2D and 3D analysis methods of facial asymmetry in comparison

Berssenbrügge, Philipp; Berlin, Nina Franka; Kebeck, Günther; Runte, Christoph; Jung, Susanne; Kleinheinz, Johannes; Dirksen, Dieter

doi:10.1016/j.jcms.2014.01.028

Cited by 83 publications

(47 citation statements)

References 34 publications

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“…In 3D models, the mirror image can be an alternative, being confirmed by Ozsoy (2016). Berssenbrügge et al (2014) determined that the study of soft tissues in facial asymmetry yields similar results when comparing 2D and 3D studies; they determined that 5 points of measurement in 2D studies is the minimum needed to make comparisons, considering that 3D measurement systems present nearly 10,000 points for use in comparisons.…”

Section: Discussionmentioning

confidence: 93%

Soft and Hard Tissue Relations in Facial Asymmetry

et al. 2016

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OLATE, S.; CANTÍN, M.; MUÑOZ, M. & VÁSQUEZ, B.Soft and hard tissue relations in facial asymmetry. Int. J. Morphol., 34(3):1058Morphol., 34(3): -1062Morphol., 34(3): , 2016. SUMMARY:The aim of this study was to determine the relations between hard and soft tissues in subjects with facial asymmetry. Included were subjects aged between 15 and 35 years who presented a chin deviation greater than 5 mm from the midline and a unilateral posterior crossbite. Cone beam computed tomography was used to determine the measurements, positioning them on the three spatial planes; then, 5 bilateral bone points were selected on the coronal image, and parallel measurements were taken to determine the range between the bone point and the most lateral soft tissue point. The statistical analysis was done using the Shapiro-Wilk test, presenting normality in the sample distribution and Levene's test, considering a value of p < 0.05 to obtain significant differences. 20 subjects were included with an average age of 23 years, observing that there were differences in the soft tissue distance in relation to the mandibular condylar head; in other measurements, there were no significant differences, although tendencies of greater or less soft tissue width in relation to the mandibular sector of the asymmetry were observed. It may be concluded that there are limited differences in soft tissue width in subjects with facial asymmetry; the low sample number and the selection of new points may have influenced the results.

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Section: Discussionmentioning

confidence: 93%

Soft and Hard Tissue Relations in Facial Asymmetry

et al. 2016

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“…Conventional methods for facial appearance analysis are based on two-dimensional (2D) measurement methods, such as capturing series 2D photographs from different angles, and using Vernier caliper and bevel protractor to measure 2D projection distances and angles [1,2]. In recent years, with the development of optical scanning technology, facial morphology research has been raised to a new level from 2D to three-dimensional (3D) with the use of 3D facial scanners [3,4]. …”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Accuracy of Facial Scan for Facial Deformities in Clinics: A New Evaluation Method for Facial Scanner Accuracy

Zhao¹,

Xiong²,

Wang³

2017

PLoS ONE

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In this study, the practical accuracy (PA) of optical facial scanners for facial deformity patients in oral clinic was evaluated. Ten patients with a variety of facial deformities from oral clinical were included in the study. For each patient, a three-dimensional (3D) face model was acquired, via a high-accuracy industrial “line-laser” scanner (Faro), as the reference model and two test models were obtained, via a “stereophotography” (3dMD) and a “structured light” facial scanner (FaceScan) separately. Registration based on the iterative closest point (ICP) algorithm was executed to overlap the test models to reference models, and “3D error” as a new measurement indicator calculated by reverse engineering software (Geomagic Studio) was used to evaluate the 3D global and partial (upper, middle, and lower parts of face) PA of each facial scanner. The respective 3D accuracy of stereophotography and structured light facial scanners obtained for facial deformities was 0.58±0.11 mm and 0.57±0.07 mm. The 3D accuracy of different facial partitions was inconsistent; the middle face had the best performance. Although the PA of two facial scanners was lower than their nominal accuracy (NA), they all met the requirement for oral clinic use.

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“…Here, the facial symmetry plane is determined on the basis of the shape of the face using the technique described in detail in [5], which is a modified version of the approach proposed by Benz et al [4]. The facial point cloud is repeatedly mirrored and registered to the original cloud using the iterative closest point algorithm [6].…”

Section: Determination Of the Asymmetry Indicesmentioning

confidence: 99%

“…First, the 30 faces are scanned, and for each of them, the color asymmetry index as well as the geometric asymmetry index is calculated. An example of local asymmetry distributions in terms of color distances or spatial distances [5] between a face and its reflection is depicted in Figures 7 and 8, respectively. In Figure 7, asymmetric features, like nevi, appear on both sides of the face in the local asymmetry map.…”

Section: Asymmetry Analysesmentioning

confidence: 99%