Three-dimensional laser scanner as a new tool for measuring lower limb volume in patients with chronic venous diseases

OBJECTIVE

Measurement of lower limb volume in patients with chronic venous disease (CVD) is necessary for assessing severity at the time of diagnosis and evaluating response to therapy administered. Existing methods have some limitations in clinical application and accuracy. The study aimed to investigate the reliability and validity of a three-dimensional laser scanner (3DLS) in measuring the lower limb volume of patients with CVD.

METHODS

A total of 30 patients with CVD (mean age, 55.6 ± 8.07 years; mean body mass index, 24.61 ± 1.87) were recruited in a vascular surgery clinic. The lower limb volumes of all participants were measured using the 3DLS and circumferential method (CM). Statistical analysis was conducted to compare the 3DLS and CM.

RESULTS

There was a strong correlation between the CM and 3DLS method (r² = 0.9065). The 3DLS had a high intraoperator and interoperator reliability. A Bland-Altman plot showed satisfactory agreement between the two methods. The 3DLS demonstrated greater bilateral limb differences than CM.

CONCLUSIONS

There was satisfactory agreement between the two investigated methods. The 3DLS method was confirmed to be accurate, repeatable, and rapid in measuring the lower limb volume in patients with CVD and is, therefore, suitable for clinical use.

Change in Anterior Crowding over 20 Years from Third Decade of Life in Untreated Angle Class I Crowding

Many studies have investigated age-related change in normal occlusion and during the post-retention phase of orthodontic treatment. None, however, have investigated such change in malocclusion. The purpose of this study was to compare age-related change in Angle Class I crowding with that in normal occlusion. Dental casts obtained from 10 men and 2 women in their 20s and then again in their 40s were digitized with a 3-dimensional laser scanner to measure anterior crowding, angulation, inclination, andarch width and length. A paired t -test was used to evaluate change in these values betweenthe two sets of casts. A student's t -test was used to compare values between the crowdingand normal groups. The casts obtained from individuals with untreated Angle Class Icrowding revealed that anterior crowding increased with age due to a decrease in thelength of the maxillary arch. Clear lingual inclination of the maxillary incisors and mesiolingual inclination of the maxillary canines were also observed. A decrease was observedin the anterior arch width and an increase in crowding due to lingual inclination of themandibular canines in the mandible. The space between the mandibular central incisors and between the mandibular lateral incisors and canines was particularly associated withan increase in crowding, suggesting that this was age-related. A comparison betweenpatients in their 40s with Angle Class I crowding and those with normal occlusion revealedthat the increase in maxillary anterior crowding was greater in the former. Mandibularanterior crowding increased at around the same rate, however.

Technical Report on the Modification of 3-Dimensional Non-contact Human Body Laser Scanner for the Measurement of Anthropometric Dimensions: Verification of its Accuracy and Precision

Introduction: Three-dimensional (3D) scanners are widely used in medicine. One of the applications of 3D scanners is the acquisition of anthropometric dimensions for ergonomics and the creation of an anthropometry data bank. The aim of this study was to evaluate the precision and accuracy of a modified 3D scanner fabricated in this study. Methods: In this work, a 3D scan of the human body was obtained using DAVID Laser Scanner software and its calibration background, a linear low-power laser, and one advanced webcam. After the 3D scans were imported to the Geomagic software, 10 anthropometric dimensions of 10 subjects were obtained. The measurements of the 3D scanner were compared to the measurements of the same dimensions by a direct anthropometric method. The precision and accuracy of the measurements of the 3D scanner were then evaluated. The obtained data were analyzed using an independent sample t test with the SPSS software. Results: The minimum and maximum measurement differences from three consecutive scans by the 3D scanner were 0.03 mm and 18 mm, respectively. The differences between the measurements by the direct anthropometry method and the 3D scanner were not statistically significant. Therefore, the accuracy of the 3D scanner is acceptable. Conclusion: Future studies will need to focus on the improvement of the scanning speed and the quality of the scanned image.