First, Do No Harm: Are White Spot Lesions Less Likely to Develop with Aligners? This Study Says Yes.

Initial and final photographs were visually assessed for the presence of white spot lesions. From Buschang et al.

BY TATE H. JACKSON & WILLIAM V. GIERIE

STUDY SYNOPSIS:
Is oral health better for patients treated with clear aligner therapy? A retrospective study from Texas A&M set out to address that question by comparing the incidence of White Spot Lesions (WSL’s) in two groups of consecutively-treated patients.



The aligner group contained 244 patients, while the group treated with braces included 204 patients. 85% of the aligner group were treated in a single private practice, while 52% of the braces group were treated in a single academic setting. There was no statistically significant difference in the gender or age of each group (both had a mean of ~30 years with a standard deviation of 11.5 to 14 years), but there was a difference in treatment duration, with the aligner group treated in less time (1.5 years vs. 2.5 years for braces).

At the end of treatment, the aligner group demonstrated a very low incidence of new WSLs, 1.2%, while the group treated with braces had an incidence of 25.7%. For both groups, maxillary teeth were more likely to be affected. Not surprisingly, WSL incidence was lower in the private setting, although the difference in incidence between groups (aligners vs. braces) was consistent in both the academic and private settings.
 
WHAT THE PROFESSORS THINK
Although this study suffers from the fact that it is observational and retrospective, there are a couple of key insights to note.

Both groups, the aligner group and the braces group, started with a similar pre-treatment prevalence of WSLs : 9% for the aligner group and 10% for the braces group, suggesting that the natural incidence of WSLs in these patients was similar before treatment began.

With treatment, only 3 out of 244 aligner patients developed new WSLs, while 52 of 204 patients in braces group did.
Given the incredibly low incidence of new WSLs in the aligner group, the authors were wise to only analyze risk factors for developing WSLs in the braces group. As expected, 1) poor oral hygiene that worsened and 2) longer treatment time both increased the risk of WSL development.

To most orthodontists in practice these results will be no surprise. Using removable appliances can allow for better oral hygiene – and thus aligners are less likely to be associated with WSL formation.

So, does that mean one might use this study to support the use of clear aligner therapy in any patient simply because their hygiene is poor? Certainly not based on that single factor alone. The authors correctly point out that this study does not account for the complexity of the malocclusion or specific treatment mechanics needed.

In this study, aligner patients were more likely to improve their oral hygiene during treatment, while braces patients were more likely to worsen. Wearing aligners requires compliance for success – just like oral hygiene. So, are patients who successfully wear aligners more capable of good oral hygiene anyway? This study does not address that question directly, but it does suggest that it might be true.

In practice, these data can be used to better communicate with the healthy motivated patient who is concerned about their individual risk for WSLs:

• Patients who successfully wear aligners, might also be more likely to have good oral hygiene practices and have a very low incidence of WLSs during treatment – perhaps less than 2%.

What about the patient who is not motivated? Should aligners be considered for patients who already have WSLs because their risk of new lesions is lower with aligners?

• As long as aligners could deliver an acceptable clinical outcome, then this study suggests yes. Why? It is possible to obtain a non-ideal treatment outcome with either aligners or braces. In high-risk situations, aligners might have a better chance of ‘doing no harm’ to a patient’s oral health, even if the esthetic outcome is less ideal.

Article Reviewed: Peter H. Buschang; David Chastain; Cameron L. Keylor; Doug Crosby; Katie C. Julien. Incidence of white spot lesions among patients treated with clear aligners and traditional braces. Angle Orthodontist. Online 2018.

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