asymmetry groups. Soft tissue 3D images were constructed from images taken from three angles using a 3D image capture and analysis device with dedicated software. The amount of soft tissue change was determined in the preoperative and postoperative soft tissue 3D images and the lateral movements of Me and soft tissue Me in the frontal plane were compared. The examination items included 1） comparison of the lateral movement of Me and soft tissue Me in the frontal plane, 2） comparison of the anteroposterior movement of Me and soft tissue Me in the sagittal plane, and 3） comparison of the lateral movement of the left and right maxillary first molar buccal cusps and intersection between Camper’s plane and a line connecting the external eye canthus with the labial commissura in the frontal plane.
A strong correlation was observed for both the symmetry and asymmetry groups in item 1）. In item 2）, a strong correlation was observed in the symmetry group. In contrast, no significant correlation was found in the asymmetry group, and in item 3）, no significant correlation was identified in either the symmetry or asymmetry groups.
The results of this study suggest that 3D photographic imaging may be a useful addition to the existing materials required for orthodontic treatment, which can be easily added without radiation exposure.
