Three-dimensional natural head position reproduction using a single facial photograph based on the POSIT method (original) (raw)
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Journal of Oral and Maxillofacial Surgery Official Journal of the American Association of Oral and Maxillofacial Surgeons, 2011
Purpose-The purpose of this study was to evaluate the clinical feasibility of a new method to orient three-dimensional (3D) computed tomography (CT) models to the natural head position (NHP). This method utilizes a small and inexpensive digital orientation device to record NHP in 3D. This device consists of a digital orientation sensor attached to the patient via a facebow and an individualized bite jig. The study was designed to answer two questions: 1) whether the weight of the new device can negatively influence the NHP; and 2) wether the new method is as accurate as the gold standard.
Development of a Technique for Recording and Transferring Natural Head Position in 3 Dimensions
Journal of Craniofacial Surgery, 2010
The purpose of this study was to develop and test a new technique for recording natural head position (NHP) in 3 dimensions and transferring it into a three-dimensional computed tomography (CT) model. In this technique, a digital gyroscope was first attached to a human head using a bite-jig and a face-bow with a set of built-in fiducial markers. The relationship between the gyroscope and fiducial markers was predetermined and kept constant. The orientation (pitch, roll, and yaw) of the head was then recorded by this gyroscope. In next step, the head was CT scanned with the bite-jig and the face-bow in place, and three-dimensional CT models of the head and fiducial markers were generated. The head model was coupled with a predetermined three-dimensional model of the gyroscope assembly via fiducial markers. The threedimensional head model was reoriented to the recorded orientation by applying the recorded pitch, roll, and yaw to the gyroscope model. Finally, the accuracy of the technique was tested on a human dry skull. The results showed that the NHP was successfully recorded and transferred to the three-dimensional CT model. The orientations between the dry skull and its three-dimensional computer model were absolutely correlated. The difference (the lack of agreement) was within a range of j1.1 to 1.1 degrees, indicating no clinical significance. The authors concluded that our technique could accurately and repeatedly record NHP three-dimensionally and transfer it to a three-dimensional CT head model.
Natural position of the head: review of two-dimensional and three-dimensional methods of recording
British Journal of Oral and Maxillofacial Surgery, 2016
Both the correct position of the patient's head and a standard system for the acquisition of images are essential for objective evaluation of the facial profile and the skull, and for longitudinal superimposition. The natural position of the head was introduced into orthodontics in the late 1950s, and is used as a postural basis for craniocervical and craniofacial morphological analysis. It can also have a role in the planning of the surgical correction of craniomaxillofacial deformities. The relatively recent transition in orthodontics from 2-dimensional to 3-dimensional imaging, and from analogue to digital technology, has renewed attention in finding a versatile method for the establishment of an accurate and reliable head position during the acquisition of serial records. In this review we discuss definition, clinical applications, and procedures to establish the natural head position and their reproducibility. We also consider methods to reproduce and record the position in two and three planes.
Applied Sciences, 2019
This paper developed a new method to easily record and automatically reproduce the 3D natural head position (NHP) of patients using a portable 3D scanner based on immediate calibration. We first optically scanned the patient’s face using a portable 3D scanner, and the scanned model was easily aligned with the global horizon based on an immediate calibration procedure using a developed calibration plate. The 3D patient NHP Computed Tomography(CT) model was reproduced automatically by performing registration between the CT model and the optically scanned model in the NHP using a modified coherent point drift (CPD) algorithm. In a phantom experiment, we evaluated the developed method’s accuracy using the error between the true and the calculated orientations in roll, pitch, and yaw directions. The mean difference was −0.05 ± 0.13°, 0.08 ± 0.22°, and −0.05 ± 0.18° in the roll, pitch, and yaw directions, respectively. The measured roll, pitch, and yaw directions were not significantly di...
Automatic Detection and Reproduction of Natural Head Position in Stereo-Photogrammetry
PLOS ONE, 2015
The aim of this study was to develop an automatic orientation calibration and reproduction method for recording the natural head position (NHP) in stereo-photogrammetry (SP). A board was used as the physical reference carrier for true verticals and NHP alignment mirror orientation. Orientation axes were detected and saved from the digital mesh model of the board. They were used for correcting the pitch, roll and yaw angles of the subsequent captures of patients' facial surfaces, which were obtained without any markings or sensors attached onto the patient. We tested the proposed method on two commercial active (3dMD) and passive (DI3D) SP devices. The reliability of the pitch, roll and yaw for the board placement were within ±0.039904°, ±0.081623°, and ±0.062320°; where standard deviations were 0.020234°, 0.045645°and 0.027211°respectively. Conclusion: Orientation-calibrated stereo-photogrammetry is the most accurate method (angulation deviation within ±0.1°) reported for complete NHP recording with insignificant clinical error.
Journal of Oral and Maxillofacial Surgery, 2014
The purpose of this study was to develop a technique to record physical references and orient digital mesh models to a natural head position using stereophotogrammetry (SP). The first step was to record the digital mesh model of a hanging reference board placed at the capturing position of the SP machine. The board was aligned to true vertical using a plumb bob. It also was aligned with a laser plane parallel to a hanging mirror, which was located at the center of the machine. The parameter derived from the digital mesh model of the board was used to adjust the roll, pitch, and yaw of the subsequent captures of patients' facial images. This information was valid until the next machine calibration. The board placement was repeatable, with standard deviations less than 0.1 for pitch and yaw angles and 0.15 for roll angles. Ó
3D imaging applications in Orthognathic Surgery and Reliability of chosen landmarks
Many 3-dimensional (3D) techniques have been utilized to register and analyze the face in 3 dimensions, but each system has its own merits and disadvantages. C3D is a relatively new 3D imaging system that was developed to capture the 3D geometry of the face. Landmark identification on 3D facial models is facilitated by a software-based facial analysis tool developed by the authors. The reproducibility of landmark identification was high for 20 of the chosen points (standard deviations of repeated placements of landmarks around their centroids were 0.5 mm or less). The method is useful in studying facial soft tissue changes following orthognathic surgery and other types of facial surgery, as well as assessing facial soft tissue growth and development of the craniofacial complex. (Int J Adult Orthod Orthognath Surg 2002;17:318-330) The correction of dentofacial deformities requires teeth and jaws to be manipulated in 3 dimensions to achieve the best results within the constraints of esthetics, stability, and function. Assessment of facial appearance, although clearly a 3-dimensional (3D) problem, has been attempted with 2D photographs and radiographs. Many 3D techniques have been used in attempts to capture facial topography and to meet the shortcomings of conventional 2D (photograph or radiograph) methods. These techniques have included: morphanalysis, 2 laser scanning, 3,4 3D computerized tomographic (CT) scanning, 5 stereolithography, 6 3D ultrasonography, 7 3D facial morphometry, 8,9 digigraph imaging, 10 Moiré topography, 11 and contour photography. This paper aims to review the techniques that have been employed to capture 3D data of patients' faces, discussing their advantages and their possible shortcomings. The application of a new stereophotogrammetric technique is presented, and the reproducibility of identifying landmarks is evaluated.
3D head anthropometric analysis
Currently, two-dimensional photographs are most commonly used to facilitate visualization, assessment and treatment of facial abnormalities in craniofacial care but are subject to errors because of perspective, projection, lack metric and 3- dimensional information. One can find in the literature a variety of methods to generate 3-dimensional facial images such as laser scans, stereo-photogrammetry, infrared imaging and even CT however each of these methods contain inherent limitations and as such no systems are in common clinical use. In this paper we will focus on development of indirect 3-dimensional landmark location and measurement of facial soft-tissue with light-based techniques. In this paper we will statistically evaluate and validate a current three-dimensional image-based face modeling technique using a plaster head model. We will also develop computer graphics tools for indirect anthropometric measurements in a three-dimensional head model (or polygonal mesh) including l...
Recording Natural Head Position Using Cone Beam Computerized Tomography
Sensors, 2021
The purpose of this study was to develop a technique to record the natural head position (NHP) of a subject using the scout images of cone beam computerized tomography (CBCT) scans. The first step was to align a hanging mirror with the vertical (XY) plane of the CBCT field-of-view (FOV) volume. Then, two scout CBCT images, at frontal and at sagittal planes, were taken when the subject exhibited a NHP. A normal CBCT scan on the subject was then taken separately. These scout images were used to correct the orientation of the normal CBCT scan. A phantom head was used for validation and performance analysis of the proposed method. It was found that the orientation detection error was within 0.88°. This enables easy and economic NHP recording for CBCT without additional hardware.
Three-dimensional imaging in orthognathic surgery: the clinical application of a new method
2002
Many 3-dimensional (3D) techniques have been utilized to register and analyze the face in 3 dimensions, but each system has its own merits and disadvantages. C3D is a relatively new 3D imaging system that was developed to capture the 3D geometry of the face. Landmark identification on 3D facial models is facilitated by a software-based facial analysis tool developed by the authors. The reproducibility of landmark identification was high for 20 of the chosen points (standard deviations of repeated placements of landmarks around their centroids were 0.5 mm or less). The method is useful in studying facial soft tissue changes following orthognathic surgery and other types of facial surgery, as well as assessing facial soft tissue growth and development of the craniofacial complex. (Int J Adult Orthod Orthognath Surg 2002;17:318-330) The correction of dentofacial deformities requires teeth and jaws to be manipulated in 3 dimensions to achieve the best results within the constraints of esthetics, stability, and function. Assessment of facial appearance, although clearly a 3-dimensional (3D) problem, has been attempted with 2D photographs and radiographs. Many 3D techniques have been used in attempts to capture facial topography and to meet the shortcomings of conventional 2D (photograph or radiograph) methods. These techniques have included: morphanalysis, 2 laser scanning, 3,4 3D computerized tomographic (CT) scanning, 5 stereolithography, 6 3D ultrasonography, 7 3D facial morphometry, 8,9 digigraph imaging, 10 Moiré topography, 11 and contour photography. This paper aims to review the techniques that have been employed to capture 3D data of patients' faces, discussing their advantages and their possible shortcomings. The application of a new stereophotogrammetric technique is presented, and the reproducibility of identifying landmarks is evaluated.