During the current survey, all consented persons will undergo a physical examination with attention to the measurement of the neck circumference, as well as the evaluation of facial characteristics relevant to the coexistence of sleep disorders, including retrognathia, nasal septum deviation, asymmetry of the nares, and palate position. The latter will be evaluated with the tongue resting inside the mouth (using the Friedman classification) and categorized into four classes according to which structures are visible: Grade I allows visualization of the entire uvula and tonsils/pillars, Grade II allows visualization of the uvula but not the tonsils/pillars, Grade III allows visualization of the soft palate but not the uvula, and Grade IV allows visualization of the hard palate only.