single arm study

A pre-experimental, single-group pretest-posttest design was performed. At stage one, each participant underwent a 2-day general sleeping test and a 2-day sleeping test with mouth tape. At stage two, participants underwent conventional impressions for TPD and TED appliances and were then randomly assigned to wear the TPD or TED; together for two days of sleeping test with their mouth taped. After a 2-day break (washout), with the same procedure, participants wore the other appliance for another 2-day sleeping test and decided accordingly the optimal appliance that had reduced their ODI scores more. At stage three, participants wore their optimal appliance mouth-taped during sleep for 6 weeks. At the end of the intervention, all participants underwent few days sleeping test for final results.

According to OSA-related variables, we can analyze participants' ODI (events/hours), mean SpO2 (%), the lowest SpO2(%), and the percentage of total record time with oxygen saturation below 90% (T90) to evaluate their objective sleep quality.

According to the number of mouth puffing by minutes, mouth puffing signals were divided into four types, including non-mouth puffing (NMP, no or less than 3 times MPSs on both sides), complete mouth puffing (CMP, regularly MPS on both sides, usually above 8-10 times), intermittent mouth puffing (IMP, irregularly MPS in both side, usually between 3-8 times), and side mouth puffing (SMP, showing one-side MPSs) to evaluate the percentage of mouth breathing while sleeping.