Floating norms and post-treatment overbite in open bite patients

Area of Science:

• Orthodontics
• Dental Cephalometry

Background:

• Open bite treatment presents challenges in predicting long-term stability.
• Floating norm systems aim to stratify patients based on relapse risk.
• Understanding risk factors is crucial for effective open bite management.

Purpose of the Study:

• To investigate the clinical significance of the Bergen Box (BB) and Segner-Hasund Harmonybox (SHH1, SHH2) systems in predicting open bite treatment outcomes.
• To assess the influence of treatment modalities on predicting open bite treatment results.
• To evaluate the reliability of these systems in distinguishing between high-risk and low-risk patients for open bite relapse.

Main Methods:

• Retrospective cephalometric analysis of 83 open bite patients before treatment (T1) and after retention (T2).
• Classification of patients into 'high risk' and 'low risk' categories based on specific skeletal configurations within the BB, SHH1, and SHH2 systems.
• Correlation of risk configurations and treatment modalities with overbite stability at T2.

Main Results:

• Low-risk patients generally achieved normal overbite post-treatment, irrespective of the system used.
• SHH1 and SHH2 risk configurations at T1 were significant predictors of overbite at T2, with SHH1 showing slightly better performance.
• Treatment modalities influenced prediction accuracy; posterior bite splints showed a bite-opening effect, while removable retention appliances had a bite-closing effect.

Conclusions:

• The SHH1 and SHH2 systems demonstrate clinical value in identifying low-risk patients for open bite treatment.
• Reliable prediction of treatment outcomes for high-risk patients is enhanced by considering both risk configurations and specific treatment modalities.
• The study supports the utility of SHH systems in guiding open bite treatment strategies and managing relapse potential.