14 research outputs found

    Cephalometric measurements performed on CBCT and reconstructed lateral cephalograms: a cross-sectional study providing a quantitative approach of differences and bias

    Get PDF
    Background: Cephalometric analysis is traditionally performed on skull lateral teleradiographs for orthodontic diagnosis and treatment planning. However, the skull flattened over a 2D film presents projection distortions and superimpositions to various extents depending on landmarks relative position. When a CBCT scan is indicated for mixed reasons, cephalometric assessments can be performed directly on CBCT scans with a distortion free procedure. The aim of the present study is to compare these two methods for orthodontic cephalometry. Methods: 114 CBCTs were selected, reconstructed lateral cephalometries were obtained by lateral radiographic projection of the entire volume from the right and left sides. 2D and 3D cephalometric tracings were performed. Since paired t-tests between left and right-side measurements found no statistically significant differences, mean values between sides were considered for both 2D and 3D values. The following measurements were evaluated: PNS-A; S-N; N-Me; N-ANS; ANS-Me; Go-Me; Go-S; Go-Co; SNA, SNB, ANB; BaŜN; S-N^PNS-ANS; PNS-ANS^Go-Me; S-N^Go-Me. Intraclass correlation coefficients, paired t-test, correlation coefficient and Bland-Altman analysis were performed to compare these techniques. Results: The values of intra- and inter-rater ICC showed excellent repeatability and reliability: the average (± SD) intraobserver ICCs were 0.98 (± 0.01) and 0.97(± 0.01) for CBCT and RLCs, respectively; Inter-rater reliability resulted in an average ICC (± SD) of 0.98 (± 0.01) for CBCT and 0.94 (± 0.03) for RLC. The paired t-tests between CBCT and reconstructed lateral cephalograms revealed that Go-Me, Go-S, PNS-ANS^Go-Me and S-N^Go-Me measurements were statistically different between the two modalities. All the evaluated sets of measurements showed strong positive correlation; the bias and ranges for the 95% Limits of Agreement showed higher levels of agreement between the two modalities for unpaired measurements with respect to bilateral ones. Conclusion: The cephalometric measurements laying on the mid-sagittal plane can be evaluated on CBCT and used for orthodontic diagnosis as they do not show statistically significant differences with those measured on 2D lateral cephalograms. For measurements that are not in the mid-sagittal plane, the future development of specific algorithms for distortion correction could help clinicians deduct all the information needed for orthodontic diagnosis from the CBCT scan

    Accuracy of automated 3D cephalometric landmarks by deep learning algorithms: systematic review and meta-analysis

    Get PDF
    Objectives The aim of the present systematic review and meta-analysis is to assess the accuracy of automated landmarking using deep learning in comparison with manual tracing for cephalometric analysis of 3D medical images. Methods PubMed/Medline, IEEE Xplore, Scopus and ArXiv electronic databases were searched. Selection criteria were: ex vivo and in vivo volumetric data images suitable for 3D landmarking (Problem), a minimum of five automated landmarking performed by deep learning method (Intervention), manual landmarking (Comparison), and mean accuracy, in mm, between manual and automated landmarking (Outcome). QUADAS-2 was adapted for quality analysis. Meta-analysis was performed on studies that reported as outcome mean values and standard deviation of the difference (error) between manual and automated landmarking. Linear regression plots were used to analyze correlations between mean accuracy and year of publication. Results The initial electronic screening yielded 252 papers published between 2020 and 2022. A total of 15 studies were included for the qualitative synthesis, whereas 11 studies were used for the meta-analysis. Overall random effect model revealed a mean value of 2.44 mm, with a high heterogeneity (I-2 = 98.13%, tau(2) = 1.018, p-value < 0.001); risk of bias was high due to the presence of issues for several domains per study. Meta-regression indicated a significant relation between mean error and year of publication (p value = 0.012). Conclusion Deep learning algorithms showed an excellent accuracy for automated 3D cephalometric landmarking. In the last two years promising algorithms have been developed and improvements in landmarks annotation accuracy have been done

    Le proverbe: une approche contrastive franco-italienne la notion de temps proverbial

    No full text
    Dans un contexte de communication, des bonnes compétences linguistiques ne suffisent pas puisque la connaissance approfondie de la culture cible s’avère également une question fondamentale. Il est donc nécessaire d’adopter une attitude communicative adéquate pour que le message puisse être reçu correctement. Parmi les aspects culturels auxquels le parlant doit accorder une grande importance figurent les proverbes. Les proverbes sont des énoncés d’origine populaire qui recèlent un contenu moral et éthique dont la visée est apprendre aux hommes à bien vivre en société. Les messages véhiculés par les proverbes sont l’héritage de l’expérience des ancêtres dont il faut faire trésor pour comprendre les mœurs, le mode de vie et la pensée d’une communauté donnée : voilà donc pourquoi les proverbes ont été dénommés «sagesse des nations». Depuis la nuit de temps, les proverbes sont transmis de père en fils par voie orale : l’usage quotidien et l’apprentissage par cœur en ont fait des formules fixées dont la structure binaire rimique et rythmique facilite la mémorisation. Par ailleurs, les proverbes sont souvent à interpréter en clé métaphorique, le figement étant l’un des traits définitoires de ce genre du discours. Si les proverbes, énoncés de sagesse populaire, étaient autrefois des sources d’autorité morale, aujourd’hui, au contraire, ils ont perdu leur valeur éthique et sont en train de tomber en désuétude en tant que forme de littérature de deuxième rang, véhiculant des contenus stéréotypés. Néanmoins, les proverbes représentent toujours une clé de lecture pour étudier les sociétés dont ils constituent une partie très importante du patrimoine linguistique et culturel, ce que l’on nomme « patrimoine immatériel ». Le travail que nous allons proposer se penche sur le rôle et l’importance des proverbes, en présentant une approche à l’analyse contrastive des proverbes concernant la notion de temps en langue italienne et française

    Spiking Neural Networks per il monitoraggio strutturale basato su vibrazioni

    No full text
    Il monitoraggio strutturale (SHM) costituisce un’importante sfida per garantire la sicurezza e l’integrità delle strutture civili e industriali. In questo studio è stato presentato un nuovo approccio all’SHM basato su reti neurali spiking (SNN), valutando in particolare la capacità di questi nuovi approcci neurali di rilevare anomalie in un caso d’uso di riferimento, ovvero il ponte Z24 in Svizzera. Attraverso una serie di esperimenti, è stato dimostrato che l'analisi delle risposte vibrazionali con SNN è in grado di individuare in modo preciso e affidabile le variazioni nel comportamento della struttura. In secondo luogo, è stata dimostrata l’efficienza delle Superlet per ottenere rappresentazioni tempo-frequenza ad alta risoluzione rispetto a metodi più tradizionali come le trasformate Wavelet e spettrogrammi. Inoltre, abbiamo dimostrato che l’impiego di SNN risulta vincente rispetto a un più tradizionale approccio incentrato sull’uso di reti neurali convoluzionali (CNN), migliorando significativamente le prestazioni in termini di accuratezza (un aumento massimo del 15%). In sintesi, il nostro studio ha dimostrato che l'approccio SNN può rappresentare una soluzione promettente per il monitoraggio della salute strutturale e il rilevamento precoce di anomalie relative a variazioni nella firma spettrale della struttura target, offrendo nuove opportunità per migliorare la sicurezza e l'affidabilità delle infrastrutture civili e industriali

    Development of de novo major involvement during follow-up in Behçet's syndrome

    No full text
    The primary aim of the study was to evaluate the incidence of de novo major involvement during follow-up in a cohort of patients with Behçet's syndrome (BS); the secondary aim was to analyse the epidemiological profile and the long-term outcome of those patients who developed new major involvement. Among our cohort of 120 BS patients, we evaluated all subjects who had no major organ involvement during the early years of their disease; specifically, at disease onset, the 52 % of the cohort presented a prevalent mucocutaneous involvement. The primary outcomes were represented by the following: Hatemi et al. (Rheum Dis Clin North Am 39(2):245-61, 2013) the incidence of de novo major involvement during the follow-up and Hatemi et al. (Clin Exp Rheumatol 32(4 Suppl 84):S112-22, 2014) the use of immunosuppressive drugs during the follow-up. We have defined the development of de novo major involvement during the follow-up as the occurrence of severe ocular, vascular or CNS involvement after a latency period from the diagnosis of at least 3 years. Among 62 patients characterized by a mild onset of disease, we observed that after at least 3 years from the diagnosis, 21 BS patients (34 %) still developed serious morbidities. Specifically, three patients developed ocular involvement, nine patients developed neurological involvement and nine patients presented vascular involvement. Comparing main epidemiological and clinical findings of the two groups, we observed that patients who developed de novo major involvement were more frequently males and younger; furthermore, 95 % of these patients were characterized by a young onset of disease (p < 0.001). Being free of major organ complication in the first years of BS is not necessary a sign of a favourable outcome. Globally, the development of de novo major involvement during the coursfce of BS suggests that a tight control is strongly recommended during the course of the disease

    Biomarkers of aging in frailty and age-associated disorders: state of the art and future perspective

    No full text
    : According to the Geroscience concept that organismal aging and age-associated diseases share the same basic molecular mechanisms, the identification of biomarkers of age that can efficiently classify people as biologically older (or younger) than their chronological (i.e. calendar) age is becoming of paramount importance. These people will be in fact at higher (or lower) risk for many different age-associated diseases, including cardiovascular diseases, neurodegeneration, cancer, etc. In turn, patients suffering from these diseases are biologically older than healthy age-matched individuals. Many biomarkers that correlate with age have been described so far. The aim of the present review is to discuss the usefulness of some of these biomarkers (especially soluble, circulating ones) in order to identify frail patients, possibly before the appearance of clinical symptoms, as well as patients at risk for age-associated diseases. An overview of selected biomarkers will be discussed in this regard, in particular we will focus on biomarkers related to metabolic stress response, inflammation, and cell death (in particular in neurodegeneration), all phenomena connected to inflammaging (chronic, low-grade, age-associated inflammation). In the second part of the review, next-generation markers such as extracellular vesicles and their cargos, epigenetic markers and gut microbiota composition, will be discussed. Since recent progresses in omics techniques have allowed an exponential increase in the production of laboratory data also in the field of biomarkers of age, making it difficult to extract biological meaning from the huge mass of available data, Artificial Intelligence (AI) approaches will be discussed as an increasingly important strategy for extracting knowledge from raw data and providing practitioners with actionable information to treat patients
    corecore