Vacuum-formed Retainer Versus Bonded Retainer to Prevent Relapse After Orthodontic Treatment

Not Applicable

Completed

Conditions: Orthodontics
Retention

Interventions: Device: CTC retainer
Device: Essix retainer maxilla
Device: Essix retainer mandible
Procedure: Alginate impression
Other: Questionnaire

Registration Number: NCT03070444

Lead Sponsor: Region Gävleborg

Brief Summary: The purpose of this trial is to evaluate and compare stability after orthodontic treatment with an Essix retainer and a bonded cuspid-to-cuspid retainer (CTC), respectively in the mandibular arch and longitudinally follow these patients over time up to 5 years. The patients' perceptions of the two methods are also evaluated with questionnaires during the follow-up period.

A further aim of this study is to analyze the relationship between diagnosis, treatment outcome, treatment time, age at start of treatment and stability with an Essix retainer in the maxilla.

The null hypotheses are:

* that there is no difference in retention capacity between Essix retainer and cuspid-to-cuspid retainer

* that there is no difference in patients' perception between Essix retainer and cuspid-to-cuspid retainer

* that there is no difference in retention capacity for Essix retainer in the maxilla concerning diagnosis before treatment, treatment outcomes, treatment time and age at start of treatment

Detailed Description: The study is conducted at the Orthodontic Clinic, Gävle, Sweden and consists of 104 patients. All patients are treated with fixed appliances in the upper and lower jaw (standard .022 straight wire), both with and without extractions. The patients are randomized into two groups with 52 patients in each group (Group A: cuspid-to-cuspid retainer, Group B: Essix retainer).

Dental cast are obtained at the debond appointment (T1) and at the follow-up controls after six months (T2), 18 months (T3) and 60 months (T4) for both groups.

At the visit two weeks in retention and at the follow-up visits after 6, 18 and 60 months the patients assess questionnaires in order to evaluate their experience of retention with the retention device.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 104

Inclusion Criteria

Patients treated with fixed appliances in both the maxilla and the mandible

Exclusion Criteria

Rapid Maxillary Expansion (RME) for patients with severe transversal malocclusion
Treatment with segmented appliances
Patients with craniofacial anomalies and patients requiring orthognatic surgery
Patients with missing mandibular incisor

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group A: CTC retainer + Essix retainer	CTC retainer	The CTC is bonded directly after debonding. The Essix retainer maxilla is handed out to the patient the same day after removal of fixed appliances. Alginate impressions are taken at the follow-up visits. Questionnaires are completed at the follow-up visits.
Group A: CTC retainer + Essix retainer	Alginate impression	The CTC is bonded directly after debonding. The Essix retainer maxilla is handed out to the patient the same day after removal of fixed appliances. Alginate impressions are taken at the follow-up visits. Questionnaires are completed at the follow-up visits.
Group B: Essix retainer + Essix retainer	Essix retainer maxilla	The Essix retainer maxilla and Essix retainer mandible are handed out to the patient the same day after removal of fixed appliances. Alginate impressions are taken at the follow-up visits. Questionnaires are completed at the follow-up visits.
Group B: Essix retainer + Essix retainer	Essix retainer mandible	The Essix retainer maxilla and Essix retainer mandible are handed out to the patient the same day after removal of fixed appliances. Alginate impressions are taken at the follow-up visits. Questionnaires are completed at the follow-up visits.
Group B: Essix retainer + Essix retainer	Alginate impression	The Essix retainer maxilla and Essix retainer mandible are handed out to the patient the same day after removal of fixed appliances. Alginate impressions are taken at the follow-up visits. Questionnaires are completed at the follow-up visits.
Group A: CTC retainer + Essix retainer	Essix retainer maxilla	The CTC is bonded directly after debonding. The Essix retainer maxilla is handed out to the patient the same day after removal of fixed appliances. Alginate impressions are taken at the follow-up visits. Questionnaires are completed at the follow-up visits.
Group B: Essix retainer + Essix retainer	Questionnaire	The Essix retainer maxilla and Essix retainer mandible are handed out to the patient the same day after removal of fixed appliances. Alginate impressions are taken at the follow-up visits. Questionnaires are completed at the follow-up visits.
Group A: CTC retainer + Essix retainer	Questionnaire	The CTC is bonded directly after debonding. The Essix retainer maxilla is handed out to the patient the same day after removal of fixed appliances. Alginate impressions are taken at the follow-up visits. Questionnaires are completed at the follow-up visits.

Primary Outcome Measures

Name	Time	Method
Changes in Tooth Position	Changes in tooth position (Little's Irregularity Index) were analysed 5 years (T4) after debonding (T1)	Analyses of changes in tooth position on dental casts Little's Irregularity Index (in mm) 0=no crowding/irregularity, higher scores= more crowding/irregularity (worse outcome)

Secondary Outcome Measures

Name	Time	Method
Patients' Perception	T4 (5 years follow up)	Analyses of patients' perception by validated self-report questionnaires to evaluate experiences of the retention techniques VAS (visual analog scale, 0-100) 0= low satisfaction 100= high satisfaction