Evaluation of the Quality of Sleep, Endothelial Function, Cardiovascular Risk, Thyroid Function, a Function of Masticatory Muscles and Psycho-emotional State of Patients With Sleep Bruxism

1. Introduction Sleep apnea is a common and serious health problem in the Polish population. According to epidemiological data problem concerns about 7% of the adult population. The most common sleep disorder is obstructive sleep apnea (OBS). The essences of OBS are episodes of airway obstruction repeated many times during sleep. As a result the oxygen level in blood decreases. The result of increased muscle tension of upper respiratory tract and throat vibrations is a very loud snoring restoring breath. Episodes of apnea with arousals cause sleep fragmentation, shortage of deep sleep and rapid eye movement (REM). Such episodes occur repeatedly, several, or even dozens of times per hour of sleep. The consequence of episodes of airway obstruction and sleep fragmentation is an inefficient, lack of rest sleep, pathological daytime sleepiness, falling asleep involuntarily, awakening with feelings of shortness of breath or throttling. Fragmentation of sleep and repeated episodes of hypoxia result in deterioration of quality of life, chronic fatigue and an increased risk of communication accidents.

The direct consequences of sleep apnea are hypoxia, awakening, increased heart rate and increased blood pressure. Frequent complications of obstructive sleep apnea (OSA) are hypertension, stroke, cardiac arrhythmia, coronary artery disease, pulmonary hypertension and heart failure. If left untreated, OSA contributes to the development of vascular endothelial dysfunction and increases the risk of premature death, especially in men under age of 50.

An additional problem in patients with sleep apnea is an increased incidence of bruxism.

Bruxism is a common problem; reports of prevalence range from 8-31% in the general population. The most common symptoms of bruxism include: hypersensitive teeth, tooth wear, damage to dental restorations (e.g. crowns and fillings), damage to periodontal and oral mucosa, masticatory muscle pain and headaches. Symptoms of bruxism may go unnoticed for a long time, which implies that patients often don't know about their condition. There are two different types of bruxism: Sleep Bruxism (SB) and Awake Bruxism (AB). Type SB consists of involuntary, episodic and rhythmic activity of masticatory muscles (Rhythmic Masticatory Muscle Activity / RMMA).

The etiology of bruxism is multifactorial and not fully understood.It can be caused by biologic, psychologic and exogenous factors. Arousals during the apnea episodes are considered to be a major cause of sleep bruxism in OSA patients.