Key Insights from a Study on Invisalign to Braces Conversion Rates

Orthodontic treatments often promise convenience and effectiveness, but how well do aligners like Invisalign live up to their claims? A recent retrospective study sheds light on key aspects of Invisalign treatment, including the percentage of patients who switch to braces, the number of refinement scans required, and the discrepancies between estimated and actual treatment lengths. This analysis, involving 500 patients across two orthodontic offices, provides valuable insights for clinicians and patients alike.

Kravitz, Neal D., Bassel Dalloul, Yara Aba Zaid, Chandani Shah, and Nikhilesh R. Vaide. "What Percentage of Patients Switch from Invisalign to Braces? A Retrospective Study Evaluating the Conversion Rate, Number of Refinement Scans, and Length of Treatment." American Journal of Orthodontics and Dentofacial Orthopedics 163, no. 4 (2023): 526–30. https://doi.org/10.1016/j.ajodo.2022.03.016.

Potential Biases in the Study

1. Affiliation with the Brand

   
   

   • As a KOL (Key Opinion Leader) for Invisalign, Neal D. Kravitz may have an interest in presenting Invisalign’s results in a more favorable light. This doesn’t necessarily mean the data was manipulated, but it could influence the focus of the analysis or the omission of negative aspects.

   • For instance, reporting a relatively low conversion rate (17.2%) could be seen as a way to highlight Invisalign’s effectiveness despite common criticisms regarding its predictability.

     
     

2. Sample Selection

   • The patients included in the study were treated at clinics with highly experienced orthodontists who hold the highest Invisalign certification level (Diamond Plus). This likely reduces the conversion rate since treatments were planned and executed by professionals with mastery of the technique.

   • These findings may not reflect the average experience of other orthodontists who are not Diamond Plus providers or who manage fewer Invisalign cases.

     
     

3. Unaccounted Variables

   
   

   • The study doesn’t discuss critical factors such as patient compliance, socioeconomic profile, or the specific complexity of malocclusions (beyond general classifications like Class I, II, III). These variables can significantly influence the outcomes.

   • Additionally, it is unclear whether the decision to switch to braces was driven by the patient’s preferences or recommended by the orthodontist, which is essential for evaluating the true effectiveness of the treatment.

Conclusion

This study highlights Invisalign’s performance but must be interpreted cautiously due to potential biases. The reported 17.2% conversion rate to braces likely underrepresents real-world scenarios, especially in complex cases or less experienced practices. As a Key Opinion Leader (KOL) for Invisalign, the lead author’s affiliation may have influenced the findings.

The sample, treated by highly skilled Diamond Plus orthodontists, and unaddressed factors like patient compliance or case complexity limit the study’s broader applicability. Orthodontists should manage patient expectations, monitor progress closely, and use advanced tools.

Future research with diverse, independent samples is essential to validate these findings.