Ricketts' E-line profile preferences among Nigerian orthodontists, orthodontic trainees, and a young undergraduate students' population.

Abstract

This study compared the perceptions of orthodontists, orthodontic trainees, and young university undergraduate students in Nigeria regarding facial profile attractiveness and the need for orthodontic treatment. We used a photo-editing software to alter the lips on Ricketts' esthetic line (E-line) in a lateral silhouette to produce five silhouette profiles with 2 mm incremental changes in the upper and lower lips from the 'normal' position on the E-line (-4 mm/-2 mm to + 4 mm/+6 mm). Two hundred and thirty-two participants (consisting of six groups) ranked the five profiles on a 5-point Likert scale (least attractive, 1 to most attractive, 5). Participants also assessed whether orthodontic treatment was needed to improve facial esthetics. Data were analysed in SPSS 20. Intra-rater reliability was assessed using Cohen's Kappa. We tested the null hypothesis (P ≤ 0.05) that ranked preferences between groups using the Kruskal-Wallis test. Mann-Whitney U test was also used to assess pairwise comparisons between the groups. Intra-rater reliability for facial profiles and treatment needs were moderately acceptable (perceptions ≥67.7%; treatment needs ≥67.0%). Perceptions between orthodontists and orthodontic trainees were not significantly different. However, orthodontists/trainees tended to rank the 'normal' Ricketts' E-line profile as most attractive, while students preferred more protrusive lips. Participants' age rather than sex significantly influenced esthetic preferences. About one-half of all participants (46.6%) ranked the 'normal' Ricketts' E-line as unacceptable; hence required orthodontic treatment to improve their facial attractiveness. Clinical/professional judgment and age significantly influenced participants' perceptions of facial attractiveness. Most participants preferred slightly protrusive lips.