1,721,199 research outputs found
Video polysomnography and dentofacial features in a case of sleep-disordered breathing and bruxism
No full textAims Obstructive sleep apnea (OSA) is the most common condition among a group of disorders, called sleep-disordered breathing, that can affect both adults and children. It is characterized by repeated episodes of airway obstruction for more than 10 seconds during sleep, resulting in pauses in breathing.
OSA is associated with significant metabolic, cardiovascular, and neurocognitive sequelae in children. Children with OSA have increased upper airway resistance during sleep due to a combination of soft tissue hypertrophy, craniofacial dysmorphology, and/or obesity.
Sleep bruxism (SB) is a sleep-movement disorder. It is characterized by rhythmic masticatory muscle activity (RMMA), which consists of recurrent episodes of phasic or tonic jaw muscle contractions during sleep with or without tooth grinding.
The gold standard for diagnosis of OSA and SB is overnight polysomnographic testing.
Case report
MB is a 10-year-old boy with loud snoring, pauses in breathing while asleep, agitated sleep with frequent awakenings, bizarre sleeping positions, bruxism, and poor academic performance in whom pharmacotherapy is being considered. Past medical history includes adenotonsillectomy and seasonal respiratory infections. BMI 18,1 (healthy weight).
A parent school-aged children questionnaire is filled in.
The orthodontic examination shows a narrow skeletal upper jaw, mandibular retrognathism and tooth wear.
The patient underwent comprehensive polysomnography with video/audio recording.
Results
Sleep macrostructure was characterized by sleep fragmentation with high number of awakenings/arousals and prolonged REM latency. Some arousals were associated with RMMA, withoud tooth grinding but with oro-buccal activity semiologically similar to bruxism. Microstructure of sleep was instable, with increase in CAP rate. The apnea hypopnea index (AHI) was 5,7/h per hour (normal < 1.0 per hour in children), min SaO2 96,7%.
The patient was treated with rapid maxillary expansion followed by a jaw advancement device.
Conclusions
When there is residual OSA after T & A is performed, other factors should be evaluated to decide the next course of action. For children with a high arched palate, rapid maxillary expansion has been shown to improve AHI.
To manage sleep disorders optimally in school-aged children and to improve quality of sleep and academic performance, it is to be hoped that dentists and sleep specialist cooperate
Terapia con propulsori mandibolari ortodontici nella sindrome delle apnee ostruttive nel sonno (OSA)
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Validation and extension of a statistical usability model for unreinforced masonry buildings with different ground motion intensity measures
Full text linkPredicting the usability of a building, i.e. its condition of being occupiable after a seismic event, is relevant both in a post-emergency situation and within a risk-reduction policy. In the past an empirical model was proposed, involving the computation of a usability index based on macroseismic intensity and on seven building parameters, combined by means of regression coefficients and weights. The statistical model was calibrated on data of about 60,000 buildings affected by the 2009 L’Aquila earthquake in Italy. Therefore, it is useful to validate the model against data from the 2002 Molise earthquake in Italy. Good agreement between predicted and observed usability is shown, despite the fact that in 2002, macroseismic intensity was attributed to an entire municipality instead of a more limited area. Moreover, given the current availability of the shakemaps for the 2009 event, a novel model replacing conventional macroseismic intensity by an instrumental intensity measure is proposed. Three ground motion parameters are considered here: peak ground acceleration, peak ground velocity, and spectral pseudoacceleration at a period of vibration of 0.3 s. The model has been streamlined by reducing the building parameters from seven to five: building position within the structural aggregate, roof type, construction timespan, structural class, and pre-existing damage to structural elements. Peak ground acceleration and spectral pseudoacceleration are shown to be less effective than peak ground velocity in predicting observed usability. Therefore, usability probability matrices are computed in terms of peak ground velocity; the model is presented with all necessary coefficients and weights, and a worked-out example shows how to apply the procedure
Census-based typological usability fragility curves for Italian unreinforced masonry buildings
Full text linkThe main vulnerability models available in the literature aim to develop damage fragility curves to estimate the damage level suffered by a building after a seismic event. However, recent earthquakes have highlighted the great importance of predicting the usability of residential buildings, i.e. the condition of a building being habitable or occupiable after a seismic event. The building usability performance can be used as an indicator for allocating economic funding after a seismic event because recent researches have demonstrated a stronger correlation between repair costs and usability assessment rather than between repair costs and structural damage. Therefore, this work focused on the development of census-based fragility curves for the preventive forecast of the usability of Italian unreinforced-masonry buildings. The proposed usability model was calibrated based on the 2009 L'Aquila earthquake database, including almost 60,000 unreinforced-masonry buildings, and this database was increased by adding data from the Italian census to account for uninspected constructions. Six typological classes were defined considering two parameters available both in the post-earthquake and Italian census databases: construction timespan and state of repair. Additionally, it was highlighted in which cases the number of stories was also relevant. The usability fragility curves were defined as a function of peak ground acceleration for two building usability states: partially unusable and unusable. The results confirmed that older buildings are more vulnerable and clearly pointed out the crucial role of the state of repair as a parameter influencing the building usability
Verification of a usability model for unreinforced masonry buildings with data from the 2002 Molise, southern Italy, earthquake
No full textIn this paper a methodology for assessing the usability of unreinforced masonry buildings, calibrated using the observed data collected after the 2009 L'Aquila, Southern Italy, Earthquake, is tested using data and performances surveyed after the 2002 Molise seismic event. The methodology is based on the computation of a Usability Index calculated as a weighted sum of seven parameters arranged in categories of decreasing usability. Each parameter represents a structural feature of the construction that may affect the building earthquake response. The Usability Index is correlated with the macroseismic intensity I MCS and Usability Probability Matrices, in terms of fully usable buildings, temporarily or partially unusable buildings, unusable buildings are derived. The application of the methodology on Molise data is rather successful especially with reference to the prediction of unusable buildings, despite the model was calibrated on a set of buildings belonging to a different region. The limited error can be at least partially explained in light of the differences in macroseismic intensity attribution
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