Choi SH, et al. – This article endeavoured to assess changes in mental health, self–reported masticatory ability, and oral health–related quality of life (OHRQoL) during orthodontic treatment in adults. This prospective study suggested that OHRQoL temporarily deteriorates, with the development of psychological and social disabilities, during orthodontic treatment. This is related to the baseline age, psychological health, and self–reported masticatory function. The findings showed that patients recover once the treatment is complete.