A noncontact three-dimensional measuring system (liquid crystal range finder system) is described. Three-dimensional facial surface data (more than 30,000 points) could be obtained in 1 second, and the resolution was approximately 0.4 mm. The reliability and repeatability of the results were validated with a calibrating apparatus and a highly accurate contact-type three-dimensional digitizer. Consequently, the average of the measurement errors on a facial plaster model was 0.3 mm. Repeatability in measuring human faces was approximately 0.3 mm. Therefore, the total error in measuring human faces was approximately 0.5 mm. Because of the shortness of measuring time, this system was capable of scanning faces of infants without the need for sedation. The output of the liquid crystal range finder was demonstrated on an infant with cleft lip. The surface points improved by cheiloplasty, and the residual deformities were observed clearly. This system was thought to be the most suitable apparatus for measuring faces of infants (especially infants with cleft lip) and enabled us to analyze facial surface structure both qualitatively and quantitatively.
[Show abstract][Hide abstract] ABSTRACT: Advances in technology have yielded systems that are capable of non-invasive, high-definition three-dimensional recordings of human body surfaces. Originally designed for use in an industrial setting, surface scanners have not been sufficiently evaluated for medical application so far. In this study six scanners based on different scanning principles (ringe projection scanners, laser scanners and photogrammetry scanner) were employed to measure five sheep skulls of different sizes. Distance measurements were done chephalometric or on the three dimensional data sets and compared concerning the accuracy. Conclusion of this work is with all scanning principles a skull can be recorded in seconds, archived and distances measured with the accuracy of a 1/10 millimeter. Best results will be achieved when the different types of scanners are applied to specific medical problems according to their special construction designs and characteristics.
[Show abstract][Hide abstract] ABSTRACT: The appearance of the nostril in cleft lip patients is very important in the subjective assessment of naso-labial forms and patient satisfaction. To improve the outcome of plastic surgery, a computer aided diagnostic system was developed. Facial forms were measured with a three-dimensional optical scanner (Ogis Range Finder RFX-IV) XYZ coordinates (256x240) and RGB (red, green, blue) image (512x480) data sets were then obtained with the apparatus. The nostril area was determined by discriminant analysis of the RGB data, and the landmarks of the nostril were extracted under geometric conditions. To assess the reliability of this technique with head inclination, five volunteers were measured in seven postures. Landmark stability was within approximately 1 mm when the Frankfort plane was 45-60 degrees. Subsequently, this system was applied to two cleft lip patients who had undergone a secondary nasal correction. For control data, 37 healthy adults (22 males and 15 females) were measured in the same manner. Nasal asymmetry in the unilateral case and wide and flat nostrils in the bilateral case were greatly improved after surgery. Conversely, the volume of the nasal tip decreased. This system was a great help in the diagnosis of nostril abnormalities.
Journal of Cranio-Maxillofacial Surgery 01/2000; 27(6):345-53. DOI:10.1054/jcms.1999.0097 · 2.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The amorphous or wide nasal tip is the most commonly encountered nasal tip deformity, but little has been done to measure the effect of standard rhinoplasty techniques on nasal tip width. In the clinical routine, nasal tip width and soft-tissue cover thickness are estimated by inspection and palpation rather than by measurement. In this study, a B-mode sonograph with a 12-MHz transducer was used in a noncontact mode to measure tip width 0.5 cm occipital to the tip defining point, distance between the alar cartilage domes, and thickness of the soft-tissue cover overlying the lower lateral cartilages. These parameters were measured 3 to 8 weeks before and 56 days to 19 months after a transdomal suture tip plasty in 18 patients. The distance between the alar cartilage domes seemed to be an important factor for tip width because interdomal distance, not soft-tissue cover thickness, correlated with tip width before surgery (correlation: 0.53). Conversely, the degree of tip refinement correlated with preoperative soft-tissue cover thickness (correlation: 0.75), but not with interdomal distance. Ultrasonic imaging of nasal soft tissues may help to assess the effect of different tip refining procedures and other soft-tissue changes after rhinoplasty.
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