scholarly journals Comparison of Hand-Traced and Computer-Based Cephalometric Superimpositions

2009 ◽  
Vol 79 (3) ◽  
pp. 428-435 ◽  
Author(s):  
S. S. Huja ◽  
E. L. Grubaugh ◽  
A. M. Rummel ◽  
H. W. Fields ◽  
F. M. Beck

Abstract Objective: To determine the ability to produce comparable superimpositions using hand tracing and digital methods (Dolphin v10). In addition, if the two methods were comparable, we wanted to determine if a difference existed between the best-fit cranial base superimposition and S-N superimpositions using the digital method. Methods and Materials: Sixty-four initial (T1) and final (T2) cephalometric film radiographs were obtained. Cranial base and regional superimpositions were completed independently for each pair of radiographs by either hand tracing and digital methods. To quantitatively evaluate the differences between the two methods, the hand and digital superimpositions were digitized to obtain x-y coordinates of routine cephalometric landmarks at T2. Linear distance between multiple corresponding (hand and digital) T2 cephalometric landmark locations (e.g., A point) were measured and defined as the T2 landmark distance (T2 LD). Additionally, 61 patient records were used to compare the digital method for best-fit cranial base superimpositions versus S-N superimpositions. A Friedman test was applied to examine for differences. Results: The upper 95% confidence limit for the mean of the T2 LD for hand and digital superimposition methods was <1 mm for all landmarks except maxillary incisor tip and apex. The upper 95% confidence interval for best-fit vs S-N was >1 mm for most landmarks. Conclusion: This study validates the use of superimpositions produced by Dolphin Imaging version 10 and is a necessary step forward toward widespread acceptance of digital superimpositions.

1998 ◽  
Vol 11 (1) ◽  
pp. 565-565
Author(s):  
G. Cayrel de Strobel ◽  
R. Cayrel ◽  
Y. Lebreton

After having studied in great detail the observational HR diagram (log Teff, Mbol) composed by 40 main sequence stars of the Hyades (Perryman et al.,1997, A&A., in press), we have tried to apply the same method to the observational main sequences of the three next nearest open clusters: Coma Berenices, the Pleiades, and Praesepe. This method consists in comparing the observational main sequence of the clusters with a grid of theoretical ZAMSs. The stars composing the observational main sequences had to have reliable absolute bolometric magnitudes, coming all from individual Hipparcos parallaxes, precise bolometric corrections, effective temperatures and metal abundances from high resolution detailed spectroscopic analyses. If we assume, following the work by Fernandez et al. (1996, A&A,311,127), that the mixing-lenth parameter is solar, the position of a theoretical ZAMS, in the (log Teff, Mbol) plane, computed with given input physics, only depends on two free parameters: the He content Y by mass, and the metallicity Z by mass. If effective temperature and metallicity of the constituting stars of the 4 clusters are previously known by means of detailed analyses, one can deduce their helium abundances by means of an appropriate grid of theoretical ZAMS’s. The comparison between the empirical (log Teff, Mbol) main sequence of the Hyades and the computed ZAMS corresponding to the observed metallicity Z of the Hyades (Z= 0.0240 ± 0.0085) gives a He abundance for the Hyades, Y= 0.26 ± 0.02. Our interpretation, concerning the observational position of the main sequence of the three nearest clusters after the Hyades, is still under way and appears to be greatly more difficult than for the Hyades. For the moment we can say that: ‒ The 15 dwarfs analysed in detailed in Coma have a solar metallicity: [Fe/H] = -0.05 ± 0.06. However, their observational main sequence fit better with the Hyades ZAMS. ‒ The mean metallicity of 13 Pleiades dwarfs analysed in detail is solar. A metal deficient and He normal ZAMS would fit better. But, a warning for absorption in the Pleiades has to be recalled. ‒ The upper main sequence of Praesepe, (the more distant cluster: 180 pc) composed by 11 stars, analysed in detail, is the one which has the best fit with the Hyades ZAMS. The deduced ‘turnoff age’ of the cluster is slightly higher than that of the Hyades: 0.8 Gyr instead of 0.63 Gyr.


Neurosurgery ◽  
2016 ◽  
Vol 79 (5) ◽  
pp. 722-735 ◽  
Author(s):  
Guillaume Coll ◽  
Jean-Jacques Lemaire ◽  
Federico Di Rocco ◽  
Isabelle Barthélémy ◽  
Jean-Marc Garcier ◽  
...  

Abstract BACKGROUND: To date, no study has compared the evolution of the foramen magnum area (FMA) and the posterior cranial fossa volume (PCFV) with the degree of cranial base synchondrosis ossification. OBJECTIVE: To illustrate these features in healthy children. METHODS: The FMA, the PCFV, and the ossification of 12 synchondroses according to the Madeline and Elster scale were retrospectively analyzed in 235 healthy children using millimeter slices on a computed tomography scan. RESULTS: The mean FMA of 6.49 cm2 in girls was significantly inferior to the FMA of 7.67 cm2 in boys (P <.001). In both sexes, the growth evolved in a 2-phase process, with a phase of rapid growth from birth to 3.75 years old (yo) followed by a phase of stabilization. In girls, the first phase was shorter (ending at 2.6 yo) than in boys (ending at 4.33 yo) and proceeded at a higher rate. PCFV was smaller in girls (P <.001) and displayed a biphasic pattern in the whole population, with a phase of rapid growth from birth to 3.58 yo followed by a phase of slow growth until 16 yo. In girls, the first phase was more active and shorter (ending at 2.67 yo) than in boys (ending at 4.5 yo). The posterior interoccipital synchondroses close first, followed by the anterior interoccipital and occipitomastoidal synchondroses, the lambdoid sutures simultaneously, then the petro-occipital and spheno-occipital synchondroses simultaneously. CONCLUSION: The data provide a chronology of synchondrosis closure. We showed that FMA and PCFV are constitutionally smaller in girls at birth (P ⩽.02) and suggest that a sex-related difference in the FMA is related to earlier closure of anterior interoccipital synchondroses in girls (P =.01).


2019 ◽  
Vol 4 (2) ◽  
pp. 363-370
Author(s):  
Romy Budhi Widodo ◽  
Mochamad Subianto ◽  
Grace Imelda

The domain of the activity is technology for the society whereas the focus is practical computer science for the society. The background of our activity is based on the needs of YPK junior high school in Malang city, Indonesia. The school need to develop computer-based school report card and also daily grade card for teachers. The method for software/application development is spiral model which consist of the cycle of system identification, risk analysis, and enhancement of the prototype to be an operational prototype. Evaluation of the product was based on the Computer System Usability Questionnaire (CSUQ) from IBM. The CSUQ using 5 scale of Likert scale contains three categories: 1) system usefulness (SYSUSE), 2) information quality (INFOQUAL), and 3) interface quality (INTERQUAL). The mean rank’s result in order from the greatest to the lowest is SYSUSE, INTERQUAL, and INFOQUAL, respectively. It was reported that SYSUSE category was superior to INFOQUAL (U = 3369.5, p = 0.0005). Overall, the user satisfaction score is 78.4%, which is in the “worthy” category


2021 ◽  
Author(s):  
Ivan Efremov ◽  
Roman Veselovskiy

<p>There are many programs for the analysis and visualization of paleomagnetic data, but each of them is good only in a certain use case and does not allow to perform a full cycle of paleomagnetic operations. Therefore, one has to resort to using a number of programs to complete the full path of processing paleomagnetic data. You often have to convert data from one format to another, manually vectorize charts, and generally spend more time and effort than could theoretically be spent. Thus, there is a long overdue need for a universal program capable of fast, convenient and high-quality performance of a full cycle of paleomagnetic operations. A set of programs written by Randy Enkin (Enkin, 1996) for DOS was taken as a time-tested example of such a program. The choice fell on them, since these programs (although they are very outdated) allow performing a full cycle of paleomagnetic operations and do it as conveniently and efficiently as possible for that time.</p><p>Our goal is to create a program devoid of all of the above disadvantages and capable of developing indefinitely as modular opensource software by the efforts of all people interested in this.</p><p>The result of our work is PMTools – a cross-platform software for statistical analysis and visualization of paleomagnetic data. PMTools supports all widely used paleomagnetic data formats and allows you to work with them simultaneously. All charts created in PMTools are vector, adapted for direct using in publications and presentations, and can be exported in both vector and raster formats. At the same time, PMTools implements a full cycle of routine paleomagnetic operations: from finding the best-fit directions to calculating the mean paleomagnetic poles. Moreover, all operations can be performed both with a mouse through a graphical user interface and with hotkeys, which significantly speeds up the data analysis process. </p><p>In the near future, PMTools will become a modular open source application, so that each user will be able to add its own modules, thereby expanding the program's functionality.</p><p><strong>References</strong></p><p>Enkin, R.J., 1996. A Computer Program Package for Analysis and Presentation of Paleomagnetic Data, Pacific Geoscience Center, Geological Survey of Canada, http://www.pgc.nrcan.gc.ca/tectonic/enkin.htm.</p>


1977 ◽  
Vol 232 (5) ◽  
pp. H537-H544
Author(s):  
H. V. Allen ◽  
M. F. Anderson ◽  
J. D. Meindl

A totally implantable pulsed Doppler ultrasonic blood flowmeter has recently been developed to provide information on the velocity-flow profile in a vessel as well as its diameter. Volume flow can be indirectly obtained according to the formula: Q = (phi/4)(diam)2-v. In order to determine the accuracy of this estimate, in vivo direct bleedout measurements were performed on the abdominal aorta of six dogs with an overall accuracy in 77 trials of +2.0 +/- 8.7% (mean +/- 1 SD). The best-fit mean linear regression line was found to be: flowmeter output = 1.013-true flow + 5.1 ml/min. The scatter in the flowmeter's accuracy is thought to be due to small variations in the angle of the transducer. The source of the 2% overestimation in the mean accuracy could not be directly attributed to any one condition; the error is sufficiently small that in many cases it can be neglected.


2020 ◽  
Vol 90 (4) ◽  
pp. 500-506
Author(s):  
Alessandro Schwertner ◽  
Renato Rodrigues de Almeida ◽  
Renata Rodrigues de Almeida-Pedrin ◽  
Thais Maria Freire Fernandes ◽  
Paula Oltramari ◽  
...  

ABSTRACT Objective To assess and compare the effects produced in the maxillary dental arch by means of Connecticut intrusion arch (CIA) with or without a cinch back on the distal end of the tube of the first molars. Materials and Methods This study included 44 patients with a mean age of 13.1 ± 1.8 years treated for deep bite with a CIA randomly divided into two groups: group 1 (G1), 22 patients with initial mean age of 12.72 ± 1.74 years treated with the CIA in the upper arch without a cinch back on the distal surface of the tube of the first molars, and group 2 (G2), 22 patients with an initial mean age of 13.67 ± 2.03 years treated with the CIA with a cinch back. Lateral cephalograms were available before treatment (T1) and after intrusion of maxillary incisors (T2). The mean treatment period was 5.5 ± 1.45 months. Intragroup and intergroup changes in the maxillary incisor and molar positions were analyzed by paired and independent t-tests associated with the Holm-Bonferroni correction method for multiple comparisons (P < .05). Results There were significant differences between groups in terms of maxillary incisor displacement. The maxillary incisors flared labially (2.17°) and proclined (1.68 mm) in group 1, whereas a palatal inclination (−1.99°) and retroclination (−1.13 mm) was observed in group 2. No significant differences were found for the molar positions between the groups. Conclusions The presence or absence of a distal bend in CIA affects incisor tipping and proclination during intrusion mechanics.


2007 ◽  
Vol 41 (12) ◽  
pp. 897-902 ◽  
Author(s):  
R Syha ◽  
M Peters ◽  
H Birnesser ◽  
A Niess ◽  
A Hirschmueller ◽  
...  

2019 ◽  
Vol 48 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Jian Xu ◽  
Haifeng Liu ◽  
Wei Lu ◽  
Zhenhan Deng ◽  
Weimin Zhu ◽  
...  

Background: Some studies have advocated the use of suture-button fixation during the Latarjet procedure to reduce complications associated with screw fixation. However, the sample size of these studies is relatively small, and their follow-up period is short. Purpose: To investigate the efficacy of the suture-button Latarjet procedure with at least 3 years of follow-up and remodeling of the coracoid graft. Study Design: Case series; Level of evidence, 4. Methods: A total of 152 patients who underwent the suture-button Latarjet procedure between February 2013 and February 2016 were selected, and 128 patients who met the inclusion criteria were enrolled in this study. Preoperative and postoperative clinical results were assessed. The position and healing condition of the coracoid graft and arthropathy of the glenoid and humeral head were also assessed using radiography and 3-dimensional computed tomography (CT). Results: The mean follow-up time was 40.3 ± 5.8 months. There were 102 patients included in this study. The mean visual analog scale score for pain during motion, the American Shoulder and Elbow Surgeons score, the Rowe score, and the Walch-Duplay score were improved considerably. A total of 100 grafts achieved bone union. The overall absorption rate was 12.6% ± 4.3%. Graft absorption mostly occurred on the edge and outside the “best-fit” circle of the glenoid. A vertical position was achieved in 98 grafts (96% of all cases) immediately postoperatively, with the mean graft midline center at the 4 o’clock position. In the axial view, CT showed that 89 grafts were flush to the glenoid, whereas 2 and 11 grafts were fixed medially and laterally, respectively. In all cases, the bone graft and glenoid tended to extend toward each other to form concentric circles during the remodeling process. During follow-up observations, the height of the 11 grafts that were positioned laterally (ie, above the glenoid level) exhibited a wave-curved change. No arthropathy was observed in any patient. Conclusion: Patient outcomes were satisfactory after the modified arthroscopic suture-button Latarjet technique. Graft absorption mostly occurred on the edge and outside the “best-fit” circle of the glenoid. The graft exhibited the phenomenon of ectatic growing when it fused with the glenoid and finally remodeled to a new concentric circle with the humeral head analogous to the original glenoid. Grafts positioned laterally did not cause arthropathy of the joints within the period of the study.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 52
Author(s):  
Nicholas A. Beckmann ◽  
Rudi G. Bitsch ◽  
Theresa Bormann ◽  
Steffen Braun ◽  
Sebastian Jaeger

Acetabular cup deformation may affect liner/cup congruency, clearance and/or osseointegration. It is unclear, whether deformation of the acetabular components occurs during load and to what extent. To evaluate this, revision multi-hole cups were implanted into six cadaver hemipelvises in two scenarios: without acetabular defect (ND); with a large acetabular defect (LD) that was treated with an augment. In the LD scenario, the cup and augment were attached to the bone and each other with screws. Subsequently, the implanted hemipelvises were loaded under a physiologic partial-weight-bearing modality. The deformation of the acetabular components was determined using a best-fit algorithm. The statistical evaluation involved repeated-measures ANOVA. The mean elastic distension of the ND cup was 292.9 µm (SD 12.2 µm); in the LD scenario, 43.7 µm (SD 11.2 µm); the mean maximal augment distension was 79.6 µm (SD 21.6 µm). A significant difference between the maximal distension of the cups in both scenarios was noted (F(1, 10) = 11.404; p = 0.007). No significant difference was noted between the compression of the ND and LD cups, nor between LD cups and LD augments. The LD cup displayed significantly lower elastic distension than the ND cup, most likely due to increased stiffness from the affixed augment and screw fixation.


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