Related Experiment Videos
Stability and relapse of dental arch alignment
1Department of Orthodontics, School of Denistry, University of Washington, Seattle 98195.
British Journal of Orthodontics
|August 1, 1990
Summary
Orthodontic treatment outcomes show predictable changes like arch length reduction and canine width decrease. Post-treatment crowding is common and unpredictable, with no clear predictors found.
Area of Science:
- Dentistry
- Orthodontics
- Dental Research
Background:
- Longitudinal study assessing orthodontic treatment stability and failure.
- Utilized a dataset of over 600 patient records spanning more than 35 years.
- Included treated (premolar extraction, non-extraction, arch enlargement) and untreated normal occlusion cases.
Purpose of the Study:
- To evaluate long-term physiological changes after orthodontic treatment.
- To identify factors influencing treatment stability and relapse.
- To assess the predictability of post-treatment changes, specifically anterior crowding.
Main Methods:
- Analysis of patient records including clinical findings, casts, and cephalometric radiographs.
- Comparison of changes in arch length, arch width, and anterior crowding over time.
- Evaluation of the influence of third molar status on treatment outcomes.
Main Results:
- Arch length reduction observed post-treatment and in untreated controls.
- Mandibular canine width typically decreases after treatment, irrespective of expansion.
- Mandibular anterior crowding is a progressive issue into adulthood.
- Third molar presence/absence/impaction showed minimal impact on relapse.
- Post-retention crowding is highly variable and unpredictable.
Conclusions:
- Orthodontic treatment and natural development share some physiological changes.
- Predicting post-treatment crowding severity is not feasible with current pretreatment data.
- Long-term stability and relapse patterns require further investigation.