The Tongue Retainer Device (TRD) is an oral appliance designed to treat Obstructive Sleep Apnoea (OSA) by holding the base of the tongue in an extended, protruded position during sleep. This study investigated the efficacy, safety and tolerability of the device.
     Twenty patients were screened against key eligibility criteria. Eligible patients completed the Epworth Sleepiness Scale (ESS) and the Functional Outcome of Sleep Questionnaire (FOSQ-10)], prior to enrolment into treatment for four weeks. Compliance during treatment was assessed through a daily diary. Patients underwent an end of treatment polysomnography (PSG) with the TARD in situ, at which time the ESS and FOSQ-10 were repeated. Device side effects were monitored during the study. Response to treatment was defined as: complete (AHI<5 events per hour) or partial (>50% reduction in AHI but AHI>5/hr).
     Ten patients (8 males, 2 females), with a baseline AHI of 24.31±16.81/hr, mean age 51.20±11.22, and a mean body mass index of 24.38±4.47 completed the trial. AHI on treatment did not significantly differ from baseline (24±17/hr to 15±13/hr). However, a treatment response was achieved in 4 out of the 10 patients. Of these, 2 patients achieved a complete response, and the remaining a partial response. While improving, there was no significant change in ESS (11±6 to 8±6) or the FOSQ-10 (14.23±3.02 to 15.72±3.06) scores with treatment. Device side effects occurred at a rate of 3 events per patient, with mild oral discomfort being the most common complaint. Compliance was high, with an average usage of 5.2 hours per night across those who completed the study.
    This pilot study showed a clinically important therapeutic outcome in 40% of patients, with reasonable tolerance and compliance. Further work is required to enhance device tolerance and efficacy, and to identify patient phenotypes associated with good treatment outcome.