Effects of different functional therapy protocols on airway dimensions during Herbst appliance therapy

ISRCTN ISRCTN69743543
DOI https://doi.org/10.1186/ISRCTN69743543
Protocol serial number 2011/107
Sponsor Erciyes University Clinical Trials Ethical Committee
Funder No funding
Submission date
08/11/2018
Registration date
06/12/2018
Last edited
26/10/2020
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Oral Health
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
The position of the lower jaw can influence the position of the hyoid bone and the tongue, which can then affect the dimensions of the airway. Lower jaw advancement is a type of surgery that moves the jaw, and can change the dimensions of the airway. A Herbst appliance is a device that is attached inside the mouth to move the jaw. The jaw can be moved in a single step (maximum advancement) or in smaller, multiple steps (incremental advancement) using a Herbst appliance.
This study aims to look at the effects of maximum and incremental advancement using a Herbst appliance on airway dimensions and position of the hyoid bone in young adults with a retruded lower jaw.

Who can participate?
Patients aged 14-18 with mandibular retrognathia

What does the study involve?
Participants will be randomly allocated to one of two groups. One group will receive maximum advancement (MA), whereas the other will receive incremental advancement (IA). Both groups will receive mandibular advancement treatment using the Herbst-RPE appliance. The MA group will receive treatment for approximately 9-10 months. The IA group will receive treatment every 2 months until the treatment is complete.

What are the possible benefits and risks of participating?
The possible benefit of participating in this study is that patients will receive treatment more quickly, as they will not have to wait to be treated. There are no known risks to participants taking part in this study.

Where is the study run from?
Erciyes University, Faculty of Dentistry, Department of Orthodontics, Kayseri (Turkey)

When is the study starting and how long is it expected to run for?
November 2011 to September 2017

Who is funding the study?
This study does not require funding as all treatments are standard orthodontic treatments performed by Erciyes University

Who is the main contact?
Nisa Gul Amuk
nisagul@erciyes.edu.tr

Contact information

Dr Nisa Gul Amuk
Scientific

Erciyes Üniversitesi diş Hekimliği Fakültesi Ortodonti Anabilim Dalı
Kayseri
38039
Türkiye

ORCiD logoORCID ID 0000-0002-3752-7100
Phone +905309237573
Email nisa.gul86@hotmail.com

Study information

Primary study designInterventional
Study designInterventional prospective single-center double-blinded randomised controlled parallel trial
Secondary study designRandomised parallel trial
Study type Participant information sheet
Scientific titleChanges in pharyngeal airway dimensions following incremental and maximum bite advancement during Herbst appliance therapy in young adult patients: a randomized prospective clinical study
Study objectivesNull hypothesis:
There is no difference between maximum bite advancement and ıncremental advancement with Herbst appliance therapy on pharyngeal airway dimensions and hyoid bone position.
Ethics approval(s)Erciyes University Clinical Trials Ethical Committee, 06/12/2011, 2011/107
Health condition(s) or problem(s) studiedSkeletal class II malocclusion with mandibular retrognathy
InterventionParticipants will be randomly allocated to receive either maximum advancement or incremental advancement in a 1:1 ratio using a random number table.
Both groups will receive mandibular advancement using the Herbst-RPE appliance with a stainless steel casted splint design.For the group receiving maximum advancement, advancement will be adjusted until a tet-a-tet incisor relation or super class I molar relationship is obtained. This will be completed for approximately 9-10 months. For the group receiving incremental advancement, a 2 mm shim will be inserted to the pivot ends of the plungers after a 4-5 mm initial forward movement of the mandible. For this group, advancement steps will continue every 2 months until a tet-a-tet incisor relation or super class I molar relationship is obtained.
Intervention typeDevice
Phase
Drug / device / biological / vaccine name(s)
Primary outcome measure(s)

Changes in pharyngeal airway and hyoid position, assessed using lateral cephalometric radiography before using the Herbst-RPE appliance and immediately after appliance removal

Key secondary outcome measure(s)

Skeletal changes, assessed using lateral cephalometric radiography before using the Herbst-RPE appliance and immediately after appliance removal

Completion date05/09/2017

Eligibility

Participant type(s)Patient
Age groupOther
SexAll
Target sample size at registration50
Total final enrolment48
Key inclusion criteria1. Skeletal Class II malocclusion (ANB angle >4°) and mandibular retrognathy (SNB <78°)
2. Bilateral Class II molar and canine relationship (at least 3.5 mm)
3. Increased overjet (more than 7 mm)
4. Normal or decreased vertical dimensions (SN-GoGn ≤32)
5. Minimal crowding (≤4) and no missing teeth on upper and lower arches
6. Aged 14-18 years
Key exclusion criteria1. Craniofacial anomalies
2. Musculoskeletal diseases
3. Severe facial asymmetry
4. Severe maxillary transverse deficiency
5. Poor oral hygiene
Date of first enrolment01/10/2014
Date of final enrolment01/10/2015

Locations

Countries of recruitment

  • Türkiye

Study participating centre

Erciyes University, Faculty of Dentistry, Department of Orthodontics
Kayseri
38039
Türkiye

Results and Publications

Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryData sharing statement to be made available at a later date
IPD sharing planThe data sharing plans for the current study are unknown and will be made available at a later date

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 24/05/2019 26/10/2020 Yes No
Participant information sheet Participant information sheet 11/11/2025 11/11/2025 No Yes

Editorial Notes

26/10/2020: The following changes were made to the trial record:
1. Publication reference added.
2. The total final enrolment was added.
19/12/2018: Internal review.