Kayamori 2015.

Study characteristics
Methods	Study design: parallel, RCT. Recruitment period: not available. Duration of study: not available. Study setting: outpatient. Sleep Laboratory of the Department of Pulmonology, Heart Institute, Hospital das Clínicas, School of Medicine, University of São Paulo, Brazil.
Participants	Key inclusion criteria: participants of both sexes, aged between 20 and 65 years old, recently diagnosed with primary snore, mild, moderate or severe OSA, who refused to use CPAP were included. Key exclusion criteria: participants with BMI equal or higher than 35 kg/m2, craniofacial deformities, edentulous, regular use of hypnotic medication, severe nasal obstruction, patients undergoing other treatments for OSA and patients with unavailability to comply with the protocol. Age (years): mean (SD): 46.3 (18.8) in therapy group and 45.5 (11.7) in control group. Gender: 34 men, 24 women. BMI: mean (SD): 28.9 (3.5) in therapy group and 28.7 (3.4) in control group. AHI (events/hour): mean (SD): 19.5 (14.2) in therapy group and 17.2 (10.94) in control group. ESS: mean (SD): 9.9 (5.0) in therapy group and 10.3(5.2) in control group. PSQI: mean (SD): 6.3 (3.5) in therapy group and 6.9 (3.3) in control group. N randomised: 60, 30 to therapy group and 30 to control group. N analysed: 58. Dropouts: 2 in control group.
Interventions	Intervention: oropharyngeal exercises. As follows: Tongue. Sweep: tip of tongue placed in the incisive papillae and slid in an anteroposterior direction against the hard palate. Initially without lingual (isotonic) pressure and then with lingual (isometric) pressure, without tightening the teeth, 20 times. Target musculature: Genioglossus and hipoglossus musculature. If it was not possible to perform this exercise, the patient was guided to push the hard palate: squeeze the anterior third of the tongue against the alveolar region of the hard palate maintaining the lip seal and without squeezing the teeth, 5 seconds, 20 times. Target musculature: suprahyoids (milohioid, genioid and digastric anterior belly). Coupling: initially isotonic tongue clicks, 20 times. Then stick the tongue against the palate isomerically maintaining the lingual coupling for 5 seconds, 20 times. Target musculature: Genioglossus, palatoglossus, hipoglossus and suprahyoids (milohioid, genioid and anterior ventral digastric). Lowering the back of the tongue: with the aid of a spatula or finger, stimulate the lowering reflex of the lingual back by 5 rapid touches in the region of the back of the tongue, 20 times. After the musculature necessary to perform the lowering is perceived, the lingual dorsum is asked to be lowered and relaxed isotonically 20 times; then the lingual dorsum is kept low, isomerically for 5 seconds, 20 times. Target musculature: hyoglossus and suprahyoid musculature. Buccinator and orbicular muscles of the mouth. Finger on the cheek: finger on the internal mucosa of the cheek, parallel to dental occlusion. The patient must press the finger with the cheek against the teeth. Initially performing isotonic exercises, 10 times each side. Afterwards isometric exercises are performed 10 seconds and 10 times each side. Target musculature: work mainly horizontal strap (buccinator mainly and orbicular mouth). Palate lift muscles, palate tensor and uvula muscle. Elevation of soft palate and uvula: intermittent vowel "A" production (isotonic exercises) 10 times, for 1 to 2 weeks. After the patient perceives the movement of the musculature, the vowel "A" is removed, performing only the intermittent elevation of the musculature of the palate, 20 times. After the gain of control and coordination of movement, the contraction of the musculature was maintained (isometric exercise), recruiting even the uvula muscle in the final phase, 5 seconds, 20 times. Target musculature: palatoglossus, palatopharyngeal, palate tensor, palate elevator and uvula. In the final stage, the soft palate lifting exercise, palate tensioner and uvula is performed for the back of the tongue, i.e. support the apex of the tongue on the incisors lower and lower the lingual dorsum while raising the soft palate and uvula, 5 seconds, 20 times. Target musculature: palatoglossus, palatopharyngeal, tensor of the palate, palate elevator and uvula. And in the last stage, also hyoglossus musculature and suprahyoids. Alternating bilateral chewing. For maintenance of tongue and facial musculature. 12 weekly sessions lasting approximately 30 minutes. Comparator: nasal dilator strips during sleep. Participants were instructed to use nasal dilator strips during sleep and to perform breathing exercises 3 times a day daily, increasing the time of inspiration and expiration during sessions using diaphragmatic expansion. 12 weekly sessions lasting approximately 30 minutes. Concomitant interventions: all patients from both groups were instructed to wash with 10 mL of saline solution in both nostrils 3 times a day.
Outcomes	Prespecified outcomes: protocol not available. Reported outcomes: Primary outcome measures: Apnea Hypopnea Index. Sleep quality (PSQI). Daytime sleepiness (ESS). Secondary outcome measures: Specific speech therapy evaluation for OSA. Upper airway anatomy assessed by magnetic resonance imaging. Time points of measurement: before and 13 weeks after the treatment.
Notes	Information from PhD thesis. 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: Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) e Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). Conflicts of interest: not reported. Registered: not reported. Sample size calculations: "The sample calculation was based on the assumption of a reduction of approximately 1.5 cm H2O in the Pcrit with previous knowledge of a drop of approximately 40% in the AHI in the Therapy group and a reduction of 5% in the Control group in a previous study. We calculated a total number of 34 patients, considering a significance value of p=0.05 and standard deviation of 1.3 and power of 90%. Considering possible withdrawals and other events the total number of 40 patients." 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	High risk	Unblinded study.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Unblinded study.
Incomplete outcome data (attrition bias) All outcomes	Low risk	2 patients lost in the control group. No imputation methods reported for their results.
Selective reporting (reporting bias)	Low risk	Provided information on results for the outcomes considered relevant for the study Protocol of the study not available.
Other bias	Low risk	The study appears to be free of other sources of bias.