This study compared the effect of a tongue retaining device versus the use of CPAP in 27 patients within a crossover RCT design. Tongue retaining devices (also known as tongue stabilising devices), are similar in appearance to a plastic tongue-sized thimble which is placed in front of the incisors during sleep. The tongue is forced into the plastic cup and, through suction, it is retained in a protruding position. These devices are typically very cheap, and a quick search on Amazon suggests that the average price is about £3-£5 each. The study shows that CPAP is more effective by a significant margin, but the tongue retaining devices (TRD) also have a reasonable effect on the apnoea hypopnoea index (AHI). The baseline mean AHI dropped from 38 to 2.5 in the CPAP crossover, which is an effective cure (AHI <5 = normal / 5-15 = mild OSA / 15-30 = moderate AHI / 30+ severe OSA). Although the TRD was not as effective as CPAP, the reduction achieved was still significant at AHI = 12.7. There were some limitations with this study, including variable sleep study technology and use of subjective adherence outcomes, but the short follow-up (three weeks in each arm) is what I would regard as the most glaring issue. In my experience CPAP and TRD both have adherence issues, and therefore it would have been useful to know what the three-month follow-up rates were, and which therapy the patients preferred. Both have very different side-effect profiles, so data on the adherence would have been interesting to see. This study does show that TRDs have a reasonable effectiveness considering the insignificant cost compared to CPAP. CPAP is still the first line option, but TRDs should be considered as a second line or adjuvant therapy. I am aware of some of my patients using TRDs or mandibular advancement devices for time spent away from home. The inconvenience of travelling with CPAP makes these oral devices more appealing.