Plaster Casts in Evidence

1943 ◽  
Vol 11 (4) ◽  
pp. 196-198
Keyword(s):  
Plaster Casts

»Gott segne Kupfer« Goethes Kunstbeschreibungen im Zeitalter der semitechnischen Reproduzierbarkeit

2017 ◽  
Vol 80 (3) ◽  
pp. 392-417
Author(s):  
Mattias Pirholt
Keyword(s):  
Crucial Role ◽  
Original Work ◽  
Continuous Process ◽  
Work Experiences ◽  
Autobiographical Accounts ◽  
Plaster Casts

Abstract This study investigates how the experience of reproductions – drawings, copperplate engravings, woodcuts, lithography, plaster casts, and so forth – influenced Johann Wolfgang von Goethe’s conception of art in general and his descriptions of art (e.g., ekphrases, reviews, and autobiographical accounts) in particular. Well acquainted with the technologies of reproduction of his time, Goethe, often in collaboration with Johann Heinrich Meyer, acknowledged the crucial role of reproductions for the understanding of the productive idea of the original work. Experiences of reproductions and comparisons between copies, drafts, and the original enabled Goethe to grasp the idea as an ever-transforming productive constant of the continuous process of becoming of the work.

Three-Dimensional Computerized Anthropometry of the Nose: Landmark Representation Compared to Surface Analysis

2007 ◽  
Vol 44 (3) ◽  
pp. 278-285 ◽  
Author(s):  
Virgilio F. Ferrario ◽  
Fabrizio Mian ◽  
Redento Peretta ◽  
Riccardo Rosati ◽  
Chiarella Sforza
Keyword(s):  
Three Dimensional ◽  
Digital Data ◽  
Limits Of Agreement ◽  
B Splines ◽  
Surface Areas ◽  
Using Data ◽  
Difference Volume ◽  
T Values ◽  
Plaster Models ◽  
Plaster Casts

Objective: To compare three-dimensional nasal measurements directly made on subjects to those made on plaster casts, and nasal dimensions obtained with a surface-based approach to values obtained with a landmark representation. Methods: Soft-tissue nasal landmarks were directly digitized on 20 healthy adults. Stone casts of their noses were digitized and mathematically reconstructed using nonuniform rational B-splines (NURBS) curves. Linear distances, angles, volumes and surface areas were computed using facial landmarks and NURBS-reconstructed models (surface-based approach). Results: Measurements on the stone casts were somewhat smaller than values obtained directly from subjects (differences between −0.05 and −1.58 mm). Dahlberg's statistic ranged between 0.73 and 1.47 mm. Significant (p < .05) t values were found for 4 of 15 measurements. The surface-based approach gave values 3.5 (volumes) and 2.1 (surface area) times larger than those computed with the landmark-based method. The two values were significantly related (volume, r = 0.881; surface, r = 0.924; p < .001), the resulting equations estimated actual values well (mean difference, volume −0.01 mm3, SD 1.47, area 0.05 cm2, SD 1.44); limits of agreement between −2.89 and 2.87 mm3 (volume); −2.88 and 2.78 cm2 (area). Conclusions: Considering the characteristics of the two methods, and for practical purposes, nasal distances and angles obtained on plaster models were comparable to digital data obtained directly from subjects. Surface areas and volumes were best obtained using a surface-based approach, but could be estimated using data provided by the landmark representation.

scholarly journals Comparison of space analysis performed on plaster vs. digital dental casts applying Tanaka and Johnston's equation

2013 ◽  
Vol 18 (1) ◽  
pp. 128-133 ◽  
Author(s):  
Júlia Olien Sanches ◽  
Lourdes Aparecida Martins dos Santos-Pinto ◽  
Ary dos Santos-Pinto ◽  
Betina Grehs ◽  
Fabiano Jeremias
Keyword(s):  
Systematic Error ◽  
Random Error ◽  
Regression Equation ◽  
Predictive Values ◽  
Error Bias ◽  
Digital Caliper ◽  
Plaster Casts ◽  
Paired T Test ◽  
Lower Incisors ◽  
Dental Casts

OBJECTIVE: The purpose of this study was to compare dental size measurements, their reproducibility and the application of Tanaka and Johnston regression equation in predicting the size of canines and premolars on plaster and digital dental casts. METHODS: Thirty plaster casts were scanned and digitized. Mesiodistal measurements of the teeth were then performed with a digital caliper on the plaster and digital casts using O3d software system (Widialabs©).The sum of the sizes of the lower incisors was used to obtain predictive values of the sizes of the premolars and canines using the regression equation, and these values were compared with the actual sizes of the teeth. The data were statistically analyzed by applying to the results Pearson's correlation test, Dahlberg's formula, paired t-test and analysis of variance (p<0.05). RESULTS: Excellent intraexaminer agreement was observed in the measurements performed on both dental casts. No random error was present in the measurements obtained with the caliper and systematic error (bias) was more frequent in the digital casts. Space prediction obtained by applying the regression equation was greater than the sum of the canines and premolars on the plaster and digital casts. CONCLUSIONS: Despite an adequate reproducibility of the measurements performed on both casts, most measurements on the digital casts were higher than those on the plaster casts. The predicted space was overestimated in both models and significantly higher in the digital casts.

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