The Impact Of Technology In The Myofunctional Therapy Treatment Of Obstructive Sleep Apnea Syndrome
Phase: NA
Conditions: Obstructive Sleep Apnea (OSA), Snoring, Sleep Quality
Sponsor: Case Western Reserve University

 
 
 
STUDY20231615 
 
 
The Impact of Technology in Obstructive Sleep Apnea Myofunctional 
Therapy 
 
 
Document Date 5/10/2024 
 

Title: The impact of technology in the myofunctional therapy treatment of Obstructive Sleep Apnea 
Syndrome 
 
PROJECT PLAN 
Background and significance 
Obstructive sleep apnea (OSA) affects an important part of the population and is characterized by 
recurrent partial or total obstruction of the upper airway (UA) during sleep. OSA can negatively affect 
the individual’s quality of life in the short and long term and constitute a significant public health problem 
for society. The estimated prevalence of OSA in the population is 34% of men and 17% of women, but 
the values may be even higher since many subjects do not have an adequate diagnosis. Individuals 
may experience severe lifelong consequences such as cardiorespiratory failure, hypertension, type 2 
diabetes mellitus, and neurophysiological deficits associated with increased mortality rate. Currently, 
any form of SDB should be considered worrisome or even harmful since even the least severe of these 
conditions can have significant consequences on the quality of life and general health. Orthodontists 
intervene in the craniofacial complex, and thus, they can assist in the recognition of sleep disorder 
breathing (SDB) problems, contributing to the identification of dentofacial components involved and, in 
some cases, to the treatment of OSA, in association with the physician and team.2 
The upper airway (UA) comprises the nasal cavity, pharynx, and larynx and thus is more relevant for 
orthodontists because it is close to their area of expertise. The pharynx is a muscular membranous tube 
that extends from the skull base to the lower edge of the cricoid cartilage. 3 The pharynx is divided into 
three parts: nasopharynx, oropharynx, and laryngopharynx or hypopharynx.3,4 The velopharynx is part 
of the oropharynx and is located between the soft palate and the posterior pharyngeal wall. The UA is 
responsible for swallowing, speech and breathing. The accomplishment of these tasks depends on the 
complex interaction of more than 20 muscles that surround the UA: muscles that regulate the soft palate 
position (elevator and tensor palatini), the tongue (genioglossus, geniohyoid, hypoglossus, and 
styloglossus), muscles attached to the hyoid bone (hypoglossus, genioglossus, digastric, geniohyoid 
and sternohyoid) and muscles of the posterolateral pharyngeal walls (palatoglossus and pharyngeal 
constrictors).5,6 These muscles act, dilating or constricting the UA lumen. The UA is not a rigid structure 
(e.g., like the trachea) and is fixed only at its upper (skull base) and lower (cricoid cartilage) ends. The 
hyoid bone is an important site of attachment for pharyngeal muscles, yet it does not have rigid 
articulation with other bony structures. Therefore, the pharyngeal cross-sectional area depends on the 
air pressure in the upper airway lumen, which can collapse due to different factors.7 Contraction of the 
upper airway dilator muscles (especially those that control the tongue, soft palate, and lateral 
pharyngeal walls) maintains respiratory patency during inspiration. A drop in the tone of pharyngeal 

dilator muscles results in airway collapse. Upper airway collapse occurs most often in the oropharynx 
in subjects with obstructive sleep apnea (OSA). 
The variety and complexity of vibrations and upper airway collapsibility during sleep depend on sleep 
stages, muscle tone, body position, head and neck position, and lung volumes. The most common sites 
of obstruction and vibration are located in the soft palate, on the lateral pharyngeal walls, including the 
tonsils and tongue base. Obstruction at the epiglottic level occurs less frequently but has clinical 
significance. Subjects with OSA present with multilevel obstruction, with a collapse in the retropalatal 
and retrolingual region in a large percentage of cases. Single-level obstruction is more common in 
subjects with mild OSA, while multilevel obstruction is more characteristic in severe OSA, which is often 
the reason for the severity of OSA.8 
The diagnosis and severity of OSA are determined by polysomnography (PSG). It is considered the 
gold standard exam, in which several sleep and respiratory parameters are monitored simultaneously 
such as electroencephalogram, electrooculogram, electromyography of the chin region, airflow 
analysis, oxygen saturation, respiratory effort, electrocardiogram/heart rate, body position, and 
movements during sleep.10 One important parameter measured is the apnea-hypopnea index (AHI), 
which assesses the mean number of apneas and hypopneas per hour of sleep. Apnea is the absence 
of inspiratory airflow for at least 10 seconds, while hypopnea is a reduction of 30% or more in airflow 
from 
baseline 
associated 
with 
a 
drop 
in 
arterial 
hemoglobin 
saturation 
and/or 
an 
electroencephalographic awakening.9 The severity of adult OSA is classified as mild (5≤AHI<15 
events/h), moderate (15≤AHI<30 events/h), or severe (AHI≥30 events/h).9 There is no specific type of 
physical finding on examination for OSA. Many individuals do not report having sleep disturbances, 
either because they are asymptomatic or do not realize they have the problem. Specific and validated 
questionnaires are essential tools to assess an individual's risk of having OSA. Another current trend is 
to provide the risk assessment for OSA based on the collapsibility of the airway.16 Ultrasound (US) is 
emerging as a promising technology that has been evolving to assess the risk for OSA in the last few 
years. The technique is radiation-free, less expensive, and the equipment is portable, allowing high 
accessibility for examination and screening. 
Preliminary studies 
The treatment of OSA should be individualized, considering the disease's pathophysiology, the subject’s 
individual characteristics, and the treatment goals. Therapeutic possibilities include behavioral changes, 
oropharyngeal exercises, positive air pressure devices (PAP), intraoral appliances, surgeries, and 
electrical stimulation.  

Oropharyngeal exercises are a non-invasive alternative that should be considered adjunct procedures 
in treating OSA. The dilator muscles of the upper airway are essential for maintaining respiratory 
patency during sleep.11 Some subjects may have flaccidity of the oropharyngeal muscles. This 
hypotonia is related to the pathophysiology of OSA and deserves therapeutic attention. 
Oropharyngeal exercises (myofunctional therapy) are derived from speech therapy and include 
exercises for the mouth and neck region. They include isometric (continuous) and isotonic (intermittent) 
exercises aimed at the tongue, soft palate, and pharyngeal lateral walls.11,12 These oropharyngeal 
exercises have recently been successfully used in the treatment to reduce the severity of OSA. They 
are focused on improving the strength, force, and coordination of upper airway muscles.13 It is believed 
that strengthening the oropharyngeal muscles, through daily exercises, could prevent upper airway 
collapse. The main problem with this therapy is the lack of long-term compliance, which is only around 
10%. The use of apps associated with smartphones can improve adherence to exercises and training.13 
Guimarães et al. conducted a randomized clinical study on 31 patients with moderate OSA. The authors 
concluded that individuals who received oropharyngeal exercise therapy for three months showed 
significant improvements in disease severity and symptoms compared to the control group.11 Another 
randomized clinical trial obtained similar results in patients with primary snoring, indicating 
oropharyngeal exercises for these individuals.15 To maintain positive results, the patients should include 
exercises in their daily routines in the long term, which can cause problems related to treatment 
adherence.11,15 New technologies are being developed to aid the treatment adherence and monitoring 
of sleep disorders patients. The use of apps provides a permanent record of feedback and accuracy of 
exercises performed.15 
Çakmakc et al. found that oropharyngeal exercise training may have improved respiratory muscle 
strength, sleep quality, and health-related quality of life in the exercise group. Forty-one patients with 
moderate and severe OSA were included in the study (20: exercise group; 21: control group). Each 
patient was assessed with CPAP usage time, maximal voluntary ventilation (MVV), maximum 
inspiratory and expiratory pressure (MIP-MEP), neck circumference, body mass index (BMI), waist-hip 
ratio, Epworth sleepiness score, Pittsburgh sleep quality index (PSQI), and short-form health survey 
(SF-36) in the first visit. The OPE was prescribed in addition to CPAP for the exercise group and 
performed by the patients for 3 months. At the end of the third month, groups were re-assessed with 
the same parameters. Most of the patients were men, and the mean age of the study population was 
51.9±7.4; the mean apnea-hypopnea index (AHI) in the last polysomnography report was 53.3±27.4. In 
the exercise group, MVV (p=0.003), MIP (p=0.002), MEP (p=0.024), and SF-36 energy/fatigue 
(p=0.020) were observed to increase while the total PSQI score (p=0.036) decreased. The neck 
circumference (p=0.006) and BMI (p=0.013) were found significantly decreased in the exercise group.16 

Myofunctional exercises are now available as application in smartphones, claiming to help increase 
adherence, and achieve better results than traditional methods.  There are no studies at this point 
comparing the myofunctional therapy through an app versus traditional methods. 
Aim of the study  
1) Compare the effects of myofunctional exercises in subjects diagnosed with OSA when using a 
smartphone app versus a traditional analog method, after 3 months of myofunctional therapy. 
2) Compare the compliance maintained when using a smartphone app versus a traditional analog 
method, after 3 months of myofunctional therapy. 
Experimental design, methods, and statistical analyses planned 
After IRB approval, subjects 18 to 75 years old with mild, moderate, and severe OSA that were being 
treated at the Division of Sleep Medicine of University Hospitals of Cleveland and who rejected/failed 
CPAP or other therapeutic options will be invited to participate in the study.  The ones who agree to 
participate will sign a written consent form agreeing to participate in the study, and will be given a $100 
gift card as incentive, built in as 4 increments of $25 earned by presence in each visit (baseline, month 
1, month 2, and final visit at month 3).  The subjects in the app group will receive the cost of the app 
included in the gift certificate.  Subjects should have a recent (within 5 years) in-lab polysomnography 
or home sleep apnea testing (HSAT) performed, following the American Academy of Sleep Medicine 
guidelines.  The test results will be used to define the severity of OSA, according to the apnea-hypopnea 
index (AHI) in mild (5–14 events/h of sleep), moderate (15–29.9 events/h), and severe (30 events/h or 
over).  A total need of 60 subjects was calculated, based on the maximum inspiratory pressure (MIP) 
from the Çakmakc et al. study.  The power sample calculation was performed with a 0.05 α value and 
80% power, using the G*Power program for Windows.16   
Exclusion criteria will include: 
a. 
Age lower than 18 or higher than 75. 
b. 
BMI > 40  
c. 
Alcoholism or drug abuse 
d. 
A-fib, pacemaker, CHF, strokes, narcotics 
e. 
Neuromuscular disease 
f. 
Use of benzodiazepine hypnotics (may affect muscle tone) 
g. 
Restricted tongue movement 
h. 
Permanently blocked nose 
i. 
TMJ disorder. 
j. 
Lost to follow-up 
k. 
Gained or lost ≥5% of body weight during 3 months 

The baseline protocol will include the following data:  
Variable 
Collected 
Age 
Self-reported 
Sex 
Self-reported 
Neck Size 
Measured on-site 
Waist 
Measured on-site 
BMI 
Measured on-site (height and weight) 
Tongue Strength 
IOPI device 
Lip Strength 
IOPI Device 
OSA Risk Assessment 
STOP-Bang Questionnaire 
Nasal Breathing Efficiency 
NOSE questionnaire 
Sleep Quality 
Pittsburgh Sleep Quality Index  
Sleepiness Assessment  
Epworth Sleepiness Scale 
Insomnia Assessment 
Insomnia Severity Index 
Airway Collapsibility 
AmCAD Ultrasound 
Oxygen Saturation 
Belun Ring Wearable 
Heart Rate Variation during sleep 
Belun Ring Wearable 
Sleep Stage Assessment 
Belun Ring Wearable 
Sleep Efficiency 
Belun Ring Wearable 
Airway muscle tone 
Surface Electromyography (EMG) 
Snoring Presence, quality and quantity.  
SnoreLab Application 
 
Regular biometric measurements will be taken in the orthodontic clinic at Case Western Reserve 
University, using a calibrated scale which included a height measuring device.   
Below is a description of the equipment specific for this project which will be used to capture and 
measure all monthly collected variables, from baseline to months 1, 2, and the final visit on the third 
month.   
Iowa Oral Performance Instrument (IOPI) 
The IOPI is a validated intra oral device that measures tongue elevation strength and endurance, and 
well as lip strength and endurance in kPa (Figure 1).  The IOPI is a pressure transducer connected to 
a battery-operated amplifier, signal-conditioning circuit, and digital voltmeter. A peak holding circuit 
displays peak pressure in kPa on a digital readout. The IOPI will be used to measure the variables up 
to three times and the highest value will be recorded.  The IOPI will be used at baseline and at every 
monthly visit, to evaluate the myofunctional therapy progress.  

 
 
Figure 1. Iowa Oral Performance Instrument (IOPI) kit, and diagrams showing data collection for the 
tongue elevation strength and lip strength.  
 
Belun Ring 
Belun Sleep Platform (BSP, Belun Technology Company, Hong Kong) is a deep learning (DL) neural 
network-enabled, PPG-and-accelerometry-based wearable developed primarily for detecting OSA 
(Figure 2). The Belun Ring sensor is an FDA-cleared Class II pulse oximeter that is positioned on the 
proximal phalanx of index finger (proximal phalangeal radialis indicis artery). It measures oxygen 
saturation, heart rate, heart rate variability, and accelerometer signals (movement) to derive total sleep 
time, classify sleep stages (wake, NREM, REM), and number of apnea/hypopnea events per hour of 
sleep.  The Belun ring showed great correlation with PSG (r=0.89), a sensitivity of 0.88 and a specificity 
of 0.83 when categorizing the apnea/hypopnea index (AHI).17 
 
Figure 2. The Belun ring and how it is positioned on the index finger.  The data collected is uploaded 
from the ring directly to a computer by placing the ring on its charging cradle, and connecting the 
cradle with an USB cable. 

AmCAD-UO Ultrasound 
The ultrasound is a non-invasive exam using a remote-controlled submental ultrasound device to detect 
obstructive sleep apnea (AmCAD-UO and AmCAD-US software). The AmCAD-UO system aims to 
standardize the ultrasound transducer pathway to reduce intra-observer variations and make the 
assessment more consistent. The software compares the images obtained in the two situations (normal 
breathing and Müller's maneuver and provides a risk assessment for OSA based on the collapsibility of 
the airway (Figure 3). The analysis is based on the VOTE Classification, which refers to the primary 
structures that contribute to upper airway obstruction in sleep-disordered breathing: Velum, 
Oropharyngeal lateral walls (including the tonsils), Tongue, and Epiglottis. 8  
 
Figure 3. AmCAD-UO taking a normal breathing and a Mueller Maneuver ultrasound volume.  Both 
airway volumes are compared in order to assess the airway collapsibility, and its tone.  
The Mueller maneuver will be standardized in this study by using an inspiratory exercise device 
(spirometer) which when the subject inspires, balls are raised and remain floating while inspiration is 
taking place (Figure 4).  This way we will be certain that the inspirational movement is taking place. 
     
 
 
Figure 4. Spirometer used to assure inspiratory activity while performing the Mueller maneuver. 

Airway Gym 
The Airway Gym is a smartphone app which teaches and aids in the performance of several airway 
related exercises, using a smartphone pressure sensors to evaluate progress and monitor proper 
performance (Figure 5).  The Airway Gym app includes proprioceptive exercises that are aimed to 
strengthen the lingual and pharyngeal muscle tone.  Those muscles are considered responsible for the 
upper airway collapse during sleep.  The Airway Gym app will be installed in the subject’s smartphone 
belonging to the App Group.  After the baseline exams, subjects will be instructed to perform the 
myofunctional exercises under the guidance of the Airway Gym app. The main objective of these 
exercises is to increase the tone of the extrinsic muscles of the tongue (genioglossus, hyoglossus, 
styloglossus, and palatoglossus)15. An initial session will be scheduled to train the subject in using the 
app and the exercises. The average training time proposed is 20 min/day, five days/week. There are 
nine exercises to enhance the tonicity of the various muscles involved in the pathogenesis of OSA 15. 
Before every exercise, there is an animated gif demonstration that shows the subject how to perform 
the exercise. Subjects can follow the development of their activity daily overtime using the app. After 
each exercise, the subject receives feedback on their performance with a point score. When the subject 
finishes the exercises, they are saved for further evaluation. 
 
 
Figure 5. Example of Airway Gym training interface, and picture showing a subject performing a 
proprioceptive exercise using Airway Gym. 
SnoreLab 
SnoreLab is a smartphone app that uses the device’s microphone to capture snoring, and uses an 
algorithm to evaluate snoring intensity and length during sleep (Figure 6).  The SnoreLab app has been 

used in several scientific studies, showing good correlation with PSG, but sometimes showing 
differences in data depending on the devices condition.  For this reason, in this project we plan on 
installing SnoreLab on iPads, and loan the iPad to the subject whose snoring is being evaluated.  All 
iPads will be tested and calibrated as to provide a standardized result.  The iPads will be recalibrated 
everytime it is received back from a subject.  The Snore app will be used to detect the snoring intensity 
and length during the exercise period, in both app and analog groups. 
 
 
Figure 6. SnoreLab app reporting snoring intensity and length during sleep. 
Surface Electromyography (EMG) 
Surface Electromyography (EMG) will be used to assess the tone of the oropharyngeal musculature 
while performing exercises in both app and analog groups.  Surface EMG is a non-invasive reliable and 
accurate alternative to the needle EMG, commonly used to evaluate muscle tone and activity.  Surface 
EMG will aid in identifying the specific muscles that are being activated, and if one group is having better 
results than the other after performing their exercises. 
Questionnaires 
The STOP-Bang questionnaire is a sleep apnea risk assessment tool with 4 self-reported (STOP: 
snoring, tiredness, observed apnea, and high blood pressure) and 4 demographic (Bang: body mass 
index [BMI, age, neck circumference, and gender) variables. In its validation study, the STOP-Bang 
questionnaire demonstrated a sensitivity of 84%, 93%, and 100% to detect all OSA (mild, moderate, 
and severe, respectively). The STOP-Bang questionnaire will be filled on a monthly basis by all subjects 
in both groups. 

The Pittsburgh Sleep Quality Index (PSQI) is a self-report questionnaire that assesses sleep quality 
over a 1-month time interval. The index consists of 19 individual items, with 7 components which 
produce one final score.  The questionnaire takes an average of 5–10 minutes to complete.  The 
Pittsburgh Sleep Quality Index will be filled on a monthly basis by all subjects in both groups. 
The Epworth Sleepiness Scale (ESS) is a validated, widely used self-administered questionnaire that 
poses 8 different situations and provides a level of sleepiness ranging from “not a chance of dozing” to 
high chance of dozing”.  
The Insomnia Severity Index is a 7-item self-administered questionnaire that assesses the severity of 
both daytime and nighttime components of insomnia.  
Data Collection 
Baseline data will be collected at the first visit, followed by monthly progress data, and final data will be 
at the 3-month mark. 
Statistical Approach 
A normality test will be applied to the data to determine if parametric or non-parametric 
statistics are to be used.  A combination of descriptive and comparative analysis will be 
performed in order to determine if there are statistical significant differences between the 
groups. 
A Bonferroni correction will be applied if too many t-tests are performed. 
SPSS 28 will be used for all statistical analysis. 
Expected outcomes  
The hypothesis is that the app group will show better compliance and better results due to the 
constant reminders and interactive approach used by the app.   
Alternative approaches if outcomes are not as expected  
Due to the non-invasive nature of this project we do not expect problems during the project.   
If outcomes are not as expected, this means that there is no significant differences between 
using an app or an analog method, which would be helpful information for future projects.