The specific branches leading to the genioglossus muscle: three-dimensional localisation using skin reference points

Biomechanical analysis of human movement is based on dynamic measurements of reference points on the subject’s body and orientation measurements of body segments. Collected data include positions’ measurement, in a three-dimensional space. Signal enhancement by proper filtering is often recommended. Velocity and acceleration signal must be obtained from position/angular measurement records, needing numerical processing effort. In this paper, we propose a comparative filtering method study procedure, based on measurement uncertainty related parameters’ set, based upon simulated and experimental signals. The final aim is to propose guidelines to optimize dynamic biomechanical measurement, considering the measurement uncertainty contribution due to the processing method. Performance of the considered methods are examined and compared with an analytical signal, considering both stationary and transient conditions. Finally, four experimental test cases are evaluated at best filtering conditions for measurement uncertainty contributions.

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Comparison of the internal fit of metal crowns fabricated by traditional casting, computer numerical control milling, and three-dimensional printing

PLoS ONE ◽

10.1371/journal.pone.0257158 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0257158

Author(s):

Wei-Ting Chou ◽

Chuan-Chung Chuang ◽

Yi-Bing Wang ◽

Hsien-Chung Chiu

Keyword(s):

3D Printing ◽

Minimum Distance ◽

Statistical Significance ◽

Three Dimensional ◽

Reference Points ◽

Numerical Control ◽

Maximum Distance ◽

Cnc Milling ◽

Low Viscosity ◽

Internal Fit

This experimental study aimed to compare the internal fit (marginal fit and internal discrepancy) of metal crowns fabricated by traditional casting and digital methods (computer numerically controlled (CNC) milling and three-dimensional [3D] printing). Thirty standard master abutment models were fabricated using a 3D printing technique with digital software. Metal crowns were fabricated by traditional casting, CNC milling, and 3D printing. The silicon replica method was used to measure the marginal and internal fit. A thin layer of low-viscosity polyvinyl siloxane material was placed inside each crown and on the die (like a seat) until the material was set. Replicas were examined at four reference points under a microscope: the central pit (M1), cusp tip (M2), axial wall (M3), and margin (M4). The measured data were analyzed using a one-way analysis of variance (ANOVA) to verify statistical significance, which was set at p < 0.05. In the traditional casting group, the minimum distance measured was at M3 (90.68 ± 14.4 μm) and the maximum distance measured was at M1 (145.12 ± 22 μm). In the milling group, the minimum distance measured was at M3 (71.85 ± 23.69 μm) and the maximum distance measured was at M1 (108.68 ± 10.52 μm). In the 3D printing group, the minimum distance measured was at M3 (100.59 ± 9.26 μm) and the maximum distance measured was at M1 (122.33 ± 7.66 μm). The mean discrepancy for the traditional casting, CNC milling, and 3D printing groups was 120.20, 92.15, and 111.85 μm, respectively, showing significant differences (P < 0.05). All three methods of metal crown fabrication, that is, traditional casting, CNC milling, and 3D printing, had values within the clinically acceptable range. The marginal and internal fit of the crown was far superior in the CNC milling method.

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Surgical benefit of mandibular morphometric analysis: A new tool to standardize mandibular reconstruction

PLoS ONE ◽

10.1371/journal.pone.0240558 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0240558

Author(s):

Alice Prevost ◽

Franck Delanoe ◽

Zoé Cavallier ◽

Samuel Muller ◽

Raphael Lopez ◽

...

Keyword(s):

Morphometric Analysis ◽

Descriptive Analysis ◽

Donor Site ◽

Three Dimensional ◽

Free Flaps ◽

Reference Points ◽

Mandibular Reconstruction ◽

Gonial Angle ◽

Custom Made ◽

Cutting Guides

Purpose The gold-standard for reconstruction of large mandibular defects is the use of free flaps of vascularized autologous bone with the fibula as the preferred donor site. The use of "custom cutting guides" for this indication is becoming increasingly prevalent. But cost of the procedure averages around 2,500 dollars per patient excluding treatment and entails selection criteria. We think it is possible to standardize mandibular reconstructions from an anatomical mean. The objective of this study was to perform a mandibular morphometric analysis in order to obtain a set of "mean" measurements, which can be used by all surgeons interested in mandibular reconstruction. Methods We performed a morphometric analysis consisting of three-dimensional mandibular reconstructions of 30 men and 30 women. Several reference points were set and defined to evaluate specific lengths and angles of interest. We conducted an intra and inter-sexual descriptive analysis of measurements obtained. Results We did not identify any major intra-sexual differences within each group. The gonial angle is more open in women and the measurements characterizing the basilar contour are more prominent in men. We did not identify any differences in alveolar region parameters. Conclusion The results of this study constitute a morphological tool for surgeons, from bone graft to free flap. These results also confirm us that the use of «custom cutting guides» for mandibular reconstruction may be excessive. It is pertinent to examine the value of "custom made" mandibular reconstructions since the differences observed are of the order of millimeters.

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Use of computed tomography data for forensic identification of an individual

Russian Journal of Forensic Medicine ◽

10.19048/fm339 ◽

2020 ◽

Vol 6 (4) ◽

pp. 41-45

Author(s):

Sergey V. Leonov ◽

Julia P. Shakiryanova

Keyword(s):

Computed Tomography ◽

Computer Tomography ◽

Soft Tissues ◽

Three Dimensional ◽

Reference Points ◽

Forensic Identification ◽

Dimensional Model ◽

Three Dimensional Model ◽

The Face ◽

Tomography Data

Background: The article presents our own experience of using computer tomography for identification of individuals with known results. Aims: The aim of the study was to verify the possibility of performing an identification study using a three-dimensional model obtained from computed tomography of the head. Identification was performed using a three-dimensional model of the head, based on computer tomography sections made in various projections, with a step of 1.231.25 mm. Two-dimensional images of the face (photos) were used for comparison. All comparative studies were conducted using approved methods of craniofacial and portrait identification: by reference points and contours. The experiment used a computer program that allows you to export DICOM-files of computed tomography results to other formats (InVesalius), as well as computer programs that directly work with the research objects (Autodesk 3ds Max, alternative programs Adobe Photoshop, Smith Micro Poser Pro). Results: In the course of research, it was found that, having computer tomography data of the head, it is possible to conduct identification studies on the following parameters: on the reconstructed three-dimensional model of the soft tissues of the face, on the three-dimensional model of the skull (craniofacial identification), on the features of the structure of the ear. Conclusion: Positive results were obtained when comparing objects, which makes it advisable to use them in practical and scientific activities.

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The Algorithm for Determining the Coordinates of a Point in Three-Dimensional Space by Using the Auxiliary Point

Artificial Satellites ◽

10.2478/arsa-2013-0012 ◽

2013 ◽

Vol 48 (4) ◽

pp. 141-145 ◽

Cited By ~ 4

Author(s):

Bartlomiej Oszczak ◽

Eliza Sitnik

Keyword(s):

Fixed Point ◽

Precise Measurement ◽

Dimensional Space ◽

Three Dimensional ◽

Satellite Navigation ◽

Reference Points ◽

Two Dimensional ◽

Approximate Location ◽

The Many ◽

Three Dimensional Space

ABSTRACT During the process of satellite navigation, and also in the many tasks of classical positioning, we need to calculate the corrections to the initial (or approximate) location of the point using precise measurement of distances to the permanent points of reference (reference points). In this paper the authors have provided a way of developing Hausbrandt's equations, on the basis of which the exact coordinates of the point in two-dimensional space can be determined by using the computed correction to the coordinates of the auxiliary point. The authors developed generalised equations for threedimensional space introducing additional fixed point and have presented proof of derived formulas.

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Stereotactic Radiosurgery Associated Neurotoxicity

Technology in Cancer Research & Treatment ◽

10.1177/153303460300200211 ◽

2003 ◽

Vol 2 (2) ◽

pp. 147-151 ◽

Cited By ~ 4

Author(s):

William H. St. Clair ◽

Curtis A. Given

Keyword(s):

Stereotactic Radiosurgery ◽

Therapeutic Option ◽

Treatment Plan ◽

Three Dimensional ◽

Reference Points ◽

Therapeutic Modality ◽

High Dose ◽

Lesion Volume ◽

Three Dimensional Mapping ◽

Effective Therapeutic Option

Stereotactic radiosurgery (SRS) is an evolving therapeutic modality for well demarcated intracranial lesions. Since the inception of stereotactic radiosurgery the types of parenchymal CNS lesions addressed by this mode of treatment has increased. All modern stereotactic radiosurgical procedures employ several common features. Patients are fitted with a stereotactic head frame or fiducial markers followed by radiographic imaging which allows for external reference points and three-dimensional mapping of the intracranial lesion. Armed with this information a highly conformal treatment plan is developed to deliver a high dose of radiation to a sharply defined target, with rapid dose fall-off outside the lesion volume. While an extremely effective therapeutic option, SRS is not without risk of neurotoxicity, with radiation necrosis being the most commonly recognized complication. The neurotoxic effects of SRS are reviewed and discussed.

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Guiding Survey Technology for Long Curved Pipe Jacking

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.639-640.247 ◽

2013 ◽

Vol 639-640 ◽

pp. 247-250

Author(s):

Shao Tang Liu ◽

Guo Rong Pan ◽

Hui Feng Zhang

Keyword(s):

Three Dimensional ◽

Reference Points ◽

Transformation Model ◽

Long Distance ◽

Time Saving ◽

Curved Pipe ◽

Survey System ◽

Guide System ◽

Pipe Jacking ◽

Datum Transformation

The paper discusses guide survey system in long distance curved pipe jacking, presents a three-dimensional datum transformation model to determine the orientation of jacking pipe，The unitary principle and the new navigating method are introduced and the methods accuracy and variance are analyzed. The intelligence guide system is carried through easily associate with total station. The mathematical model, the operation principle, the hardware realization of extra long pipe jacking automatic guidance are introduced. Practice shows that all the reference points are used more efficiently in the new model than in the general model, and the surveying and navigating system gets enormous time-saving against conventional methods

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Variation of Femoral Component Size by Reference Points and Target Alignments in Total Knee Arthroplasty

10.21203/rs.3.rs-404360/v1 ◽

2021 ◽

Author(s):

Shojiro Ishibashi ◽

Hideki Mizu-uchi ◽

Shinya Kawahara ◽

Hidetoshi Tsushima ◽

Yukio Akasaki ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Femoral Component ◽

Knee Arthroplasty ◽

Three Dimensional ◽

Reference Points ◽

Component Size ◽

Reference Guide ◽

Standard Position ◽

Total Knee ◽

Cutting Direction

Abstract Selecting appropriately sized components is important in total knee arthroplasty because they can affect postoperative knee function and pain. This study investigated size differences of 19 different femoral component placements from the standard position by three-dimensional virtual surgery using three-dimensional bone models of 101 varus osteoarthritic knees. Distal femoral bone was cut perpendicular to the femoral mechanical axis (MA) in the coronal plane. Twenty different component placements consisting of five cutting directions (perpendicular to MA, 3° and 5° extension/flexion relative to MA in the sagittal plane), two rotational alignments (clinical and surgical epicondylar axes), and two rotational types of anterior reference guide (central and medial) were simulated. The mean anteroposterior dimension of the standard position was 55.5 mm which means that the difference compared to 19 different methods ranged from -1.2 ± 0.2 mm to 7.1 ± 1.3 mm. Multiple regression analysis revealed that flexion cutting direction, surgical epicondylar axis, and central were associated with smaller component size. In conclusion, the femoral component size can be affected easily by not only cutting direction but also the reference guide type and the target alignment. Our findings could provide surgeons with clinically useful information to fine-tune for unintended loose or tight joint gaps by adjusting the component size.

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Three-Dimensional Analysis of Morphological Changes in the Maxilla of Patients with Cleft Lip and Palate

The Cleft Palate-Craniofacial Journal ◽

10.1597/1545-1569_2002_039_0001_tdaomc_2.0.co_2 ◽

2002 ◽

Vol 39 (1) ◽

pp. 1-11 ◽

Cited By ~ 11

Author(s):

Bert Braumann ◽

Ludger Keilig ◽

Christoph Bourauel ◽

Andreas Jäger

Keyword(s):

Cleft Lip ◽

Cleft Lip And Palate ◽

Morphological Changes ◽

Three Dimensional ◽

Laser Scanner ◽

Computer Software ◽

Reference Points ◽

Starting Point ◽

Ideal Tool ◽

Infant Orthopedics

Objective Three-dimensional (3-D) morphological changes in the maxilla of patients with cleft lip and palate (CLP) have been recorded, mainly using two-dimensional cast analyses. Although these seem to be insufficient, no standardized 3-D method has been developed until now. In this study, accuracy, precision, and validity of a newly developed 3-D digital computer-aided procedure to visualize and metrically analyze the growth of the edentulous maxilla of infants with CLP have been evaluated. Patients The method was applied to 10 infants with complete unilateral CLP. Interventions Consecutive casts of the maxilla (1 week and 3, 6, and 12 months) of each patient were optically measured with a 3-D laser scanner. Following digitizing, the casts were computer reconstructed, aligned, and superimposed using specialized computer software. The distances between the surfaces were measured. Additionally, the surfaces were segmented perpendicular to the alveolar crest, the reference points being C1, C1′, C2, C2′, and I. The volumes of the resulting segments were determined and compared with one another. Results The newly developed analysis enables a visualization of the extent and direction of morphological changes in the maxilla of infants with CLP. With this method it is possible to quantify these changes of the volume of defined alveolar segments. Conclusions The 3-D analysis developed is an ideal tool for the examination of 3-D morphological changes in the edentulous maxilla of patients with CLP. The results will serve as the starting point for a longitudinal study on the efficacy of different methods, not only of presurgical infant orthopedics but also of surgical procedures.

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Reproducibility of Novel Soft-Tissue Landmarks on Three-Dimensional Human Facial Scan Images in Caucasian and Asian

Aesthetic Plastic Surgery ◽

10.1007/s00266-021-02642-4 ◽

2021 ◽

Author(s):

Zhouxiao Li ◽

Riccardo Enzo Giunta ◽

Konstantin Frank ◽

Thilo Ludwig Schenck ◽

Konstantin Christoph Koban

Keyword(s):

Soft Tissue ◽

Three Dimensional ◽

Reference Points ◽

Full Description ◽

Surface Imaging ◽

Facial Soft Tissue ◽

Level Of Evidence ◽

Race And Gender ◽

Facial Region ◽

And Gender

Abstract Background Three-dimensional surface imaging is established in many disciplines for objective facial acquisition regarding anthropometry. Former studies addressed the validation of landmark-based measurements for single race. In order to distinguish racial difference, the reproducibility of the landmark measurements must first be validated. Objectives Our purpose is to validate the reproducibility of 46 facial soft-tissue landmarks on x, y, z axes to prove their reliability as 3D reference points. Methods The study included 80 European Caucasian and 80 Chinese volunteers. Standardized 3D surface imaging was performed using Vectra 3D system. Two raters identified and defined 46 landmarks (138 coordinates), then repeatedly 3D-imaged volunteers' facial region in separate sessions. Coordinates' reproducibility of landmarks is divided into three categories (< 0.5 mm, < 1 mm, and >1 mm) for intra- and inter-rater reproducibility assessments. Results Coordinates' reproducibility of 160 samples was distributed as follows: Intra-rater: < 0.5 mm (45%), < 1 mm (42%), >1 mm (13%); inter-rater: < 0.5 mm (31.2%), < 1 mm (42%), > 1 mm (26.8%). The reproducibility of landmarks in nasal tip region differs slightly between Caucasians and Asians. Compared to females, males typically have higher landmark reproducibility in lip and chin region. However, there were no differences in the reproducibility ranking of landmarks by gender. Conclusion The majority of the 46 landmarks in the 3D plane are reproducible to 1 mm, which is clinically acceptable. All selected landmarks showed strong consistency across race and gender, suggesting their potential use as reference points in prospective clinical practice. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

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