An intraoral mandibular advancement device to treat problems associated with sleep disorders in a user having an obstructed
airway, the disorders including, without limitation, snoring,
obstructive sleep apnea, gastroesophageal
reflux disease and / or bruxism having a main body for attachment to the user's mouth and having a central portion; a protrusive element distending from the central portion of the main body such that when worn by the user the element causes mandibular advancement sufficient to expand the oropharangeal space and reduce the obstruction; and a
retainer extending from the main body for retention of the device in the user's mouth when worn during the user's
sleep state. The main body is either complimentary with the user's palate and lingual surfaces of the maxillary teeth, rests against the palate and
lingual surface of the user's anterior
mandibular teeth when the device is inserted in the user's mouth, or customized to rest against two, four or six of the user's front teeth. The protrusive element is of
distension between 5 and 15 mm, and optimally 10 mm downwardly from the main body, and can be adjusted such that the advancement ranges between 1.0 and 7.0 mm, and having an
initial treatment protrusion of 3.0 to 4.0 mm, or ½ of the total potential maximum protrusive range. A method for diagnosis and delivery of the device is also shown.