Limitations of a method used for adolescent assessment of smile aesthetics

To establish whether adolescent orthodontic patients with hypodontia have a preference between the aesthetic outcomes of two treatment strategies for lateral incisor agenesis.

Standardized photographs of pre-orthodontic patients with missing lateral incisors were manipulated to produce images that represented space opening and tooth replacement in the lateral incisor space and space closure with canine substitution into the lateral incisor space. Adolescent orthodontic patients with hypodontia were recruited to assess the aesthetics of the images. A control group of subjects without tooth agenesis was recruited. Each examiner undertook two tests to assess the smile aesthetics of the images: (1) rating attractiveness using visual analogue scale (VAS) and (2) choice of preference between pairs of images.

Difficulties experienced with image manipulation and poor intra-examiner reliability of the VAS make interpretation of the results challenging. Care should be taken if findings are used to aid clinical decisions, as the validity of the main findings is questionable. Results suggest that although adolescents perceive a difference in the aesthetic result of space opening and space closure for missing lateral incisors, the impact on the smile attractiveness is not clinically significant. When forced to choose between the aesthetics of space opening or space closure, the majority of examiners chose space opening with tooth replacement. No difference was found in smile ratings or preferences between adolescents with hypodontia and those with no missing teeth.

The methods used in this study may not be reliable for adolescent assessment of aesthetics.