Current methods of assessing the accuracy of three-dimensional soft tissue facial predictions: technical and clinical considerations

Khambay, Balvinder; Ullah, Rehan

doi:10.1016/j.ijom.2014.04.007

Cited by 41 publications

(46 citation statements)

References 15 publications

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“…In more homogenous group of cases the accuracy of 3D soft tissue predictions using 3dMD Vultus, after Le Fort I advancement, was evaluated. 17,18 The differences between the actual and the predicted facial soft tissue changes were below 3 mm for all segmented anatomical regions. The studies proved the limited accuracy of the soft ware, which is based on mass-tensor model, in predicting the changes in response to Le Fort I osteotomy at the nasal and paranasal region.…”

Section: Discussionmentioning

confidence: 86%

The accuracy of three-dimensional prediction of soft tissue changes following the surgical correction of facial asymmetry: An innovative concept

Mundluru

Almukhtar

et al. 2017

International Journal of Oral and Maxillofacial Surgery

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Abstract:The accuracy of three dimensional predictions of soft tissue changes following surgical correction of facial asymmetry has been evaluated in this study. The preoperative (T1) and 6-12 months postoperative (T2) CBCT scans of 13 patients were studied. All patients had surgical correction for facial asymmetry as part of the multidisciplinary treatment protocol.The magnitude of surgical movement was measured; virtual surgery was carried out on the preoperative scans using Maxilim software. The predicted soft tissue changes were compared to the actual postoperative appearance (T2) at specific anatomic facial regions. Mean (signed) distances and the mean (absolute) distances between the predicted and actual 3D surface meshes for each region were calculated. One sample Student t-test was applied. Additionally, a novel directional soft tissue analysis was applied to analyse the accuracy of the prediction of soft tissue. The results showed that the distances between the predicted and actual postoperative soft tissue changes were within 2.0mm (p<0.05) at all regions. The predicted facial morphology was narrower than the actual surgical changes at the cheek regions. Three dimensional soft tissue prediction for the correction of asymmetric cases is clinically acceptable using Maxilim software. Introduction:

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Section: Discussionmentioning

confidence: 86%

The accuracy of three-dimensional prediction of soft tissue changes following the surgical correction of facial asymmetry: An innovative concept

Mundluru

Almukhtar

et al. 2017

International Journal of Oral and Maxillofacial Surgery

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“…The software generated the coordinates for each landmark and the Euclidean distances between corresponding landmarks. 22 These values were statistically analyzed in three different ways to assess the intra- and inter-observer reproducibility and the consistency of the regions of reference.…”

Section: Image Analysismentioning

confidence: 99%

Comparison and reproducibility of 2 regions of reference for maxillary regional registration with cone-beam computed tomography

Ruellas

Ghislanzoni

Gomes

et al. 2016

American Journal of Orthodontics and Dentofacial Orthopedics

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Introduction the aim of this study was to evaluate the differences between 2 regions of maxillary voxel-based registration and to test the reproducibility of the registration. Methods 3D models were built for before treatment (T1) and after treatment (T2) Cone Beam CTs for 16 growing subjects. Landmarks were labeled in all T2 models of the maxilla, and voxel-based registration was performed independently by two observers, at two different times, using two different reference regions: 1) the Maxilla region (MAX) included the maxillary bone clipped inferiorly at the dentoalveolar processes, superiorly at the plane passing through the right and left orbitale points, laterally at the zygomatic processes through the orbitale point, and posteriorly at a plane passing through the distal surface of the second molars. 2) the Palate and Infra-zygomatic region (PIZ) had different posterior and anterior limits (at the plane passing through the distal of the first molar and distal of the canines, respectively). The differences between the registration regions were measured by comparing the distances between corresponding landmarks in the T2 registered models and comparing corresponding x,y,z coordinates from corresponding landmarks. Statistical analysis of the differences between T2 surface models was performed by evaluating the means and standard deviations of the distances between landmarks and by testing the agreement between coordinates from corresponding landmarks (ICC and Bland-Altman method). Results The means of the differences between landmarks from PIZ to MAX 3D T2 surface models for all of the regions of reference, times of registrations and observers combinations were smaller than 0.5 mm. The ICC and the Bland-Altman plots indicated adequate concordance. Conclusions Both regions of regional maxillary registration (MAX and PIZ) showed similar results and adequate intra- and inter-observer reproducibility.

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“…The method is based on the application of generic facial mesh, a mathematical face mask which consists of a fixed number of thousands of quasi landmarks (vertices) (20) . The mesh is conformed "wrapped" on the 3D image of the face for the comprehensive representation of the facial morphology.…”

Section: Introductionmentioning

confidence: 99%

Reproducibility of the dynamics of facial expressions in unilateral facial palsy

Alagha

Morley

et al. 2018

International Journal of Oral and Maxillofacial Surgery

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Abstract:The aim of this study was to assess the reproducibility of non-verbal facial expressions in unilateral facial paralysis using the dynamic 4D imaging. Di4D system was utilized to record 5 facial expressions of 20-adult patients. The system captured 60 3D images/second; each facial expression took 3-4 seconds to record which generated a set of 180 3D facial images for each expression. The procedure was repeated after 30 minutes to assess the reproducibility of the expressions. A mathematical facial mesh which consists of thousand of quasi points "vertices" was conformed to the face to disclose the morphological characteristics in a comprehensive manner. The vertices of the conformed mesh were tracked throughout the sequence of the 180 3D images. Five key 3D facial frames of each sequence of images were analyzed.. We compared the 3D facial morphology at each of the five key frames of the first and the second capture of each facial expression to assess the reproducibility of the facial movements. The corresponding images were aligned using partial Procrustes analysis, the root square mean of the distances between these was calculated and statistically analyzed using paired student t-test at P=0.05. Facial expressions of lip purse, cheek puff and raising of the eyebrows were reproducible. The facial expressions of maximum smile and forceful eye closure were not reproducible. The limited coordination of various groups of facial muscles contributed to the lack of reproducibility of these facial expressions. The 4D imagining is a useful clinical tool for the assessment of facial expressions.Introduction:

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Current methods of assessing the accuracy of three-dimensional soft tissue facial predictions: technical and clinical considerations

Cited by 41 publications

References 15 publications

The accuracy of three-dimensional prediction of soft tissue changes following the surgical correction of facial asymmetry: An innovative concept

The accuracy of three-dimensional prediction of soft tissue changes following the surgical correction of facial asymmetry: An innovative concept

Comparison and reproducibility of 2 regions of reference for maxillary regional registration with cone-beam computed tomography

Reproducibility of the dynamics of facial expressions in unilateral facial palsy

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