Influence of panel composition on aesthetic evaluation of adolescent faces.

The objective of this study was to evaluate the influence of professional background, age, gender, and geographical region of panel members on their evaluation of the facial aesthetics of adolescents, and to assess the optimal panel size for epidemiological studies on facial aesthetics. A panel of 76 adult laymen from two different regions (Belgium and The Netherlands) and a panel of 89 orthodontists from the same two regions, evaluated photographic sets (one frontal, one three-quarter smiling, and one lateral view) of 64 adolescents (32 boys, 32 girls) on a visual analogue scale (VAS) in relation to a reference set of photographs. The effects of the characteristics of the panel members on the VAS scores for boys and girls separately, as well as their interactions, were evaluated by multilevel models. The adolescents entered the model as a random effect and four characteristics of the panel members were included in the model as fixed effects. The multilevel model with main effects and first-order interactions revealed that laymen rated adolescents as more attractive than orthodontists. This finding was significant for all laymen, except for older males, and Belgian laymen, when rating girls. Older panel members rated boys significantly more attractive than younger panel members. Males rated adolescents more attractive than females. The latter was significant for all male subgroups, except for the lay male subgroup. There were regional differences. Based on the intraclass correlation coefficient, a panel of seven randomly selected laymen and/or orthodontists is sufficient to obtain reliable results in the aesthetic evaluation of adolescent faces, using photographs and a VAS.