Tongue Retaining Device (TRD/TSD)

A tongue retaining device (TRD) is a single-piece oral appliance worn during sleep that holds the tongue in a forward position using a small suction bulb positioned just in front of the lips and teeth. The tongue is drawn into the bulb and held there by negative pressure.

Unlike a mandibular advancement device (MAD) or most other anti-snoring or anti-apnea mouthpieces, a TRD has no dental anchorage at all: it does not clip, mold, or attach to the teeth or gums in any way. "Tongue retaining device" (TRD) and "tongue stabilizing device" (TSD) are two names for the same category of appliance, used interchangeably across the clinical literature and commercial product pages.

Because it needs no teeth for retention and does not load the jaw joint, a TRD is fitted differently from a MAD and, like a MAD, does not generate flow, pressure, or event data that a device like AirwayLab can read.