Effects of Oral Appliances for Obstructive Sleep Apnoea in Reduced Periodontium: A Finite Element Analysis.

BACKGROUND AND OBJECTIVE: In the literature, no studies correlate the effects of mandibular advancement devices (MADs) with different titration systems to periodontitis. Through a finite element analysis (FEA), this study investigates the effects generated on periodontal ligaments (PDLs) and teeth by four commercial MADs in periodontal health and with 15% bone resorption. METHODS: Four MADs (Somnodent Flex™, Somnodent Avant™, Orthoapnea™, and Herbst™) were digitalised starting from the impressions of a patient's dental arches. A force of 11.18 N, representing an advancement of 9.5 mm, was applied, and a FEA was subsequently performed. After measuring the stresses and displacements on the PDLs and teeth in healthy periodontal conditions, the vertical dimension of the alveolar bone was reduced by 15%, and measurements were repeated. RESULTS: In terms of PDL stress, Herbst™ is the device which guarantees a more uniform increment in case of the first stage of periodontitis (+7% for mandibular and maxillary PDLs compared to the healthy condition). For Somnodent™ devices, the PDLs stress increment is almost null for mandibular PDLs but much higher than Herbst™ for maxillary PDLs (+17% and +21% for Flex™ and Avant™). Orthoapnea™ determines a PDL stress augmentation between the other devices (+16% and +7%, respectively, for maxillary and mandibular PDLs). Concerning teeth movement, Herbst™ and Orthoapnea™ determine a lower and more uniform displacement than Somnodent devices. CONCLUSIONS: The stress distribution and teeth displacement are strictly related to MAD geometry. Since its minor effects on teeth and PDLs, the Herbst™ could be more appropriate in patients with periodontitis.

Healthy Ageing: A Decision-Support Algorithm for the Patient-Specific Assignment of ICT Devices and Services.

In response to rapid population ageing, digital technology represents the greatest resource in supporting the implementation of active and healthy ageing principles at clinical and service levels. However, digital information platforms that deliver coordinated health and social care services for older people to cover their needs comprehensively and adequately are still not widespread. The present work is part of a project that focuses on creating a new personalised healthcare and social assistance model to enhance older people's quality of life. This model aims to prevent acute events to favour the elderly staying healthy in their own home while reducing hospitalisations. In this context, the prompt identification of criticalities and vulnerabilities through ICT devices and services is crucial. According to the human-centred care vision, this paper proposes a decision-support algorithm for the automatic and patient-specific assignment of tailored sets of devices and local services based on adults' health and social needs. This decision-support tool, which uses a tree-like model, contains conditional control statements. Using sequences of binary divisions drives the assignation of products and services to each user. Based on many predictive factors of frailty, the algorithm aims to be efficient and time-effective. This goal is achieved by adequately combining specific features, thresholds, and constraints related to the ICT devices and patients' characteristics. The validation was carried out on 50 participants. To test the algorithm, its output was compared to clinicians' decisions during the multidimensional evaluation. The algorithm reported a high sensitivity (96% for fall monitoring and 93% for cardiac tracking) and a lower specificity (60% for fall monitoring and 27% for cardiac monitoring). Results highlight the preventive and protective behaviour of the algorithm.

Stress responses in high-fidelity simulation and standard simulation training among medical students.

BACKGROUND: Simulation has been recognized as a shift in healthcare education that can improve skills and patient safety and outcomes. High-fidelity simulation of critical medical situations can be a source of stress among participants that can interfere with students' abilities leading to unexpected emotional responses. The aim of this study is to determine if two simulation methods, high-fidelity (HF) and procedural simulation (PS), may be associated with stress responses at a self-perceived and biological level (salivary cortisol variations), and to compare stress levels of the two different simulation method. We also wanted to find independent variables associated with cortisol total hormonal output. METHODS: A quasi-experimental before-after study was used including the administration of questionnaires, and biomarkers evaluation by salivary cortisol samples before and after simulation. A total of 148 students were eligible and agreed to participate in the study. We used paired T-test for mean comparison regarding State-trait anxiety for both HF and PT simulations. For NASA-TLX we performed a T-test mean comparison between groups. We used paired T-test mean comparison for cortisol analysis. Multivariable linear regression has been used to assess variables associated with AUCg values and perceived stress. RESULTS: values of STAI-Y scores were relatively higher at the end of the HF and PS sessions. NASA-TLX was significantly higher at baseline for the HF simulations, with respect to the PS simulation. Cortisol fold increase was significantly different in the two groups. Linear regression showed that cortisol AUCg was related to the STAI-Y score in both groups. CONCLUSION: Participating students developed a stress response both after in the HF and PS training, testified by psychological and biological outputs. According to our results, stress levels were increased for simply being in a simulation scenario than to the intrinsic complexity of the task required. More studies are needed to confirm this trend and to clarify the role of simulated stress response in a long-term learning scenario.

Comparison of Three 3D Segmentation Software Tools for Hip Surgical Planning.

In hip arthroplasty, preoperative planning is fundamental to reaching a successful surgery. Nowadays, several software tools for computed tomography (CT) image processing are available. However, research studies comparing segmentation tools for hip surgery planning for patients affected by osteoarthritic diseases or osteoporotic fractures are still lacking. The present work compares three different software from the geometric, dimensional, and usability perspectives to identify the best three-dimensional (3D) modelling tool for the reconstruction of pathological femoral heads. Syngo.via Frontier (by Siemens Healthcare) is a medical image reading and post-processing software that allows low-skilled operators to produce prototypes. Materialise (by Mimics) is a commercial medical modelling software. 3D Slicer (by slicer.org) is an open-source development platform used in medical and biomedical fields. The 3D models reconstructed starting from the in vivo CT images of the pathological femoral head are compared with the geometries obtained from the laser scan of the in vitro bony specimens. The results show that Mimics and 3D Slicer are better for dimensional and geometric accuracy in the 3D reconstruction, while syngo.via Frontier is the easiest to use in the hospital setting.

Assessing 3-D Printing in Hip Replacement Surgical Planning.

PURPOSE: To evaluate the accuracy of 3-D printed models of the femoral head based on preoperative computed tomography (CT) images. Other goals were to compare the cartilage thickness of bony specimen to the printed models and calculate the standard deviation between 3-D printed models based on CT images and laser scan models. METHODS: This retrospective study analyzed 10 patients who underwent preoperative CT imaging and hip replacement. Preoperative femoral head 3-D printed models were produced from CT images. Bony specimens were collected from surgical operations and scanned using CT and 3-D laser scanning, and cartilage thickness subsequently was measured by histological analysis. Comparisons of printed models based on CT images and printed models based on 3-D laser scanning were performed by overlapping their external surfaces using dedicated software and the standard deviation was calculated. RESULTS: The average standard deviation between the bony specimen 3-D models and preoperative 3-D printed CT femoral head models was 0.651 mm. The cartilage was approximately 1.487 mm thick. DISCUSSION: The comparison between preoperative CT image-based 3-D models and the postoperative bony specimen-based models permitted evaluation of the accuracy of preoperative CT image-based 3-D printed models. Cartilage thickness was estimated indirectly by comparing models obtained by CT and laser scanning, and it was related to the calculated standard deviation to overcome the cartilage detection limit of CT. This study shows how each step can generate accuracy errors on the final 3-D printed model. A repeatable and sustainable workflow for creating accurate and reproducible 3-D printed models could overcome this issue. Moreover, orthopedic surgeons should be aware of 3-D printed model precision in clinical practice. CONCLUSIONS: This study provides encouraging results on the accuracy of 3-D printed models for surgical planning.

Periodontal effects of two Somnodent oral devices for the treatment of OSA: A finite element study.

OBJECTIVE: The study aims to evaluate the stresses and the deformations generated at the periodontal level by two mandibular advancement devices (MADs) using finite element analysis. METHODS: A three-dimensional digital model of the skull of a 29-year-old patient was created using a CBCT. The 3D models of two MADs (Somnodent FlexTM and Somnodent AvantTM) were reconstructed from scanning prototypes based on the patient's anatomy. The overall geometry was imported into software for the finite element study. A force of 11.18 N representing an advancement of 9.5 mm was applied to the devices. A finite element analysis wfas subsequently performed. RESULTS: Somnodent FlexTM generates a peak of 3.27 kPa on periodontal ligaments and 287 kPa on teeth. For Somnodent AvantTM the maximum stress is 4.53 kPa on periodontal ligaments and 467 kPa on teeth. CONCLUSION: Different activation mechanisms of the devices generate stresses of different entities.

Development of the optimal touchscreen interface for patients with scleroderma.

Impaired hand function is a major contributor to overall disability and reduced health-related quality of life in scleroderma patients. A relevant issue concerns interaction of scleroderma subjects with touchscreen interfaces. This study aims at investigating this problem assessing scleroderma patients' performance with a novel, aptly designed, touchscreen application in order to identify critical items of touchscreen technology which may impair or facilitate the use by scleroderma subjects. Eighty scleroderma patients performed this novel application including three games, each of which tested a different gesture: tapping, dragging/dropping, and pinching-to-zoom. Eighty healthy subjects without hand impairments were recruited as controls. Scleroderma patients performed worse than healthy users in each game, and statistically significant negatively impacting items were identified. In the second phase of the study, the 10 worst touchscreen performers within the scleroderma cohort were recruited for a physio-rehabilitation trial based on the daily use at home of a modified version of the software application downloaded into the personal devices of patients. The results of this study allow introduction of guidelines to design accessible touchscreen interfaces for subjects with scleroderma and suggest that touchscreen technology may be included in self-administered physio-rehabilitation programs for scleroderma hand.

A Procedure for Designing Custom-Made Implants for Forehead Augmentation in People Suffering from Apert Syndrome.

This paper presents a methodological procedure, based on the anatomical reconstruction and constrained deformation, to design custom-made implants for forehead augmentation in people affected by Apert syndrome, experiencing a frontal bone deficiency. According to the anthropometric theory, a cranial landmarks identification procedure was applied to retrieve, from a repository, a healthy skull, used as reference geometry for implant modelling. Then, using constrained deformation and free-form modelling techniques, it was possible to design a patient-specific implant. At last, the implant was realised using a custom mould, specially designed according to the patient's needs to provide an accurate fit of the defect site. The design procedure was tested on a patient suffering from Apert syndrome. Three implants were virtually modelled and 3D-printed for pre-surgical evaluation. Their shapes were 3D compared with a reference one (handcrafted by a surgeon) to test the accuracy. Deviations are negligible, and the customised implant fulfilled the surgeon's requirements.

Preliminary simulation model toward the study of the effects caused by different mandibular advancement devices in OSAS treatment.

The paper aims to evaluate the effects caused by a Mandibular Advancement Device (MAD) for Obstructive Sleep Apnoea Syndrome (OSAS) treatment. This study is based on Finite Element Method (FEM) for evaluating the load distribution on temporomandibular joint, especially on the mandibular condyle and disc, and on periodontal ligaments. The stress values on condyle and periodontal ligaments lead authors to consider MAD a safe procedure even for a long period. The obtained results also show the relationship between MAD material and load distribution at the periodontal ligaments. The paper is a step toward future analyses for studying and comparing the effects of MAD features, such as material, shape and dimensions, in order to allow the clinician prescribing the most fitting device.