Furkan Dindaroğlu1, Gökhan Serhat Duran2, Serkan Görgülü3. 1. Research assistant, Department of Orthodontics, Dental Sciences Center, Gülhane Military Medical Academy, Etlik, Ankara, Turkey. Electronic address: furkandindaroglu@yahoo.com.tr. 2. Postgraduate student, Department of Orthodontics, Dental Sciences Center, Gülhane Military Medical Academy, Etlik, Ankara, Turkey. 3. Associate professor, Department of Orthodontics, Dental Sciences Center, Gülhane Military Medical Academy, Etlik, Ankara, Turkey.
Abstract
INTRODUCTION: In this study, we evaluated the reproducibility of the lip position at rest in 3 dimensions using reverse engineering software and stereophotogrammetric images. METHODS: We used 3dMD Flex (3dMD, Atlanta, Ga) to obtain 60 stereophotogrammetric images from the same participant. Thirty images were obtained in 3 sessions on the same day, and the procedure was repeated 6 weeks later for 30 more images. The surface-base registration, the segmentation of the upper and lower lips, and the 3-dimensional deviation analysis were performed with Geomagic Control (3D Systems, Rock Hill, SC) software. The Shapiro-Wilk test, paired sample t test, Bland-Altman plots, and Wilcoxon signed rank test were used for statistical analysis at a significance level of P <0.05. RESULTS: The deviations of the upper lip on the first images were between 0.16 and 1.39 mm. The mean total deviation was 0.25 ± 0.12 mm. The mean deviation of the lower lip was 0.34 ± 0.17 mm. The deviations were observed between -1.96 and 1.97 mm. When the mean positive (P = 0.633 and P = 0.171, respectively) and the mean negative (P = 0.771 and P = 0.842, respectively) deviations of the upper and lower lips were analyzed, there was no significant difference between the 2 time points. CONCLUSIONS: The results suggest that the rest position can be reproduced within a small range both on the same day and between the sessions. More research with larger samples is needed to confirm these results.
INTRODUCTION: In this study, we evaluated the reproducibility of the lip position at rest in 3 dimensions using reverse engineering software and stereophotogrammetric images. METHODS: We used 3dMD Flex (3dMD, Atlanta, Ga) to obtain 60 stereophotogrammetric images from the same participant. Thirty images were obtained in 3 sessions on the same day, and the procedure was repeated 6 weeks later for 30 more images. The surface-base registration, the segmentation of the upper and lower lips, and the 3-dimensional deviation analysis were performed with Geomagic Control (3D Systems, Rock Hill, SC) software. The Shapiro-Wilk test, paired sample t test, Bland-Altman plots, and Wilcoxon signed rank test were used for statistical analysis at a significance level of P <0.05. RESULTS: The deviations of the upper lip on the first images were between 0.16 and 1.39 mm. The mean total deviation was 0.25 ± 0.12 mm. The mean deviation of the lower lip was 0.34 ± 0.17 mm. The deviations were observed between -1.96 and 1.97 mm. When the mean positive (P = 0.633 and P = 0.171, respectively) and the mean negative (P = 0.771 and P = 0.842, respectively) deviations of the upper and lower lips were analyzed, there was no significant difference between the 2 time points. CONCLUSIONS: The results suggest that the rest position can be reproduced within a small range both on the same day and between the sessions. More research with larger samples is needed to confirm these results.