Table 1.
Summary of studies included
| Study, design, country | Objectives/participants | Intervention | Outcomes of interest | Results |
|---|---|---|---|---|
| Guimarães et al38 RCT Brazil |
To verify the effects of oropharyngeal exercises in patients with moderate OSAS on objective measurement of severity derived from PSG OE group – N: 16 Age: 51.5±6.8 Male: 63% BMI: 29.6±3.8 Control group – N: 15 Age: 47.7±9.8 Male: 73% BMI: 31.0±2.8 |
Three months for all groups, with weekly visits OE group Nasal lavage and OE HT: Three times a day Control group Nasal lavage Deep breathing exercises through the nose while sitting HT: Once a day, 30 min |
Full-night PSG AHI Lowest oxygen saturation SaO2 Sleep-related questionnaires Anthropometry |
Patients in OE group had significant improvement of PSG measures, snoring symptoms, subjective sleepiness, and sleep quality scores, and decreased NC Before vs after AHI: 22.4±4.8 vs 13.7±8.5 AHI REM: 29.8±12.7 vs 7.4±15.9 AI: 6.6±4.7 vs 3.3±3.2 Lowest SaO2 (%): 83±6 vs 85±7 NC: 39.6±3.6 vs 38.5±4.0 Control group showed no significant changes AHI: 22.4±5.4 vs 25.9±8.5 AHI REM: 29.9±11.6 vs 22.4±5.4 AI: 9.1±6.6 vs 9.6±6.0 Lowest SaO2 (%): 82±4 vs 80±4 NC: 40.9±3.5 vs 40.7±3.7 |
| Baz et al50 PCS Egypt |
To evaluate the effect of OMT as a simple method for treatment of patients with mild- to-moderate OSA N: 30 OMT Age: 44.07±7.54 Male: 73.3% BMI: 33.59±1.98 |
Three months, with two sessions weekly OMT HT: 3–5 times per day with minimum 10 min for each time |
Full PSG History Anthropometry ESS |
Patients showed significant improvement of PSG measures, snoring symptoms, subjective sleepiness, and decreased NC AHI: 22.27±4.51 vs 11.53±5.38 Minimum SaO2%: 84±4 vs 87±5 Arousal index: 28.87±8.41 vs 15.33±6.11 % TSTS: 14.05±4.89 vs 3.87±4.12 ESS: 16.40±1.96 vs 9.27±2.89 NC (cm): 42.77±1.67 vs 42.01±1.96 Subjective snoring (n): 30 vs 16 Excessive daytime sleepiness (n): 30 vs 12 Morning headache (n): 18 vs 6 |
| Diaféria et al40 RCT Brazil |
To assess the effect of ST alone and combined with CPAP on the QoL of patients with OSA Placebo group – N: 24 Age: 42.9±10.5 Male: 100% AHI: 27.8±20.3, BMI: 28.6±4.0 ESS: 12.8±3.1 ST group – N: 27 Age: 45.2±13.0 Male: 100% AHI: 28.0±22.7, BMI: 25.0±7.4 ESS: 13.7±3.2 CPAP group – N: 27 Age: 46.4±9.1 Male: 100% AHI: 34.4±22.4, BMI: 28.7±3.3 ESS: 12.0±2.1 Combination group – N: 22 Age: 47.5±10.9 Male: 100% AHI: 30.4±19.8, BMI: 27.9±2.4 ESS: 12.0±2.6 |
The patients were treated for three months Placebo group: head movements without any therapeutic function HT: Three times a day, with 20 min each ST group: OE HT: Three times a day, with 20 min each CPAP group: device with nasal mask, without humidifier, which was set to the optimal pressure according to the PSG to each patient Combination group (ST+CPAP): both protocols |
ESS, FOSQ, WHOQoL-Bref, and SF-36 PSG All outcomes were measured before and after therapy and after 3-week washout |
Significant improvement was observed in the physical domain of the WHOQoL-Bref in the ST and combination groups after treatment and washout compared to the pretreatment assessment. The functional capacity domain of the SF-36 improved in the ST group After ST vs washout Placebo group AHI: 30.6±21.8 vs 27.8±15.0 BMI: 28.3±3.9 vs 29.0±4.0 ESS: 12.2±5.2 vs 10.5±5.1 ST group AHI: 13.9±18.5 vs 21.3±21.4 BMI: 26.7±2.9 vs 26.9±2.9 ESS: 7.5±3.7 vs 10.4±4.3 CPAP group AHI: 4.3±4.0 vs 29.7±25.4 BMI: 29.5±3.2 vs 27.4±6.9 ESS: 7.2±3.6 vs 8.8±4.4 Combination group AHI: 3.4±2.7 vs 29.6±25.1 BMI: 28.3±2.6 vs 28.2±2.8 ESS: 7.3±5.7 vs 9.5±6.3 |
| Suzuki et al51 PCS Japan |
To assess the OMT for improving AHI and SpO2 during sleep N: 6 – Age: 22±0.5 Male: 50% BMI: 23.8±1.8 |
Two months of LCF training at the clinic with lip trainer | LCF measurement SpO2 and AHI obtained during sleep at home |
Patients had significant improvement of LCF, AHI, and SpO LCF: 8.8±1.6 vs 12.9±0.6 AHI: 15.1±3.4 vs 9.2±1.5 SpO2 (%): 90.0±2.9 vs 96.8±0.8 |
| Matsumura et al52 PCS Brazil |
To assess perceptions of the bed partner and the self-evaluation of snoring, myofunctional evaluation, AC and NC of individual with snoring or mild–severe OSA, before and after therapy N: 9 (7 OSA, 2 primary snoring) Age: 55.1 Male: 44.44% |
Twelve sessions lasting 40 min each OE | Snoring intensity and frequency indexes ESS Myofunctional evaluation Anthropometry |
The group had significant improvement of snoring intensity, snoring frequency, and ESS score (11.67 vs 4.67) Positive changes were observed in myofunctional evaluation NC: 40.3 vs 39.4 (p>0.05) AC: 96.8 vs 97.1 (p>0.05) |
| Ieto et al39 RCT Brazil |
To determine the effects of OE on snoring patients with a primary complaint of snoring and diagnosis of primary snoring or mild-to-moderate OSA OE group – N: 19 Age: 48±14 Male: 57.9% BMI: 28.3±2.7, AHI: 15.6±9.3 Control group – N: 20 Age: 45±13 Male: 55% BMI: 28.3±2.5, AHI: 15.1±9.5 |
Three months for all groups, with weekly visits OE group Nasal lavage and OE Control group Nasal lavage, deep breathing exercises, nasal dilator strips during sleep |
Objective snore index and the total snore index obtained after snore recording during PSG plus anthropometry questionnaires | OE group had significant lower snore index, total snore index, NC, intensity and frequency of snoring as reported by the bed partner Only a subgroup of patients with moderate OSA had a significantly decreased AHI (n=8, AHI: 25.4 [22.1–28.7] vs 18.1 [15.4–24.1], p=0.017) Control group showed only decrease on the subjective frequency of snoring reported by the patient |
| Villa et al41 PR Italy |
To evaluate the efficacy of OE as a means of reducing residual OSA in children after AT Children with residual OSA after AT (AHI>1) and persistence of respiratory symptoms after AT Group 1 – N: 14 Age: 6.01±1.55, AHI: 4.87±2.96 BMI (centile): 81.85±29.94 Group 2 – N: 13 Age: 5.76±0.82, AHI: 4.56±3.22 BMI (centile): 68.22±28.68 |
Two months, three meeting with the therapist Group 1: nasal washing and exercises HT: three times a day, with 10–20 repetitions each time Group 2: nasal washing HT: two times a day, in the morning and evening |
Full-night PSG before AT, 6 months after AT and after 2 months of exercises The improvement in OSA was defined by ΔAHI: (AHI at T1−AHI at T2)/AHI at T1×100 Morphofunctional evaluation |
Group 1 had significantly decreased AHI, reduction in oral breathing, a positive Glatzel test, a positive Rosenthal test, as well as increased labial seal and lip tone Group 2 had no significant difference after two months of nasal washing |
| Verma et al53 PCS India |
To evaluate the effect of oropharyngeal exercises in graded level of difficulty for mild-to-moderate OSA Patients with OSAS, N: 20 Age: 41.1±10.6 Male: 75% AHI: 20.1±9.1, BMI: 25.6±3.1 |
Three months, with weekly visits Three phases of OE in graded level of difficulty HT: 5 sets per day, with 10 repetitions of each exercise |
ESS PSG |
Patients showed significant improvement of ESS and PSG parameters and reduced NC ESS: 15.4±2.3 vs 13.6±3.1 AHI:19.7±9.4 Arousal index: 15.6±9.5 vs 12.8±7.1 Minimum SaO2 (%): 87.6±1.1 vs 88.5±1.6 Time duration for SaO2<90%: 6.7±6.6 vs 5.1±6.1 |
| Diaféria et al40 RCT Brazil |
To evaluate the effect of myofunctional therapy on CPAP adherence N=100 Male: 100% Placebo group – N: 24 Age: 42.9±10.5, AHI: 27.8±20.3 BMI: 28.6 ± 4.0 MT group – N: 27, Age: 45.2±13 AHI: 28±22.7, BMI: 25.0±7.4 CPAP group – N: 27 Age: 46.4±9.1, AHI: 34.4±22.4 BMI: 28.7±3.3 CPAP+OMT group – N: 22 Age: 47.5±10.9, AHI: 30.4±19.8 BMI: 27.9±2.4 |
Three months for all groups. Weekly visits for placebo, MT, and MT+CPAP groups Three visits for CPAP Placebo: relaxation and stretching of the neck muscles HT: Three times a day, 20 min each MT: OE HT: Three times a day, 20 min each CPAP device with nasal mask, without humidifier MT+CPAP: both protocols |
Adherence evaluation PSG, ESS, scale of snoring intensity and snoring frequency, myofunctional evaluation, Malampatti index All outcomes measured before and after three months of treatment, and after a 3-week washout period |
The average adherence to treatment was placebo (55%), MT (63%), CPAP (30%), MT+CPAP (65%) Time using the device: MT+CPAP>CPAP after one week and after three months of treatment The AHI decreased in the MT (50%), CPAP (87%), and MT+CPAP (89%). All groups were significantly different from the placebo ESS: Only the OMT group maintained the improvement in the snoring intensity and frequency after the washout period The Mallampati index improved in the OMT and CPAP+OMT groups and it was correlated with the increased strength of the tongue and soft palate |
| Villa et al1 PC-C Italy |
To evaluate the efficacy of MT to reduce oral breathing in children with SDB and to evaluate the increase in tongue tone 54 children with SDB (14 primary snoring [PSG, AHI 0.35±0.3] and 40 mild–moderate OSA [AHI 2.2±2.0]) MT group: (n: 36) Age: 6.7±2.3 Male: 38.8% Non-MT group: (n: 18) Age: 6.7±2.8 8 Male: 44.4% Healthy group: (n: 38) Age: 7.8±2.2 Male: 65.8% |
Two months, with two monthly meetings with a therapist MT group: MT plus nasal washing HT: three times a day, with 10–20 repetitions each time Non-MT group: nasal washing, two times a day, in the morning and evening. |
All the patients were evaluated before (T0) and after (T1) two months of treatment: tongue strength, tongue peak pressure, and endurance using the IOPI, myofunctional evaluation, nocturnal pulse oximetry The Healthy group underwent only IOPI measurements |
T0: MT vs non-MT (p>0.05) Compared to healthy group, MT and non-MT groups had lower tongue strength, tongue peak, and longer endurance (s) T1: MT group showed significant increase of tongue strength, tongue peak, endurance, mean and minimum SaO2, decrease of oxygen desaturation index, as well as decrease of the number of children with oral breathing habit (15 vs 3) and lip hypotonia (14 vs 6) and abnormal tongue resting position (17 vs 12) No differences were observed in the non-MT |
| Mohamed et al54 PCS Egypt |
To evaluate the effect of upper airway muscle exercise and rehabilitation as a new and simple technique to treat OSAS Group I moderate OSAS N: 15 Age: 46.39±2.04 Male: 80% BMI: 28.62±1.86 Group II: severe OSAS N: 15 Age: 47.5±9 Male: 86.7% BMI: 27.2±2.03 |
Three months, with weekly visits OE HT: 3–5 times per day with minimum 10 min for each time |
Full-night PSG AHI Lowest SaO2 Snoring ESS Neck circumference |
Daytime sleepiness (ESS), AHI, SaO2, and snoring index improved significantly in Group I (all p≤0.003), but not in Group II Group I: ESS: 14±6 vs 9.5±4.9 AHI: 22.51±5.03 vs 12.4±5.12 Snoring index: 312±8.8 vs 237.8±27.4 SaO2 (%): 83±4 vs 86±5 NC: 39.65±3.52 vs 38.92±2.92 Group II: ESS: 20.9±6.2 vs 18.91±5.1 AHI: 46.1±21.1 vs 42.8±15.65 SaO2 (%): 75±5.8 vs 78±4.9 Snoring index: 615±96.8 vs 554.6±81.43 NC: 43.02±2.06 vs 42.86±1.87 |
Note: Study type: RCT, PR, PC-C, and PCS; diagnosis: OSAS, OSA, and SDB; intervention: OE, MT, OMT, HT, ST, CPAP, AT, and LCF; age and anthropometric measures: age (mean age in years), BMI, AC, NC, and PSG and its variables such as AI, AHI, AHI REM, SaO2, SpO2, and TSTS; subjective scale: ESS, QoL, FOSQ, WHOQoL-Bref, SF-36, and IOPI.
Abbreviations: RCT, randomized controlled trial; PR, prospective randomized; PC-C, prospective case–control; PCS, prospective case series; OSAS, obstructive sleep apnea syndrome; OSA, obstructive sleep apnea; SDB, sleep-disordered breathing; OE, oropharyngeal exercises; MT, myofunctional therapy; OMT, orofacial myofunctional therapy or oral myofunctional therapy; HT, home training; ST, speech therapy; CPAP, continuous positive airway pressure; AT, adenotonsillectomy; LCF, labial closure force; Age, mean age in years; BMI, body mass index (kg/m2); AC, abdominal circumference; NC, neck circumference; PSG, polysomnography; AI, apnea index (events/hour); AHI, apnea–hypopnea index (events/hour); AHI REM, apnea–hypopnea index during rapid eye movement (events/hour); SaO2, oxygen saturation; SpO2, saturation of peripheral oxygen; TSTS, total sleep time snoring; ESS, Epworth Sleepiness Scale; QoL, quality of life; FOSQ, Functional Outcomes of Sleep Questionnaire; WHOQoL-Bref, World Health Organization Quality of Life Assessment; SF-36, Medical Outcomes Study 36-Item Short-Form Health Survey; IOPI, Iowa Oral Performance Instrument.