A comparison of mandibular archwidth changes using two different bracket systems

• Register: ISRCTN
• Last refreshed on: 12 February 2013
• Main ID: ISRCTN68289972
• Date of registration: 03/01/2012
• Primary sponsor: Queen Alexandra Hospital (UK)
• Public title: A comparison of mandibular archwidth changes using two different bracket systems N/A
• Scientific title: A comparison of mandibular archwidth changes using two different bracket systems: a randomised controlled clinical trial
• Date of first enrolment: Dec 1 2011
• Target sample size: The target total recruitment of participants for the trial is 86 patients
• Recruitment status: Ongoing/Recruiting
• URL: http://isrctn.org/ISRCTN68289972
• Study type: Interventional
• Study design: Randomised controlled trial

Countries of recruitment

United Kingdom

Contacts

• Name: Becky Walker

Key inclusion & exclusion criteria

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
Exclusion criteria: 1. Impacted teeth in the lower arch
2. Hypodontia in the lower arch
3. Extractions in the lower arch

Age minimum:
Age maximum:
Gender:

Health Condition(s) or Problem(s) studied

Orthodontics ? mandibular archform

Intervention(s)

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

Primary Outcome(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.

Secondary Outcome(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

Secondary ID(s)

11/SC/0421

Source(s) of Monetary Support

Investigator initiated and funded

Secondary Sponsor(s)

N/A