COVID-19 studies are our top priority.

For new and updated trial submissions, we are processing trials as quickly as possible and appreciate your patience. We recommend submitting your trial for registration at the same time as ethics submission.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Oral appliance with built in airway for the treatment of obstructive sleep apnoea.
Scientific title
Safety and efficacy of Oventus O2Vent and the effect of incorporation of an enclosed airway on compliance in patients with obstructive sleep apnoea
Secondary ID [1] 289313 0
Secondary ID [2] 289346 0
nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obstructive sleep apnoea 298913 0
Condition category
Condition code
Respiratory 298985 298985 0 0
Sleep apnoea

Study type
Description of intervention(s) / exposure
The Oventus O2Vent is an oral appliance similar in appearance to a mouth guard. It is a modification to the Oventus Clearway, designed to treat snoring and sleep apnoea. It is made up of two parts. The main structure which forms the breathing port at the front leading to the airways on each side to the rear of the appliance, is made from polished medical grade titanium with a polymer insert. The lower portion is made from dual laminate and is positioned in an advanced position to bring the jaw forward. Further adjustment of the jaw position is much easier with a screw mechanism.

The device will be delivered by a dentist in a dedicated dental clinic. Eligibility for a dental appliance will have been confirmed on a visit prior to enrollment into the trial. The appliance is custom made and has a built in airway to allow airflow through the device. The device will be fitted by the dentist with either the built in airway open (Treatment 1) or closed (Treatment 2). During the dental fitting, the dentist will check the fit of the appliance and provide instructions on use and cleaning. The device will be worn every night during sleep and removed on waking for the duration of the study. During an acclimatization phase of 2-8 weeks, ongoing symptoms, side effects, comfort and usage will be assessed via questionnaires every 2 weeks and device adjusted to achieve optimal lower jaw advancement. When treatment has been optimized, efficacy may be confirmed using a level 3 home sleep study to inform clinical opinion that treatment is optimized. Comfort and compliance will then be assessed using a questionnaire and sleep diary over a 2 week period with efficacy established on a level 1 in laboratory sleep study at the end of the 2 weeks.. Participants will then cross over into the other Treatment group and comfort, compliance and efficacy assessed over a 2 week period as described.. In the interest of not withdrawing treatment, there is no washout period between the 2 treatment arms.
Intervention code [1] 294867 0
Treatment: Devices
Comparator / control treatment
Comfort and compliance with the airway open (Treatment 1) will be compared to comfort and compliance with the airway closed (Treatment 2). Airway closed will be considered as the control.
Control group

Primary outcome [1] 298482 0
Difference in compliance with airway open and closed assessed using a 2 week participant self-reported sleep diary.

Timepoint [1] 298482 0
Compliance assessed for a period of 2 weeks on each treatment arm, following a 2-8 week period of acclimatization and optimization of jaw position.

Primary outcome [2] 298483 0
Device related adverse events.
Known device related events include the following assessed via questionnaires:
1. Excess salivation
2. Dry mouth
3. Gum irritation
4. Cheek or tongue pain
5. Jaw discomfort/pain
6. Jaw set (lock)
7. Tooth movement or loosening
8. Tooth discomfort/pain

The questionnaire used to assess side effects is part of the Usage and Comfort questionnaire developed internally for the study to enable clinicians to evaluate and monitor side effects and acclimatization to treatment.
Timepoint [2] 298483 0
Compliance assessed at over 2 weeks on active Treatment 1 and Treatment 2 with data collected and entered into the EDC at the end of the 2 week period.
Adverse events assessed during acclimatization phase every 2 weeks and after 2 weeks on each treatment.
Primary outcome [3] 298484 0
Change in Apnoea-Hypopnoea Index (AHI) from baseline to treatment with O2Vent airway open.
Timepoint [3] 298484 0
AHI assessed at baseline using polysomnography and again at the end of 2 weeks on active treatment (Treatment 1), following a period of acclimatization and optimization of jaw position.
Secondary outcome [1] 324293 0
Response rate in subjects with nasal congestion using rhinomanometry as an objective measure of nasal congestion. Response rate is defined as a greater than or equal to 50% reduction in AHI.
Timepoint [1] 324293 0
Nasal congestion assessed prior to polysomnography on the last night of active treatment. Response rate is calculated from the polysomnogrphy defined AHI.

Key inclusion criteria
1. Age greater than or equal to 18 years old.
2. Obstructive sleep apnoea as diagnosed by a sleep physician within the last 12 months (diagnoses from polysomnography) and:
a) Recommended for oral appliance therapy as at least part of the treatment or
b) Recommended CPAP but are CPAP Intolerant as documented by affidavit.
3. Eligible to receive a mandibular advancement device
4. Must have at least 8 upper and 8 lower teeth
5. Is able to provide written informed consent to all study procedures and agrees to adhere to all protocol requirements.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. Pregnant or lactating females
2. Participating in another clinical trial
3. Periodontal disease
4. Exaggerated gag reflex
5. Medication usage that could influence respiration or sleep (e.g. regular use of sedatives, heavy alcohol consumption)
6. OSA with uncontrolled or untreated cardiovascular disease
7. Central Sleep Apnoea events (greater than or equal to 5/hr)
8. Previous Uvulopalatopharyngoplasty (UPPP)
9. Severe somatic or psychiatric disorders
10. Periodic limb disorder
11. Reversible morphological upper airway abnormalities e.g. enlarged tonsils
12. Temporomandibular disorders
13. Dental pain

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation via sealed envelopes.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomization in permuted blocks will be performed to achieve balance across treatment groups.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people analysing the results/data
Intervention assignment
Other design features
sleep studies analysed with scorer blinded to treatment.
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Compliance (Nightly Usage): Prior data indicate that nightly use of the first generation Oventus appliance was average 7 hours with SD of 2. For a 10% reduction in usage with airway closed, we expect a difference of 0.7, and using SD of differences of 1, we will need to study 29 subjects to be able to reject the null hypothesis that this response difference is zero with probability (power) 0.95. The Type I error probability associated with this test of this null hypothesis is 0.05. Paired t tests will be used to compare Treatment 1 and Treatment 2 compliance.

A total of 40 subjects will be recruited to allow for 25% drop out rate.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 5878 0
Breathing Assist Solutions - Indooroopilly
Recruitment postcode(s) [1] 13323 0
4068 - Indooroopilly

Funding & Sponsors
Funding source category [1] 293711 0
Commercial sector/Industry
Name [1] 293711 0
Oventus Pty Ltd
Address [1] 293711 0
1 Swann Road
Indooroopilly QLD 4068
Country [1] 293711 0
Primary sponsor type
Commercial sector/Industry
Oventus Pty Ltd
1 Swann Road
Indooroopilly QLD 4068
Secondary sponsor category [1] 292545 0
Name [1] 292545 0
Address [1] 292545 0
Country [1] 292545 0

Ethics approval
Ethics application status
Ethics committee name [1] 295146 0
Bellberry Limited
Ethics committee address [1] 295146 0
129 Glen Osmond Road
South Australia 5063
Ethics committee country [1] 295146 0
Date submitted for ethics approval [1] 295146 0
Approval date [1] 295146 0
Ethics approval number [1] 295146 0

Brief summary
Like other oral appliances to treat snoring and sleep apnoea, the O2Vent brings the jaw forward to reduce airway collapse. However, it also has a built in airway to allow breathing through the device. This may make it suitable for use by patients who find it difficult to breathe exclusively through the nose. A recent pilot study showed that original design, the Oventus Clearway, was safe, effective and well tolerated with a 62% reduction in the number of times patients stopped or reduced their breathing during sleep. No difference in response rate was observed in patients with or without subjective symptoms of nasal congestion.

The new generation Oventus device, the O2Vent, has the built in airway of the original design, however it is 2 parts, an upper and lower part. This makes it much easier to adjust and find the optimal jaw position..

The aims of the present study are to:
1. To demonstrate safety and efficacy of O2Vent oral appliance
2. To demonstrate that the incorporation of an enclosed airway into the O2Vent improves comfort and compliance
3. To confirm the equivalent response rate in subjects with nasal congestion using rhinomanometry as an objective measure of nasal congestion

The above aims will be addressed using a randomized crossover study design with patients in one arm using the O2Vent with the built in airway open and in the other arm using the device with the built in airway closed.

Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 66218 0
Dr Damian Lavery
Address 66218 0
Breathing Assist Solutions
1 Swann Road
Indooroopilly QLD 4068
Country 66218 0
Phone 66218 0
+61 7 3180 3193
Fax 66218 0
Email 66218 0
Contact person for public queries
Name 66219 0
Dr Irene Szollosi
Address 66219 0
Oventus Pty Ltd
1 Swann Road
Indooroopilly QLD 4068
Country 66219 0
Phone 66219 0
+61 1300 533 159
Fax 66219 0
Email 66219 0
Contact person for scientific queries
Name 66220 0
Dr Chris Hart
Address 66220 0
Oventus Pty Ltd
1 Swann Road
Indooroopilly QLD 4068
Country 66220 0
Phone 66220 0
+61 1300 533 159
Fax 66220 0
Email 66220 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary