Myofunctional therapy (MT) is a recent treatment option for obstructive sleep apnea (OSA). The Iowa Oral Performance Instrument (IOPI) is a useful but expensive tool for measuring tongue strength in patients with OSA. We validated the Tongue Digital Spoon (TDS) to monitor tongue hypotonia in patients with OSA. Measurements with the IOPI and TDS were compared in patients with OSA before and after MT for tongue hypotonia. Baseline mean tongue strength measured with the IOPI in patients with moderate and severe OSA were 35.36 ± 9.05 and 33.83 ± 12.05, respectively, and that with the TDS were 168.55 ± 42.8 and 129.61 ± 53.7, respectively. After MT, mean tongue strength significantly improved: measured with the IOPI in patients with moderate and severe OSA were 53.85 ± 10.09 and 55.50 ± 9.64 (p = 0.8), and that with the TDS were 402.36 ± 52.92 and 380.28 ± 100.75 (p = 0.01), respectively. The correlation between the IOPI and TDS was high (r = 0.74; p = 0.01 pre-treatment, and r = 0.25; p = 0.05 post-treatment). The TDS is a useful tool for monitoring the efficacy of MT in patients with short-term OSA. Future randomized studies will determine the effectiveness of MT for the treatment of OSA.
Keywords: Iowa Oral Performance Instrument (IOPI); Tongue Digital Spoon; myofunctional therapy; sleep apnea; tongue strength.