The psychological dimension in the quality of life assessment in association with dental aesthetics Objectives The purpose of this study was to translate and test the reliability and validity of the PIDAQ and OIDP questionnaires; to explore the relationship between age, gender, education level, periodontal and dental status, and degree of patient satisfaction with appearance, color and position of the teeth and gingival tissue; to compare the patient's impression of maxillary anterior teeth and gingival tissue appearance with clinical examination for dentists; to determine how the patients’ desires matched the actual state of periodontal and dental status (color, shape, compression, visibility) in terms of improving the appearance; to determine how all previous dental procedures associated with patient satisfaction of tooth appearance; to examine which of the measured parameters (color, shape, tooth size, visibility ...) were significant predictors of patient satisfaction regarding the tooth appearance, as well as to examine which of the psychological, social and functional dimensions mostly discriminated the people who are happy with their dental aesthetics from the dissatisfied ones. Patients and Methods The sample consisted of 700 participants of both genders who were scheduled for dental treatment at the Clinic of Dental Medicine, Clinical Hospital Center Rijeka. The study consisted of completion of the Aesthetic questionnaire specially constructed for this purpose, as well as completion of two psychological measuring instruments - (Psychosocial Impact of Dental Aesthetic Questionnaire - PIDAQ) and (Oral Impact on Daily Performances - OIDP ). Results The hypothesis was confirmed. Participants who wanted a fixed prosthetic appliances on the front teeth were significantly older (M = 48.24 years) compared to those who did not want them (M = 43.63 years, p = 0.001). Factor analysis of the Aesthetic questionnaire indicated that the assessment scale created for this purpose and based on an assessment of the five elements of satisfaction was one-dimensional, e.g. it measured the overall level of satisfaction. Reliability of such scale defined by internal consistency was high (Cronbach α = 086). Pearson correlation indicated that there was no statistically significant correlation between age and patients’ satisfaction with their teeth regarding either the individual aspects or the general level of satisfaction. There are statistically significant effects of tone and intensity of color, and border interactions and color tone and intensity to the satisfaction of the color of teeth. The participants with darker teeth give lower estimates of satisfaction teeth. Negative predictors of the overall satisfaction with tooth appearance were plaque index and tooth fracture, in contrast to the tooth visibility when smiling which was proven as the satisfaction predictor of tooth appearance. The most common dental procedures performed in the investigated population were professional tooth cleaning and root canal treatment; the fewest had dental implants or undertook tooth whitening procedures. Subjects with composite fillings commonly expressed the desire for general improvement in tooth appearance, orthodontic therapy, placement of crowns and tooth whitening. Factor analysis of the PIDAQ instrument indicated that factors 2, 3 and 4 which correspond to the Psychological impact of dental aesthetics, Social impact of dental aesthetics and Dental self-confidence have sufficient confidence of the average correlation coefficient (r = 0.56- 0.76) and coefficient of internal consistency (α Cronbach 0.88-0.95), while the first factor (dimension of aesthetic concern) had a low average correlation and internal consistency (r = 0.32 and α = 0.58). Particles of the OIDP questionnaires showed high internal consistency reliability (Cronbach α = 0.79), and the average correlation between the particles was 0.36 (from 0.16 to 0.84). We performed a regression analysis to examine the extent to which the results of the PIDAQ and OIDP questionnaires affected the overall satisfaction with dental aesthetics, but we can say that the deciding factor of the PIDAQ and OIDP questionnaires does not predict the patients’ satisfaction with tooth appearance (F5, 531 = 0.43, p =0.82). Conclusions Aesthetic questionnaire specifically designed for this study showed an extremely high degree of consistency (Cronbach α = 0.86), which gives us the possibility to register the same quality level as the readout in future scientific research. Patient satisfaction with tooth appearance is associated with the visibility, color and shape of the teeth, level of education, amount of plaque on the teeth, the presence of fractures of the teeth and some dental surgery in the anterior segment. The procedure most frequently desired by the patients was tooth whitening. Furthermore, the research confirmed the hypothesis that the older participants preferred fixed prosthetic works unlike the younger ones who were satisfied with composite fillings. We validated the reliability of the PIDAQ and OIDP instruments, whereby we came to the conclusion that in the Croatian language the 4 dimensions of the PIDAQ instrument would probably be better interpreted if reduced to two dimensions, with the Aesthetic concerns posing as one dimension, and the remaining three should be consolidated into the second dimension. OIDP questionnaire also had a high degree of consistency (Cronbach α =0.79)