Three-dimensional determining the midsagittal plane of the facial skull on CBCT volume tomogram

2020 ◽  
Author(s):  
Zsolt Markella ◽  
Dobai Adrienn ◽  
Tamas Vizkelety
Keyword(s):  
Three Dimensional ◽  
Midsagittal Plane ◽  
Facial Skull

scholarly journals Three-Dimensional Soft Tissue Nasal Changes After Nasoalveolar Molding and Primary Cheilorhinoplasty in Infants With Unilateral Cleft Lip and Palate

2018 ◽  
Vol 56 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Laura Mancini ◽  
Travis L. Gibson ◽  
Barry H. Grayson ◽  
Roberto L. Flores ◽  
David Staffenberg ◽  
...  
Keyword(s):  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Three Dimensional ◽  
Case Series ◽  
Midsagittal Plane ◽  
Retrospective Case ◽  
Anthropometric Measures ◽  
Nasal Tip ◽  
Nasoalveolar Molding ◽  
Nasal Changes

Objective: To quantify 3-dimensional (3D) nasal changes in infants with unilateral cleft lip with or without cleft palate (UCL±P) treated by nasoalveolar molding (NAM) and cheilorhinoplasty and compare to noncleft controls. Design: Retrospective case series of infants treated with NAM and primary cheilorhinoplasty between September, 2012 and July, 2016. Infants were included if they had digital stereophotogrammetric records at initial presentation (T1), completion of NAM (T2), and following primary cheilorhinoplasty (T3). Images were oriented in 3dMD Vultus software, and 16 nasolabial points identified. Patients: Twenty consecutively treated infants with UCL±P. Interventions: Nasoalveolar molding and primary cheilorhinoplasty. Main Outcome Measures: Anthropometric measures of nasal symmetry and morphology were compared in the treatment group between time points using paired Student t tests. Postsurgical nasal morphology was compared to noncleft controls. Results: Nasal tip protrusion increased, and at T3 was 2.64 mm greater than noncleft controls. Nasal base width decreased on the cleft side by 4.01 mm after NAM and by 6.73 mm after cheilorhinoplasty. Columellar length of the noncleft to cleft side decreased from 2:1 to 1:1 following NAM. Significant improvements in subnasale, columella, and nasal tip deviations from midsagittal plane were observed. Treatment improved symmetry of the alar morphology angle and the nasal base–columella angle between cleft and noncleft sides. Conclusions: Three-dimensional analysis of UCL±P patients demonstrated significant improvements in nasal projection, columella length, nasal symmetry, and nasal width. Compared to noncleft controls, nasal form was generally corrected, with overcorrection of nasal tip projection, columella angle, and outer nasal widths.

Flight performance and visual control of flight of the free-flying housefly ( Musca domestica L.) I. Organization of the flight motor

1986 ◽  
Vol 312 (1158) ◽  
pp. 527-551 ◽  
Keyword(s):  
Coordinate System ◽  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Rigid Bodies ◽  
The Body ◽  
Midsagittal Plane ◽  
Torque Vector ◽  
Translation Velocity ◽  
Flight Motor

Free-flying houseflies have been filmed simultaneously from two sides. The orientation of the flies’ body axes in three-dimensional space can be seen on the films. A method is presented for the reconstruction of the flies’ movements in a fly-centred coordinate system, relative to an external coordinate system and relative to the airstream. The flies are regarded as three-dimensionally rigid bodies. They move with respect to the six degrees of freedom they thus possess. The analysis of the organization of the flight motor from the kinematic data leads to the following conclusions: the sideways movements can, at least qualitatively, be explained by taking into account the sideways forces resulting from rolling the body about the long axis and the influence of inertia. Thus, the force vector generated by the flight motor is most probably located in the fly’s midsagittal plane. The direction of this vector can be varied by the fly in a restricted range only. In contrast, the direction of the torque vector can be freely adjusted by the fly. No coupling between the motor force and the torques is indicated. Changes of flight direction may be explained by changes in the orientation of the body axes: straight flight at an angle of sideslip differing from zero is due to rolling. Sideways motion during the banked turns as well as the decrease of translation velocity observed in curves are a consequence of the inertial forces and rolling. The results are discussed with reference to studies about the aerodynamic performance of insects and the constraints for aerial pursuit.

Image Corrected Cephalometric Analysis (ICCA): Design and Evaluation

1993 ◽  
Vol 30 (6) ◽  
pp. 528-541 ◽  
Author(s):  
John L. Spolyar ◽  
William Vasileff ◽  
Robert B. Macintosh ◽  
Bodil Rune ◽  
John L. Spolyar
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Bilateral Symmetry ◽  
Bone Marker ◽  
Cephalometric Analysis ◽  
Two Dimensional ◽  
Midsagittal Plane ◽  
Two Dimensional Image ◽  
Marker Point ◽  
Serial Measurements

Image corrected cephalometric analysis (ICCA) Is a method for eliminating serial image parallax error. In a radiographic survey, image parallax is an inherent and random property of the two-dimensional Image of the subject. Radiographs of the same subject taken at different times will be different in image parallax. This difference, parallax error, is routinely displayed between serial radiographic studies. Parallax error discourages the use of conventional serial cephalometric surveys for tracking and studying changes in discrete craniofacial structures lying outside the midsagittal plane, unilaterally disposed, or changing without bilateral symmetry. Anatomic outlines or discrete points of such structures would routinely display measurement perturbations caused by image parallax differences between surveys. The ICCA method eliminates this problem. Therefore, accurate serial measurements of bone marker point displacements are made possible with two-dimensional reconstructions of points lying in three-dimensional space. The method of ICCA was tested for accuracy by using zero time serial cephalometric surveys of five subjects. Mean implant error of 0.12 mm (SD = 0.1) was found between predicted (ICCA) and actual measured Implant movement caused by the image parallax error. After applying this method, bone marker movements are unlikely to be caused by parallax error between conventional serial cephalometric studies. Furthermore, displacement growth can be related to the relocation of composite growth outlines and midline anatomic landmarks. One plagiocephaly case and one hemifacial microsomia case were used to demonstrate ICCA for growth and treatment effect documentation.

Use of a triaxial magnetometer for respiratory measurements

1991 ◽  
Vol 70 (5) ◽  
pp. 2311-2321 ◽  
Author(s):  
S. Levine ◽  
D. Silage ◽  
D. Henson ◽  
J. Y. Wang ◽  
J. Krieg ◽  
...  
Keyword(s):  
Chest Wall ◽  
Three Dimensional ◽  
Vertical Movement ◽  
The Body ◽  
Processing Unit ◽  
Midsagittal Plane ◽  
Posterior Spine ◽  
P Movement ◽  
Normal Men ◽  
Spinal Flexion

We describe a triaxial magnetometer (Tri-mag) system, which consists of a transmitter, four sensors, a processing unit, and a personal computer (PC). The Tri-mag processing unit outputs the position of each sensor relative to the transmitter in three orthogonal coordinates, and this information is communicated to the PC. First, we demonstrated that within a defined octant of a sphere in which the center is the transmitter, we can measure radial distances with an accuracy of +/- 1 mm over a range extending from 10 to 70 cm from the transmitter. Second, we recorded the three-dimensional movement of sensors on the anterior and posterior surfaces of the chest wall during maximum voluntary ventilation in four normal men; all sensors were placed in the midsagittal plane of the body. Anterior sensors were located on the sternum at the level of the third intercostal space and at 2 cm above the umbilicus, whereas posterior sensors were located on the posterior spine at the same vertical levels as the anterior sensors. In all subjects the following was found. 1) Both anterior sensors moved anterior and cephalad during inspiration. The anterior thoracic sensor showed greater vertical than anteroposterior (A-P) movement, whereas the anterior abdominal sensor showed greater A-P than vertical movement. 2) Inspiration was associated with spinal extension, whereas expiration was associated with spinal flexion. Third, we used Tri-mag information to 1) measure tidal volume (VT) over a range extending from 500 ml to inspiratory capacity and 2) measure the change in end-expiratory lung volume (EELV) over a range extending from FRC to FRC plus a minimum of 1.5 liters. Our results indicate that greater than 96% of the changes in VT and greater than 82% of the changes in EELV can be accounted for by changes in A-P, vertical, and lateral dimensions of the chest wall.

scholarly journals MODERN METHODS OF DIAGNOSIS IN ORTHODONTICS

2016 ◽  
Vol 1 (2) ◽  
pp. 10-13
Author(s):  
AV V Arkhipov ◽  
EA A Loginova ◽  
VD D Arkhipov
Keyword(s):  
Computed Tomography ◽  
Temporomandibular Joint ◽  
Cone Beam Computed Tomography ◽  
Orthodontic Treatment ◽  
Three Dimensional ◽  
Cone Beam ◽  
Cephalometric Analysis ◽  
Facial Region ◽  
Facial Skull

The paper presents the possibilities of the virtual planning of orthodontic treatment with programs In Vivo Anatomage and 3Shape Ortho Analyzer, which allows you to create an individual plan of orthodontic treatment. Using three-dimensional cephalometric analysis and cone-beam computed tomography eliminates the risk of complications during orthodontic tooth moving. Aim - to determine the main directions of application of three-dimensional cephalometric analysis in orthodontist’s practice Materials and methods. The study involved 20 patients aged between 18 and 35 years (women 85%, men 15%). All patients underwent cone-beam computed tomography of the facial region of the skull conducted on a tomograph with a matrix 16h10. To obtain the most objective data, a wide range of clinical and other diagnostic methods was used in the study: clinical (survey, visual examination of face and oral cavity, clinical functional tests), anthropometric (measurement of jaw models in the program 3Shape Ortho Analyzer), CBCT of the facial region of the skull and cervical part of the spine. The survey was conducted on every patient according to the developed protocol. 1. Assessment of the dental hard tissues (diagnosis of caries, pulpitis and periodontitis), periapical periodontal tissues, and the state of the cortical bone; construction of three-dimensional panoramic reconstruction to determine the parallelism of the roots and their position in the bone of the alveolar processes on the vestibular and lingual surfaces. 2. Assessment of the patency of airways. 3. Evaluation of the bone elements of the temporomandibular joint on both sides, determining the position of articular head in the glenoid fossa. 4. Three-dimensional cephalometric analysis. 5. Superimposition of the data of the facial skull computed tomography; analysis of the changes in the course of dental treatment. The results of research. The obtained CBCT of the facial skull, processed in the program In Vivo Anatomage version 5.2, allows specifying the status and location of the bony structures of the temporomandibular joint, sinuses, individual structural features of the upper and lower jaws, dental roots deep in the alveolar processes and their correlation to the cortical plate. Additional features of the program are the opportunity to study the airways, combination of the scanned plaster models in .Stl format and superimposition of one CT scan to the other to produce a report on the changes that occurred. Discussion. The computer program allows correction of congenital abnormalities of dentition, reducing the risk of complications to a minimum. Moreover, the expected result can be predicted at the initial stage of treatment. The main advantage of CBCT is the possibility to determine the exact anatomical parameters of a patient without overlapping of adjacent structures and projection distortion of the sizes of anatomical structures.

scholarly journals Reliability of different three-dimensional cephalometric landmarks in cone-beam computed tomography: A systematic review

2018 ◽  
Vol 89 (2) ◽  
pp. 317-332 ◽  
Author(s):  
Alycia Sam ◽  
Kris Currie ◽  
Heesoo Oh ◽  
Carlos Flores-Mir ◽  
Manuel Lagravére-Vich
Keyword(s):  
Computed Tomography ◽  
Systematic Review ◽  
Cone Beam Computed Tomography ◽  
Human Subjects ◽  
Three Dimensional ◽  
Cone Beam ◽  
Data Sets ◽  
Midsagittal Plane ◽  
Landmark Identification ◽  
Minimum Number

ABSTRACT Objectives: Conventional two-dimensional (2D) cephalometric radiography is an integral part of orthodontic patient diagnosis and treatment planning. One must be mindful of its limitations as it indeed is a 2D representation of a vaster three-dimensional (3D) object. Issues with projection errors, landmark identification, and measurement inaccuracies impose significant limitations, which may now be overcome with the advent of cone-beam computed tomography (CBCT). A systematic review of the reliability of different 3D cephalometric landmarks in CBCT imaging was conducted. Materials and Methods: Electronic database searches were administered until October 2017 using PubMed, MEDLINE via OvidSP, EBMR and EMBASE via OvidSP, Scopus, and Web of Science. Google Scholar was used as an adjunctive search tool. Results: Thirteen articles considering CBCT scans of human subjects from preexisting data sets were selected and reviewed. Most of the studies had methodological limitations and were of moderate quality. Because of their heterogeneity, key data from each could not be combined and were reported qualitatively. Overall, in 3D, midsagittal plane landmarks demonstrated greater reliability compared with bilateral landmarks. A minimum number of dental landmarks were reported, although most were recommended for use. Conclusions: Further research is required to evaluate the reliability of 3D cephalometric landmarks when evaluating 3D craniofacial complexes.

scholarly journals P25.10: Use of three-dimensional (3D) sonography to assess the true midsagittal plane of fetal spine

2010 ◽  
Vol 36 (S1) ◽  
pp. 267-267
Author(s):  
M. Chen ◽  
X. Yang ◽  
T. Leung ◽  
S. Wong ◽  
T. Lau
Keyword(s):  
Three Dimensional ◽  
Midsagittal Plane ◽  
Fetal Spine ◽  
3D Sonography
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