Orthodontics, Retention
Conditions
Keywords
Essix retainer, Vacuum-formed retainer, Cuspid-to-cuspid retainer
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.
Interventions
DEVICECTC retainer
The CTC retainer consists of 0.8 hard Remanium® wire (Dentaurum, Germany) and is bonded with Tetric Flow (Ivoclar Vivadent, Liechtenstein) to the lower canines directly after debonding.
DEVICEEssix retainer maxilla
The Essix retainer is made of 1 mm Essix C+® Plastic (Dentsply, USA) and is handed out to the patient the same day after removal of fixed appliances.
DEVICEEssix retainer mandible
The Essix retainer is made of 1 mm Essix C+® Plastic (Dentsply, USA) and is handed out to the patient the same day after removal of fixed appliances.
PROCEDUREAlginate impression
Alginate impressions are taken to made the cuspid-to-cuspid and Essix retainers, respectively. Dental casts are obtained at the debond appointment and at the follow-up visits after 6, 18 and 60 months.
OTHERQuestionnaire
A questionnaire is completed at the follow-up visits.
Sponsors
Umeå University
Region Gävleborg
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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 |
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Group A: CTC Retainer + Essix 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.
CTC retainer: The CTC retainer consists of 0.8 hard Remanium® wire (Dentaurum, Germany) and is bonded with Tetric Flow (Ivoclar Vivadent, Liechtenstein) to the lower canines directly after debonding.
Essix retainer maxilla: The Essix retainer is made of 1 mm Essix C+® Plastic (Dentsply, USA) and is handed out to the patient the same day after removal of fixed appliances.
Alginate impression: Alginate impressions are taken to made the cuspid-to-cuspid and Essix retainers, respectively. Dental casts are obtained at the debond appointment and at the follow-up visits after 6, 18 and 60 months.
Questionnaire: A questionnaire is completed at the follow-up visits. | 52 |
| Group B: Essix Retainer + Essix Retainer 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.
Essix retainer maxilla: The Essix retainer is made of 1 mm Essix C+® Plastic (Dentsply, USA) and is handed out to the patient the same day after removal of fixed appliances.
Essix retainer mandible: The Essix retainer is made of 1 mm Essix C+® Plastic (Dentsply, USA) and is handed out to the patient the same day after removal of fixed appliances.
Alginate impression: Alginate impressions are taken to made the cuspid-to-cuspid and Essix retainers, respectively. Dental casts are obtained at the debond appointment and at the follow-up visits after 6, 18 and 60 months.
Questionnaire: A questionnaire is completed at the follow-up visits. | 52 |
| Total | 104 |
Baseline characteristics
| Characteristic | Group A: CTC Retainer + Essix Retainer | Group B: Essix Retainer + Essix Retainer | Total |
|---|---|---|---|
| Age, Continuous | 17.1 years STANDARD_DEVIATION 1.9 | 17.1 years STANDARD_DEVIATION 2.4 | 17.1 years STANDARD_DEVIATION 2.2 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 52 Participants | 52 Participants | 104 Participants |
| Region of Enrollment Sweden | 52 participants | 52 participants | 104 participants |
| Sex: Female, Male Female | 26 Participants | 26 Participants | 52 Participants |
| Sex: Female, Male Male | 26 Participants | 26 Participants | 52 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 52 | 0 / 52 |
| other Total, other adverse events | 0 / 52 | 0 / 52 |
| serious Total, serious adverse events | 0 / 52 | 0 / 52 |
Outcome results
Primary
Changes in Tooth Position
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)
Time frame: Changes in tooth position (Little's Irregularity Index) were analysed 5 years (T4) after debonding (T1)
Population: Dental casts were analysed. As data were not normal distributed, median values are reported.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Group A: CTC Retainer + Essix Retainer | Changes in Tooth Position | 0.05 millimeters |
| Group B: Essix Retainer + Essix Retainer | Changes in Tooth Position | 0.62 millimeters |
p-value: 0.000295% CI: [0.48, 1.51]GEE analysis
Secondary
Patients' Perception
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
Time frame: T4 (5 years follow up)
Population: Adolescent patients at debond (baseline), adults after 5 years
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Group A: CTC Retainer + Essix Retainer | Patients' Perception | 93 score on a scale |
| Group B: Essix Retainer + Essix Retainer | Patients' Perception | 92 score on a scale |
p-value: 0.55Wilcoxon (Mann-Whitney)