1,720,978 research outputs found
Maxillary expansion with clear aligners in the mixed dentition: A preliminary study with Invisalign® First system
Full text linkAim The aim of this study was to evaluate maxillary arch changes in patients treated with Invisalign® First system in the mixed dentition, focusing on arch width, arch perimeter, arch depth, molar inclination and alveolar expansion. Materials and methods A retrospective study was carried out. The sample consisted of 20 patients, 12 females and 8 males, treated with clear aligners for maxillary expansion. Arch widths, arch perimeter, arch depth and molar inclination were measured on pre-treatment and post-treatment digital dental models. Superimposition of digital models was performed to evaluate alveolar expansion. Results There were significant increases in all measurements regarding arch width and arch perimeter, while arch depth and molar inclination significantly decreased. Alveolar expansion was recorded at all the reference points considered. Shapiro-Wilk test was used to check normal distribution. Average and standard deviations were calculated for all measurements. Paired t-test was run to report significant changes between T0 and T1. The statistical significance was set at p<0.05. Intraclass correlation coefficient was used to assess reliability. Conclusions In case of mild crowding or limited transverse maxillary deficiency, Invisalign® First clear aligners could be a reasonable alternative to traditional slow maxillary expanders
Chewing Efficiency Test in Subjects with Clear Aligners
No full textThe aim of this study was to evaluate the masticatory function of subjects with clear aligners and to propose a simple and repeatable method for the clinical and experimental evaluation of masticatory function. For the testing we used almonds, a natural substance that can be easily found and stored, has intermediate consistency and hardness, is insoluble in saliva, and has the ability easily lose the moisture absorbed in the mouth. Thirty-four subjects using the Invisalign® (Align Technology, Santa Clara, CA, USA) protocol were randomly selected. This was an “intercontrol test”, i.e., all subjects under the same conditions acted as controls but also as cases whilst wearing the clear aligners. Patients were asked to chew an almond for 20 s, once with aligners and once without aligners. The material was then dried, sieved, and weighted. Statistical analysis was performed to investigate any significative differences. In all our subjects, the efficiency of chewing with clear aligners was found to be comparable to the efficiency of chewing without clear aligners. In detail, the average weight after drying was 0.62 g without aligners and 0.69 g with aligners, while after sieving at 1 mm, the average weight was 0.08 g without aligners and 0.06 g with aligners. The average variation after drying was of 12%, and after sieving at 1 mm, it was 25%. In summary, there was no substantial difference between chewing with or without clear aligners. Despite some discomfort in chewing, the clear aligners were well tolerated by most subjects, who wore them without difficulty even during meals
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Effectiveness of Preformed Myofunctional Devices in the Treatment of Malocclusions: A Pilot Study
No full textIntroduction: Preformed myofunctional appliances are increasingly being studied in orthodontics and are typically used to address oral function anomalies as well as malocclusions and development defects of the jaws. The aim of this study is to evaluate the efficacy of a protocol based on the use of preformed devices and myofunctional therapy for the correction of malocclusions. Materials and Methods: A retrospective study was conducted to evaluate the effectiveness of a preformed myofunctional devices in correcting certain orthodontic problems related to overbite, overjet, and cross-bite. Thirty-six patients in the mixed dentition phase were analyzed along with their clinical records, photos, and scans. Overjet, Overbite, and Crossbite were measured by analyzing the files exported in the Standard Tesselation Language format (Stl) of patients’ arches using Zeiss Inspect® software (version 2025.1.0.1985). Results: The data analysis reveals a statistically significant improvement in the correction of deep bite, overjet, and crossbite. Specifically, regarding the overbite (OVB), the initial measurement at T0 showed an average of 2.52 mm. The average OVB decreased to 1.73 mm at T1. The overjet had an initial average of 3.59 mm at T0, which decreased to 1.77 mm at T1. In this case as well, the difference between the measurements at T0 and T1 was statistically significant. Finally, the crossbite was evaluated by comparing the difference between mandibular and maxillary intermolar widths at T0 and T1. The average difference decreased from 5.84 mm at T0, to 1.68 mm at T1. Conclusions: Preformed myofunctional appliances represent a valid alternative in interceptive orthodontics for correcting and preventing orthodontic issues, especially of mild severity
Variations on the Author
Full text link“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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Orthodontic treatment in patients with special needs: confort assessment with VAS scale of intraoral scanner
No full textSalivary pH after taking coffee with and without sugar
No full textBACKGROUND: Caries weakens and destroys the hard structures of the tooth, affecting up to 90% of the population and which manifests itself very early. The aim of this study was to evaluate the pH variation by taking coffee and coffee with or without sugar having performed or not the usual home oral hygiene. METHODS: Fourteen adult volunteers in good oral health and no history of any type of systemic disease, with PSR2 and DMFT = 0. The oral pH was measured for a total duration of 40 minutes with the aid of a pH Day2® pH meter. In all, 56 surveys were carried out on the 14 volunteers. Five minutes after the base pH procedure, the subject was given an espresso (Nescafè Dolce Gusto, Espresso Intenso, Nestlè, S.A Vevey), with or without sucrose, and the pH measurements continued for another 35 minutes; at the end of which the instrument was turned off, and the instrument data was downloaded to the PC. The volunteers were asked to suspend their routine oral hygiene from the evening before both for the administration of coffee without sucrose and for the administration of coffee with sucrose. In the other two surveys, they were asked to carry out their routine oral hygiene in the case coffee with sugar or without sugar. RESULTS: In all the subjects there was a clear reduction in salivary pH about four minutes after finishing the coffee. Subsequently, in those who had taken coffee without sucrose there was an immediate rise in salivary pH; on the other hand, those who had taken coffee with sugar. CONCLUSIONS: This study shows that in order to maintain a basic pH of the oral cavity it is advisable to drink coffee without sugar, and carrying out proper oral hygiene correctly
An open-source AI tool for predicting cephalometric measurements from clinical data and photographic images
Full text linkIntroduction: Traditional orthodontic diagnostics rely significantly on lateral cephalometric radiographs, posing health risks due to ionising radiation, particularly in paediatric patients. Artificial intelligence (AI) represents a promising alternative by enabling predictions of cephalometric parameters from non-radiographic clinical data. This study evaluates the accuracy and clinical utility of CEPHCLINIC, an open-source AI software designed to predict conventional cephalometric measurements using clinical photographs and intraoral 3D scans, thus adhering to radiation protection principles. Materials and methods The dataset comprised 1255 subjects from the American Association of Orthodontists Foundation (AAOF) craniofacial collection, encompassing demographic and clinical variables (age, gender, overbite, overjet, facial dimensions). This dataset was randomly divided into training (80%, n = 1004) and validation (20%, n = 251) subsets. Additionally, an independent external test set of 51 untreated orthodontic cases was employed for rigorous evaluation. Input variables for model training included clinical parameters derived from photographs (WebCeph software) and intraoral scans (iTero scanner, MeshMixer software). Supervised predictive regression models, including ExtraTreesRegressor, CatBoostRegressor, and Support Vector Regression, were optimised through GridSearchCV and validated using repeated random subsampling. Predictive accuracy was assessed statistically using Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), Spearman correlation coefficients, R-squared values, and paired t-tests. Results The ExtraTreesRegressor demonstrated superior performance across multiple cephalometric parameters, achieving notably low RMSE values in the independent test set for ANB (2.772 degrees) and NP2PA (2.317 mm). However, parameters like COPAD exhibited higher prediction errors (RMSE 12.121 mm). Spearman correlation analysis indicated strong prediction consistency for COPOD (0.850), moderate for U1SNA (0.548), and poor predictability for NP2PO (-0.052). Despite statistically significant biases observed in predictions for some parameters (paired t-test, p < 0.05), overall predictive accuracy was clinically acceptable, emphasising parameters such as COPOD, COPAD, ANB, and U1SNA as particularly reliable. Conclusions The CEPHCLINIC software reliably predicts key cephalometric measurements from non-radiographic clinical data, significantly reducing radiation exposure risks. Despite promising performance, model refinement, dataset expansion with broader demographic representation, and integration with digital orthodontic technologies are essential for enhancing precision, clinical reliability, and global applicability
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