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 NURBS (Non Uniform Rational B-Splines) 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<0.05) 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<0.001), the resulting equations well estimated actual values (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.
Three-dimensional computerized anthropometry of the nose: landmark representation compared to surface analysis / V.F. Ferrario, F. Mian, R. Peretta, R. Rosati, C. Sforza. - In: CLEFT PALATE-CRANIOFACIAL JOURNAL. - ISSN 1055-6656. - 44:3(2007), pp. 278-285.
Three-dimensional computerized anthropometry of the nose: landmark representation compared to surface analysis
V.F. FerrarioPrimo
;F. MianSecondo
;R. Peretta;R. RosatiPenultimo
;C. SforzaUltimo
2007
Abstract
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 NURBS (Non Uniform Rational B-Splines) 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<0.05) 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<0.001), the resulting equations well estimated actual values (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.Pubblicazioni consigliate
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