Effects of the mandibular advancement oral appliance (MOA) on the biodynamics of masticatory muscles, physiological sleep variables, sleep disturbances, and body fat distribution in patients with Down Syndrome and obstructive sleep apnea
Introduction: Down Syndrome (DS), caused by the chromosome 21 trisomy, is a more frequent genetic abnormality in the population, with one case in each 319 to 1,000 births. Its main phenotypic aspects are intellectual deficiency in varying degrees, short stature, generalized muscular hypotonia, craniofacial dysmorphia, and congenital heart diseases. Other comorbidities may be associated with this abnormality, such as: gastrointestinal, hands/feet, renal and urogenital (cryptorchidism and hypospadias) malformations, overweight and obesity, decrease of sensorial function, respiratory disorders as obstructive sleep apnea (OSA), thyroid dysfunction, leukemia, immune system defects, neuropathy leading to dementia as Alzheimer's Disease, and others. Objective: The objective of this research will be to evaluate the effect of the mandibular advancement oral appliance (MOA), monitored by a thermosensitive microchip, on the biodynamics of the masseter and temporal muscles and the physiological sleep variables in adult patients with Down´s syndrome (DS) and obstructive sleep apnea (OSA). We will also investigate the presence of sleep disorders and the distribution of body fat in these individuals.Methodology: Ten (10) research subjects with SD and OSA will be selected and submitted to the MOA therapy in a period of 2 consecutive months. The MOA will be only used during the period of patient´s sleep. A thermosensitive microchip will be coupled to the MOA to record and to measure the adhesion of the use of the MOA by the patient. The therapeutic effects on the electrical activities of the masseter (superficial portion) and temporal (anterior portion) muscles and the physiological sleep variables will be investigated through the surface electromyography (sEMG) and polysomnography - type II (PSG-II). The amplitude of mouth opening and intensity of bite force will also be measured by an analogical pachymeter and a force transducer, respectively. The distribution of body fat will be verified by the anthropometric analysis, including body mass index (BMI), neck circumference (NC), waist circumference (WC) and waist and hip ratio (WHR). Sleep disorders will be investigated through the applying of the Epworth Sleepiness Scale (ESS), STOP-BANG, and Fletcher & Luckett (F & L) questionnaires to identify excessive daytime sleepiness, the risk of obstructive sleep apnea (OSA), and quality respectively. These methods of analysis will be performed before and after the proposed therapy. Expected results: Considering that people with Down syndrome commonly have generalized hypotonia, craniofacial anatomical alterations, dysfunction of the oropharyngeal muscles and, as a consequence, obstructive sleep apnea (OSA), the use of AIOm may promote improvements and / or reestablishment of muscle function masticatory variables and physiological sleep variables in this target audience. This may reverberate in the good quality of life and social inclusion of these individuals.
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