A comparison of mandibular archwidth changes using two different bracket systems

ISRCTN	ISRCTN68289972
DOI	https://doi.org/10.1186/ISRCTN68289972
Protocol serial number	11/SC/0421
Sponsor	Queen Alexandra Hospital (UK)
Funder	Investigator initiated and funded

Submission date: 09/11/2011
Registration date: 03/01/2012
Last edited: 28/02/2018

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Oral Health

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Orthodontic treatment with fixed braces is used to improve the appearance, position and function of crooked or abnormally arranged teeth. Fixed braces are made up of brackets that are glued to each tooth and linked with wires. Conventional (non-self-ligating) brackets use an elastic module to hold the wire in place, whereas self-ligating brackets do not. The aim of this study is to compare the results of these two types of orthodontic bracket, looking at changes in the width of the lower tooth arch.

Who can participate?
Patients aged between 11 and 21 who require fixed braces.

What does the study involve?
Participants are randomly allocated into one of the two groups. Each group is treated with braces with a different bracket system, either self-ligating brackets or non-self-ligating brackets. A questionnaire is used to assess patient pain and anxiety, and any appliance breakages are recorded.

What are the possible benefits and risks of participating?
Not provided at time of registration

Where is the study run from?
Queen Alexandra Hospital (UK)

When is the study starting and how long is it expected to run for?
December 2011 to December 2013

Who is funding the study?
Investigator initiated and funded

Who is the main contact?
Dr Becky Walker

Contact information

Dr Becky Walker
Scientific

Orthodontic Department
Queen Alexandra Hospital
Cosham
Portsmouth
PO6 3LY
United Kingdom

Study information

Primary study design	Interventional
Study design	Randomised controlled trial
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title	A comparison of mandibular archwidth changes using two different bracket systems: a randomised controlled clinical trial
Study objectives	Null hypothesis: There is no significant difference in archform changes between self-ligating brackets and non-self ligating brackets using super elastic nickel titanium archwires
Ethics approval(s)	NRES Committee South Central - Oxford A, 12/10/2011, ref: 11/SC/0421
Health condition(s) or problem(s) studied	Orthodontics mandibular archform
Intervention	Patients will be randomised into one of the two arms of study. Each arm of study will use a different bracket system, either: 1. Self-ligating brackets (Damon Q) 2. Non self-ligating brackets Treatment will then proceed with both bracket systems using the same archwire sequence: 1. 0.014 inch round NiTi archwire 2. 0.014x 0.025 inch Damon Copper NiTi archwire 3. 0.018x 0.025 inch Damon Copper NiTi archwire
Intervention type	Other
Primary outcome measure(s)	Mandibular archwidth changes 1. Alginate impressions for study models of the maxillary and mandibular arches will be taken at: T0: Before placement of fixed appliances, at the start of treatment. T1: Removal of 0.014 inch round NiTi archwire and placement of 0.014 x 0.025 inch NiTi archwire T2: Removal of 0.014 x 0.025 inch NiTi archwire and placement of 0.018 x 0.025 inch NiTi archwire T3: Removal of 0.018 x 0.025 inch NiTi archwire and placement of next archwire These study models will be used to measure mandibular archwidth between the 2 groups at T0, T1, T2, and T3 measured at 4 places across arch (c-c, p1-p1, p2-p2, m-m). 2. Arch width measurements (from study models) c-c: Intercanine width: distance between the mandibular canine tips or between the central fossae on the surfaces in case of worn cusps p1-p1: First inter premolar width: distance between the central fossae on the occlusal surfaces of the maxillary first premolars p2-p2: Second inter premolar width: distance between the central fossae on occlusal surfaces of the maxillary second premolars m-m: Intermolar width: distance between the mesial ends of the central fissures on the occlusal surfaces of the maxillary first molars Measurement for the inter arch distances will be measured in mm using fine-pointed digital callipers. The measurements will be approximated to the first decimal place. All measurements will be carried out by a single investigator to avoid inter-operator error. Intra-operator reliability will be assessed by repeating measurements on 10 study casts 2 weeks apart and carrying out an error analysis.
Key secondary outcome measure(s)	1. Pain perception will be recorded using a pain questionnaire, to be completed by patients following each archwire change at: 1.1. 2 hrs 1.2. 6 hrs 1.3. Bedtime on day of appointment 1.4. When they wake up the day after their appointment 1.5. When they wake up 2 days after their appointment 1.6. When they wake up 3 days after their appointment 2. Anxiety experienced will be recorded using an anxiety questionnaire, to be completed by participant at end of appointment 3. Any appliance breakages during treatment will be recorded
Completion date	01/12/2013

Eligibility

Participant type(s)	Patient
Age group	Child
Lower age limit	11 Years
Upper age limit	21 Years
Sex	All
Target sample size at registration	86
Key inclusion criteria	Patients: 1. Aged between 11 and 21 years of age 2. In the permanent dentition 3. Requiring upper and lower fixed appliances 4. Receiving treatment in the lower arch on a non-extraction basis 5. With mild lower arch crowding 6. All malocclusions
Key exclusion criteria	1. Impacted teeth in the lower arch 2. Hypodontia in the lower arch 3. Extractions in the lower arch
Date of first enrolment	01/12/2011
Date of final enrolment	01/12/2013

Locations

Countries of recruitment

United Kingdom
England

Study participating centre

Queen Alexandra Hospital

Portsmouth
PO6 3LY
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

28/02/2018: No publications found, verifying study status with principal investigator.
21/01/2016: Plain English summary added