Related Experiment Video
Updated: Jun 13, 2026
07:32
Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition
Published on: February 23, 2024
Noncompliance maxillary molar distalization with the first class appliance: a randomized controlled trial
Moschos A Papadopoulos1, Aristides B Melkos, Athanasios E Athanasiou
1Associate professor and program coordinator, Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece. mikepap@dent.auth.gr
Summary
The First Class Appliance (FCA) effectively distalizes maxillary molars in mixed dentition patients with Class II malocclusion. However, this movement can cause molar tipping and anterior tooth anchorage loss.
Area of Science:
- Orthodontics
- Dental Biomaterials
Background:
- Class II malocclusion is a common dental issue.
- Maxillary molar distalization is a key orthodontic treatment strategy.
- The First Class Appliance (FCA) is a non-compliance device for molar distalization.
Purpose of the Study:
- To evaluate the treatment effects of the First Class Appliance (FCA) for distalizing maxillary first molars.
- To assess FCA efficacy in patients with Class II malocclusion and mixed dentition.
Main Methods:
- A randomized controlled trial was conducted with 26 patients (15 treatment, 11 control).
- Lateral cephalograms and dental casts were analyzed before and after treatment.
- Statistical analysis involved mixed 2-way ANOVA.
Main Results:
- The FCA achieved significant maxillary first molar distalization (4.00 mm) compared to controls (0.95 mm) in a mean of 17.2 weeks.
- Molar movement rate was 1.00 mm/month, with associated distal tipping (8.56 degrees).
- Anchorage loss observed included overjet increase (0.68 mm) and mesial movement/inclination of anterior teeth.
Conclusions:
- The FCA is an effective non-compliance appliance for molar distalization in mixed dentition.
- Treatment with FCA results in distal molar tipping and anterior anchorage loss.