Clear aligner orthodontic therapy of rotated mandibular round-shaped teeth: A finite element study

To evaluate, using the finite element method, the orthodontic rotational movement of a lower second premolar obtained with clear aligners, analyzing different staging and attachment configurations

Multiplicative effect of stress and poor sleep quality on periodontitis: A university-based cross-sectional study

BackgroundThe aim of this study was to evaluate the association of perceived stress and poor sleep quality with periodontitis in a university-based cohort of individuals. MethodsA total of 235 individuals were included in this cross-sectional study. Perceived stress and sleep quality were evaluated through validated questionnaires, while periodontitis was identified with a full-mouth periodontal examination protocol using both European Federation of Periodontology/American Academy of Periodontology (EFP/AAP) and Centers for Disease Control and Prevention (CDC)/AAP case definitions. Simple and multiple linear and ordinal logistic regression analyses were performed to evaluate the association between perceived stress and sleep quality with periodontitis prevalence and severity. ResultsStage III/IV periodontitis resulted associated with both moderate/high perceived stress (odds ratio [OR] = 5.4; 95% confidence interval [CI]: 2.2-13.5; p < 0.001) and poor sleep quality (OR = 3.0; 95% CI: 1.2-7.4; p < 0.05). The interaction between moderate/high perceived stress and poor sleep quality presented a multiplicative association with stage III/IV periodontitis (EFP/AAP; OR = 5.8; 95% CI: 1.6-21.3; p < 0.001). Multiple linear regression analyses indicated a similar trend of association also with linear periodontal parameters, that is, mean clinical attachment level (CAL) and mean probing pocket depth (PPD). ConclusionsThe findings from the present study suggest that stress and poor sleep quality may exert a multiplicative effect on periodontitis prevalence and severity

a computer assisted robotic platform for vascular procedures exploiting 3d us based tracking

AbstractBackground: Cardiovascular diseases are the first cause of death globally: an estimated 17.5 million people died in 2012. By combining the benefits of magnetic navigation and ultrasound (US) imaging, the authors proposed a robotic platform (i.e. the MicroVAST platform) for intravascular medical procedures.Methods: A 3D imaging US-based tracking algorithm is implemented for the navigation of a magnetic-dragged soft-tethered device. Tests were performed to evaluate the algorithm in terms of tracking error and precision of locomotion.Results: The 3D imaging US-based algorithm tracked the endovascular device with an error of 6.4 ± 2.8 pixels and a mean displacement between the endovascular device and the preoperative path of 13.6 ± 4.5 mm (computational time of 12.2 ± 1.5 ms and 30.7 ± 6.1 matched features).Conclusions: The MicroVAST platform includes innovative solutions for navigation allowing for an assisted magnetic locomotion of medical devices in the cardiovascular district by combining a 3D ima..

Root resorption during orthodontic treatment with Invisalign®: a radiometric study

Abstract Background Root resorption (RR) is described as a permanent loss of tooth structure from the root apex. Many reports in the literature indicate that orthodontically treated patients are more likely to have severe apical root shortening, interesting mostly maxillary, followed by mandibular incisors. The aim of the study was to investigate the incidence and severity of RR in adult patients treated with aligners. The study group consisted of 71 class I adult healthy patients (mean age 32.8 ± 12.7) treated with aligners (Invisalign®, Align Technologies, Santa Clara, CA, USA). All incisors, canines, upper first premolars, and first molars were assessed. Root and crown lengths of 1083 teeth were measured in panoramic radiographs at the beginning (T0) and at the end (T1) of clear aligner therapy. Individual root-crown ratio (RCR) of each tooth and therefore the relative changes of RCR (rRCR) were determined. A decrease of rRCR was assessed as a reduction of the root length during treatment. Results All patients had a minimum of one teeth affected with a reduction of root length, on average 6.38 ± 2.28 teeth per patient. Forty one, 81% of the 1083, measured teeth presented a reduction of the pre-treatment root length. A reduction in percentage of >0% up to 10% was found in 25.94% (n = 281), a distinct reduction of >10% up to 20% in 12.18% (n = 132) of the sample. 3.69% (n = 40) of the teeth were affected with a considerable reduction (>20%). Conclusions Orthodontic treatment with Invisalign® aligners could lead to RR. However, its incidence resulted to be very similar to that described for orthodontic light forces, with an average percentage of RR < 10% of the original root length