In vitro retention of a new thermoplastic titratable mandibular advancement device.

Oral appliance (OA) therapy with a mandibular advancement device (OAm) is a non-invasive, alternative approach to maintaining upper airway patency. The main requirement for an OAm to be effective is the adequate retention on the teeth while the patient is asleep. We evaluated the retentive forces of a new low-cost, customizable, titratable, thermoplastic OAm (BluePro (®); BlueSom, France). Dental impressions and casts were made for one patient with complete upper and lower dental arches including the third molars and class II bite proportions. A setup based on Frasaco ANA-4 models was also used. Two protrusive positions of the mandible were investigated: 3 mm and 8 mm, representing respectively 25% and 65% of the maximal protrusion. The forces required to remove the BluePro (®) device from the carriers were recorded continuously over 730 cycles (=365 days, twice a day) to simulate 1 year of clinical use. At 8 mm protrusion the BluePro (®) device showed retentive forces of ~27N. There was a slight but non-significant decrease in retentive forces in the tests on the epoxified carriers which was not found on the ANA-4 carriers. There were no significant differences between the carriers as a function of protrusion. The BluePro (®) device tested in the present study possesses sufficient retention forces to resist initial jaw opening forces and full mouth opening forces estimated to be ~20N. It could therefore broaden the indications for use of thermoplastic OAms. It could provide a temporary OAm while a custom-made OAm is being manufactured or repaired. Patients could be provided with a low-cost try-out device capable of reliable titration, providing an indication of effectiveness and of patient acceptance of an OAm, although the effect of device shape and size on therapeutic outcome is not yet known. Finally it could provide an affordable OAm solution in resource-restricted healthcare settings.