Psychosocial reward of orthodontic treatment in adult patients. 
The purpose of this study was to assess the short-term psychosocial impact of dental aesthetic improvement in adult subjects.  Sixty-nine adult patients (61 females and 8 males, aged 21-59 years) requesting aesthetic dental improvement were prospectively and randomly recruited for the study in a private orthodontic office.  A general interview included patient motivation and expectations from treatment.  After clinical examination, discussion of the mode of treatment and the expected outcome, the patients were requested to complete the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) with several additions.  The duration of their treatment was 6-14 months, and the main goals were tooth alignment, crowding alleviation, or space closure.  After removal of the appliances, they completed an identical PIDAQ.  Each patient served as his/her own control.  Assessment of the impact of aesthetic improvement was based on the responses to the same questions relating to the patients' perceived dental aesthetics before and after treatment, their self-esteem, and changes in their social behaviour resulting from the treatment.  The data were analysed using Cohen's and Pearson's correlation analyses and chi-square and Student's t-tests.  A statistically significant improvement (P < 0.001) was found for all four factors: dental self-confidence (DSC), social impact (SI), psychological impact (PI), and aesthetic concern (AC).  The reliability of the questionnaire, using Cronbach's alpha, was between 0.709 and 0.947.  The degree of significance was not related to age, marital status, education, or gender.  Dental aesthetics generated a significant improvement in adult patients' quality of life for the period examined (up to 6 months post-treatment).