Guimaraes 2009.

Study characteristics
Methods	Study design: parallel, RCT. Recruitment period: February 2004 to October 2007. Duration of study: study start date: February 2004. Actual primary completion date: October 2007. Actual study completion date: April 2008. Study setting: outpatient. Universidade Federal de São Paulo, São Paulo, Brazil.
Participants	Key inclusion criteria: participants aged between 25 and 65 years old with a recent diagnosis of moderate obstructive sleep apnoea. Key exclusion criteria: BMI higher than 40 kg/m2; facial malformations; regular use of hypnotic medications; hypothyroidism; previous stroke; neuromuscular disease; heart failure; coronary disease; severe obstructive nasal disease. Age (years)*: mean (SD): 47.7(9.8) in myofunctional therapy group and 51.5 (6.8) in control group. Gender*: 10 women, 21 men. Comorbidities*: 26/31 hypertension; 2/31 diabetes. BMI*: mean (SD): 29.6 (3.8) in myofunctional therapy group and 31.0 (2.8) in control group. AHI (events/hour)*: mean (SD): 22.4 (4.8) in myofunctional therapy group and 22.4 (5.4) in control group. ESS*: mean (SD): 14 (5) in myofunctional therapy group and 14 (7) in control group. PSQI*: mean (SD): 10 (4) in myofunctional therapy group and 11 (4) in control group. * Data from the 31 included in analysis. N randomised: 39. N analysed: 31, 16 myofunctional therapy and 15 control. Dropouts: 8 participants, 3 in the myofunctional therapy and 5 in control group.
Interventions	Intervention: oropharyngeal exercises. The participants were instructed by one speech pathologist to perform the following tasks: Soft palate. Pronounce an oral vowel intermittently (isotonic exercise) and continuously (isometric exercise). The palatopharyngeus, palatoglossus, uvula, tensor veli palatini, and levator veli palatini muscles are recruited in this exercise. The isotonic exercise also recruits pharyngeus lateral wall. These exercises had to be repeated daily for 3 minutes and were performed once a week under supervision to ensure adequate effort. Tongue. Brushing the superior and lateral surfaces of the tongue while the tongue is positioned in the floor of the mouth (five times each movement, three times a day). Placing the tip of the tongue against the front of the palate and sliding the tongue backward (a total of 3 minutes throughout the day). Forced tongue sucking upward against the palate, pressing the entire tongue against the palate (a total of 3 minutes throughout the day). Forcing the back of the tongue against the floor of the mouth while keeping the tip of the tongue in contact with the inferior incisive teeth (a total of 3 minutes throughout the day). Facial. The exercises of the facial musculature use facial mimicking to recruit the orbicularis oris, buccinator, major zygomaticus, minor zygomaticus, levator labii superioris, levator anguli oris, lateral pterygoid, and medial pterygoid muscles. The exercises include: orbicularis oris muscle pressure with mouth closed (isometric exercise); recruited to close with pressure for 30 seconds, and right after, requested to realize the posterior exercise; suction movements contracting only the buccinator. These exercises were performed with repetitions (isotonic) and holding position (isometric). Recruitment of the buccinator muscle against the finger that is introduced in the oral cavity, pressing the buccinator muscle outward. Alternated elevation of the mouth angle muscle (isometric exercise) and after, with repetitions (isotonic exercise). Patients were requested to complete 10 intermittent elevations 3 times. Lateral jaw movements with alternating elevation of the mouth angle muscle (isometric exercise). Stomatognathics functions: Breathing and Speech. Forced nasal inspiration and oral expiration in conjunction with phonation of open vowels, while sitting; balloon inflation with prolonged nasal inspiration and then forced blowing, repeated five times without taking the balloon out of the mouth. Swallowing and Chewing. Alternate bilateral chewing and deglutition, using the tongue in the palate, closed teeth, without perioral contraction, whenever feeding. The supervised exercise consisted of alternate bread mastication. This exercise aims for the correct position of the tongue while eating and targets the appropriate functionality and movement of the tongue and jaw. The patients were instructed to incorporate this mastication pattern whenever they were eating. The same schedule and set of instructions applied to the control group were given to participants with the substitution of deep breathing by effective therapy. Comparator: sham therapy A weekly, supervised session (30 minutes) of deep breathing through the nose while sitting. The patients were also instructed to perform the same procedure at home once a day (30 minutes), plus nasal lavage with application of 10 mL of saline in each nostril three times a day. At study entry, bilateral chewing was recommended when eating meals. Concomitant interventions: none.
Outcomes	Prespecified outcomes: Primary outcome: AHI. Secondary outcomes: Lowest oxygen saturation. Daytime sleepiness (ESS). Sleep quality (PSQI). Snoring frequency. Snoring intensity. Time points of measurement: 3 months. Reported outcomes: all prespecified outcomes.
Notes	Additional information requested and received from authors on allocation procedures. Three of the RCTs included in this review were leaded by the same researcher and allocation procedure were similar (Guimaraes 2009, Ieto 2015 and Kayamori 2015). Funding for trial: supported by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Conselho Nacional de Desenvolvimento Científico e Tecnológico, and the E. J. Zerbini Foundation. Conflicts of Interest: quote: “None of the authors has a financial relationship with a commercial entity that has an interest in the subject of this manuscript.” Registered: ClinicalTrials.gov NCT00660777. Sample size calculations: not reported. Data sharing statement: none.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "We typed equal number of (1 or 2), corresponding to control or treatment and put all the small papers (A or B) in a sealed envelope. One paper was picked up for each patient in the moment of randomisation by someone that was not involved in the study.”
Allocation concealment (selection bias)	Low risk	See random sequence generation above.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: “Masking: Single (Participant)”.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: “Masking: Single (Participant)”.
Incomplete outcome data (attrition bias) All outcomes	High risk	Relevant percentages of losses in follow‐up. Quotes: “we recruited 39 patients. Eight patients (3 in the active treatment arm) were excluded due to low adherence”. “Patients who failed to return for three consecutive weeks or failed to comply with the exercises at home (performing 85% of the exercises) were excluded from the study." Per protocol analysis "31 patients included in the final analysis".
Selective reporting (reporting bias)	Low risk	Prespecified outcomes in clinicaltrials.gov were reported.
Other bias	Low risk	The study appears to be free of other sources of bias.