A Commentary on

Doğramacı E J, Brennan D S.

The long-term influence of orthodontic treatment on adults' psychosocial outcomes: An Australian cohort study. Orthod Craniofac Res 2019: DOI: 10.1111/ocr.12327. [Epub ahead of print] PMID: 31132228.

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Commentary

Baseline orthodontic need among 13-year-olds was established in 1988-891 and these individuals were contacted in 2005-06 to take part in a long-term population based study 'Oral Health of Adults Entering their Fourth Decade'. This cohort of participants (who were 30 years old) answered a questionnaire about their education, income, demographics, history of orthodontic treatment and psychosocial health. These variables provided data for the study. An obvious question relates to the timing of publication. Even though the data collection was completed in 2006, the current paper is published in 2019, a significant time lapse for which the authors provide no explanation.

It is not clear if the central question asked in this study 'Does fixed appliance therapy in adolescents have a positive influence on psychosocial outcomes?' was an a priori hypothesis of the 1988 study or was it chosen ad-hoc after collection of 2005 survey data. If it were not a part of the original study, it would be improper to combine data collected for different purposes.

A major concern in the study is the lack of justification behind choosing the psychosocial outcomes and the relevance of survey instruments used. For example, it is hard to understand the rationale for association between Perceived Health Competence Scale (PHCS) - a measure of the degree to which an individual feels capable of effectively managing his or her health outcomes - and orthodontic treatment received during adolescence. Similarly, Multidimensional Scale of Perceived Social Support (MSPSS) measures an individual's perception of how much he or she receives outside social support. While social support has been studied in the context of preventing and managing depression, emotional distress in physically ill patients, adverse psychological impacts among adolescents2 as well as chronic diseases,3 there is no precedent or rationale for using this scale against the backdrop of orthodontic treatment at adolescence and social support at 30 years.

The authors could have used any of a variety of relevant validated indices that have been successfully used in orthognathic surgery including the Problems With Oral Function questionnaire; the Rosenberg Self-Esteem Scale; Oral Health Status Questionnaire; and Oral Health Impact Profile.4

If the intent of the authors was to evaluate the influence of orthodontic treatment on psychosocial outcomes, choosing the most severe malocclusion (DAI >36) as reference is not appropriate. The group with minor malocclusion (DI <25) instead should have served as reference. Choosing the most severe group as reference erases the potential impact of orthodontic therapy because it is in these patients treatment would have been most useful.

Focusing on the results themselves, the data reveals that education level and annual income were the most reliable predictors of psychosocial wellbeing, as reflected by statistical significant differences across all four domains. However, data was rarely coherent for early orthodontic treatment: participants with definite malocclusion who did not receive treatment had a significantly better outcome in optimism domain but not in the other three measures. It is also important that many of the significant predictors became insignificant after adjustments were made to the statistical models.

The finding that untreated participants across the cohort had a better psychosocial outcome (significant only for optimism) could be partly attributed to the fact that the number of survey responders who did not receive orthodontic treatment (291) were almost twice the number of participants that had prior orthodontic treatment (157).

Overall, the authors concluded that prior orthodontic treatment makes no difference to psychosocial outcomes. This statement goes beyond the data that were available. The conclusion that can be drawn is that orthodontic treatment may not improve psychosocial outcomes but that this study does not provide enough evidence to show that it does not.