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

AIM: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: Clinical/professional judgment and age significantly influenced participants' perceptions of facial attractiveness. Most participants preferred slightly protrusive lips.