1,720,977 research outputs found
Diagnostic performance of 3-dimensional evaluation of palatal vault changes in assessing successful treatment of constricted maxilla in growing subjects.
Influence of sucking habits and breathing pattern on palatal constriction in unilateral posterior crossbite - a controlled study.
The aim of this study was to evaluate the influence of prolonged sucking habits and mouth breathing on palatal vault morphology in a group of subjects with unilateral functional crossbite [crossbite (CB) group] compared with a group of subjects with normal occlusion [non-crossbite (NCB) group]. A sample of 80 Caucasian subjects (51 CB and 29 NCB; aged 5.3 ± 0.8 years) in the deciduous dentition was selected. A questionnaire regarding the subject's sucking habits was answered by the parents. Any sucking habit that lasted more than 24 months was considered as a prolonged sucking habit. The breathing pattern was assessed by an experienced otorinolarygologist and was classified either mainly nose or mouth breathing. Intercanine and intermolar distances and palatal surface area and volume were recorded three dimensionally on study casts. Univariate and multivariate analyses were employed. Posterior CB was negatively correlated with all the dental and palatal parameters (P < 0.01) with the exception of the palatal surface area that did not reach the statistical significance. Only prolonged sucking habits (but not mouth breathing) was a significant risk indicator for unilateral functional CB (P < 0.001). However, the prolonged sucking habits were not significantly correlated with any of the investigated parameter, and mouth breathing was negatively correlated with the intermolar distance only. Therefore, maxillary constriction in unilateral functional CB might not be influenced by the presence or absence of prolonged sucking habits or mouth breathing
The association of tongue posture with the dentoalveolar maxillary and mandibular morphology in Class III malocclusion: a controlled study.
The aim of the present study was to evaluate the association of tongue posture with the dentoalveolar maxillary and mandibular morphology in a group of Class III subjects in comparison to a group of Class I subjects. Twenty Class III subjects (9 males, 11 females, 19.2 ± 4.6 years) and 20 Class I subjects (6 males, 14 females, 17.4 ± 1.7 years) were included in the present study. Maxillary and mandibular morphology was defined by the intermolar and intercanine distances, at both the cusps and gingival levels, and by measuring surface area and volume of the palatal vault and mouth floor assessed on three-dimensional digital models. Tongue-to-palate distances were measured on lateral cephalograms. The groups were compared using the Mann-Whitney U-test and correlations between each morphological parameter and the tongue-to-palate distances were calculated using the Spearman correlation coefficient. The mandibular intermolar width at the gingival level was significantly greater in the Class III group (P < 0.01), while the maxillary intercanine widths were significantly smaller in the Class III group (P < 0.05). The mouth floor area and volume and the respective ratios between the mouth floor and palate were significantly greater in the Class III group (P = 0.01). The tongue-to-palate distances were generally greater, i.e. lower tongue posture, for the Class III subjects. Significant correlations were seen between tongue-to-palate distances in the posterior region with the area ratio (rho = 0.44, P < 0.05). Tongue posture is significantly lower in Class III subjects and is associated with the dentoalveolar characteristics of the maxilla and mandible
Three-dimensional evaluation of facial asymmetry in association with unilateral functional crossbite in the primary, early, and late mixed dentition phases.
OBJECTIVE: To assess the degree of facial asymmetry associated with subjects with unilateral functional crossbite (CB) in the primary, early/intermediate, and late mixed dentition phases in comparison with a group of subjects without CB.
SUBJECTS AND METHODS: A group of 234 white subjects, 78 with CB (42 girls and 36 boys) and 156 without CB (73 girls and 83 boys), aged 3.9-11.9, grouped according to the dentition phase, were included. Three-dimensional laser scans of the subjects' faces were used to assess facial asymmetry. For each part of the face two-way multivariate analysis of covariance was performed to assess differences among the subjects, and an independent sample t-test was used to assess the significance of the differences between data sets.
RESULTS: Within all dentition phases, the subjects with CB had statistically significantly greater facial asymmetry of the whole face than the subjects without CB, with the greatest values in the lower part of the face (P < .05). In the middle part of the face a significant difference was observed in the mixed dentition phases.
CONCLUSIONS: Children with unilateral functional CB exhibited a greater facial asymmetry than children without this malocclusion in all the dentition phases herein investigated. The greatest differences were seen for the lower part of the face. Further, facial asymmetry in the middle part of the face became clinically relevant in combination with the transition from primary to mixed dentition phase
Three-dimensional evaluation of palatal vault changes in children. A longitudinal study
OBJECTIVE: To evaluate palatal vault change in children and to assess the reliability of two palatal parameters in assessing growth modifications.
SUBJECTS AND METHODS: A group of 26 healthy white children aged 5.3 ± 0.3 years (15 boys, 11 girls) were randomly selected. Impressions of the upper dental arches were obtained at baseline and at 12, 18, and 30 months follow-up. Three-dimensional digital images of study casts were obtained using a laser scanning device. Palatal surface area and palatal volume were measured on the digital study casts at each time point. Effect size (ES) coefficients were calculated for both parameters as indices of diagnostic reliability in individual subjects when at least equal to 1.0.
RESULTS: Significant increases in palatal surface area and volume were seen over the observation period (P < .001). ES coefficients for palatal surface area were greater than those for palatal volume. However, even for the former parameter, only the value taken at 30 months was above the threshold.
CONCLUSIONS: Growth of the palatal vault was significant during the observation period, which coincides with primary and mixed dentition stages. Palatal surface area appears to be more reliable than palatal volume in assessment of growth modifications in individual subjects
Assessment of facial asymmetry in growing subjects with a three-dimensional laser scanning system
OBJECTIVES: To evaluate facial asymmetry in growing subjects with no malocclusion on three-dimensional laser facial scans.
SETTING AND SAMPLE POPULATION: Twenty-seven healthy Caucasian children (15 boys and 12 girls, aged 5.4 ± 0.3 years) in the primary dentition without malocclusion were randomly selected from a local kindergarten in Slovenia.
MATERIAL AND METHODS: Surface facial images were obtained using a three-dimensional laser scanning system at baseline and at 18, 30, 42 and 54 months of follow-up. Facial asymmetry was assessed quantitatively by measuring the average distance between facial image and mirrored image. Further, the percentage of asymmetry was calculated as the percentage of image to mirrored image not coinciding within 0.5 mm. Qualitative assessment was performed on colour deviation maps by recording the predominant side of the face for the upper, middle and lower parts of the face separately. Nonparametric tests were used for data analysis.
RESULTS: No face was perfectly symmetric. The average distance between the mirrored images for the whole face ranged 0.22-0.85 mm and the percentage of asymmetry 7.8-66.9. There were no significant gender differences (p > 0.05), and no significant change was found over the observed period. The upper part of the face was the least asymmetric, while the lower and middle parts showed similar degrees of asymmetry.
CONCLUSION: Facial asymmetry is already present at an early developmental stage and does not show any tendency to increase or decrease with growth in the pre-pubertal period
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Assessment of facial asymmetry in growing subjects with a three-dimensional laser scanning system
Authors – Primozic J, Perinetti G, Zhurov A, Richmond S, Ovsenik M
Objectives – To evaluate facial asymmetry in growing subjects with no malocclusion on three-dimensional laser facial scans.
Setting and Sample Population – Twenty-seven healthy Caucasian children (15 boys and 12 girls, aged 5.4 ± 0.3 years) in the primary dentition without malocclusion were randomly selected from a local kindergarten in Slovenia.
Material and Methods – Surface facial images were obtained using a three-dimensional laser scanning system at baseline and at 18, 30, 42 and 54 months of follow-up. Facial asymmetry was assessed quantitatively by measuring the average distance between facial image and mirrored image. Further, the percentage of asymmetry was calculated as the percentage of image to mirrored image not coinciding within 0.5 mm. Qualitative assessment was performed on colour deviation maps by recording the predominant side of the face for the upper, middle and lower parts of the face separately. Nonparametric tests were used for data analysis.
Results – No face was perfectly symmetric. The average distance between the mirrored images for the whole face ranged 0.22–0.85 mm and the percentage of asymmetry 7.8–66.9. There were no significant gender differences (p > 0.05), and no significant change was found over the observed period. The upper part of the face was the least asymmetric, while the lower and middle parts showed similar degrees of asymmetry.
Conclusion – Facial asymmetry is already present at an early developmental stage and does not show any tendency to increase or decrease with growth in the pre-pubertal period
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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