Stability of Bimaxillary Proclination Cases Following Fixed Appliances Treatment: A Randomized Control Trial

Study Overview
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Brief Summary
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Bimaxillary dental proclination is the condition where the upper and lower dental arches are procline thus increase lip fullness. Since the aim of orthodontic treatment in bimaxillary proclination in to get flatten profile where the incisor inclinations are purposely reduced or interincisal angle are increased, therefore it is guarded for corrected dentition to maintain stable or not post orthodontic treatment.Therefore, this study is looking into evidence which is the best retainer to maintain stability of bimaxillary proclination cases following fixed appliances treatment.

Detailed Description
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Study title Stability of Bimaxillary Proclination Cases Following Fixed Appliances Treatment: A Randomized Control Trial Study Population Pre-treatment of bimaxillary proclination patient who completed active orthodontic treatment with fixed appliances and are scheduled to debond at Orthodontic Clinic, Faculty of Dentistry, University of Malaya. Study Design Randomized, prospective, single-center control trial. Three parallel arm groups of patients will be assigned for 3 types of retention methods; 1.VFR 2.Fixed bonded retainer 3.Double regime (bonded & VFR) Aim of study To determine the best mode of retention to maintain the stability of bimaxillary proclination cases treated by four premolars extraction and fixed appliances. Specific Objectives To measure the post treatment dental and soft tissue stability in the retention phase up to one-year post treatment To compare the effectiveness the different types of retainers to maintain the stability of orthodontically corrected bimaxillary proclination To determine the impact of the different types of retainers on the OHRQoL Sample Size The sample size calculation was done using G*power software version 3.1.The f-test, repeated measures ANOVA, within-between interaction were used. Based on the effect size of 0.43 (Keating PJ 1986), maximum accuracy (power) of 80% (0.80), error of 5% (0.05), number of groups are 3, number of measurements are 2, correlation among repetitive measures is 0.5, nonsphericity correlation is 1, total number of 18 subjects needed for entire study. Allowing for 50% dropout, a final sample size of 27 subjects with 9 subjects per group will be used. Study Duration September 2019 - Disember 2021

Official Title
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Stability of Bimaxillary Proclination Cases Following Fixed Appliances Treatment: A Randomized Control Trial

Conditions
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Bimaxillary Proclination

Intervention / Treatment
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* Other: Vacuum formed retainer, fixed bonded retainer, vacuum formed and fixed bonded retainer


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pretreatment bimaxillary proclination patients with interincisal angle less than 125º (Keating PJ 1986). Patients with fixed orthodontic appliances treatment on both arches consisting of the extraction of 4 premolars (Keating 1986). Both arches are indicated for retainers. Pre-treatment lateral cephalometric radiograph of adequate diagnostic quality. Exclusion Criteria: Pretreatment spacing eg: Median diastema. No change or proclined lower labial segment post treatment. Early debond patient. Patient intended to relocate within study period. Hypodontia that require prosthesis, cleft lip and/or cleft palate, or orthognathic cases. Patients with learning disabilities and unable to listen, speak and read written instructions in Bahasa Melayu or English.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: This study will be encompassed 3 groups of patients that will be assigned for 3 types of retention methods; VFR (upper and lower arches) Fixed bonded retainers (upper and lower arches) Double regime (bonded retainers & VFR for upper and lower arches). (Abd Rahman 2016)
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Vacuum formed retainer group<br>It will be constructed following manufacturer's instructions for the thickness. | Other: Vacuum formed retainer, fixed bonded retainer, vacuum formed and fixed bonded retainer<br>* Patients will be instructed to wear the removable vacuum form retainer for 8 to 10 hours per day and only removed the retainers during tooth brushing. (Thickett 2010), (Gill 2007). The vacuum formed retainer will be constructed using thermoplastic material that will be purchased from manufacturer at 1.0mm thickness. Meanwhile, bonded retainer will be done using Ormco ® response deadsoft retainer wire size 0.190 round, made in USA by ORMCO Corporation, the fixed bonded wire will be extended distal to the extraction spaces that were previously closed by fixed appliances on both the upper and lower arches. The bonded retainer will be wearing by patients for 24 hours. Double regime retainer that will be comprised of vacuum formed and bonded retainer will be constructed using the same properties as vacuum formed retainer and bonded retainer. A standard oral and written instruction will be given to patients regarding retainer's uses. (Shawesh M et.al, 2009).<br>|
| Experimental: Fixed bonded retainer group<br>fixed bonded wire will be bonded on individual tooth extended distal to extraction space that were previously closed by fixed appliances treatment. | Other: Vacuum formed retainer, fixed bonded retainer, vacuum formed and fixed bonded retainer<br>* Patients will be instructed to wear the removable vacuum form retainer for 8 to 10 hours per day and only removed the retainers during tooth brushing. (Thickett 2010), (Gill 2007). The vacuum formed retainer will be constructed using thermoplastic material that will be purchased from manufacturer at 1.0mm thickness. Meanwhile, bonded retainer will be done using Ormco ® response deadsoft retainer wire size 0.190 round, made in USA by ORMCO Corporation, the fixed bonded wire will be extended distal to the extraction spaces that were previously closed by fixed appliances on both the upper and lower arches. The bonded retainer will be wearing by patients for 24 hours. Double regime retainer that will be comprised of vacuum formed and bonded retainer will be constructed using the same properties as vacuum formed retainer and bonded retainer. A standard oral and written instruction will be given to patients regarding retainer's uses. (Shawesh M et.al, 2009).<br>|
| Experimental: Vacuum formed retainer and fixed bonded retainer<br>Double regime retainer that will be consisted of bonded retainer and vacuum formed retainer for upper and lower arch. | Other: Vacuum formed retainer, fixed bonded retainer, vacuum formed and fixed bonded retainer<br>* Patients will be instructed to wear the removable vacuum form retainer for 8 to 10 hours per day and only removed the retainers during tooth brushing. (Thickett 2010), (Gill 2007). The vacuum formed retainer will be constructed using thermoplastic material that will be purchased from manufacturer at 1.0mm thickness. Meanwhile, bonded retainer will be done using Ormco ® response deadsoft retainer wire size 0.190 round, made in USA by ORMCO Corporation, the fixed bonded wire will be extended distal to the extraction spaces that were previously closed by fixed appliances on both the upper and lower arches. The bonded retainer will be wearing by patients for 24 hours. Double regime retainer that will be comprised of vacuum formed and bonded retainer will be constructed using the same properties as vacuum formed retainer and bonded retainer. A standard oral and written instruction will be given to patients regarding retainer's uses. (Shawesh M et.al, 2009).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stability: Change in the incisal inclinations | To measure any changes in the upper incisor to maxillary plane angle, lower incisor to mandibular plane angle and changes in interincisal angle. This angular measurement will be measured in degree. | 1 year post debond of orthodontic fixed appliances | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stability: Soft tissue changes | To measure any changes in the nasolabial angle, labiomental angle. These will be measured in degree. The upper and lower lips distances in relation to Rickett's Esthetic line will be measured in millimeter (mm). | 1 year post debond of orthodontic fixed appliances | 
| Stability of dentition | Any irregularity at lower labial segment will be measured using Little Irregularity Index. This will be measured in millimeter (mm). | 1 year post debond of orthodontic fixed appliances | 
| Changes in arches parameters | Intra arch changes will be measure based on intermolar width, intercanine width, arch length, overbite and overjet. This will be measured in millimeter (mm). | 1 year post debond of orthodontic fixed appliances | 
| Impact of retainers on Oral Health Related Quality of Life | Patients perception towards retainer will be measured using an Oral Health Related Quality of Life (OHIP) questionnaire. Patients will be assessed on how often they experienced the problems mentioned in the questionnaire throughout the time they use the retainers. The scale will be recorded as very often, quite often, sometimes, never, don't know. | 1 year post debond of orthodontic fixed appliances | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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stability, retainers