With profound interest, we read and discussed an article in the September issue investigating oral health–related quality of life (OHRQOL) in children treated for anterior open bite (AOB) (Pithon MM, Magno MB, da Silva Coqueiro R, de Paiva SM, Marques LS, Paranhus LR, et al. Oral health–related quality of life of children before, during, and after anterior open bite correction: a single-blinded randomized controlled trial. Am J Orthod Dentofacial Orthop 2019;156:303-11). We appreciate the authors for taking efforts to conduct and publish this research. After reading it, we have queries, some generic in nature and a few specific to the context of the article.
It is well accepted that quality of life (QOL) and oral health–related QOL (OHRQOL) are multidimensional constructs with many measurable and even unmeasurable dimensions. A finite number of measurable dimensions have been incorporated into various psychometric scales to assess OHRQOL. However, we noted a tendency to dilute these constructs recently. After orthodontic treatment, an improvement in the OHRQOL status of patients can be expected, but an assessment a few weeks after appliance placement merely reflects an appliance-induced transient discomfort rather than a true OHRQOL change because the constructs of OHRQOL are relatively permanent. This has been rightly pointed out by Locker when he mentioned that there is a general tendency among researchers to use QOL as a universal suffix, for example, smile-related QOL or nutrition-related QOL.
We are interested in knowing how the institution’s ethics committee condoned the 1-year delay in starting treatment for the control group subjects, and how the investigators handled the situation when a concealed brown envelope was drawn by the control subjects, placing them in the no-treatment group. The ethical issues attached to randomized clinical trials, along with other problems such as lack of generalizability of results, have made at least some researchers ask whether randomized clinical trials are needed to answer everything in orthodontics.
To be more specific to this research, we have the following queries:
Was sex-based stratification performed to get an equal number of males and females in the control and intervention groups?
The specific outcome of the pilot study on which the main sample size was based was not explained in the manuscript.
The possibility of an enhancing Hawthorne effect because of repeated questionnaire administration in young children biasing the outcome cannot be overlooked.
The normative outcome of AOB correction (although not the primary outcome of this study) was not quantified or evaluated; however, a correlation of this change with the improvement in OHRQOL (primary outcome of this study) is essential for a meaningful interpretation of the results.
It could not be differentiated from this research whether the positive change in OHRQOL status after treatment was due to AOB correction or appliance removal, because appliance placement itself was associated with worsening of OHRQOL initially.
We hope a response from the authors will help a discerning researcher or clinician to interpret the results of this study meaningfully.
∗ The viewpoints expressed are solely those of the author(s) and do not reflect those of the editor(s), publisher(s), or Association.