Abstract
This study investigated the reproduction of a human model using data acquired by means of three-dimensional facialmeasurement with an optical surface scanner and examined the tolerance in clinical use. Furthermore, three-dimensional analysis of pre- and postoperative midfacial soft tissue change, especially the morphology of external nose regions, was carried out on patients who had undergone bimaxillary orthognathic surgery. Six adults (two males and four females age 25 to 33 years) were recruited to investigate the reproduction of the human model. To compare pre-and postoperative midfacial soft tissue change, 17 patients (two males and 15 females age 16 to 24 years) were examined prior to and 6 months after bimaxillary orthognathic surgery. Surgical procedures performed were Le Fort I osteotomy and bilateral sagittal split osteotomy in all patients. The reproduction of the model in this study ranged from 0.23 to 1.26 mm. The results showed that there was a small error in areas of the forehead and orbita, whereas there was a large error in the lower face. With respect to the postoperative shape of the external nose region, the correlation between the displacement of hard and soft tissue was detected at the landmark of subnasal (R=0.73), and several landmarks measured surrounding the external nose moved more forward than subnasal. In addition, the postoperative width of alar increased (3.5±1.7mm). In cases of maxilla moving forward by more than 3.0mm, the displacement of pronasal that tended to move upward had an influence on postoperative facial change. In conclusion, as far as the shape of the external nose is concerned, the distance between the landmark of pronasal and alar base was reduced and the amplitude of alar showed an increase postoperatively, resulting in a wider nose. Morphological change of the external nose plays a great role in overall facial alteration after surgery.
