Edit Article Moulding Instructions: Edited by SleepSpecialist, Teresa, Maluniu, Ilias Ismanalijev and 7 others Anti-snoring mouthpieces are also known as dental appliances, or mandibular advancement splints. They have been effective for many snorers, including those suffering from mild or moderate obstructive sleep apnea, in fact they have been in use for the last 10 years and clinical trials have reported an 85% success rate.