Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
Obstructive sleep apnoea- hypopnoea syndrome (OSAHS) is a common condition in which the upper airways (wind pipe) collapse repeatedly during sleep, completely (apnoea) or partially (hypoapnoea) blocking the flow of air into the lungs. This prevents the sufferer from being able to breathe properly while they are asleep, causing excessive sleepiness throughout their waking hours. Many studies have shown that people who are obese have a higher risk of developing it and that the incidence of OSAHS is increasing with the rise in obesity. Although there is a strong relationship with obesity however, this does not mean that all obese people have OSAHS and normal weight people do not. Previous studies have tried to use facial characteristics such as face shape (phenotype) to predict the occurrence of OSAHS, however this screening technique is widely debated. The aim of this study is to find out whether the visual characteristics of the face and neck (phenotyping) can be used in order to develop a new pre-screening tool for people suffering from OSAHS.

Who can participate?
Caucasian men aged between 45 and 65, either normal weight or obese who either have OSAHS or show no signs of it.

What does the study involve?
All participants then attend two study visits. At the first study visit, all participants complete a number of questionnaires as well as having their weight and height measured and medical history taken. Then then have a simple physical examination in order to assess their neck and facial characteristics. At the second study visit, participants all participants have a cone beam computed tomography scan (a high resolution type of x-ray) and have a 3D analysis of their facial characteristics. At the end of the second visit, the characteristics of all participants are compared between the those with OSAHS and those without.

What are the possible benefits and risks of participating?
There are no direct benefits to participants; however the participants with OSAHS may be able to gain a better understanding of the underlying causes of their condition. Participants are exposed to a very small amount of radiation during the scanning procedures, however this is not considered to be harmful.

Where is the study run from?
Bart’s & The London Dental Institute (UK)

When is the study starting and how long is it expected to run for?
November 2015 to November 2017

Who is funding the study?
Queen Mary University of London (UK)

Who is the main contact?
Dr Bahn Agha

Trial website

Contact information



Primary contact

Dr Bahn Agha


Contact details

Bart’s & The London Dental Institute
Queen Mary University of London
Turner Street
E1 2AD
United Kingdom
+44 20 7882 8629

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The relationship between facio-cervical phenotyping and upper airway morphology in obstructive sleep apnoea-hypopnoea syndrome: A 3-dimensional approach


Study hypothesis

Null hypotheses:
1. Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) subjects cannot be identified from their facio-cervical form (phenotype)
2. There is no correlation between the soft tissue facial morphology and underlying skeletal morphology
3. There is no correlation between the surface facial morphology and the upper airway of OSAHS subjects
4. It is not possible to identify or create a facio-cervical prediction tool (marker) for OSAHS subjects

Ethics approval

London - City & East Research Ethics Committee, 17/05/2016, ref: 16/LO/0554

Study design

Single-centre case-control study

Primary study design


Secondary study design

Case-control study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet.


Obstructive sleep apnoea-hypopnoea syndrome (OSAHS)


Interventions as of 02/06/2016:
In the first study visit, both obstructive sleep apnoea-hypopnoea syndrome (OSAHS) diagnosed participants and suspected non-OSAHS participants will complete the consent form and undergo the baseline assessment including simple clinical examination to determine the number of teeth and examine the back of the throat (Mallampati airway classification (MAC)) and anthropometric measurements to measure the body mass index (BMI) and neck circumference (NC). Then the suspected non-OSAHS (healthy) subjects will be asked to complete a series of questions and undergo an overnight sleep test (at home). The sleep test and questions will help to identify if they suffer from obstructive sleep apnoea.

At the second study visit, all participant will undergo cone-beam computed tomography (CBCT) first then three-dimensional (3D) stereophotogrammetry scan.

For whole participation, the average time taken for each participant is around 1 hour ± 5 minutes (over the two visits).

Original interventions:
Both obstructive sleep apnoea-hypopnoea syndrome (OSAHS) diagnosed participants and healthy participants added a study visit which involves the completion of a consent form, history & clinical examination, weight and height assessment and pre-screening questionnaires. All participants will undergo a simple clinical examination (to determine the number of their teeth, body mass index (BMI), neck circumference (NC), and Mallampati airway classification (MAC). In addition, the control subjects (non-OSAHS), will complete pre-screening questionnaires (Epworth sleepiness scale (ESS), sleep apnoea clinical score (SACS) and sleep partner questionnaire (SPQ)) to exclude OSAHS.

At a second visit, all participants undergo imaging procedures. OSAHS participants will undergo cone-beam computed tomography (CBCT) and then three-dimensional (3D) stereophotogrammetry scan and non-OSAHS participants will undergo a lateral cephalometric radiograph, followed by a 3D stereophotogrammetry scan.

For whole participation, the average time taken for each participant is around 1 hour ± 5 minutes (over the two visits).

Intervention type



Drug names

Primary outcome measure

Facio-cervical morphology (phenotype)measured using image analysis software for stereophotogrammetry scan, lateral cephalometric radiograph, and cone-beam computed tomography (CBCT) at the second visit after baseline assessment.

Secondary outcome measures

1. The correlation between the surface and skeletal facio-cervical morphology and upper airway dimensions using correlation analysis after the second visit
2. Potentially identifying a facio-cervical marker for OSAHS subjects using multiple regression analysis after the second visit

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. 40 to 65 years old males
2. Clinically normal weight (BMI <25 Kg/m2) or obese (BMI >30Kg/m2)
3. Caucasian
4. Confirmed diagnosis of OSAHS in the study group and no clinically demonstrable OSAHS in control group
5. Dentate
6. The skin over the face and neck must be free of significant hair.

Participant type


Age group




Target number of participants

132 dentate Caucasian male adults meeting selection criteria

Participant exclusion criteria

1. Edentulous subjects or the absence of 8 or more teeth in each dental arch
2. Facial neuromuscular disorders, craniofacial deformity or history of craniofacial surgery
3. Overweight subjects (BMI between 25 and 30 Kg/m2)

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Barts and the London School of Medicine & Dentistry
Bart's & The London Dental Institute Garrod Building Turner Street
E1 2AD
United Kingdom

Sponsor information


Bart’s & The London Dental Institute

Sponsor details

Queen Mary University of London
Turner Street
E1 2AD
United Kingdom
+44 20 7882 8669

Sponsor type




Funder type


Funder name

Queen Mary University of London

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

The results of the study will be published in peer-reviewed medical and dental journals. In addition, they will be presented at sleep conferences. A summary of the key findings will be sent to all participants.

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

18/01/2019: The intention to publish date has been changed from 30/06/2018 to 31/07/2019 02/06/2016: Ethics approval information added. The interventions section has also been updated following review by the approving ethics committee. 15/03/2016: Internal review