Cephalometric study of treated orthodontic patients with acceptable esthetic profiles compared to adult Thai normative values
Authors:   , Pornsirianand Visessan 
Published: April 2023

Objective: This study aimed to compare cephalometric variables between esthetically acceptable normal, concave, and convex profile groups as well as between each group and adult Thai normative values.

Materials and Methods: Three-hundred and three profile silhouettes from post-treatment lateral cephalometric radiographs of 18–37 year-old orthodontic patients were scored by 5 Thai orthodontists and 15 orthodontic patients. The Likert 5-point scale was used to judge the attractiveness. Two-hundred and seven radiographs passing the minimum score of 3 were divided into acceptable normal, concave, and convex profile (AN, ACC, ACV) groups. Thirty-five skeletal, 17 dental, and 34 soft tissue cephalometric variables were measured. One-way ANOVA and Multiple comparisons (Bonferroni) or Kruskal-Wallis H tests and Post Hoc tests with Mann-Whitney U tests were used to compare the data between AN, ACC, and ACV groups. One-sample t-test or One-sample Wilcoxon Signed Rank test were performed to analyze the difference between each group and adult Thai normative values.

Results: For skeletal part, maxilla was more retrusive in all groups compared the norms. While, ACC group had similar mandibular position, but more protrusive chin; and ACV and AN groups had more retrusive mandible and chin compared with the norms. ACC group presented skeletal and dental base Class III tendency, while ACV group showed skeletal and dental base Class II tendency. ACC had similar vertical relationship, while the others had open bite tendency, with more open bite in ACV group, compared with the norms.

For dental part, AN had similar dental characteristics compared with the norms. ACC group showed more protruded and proclined upper incisors, and retruded and retroclined lower incisors, while ACV group showed more retruded and retroclined upper incisors, and protruded and proclined lower incisors compared with the norms.

For soft tissue, AN group had similar soft tissue characteristics compared with the norms. ACC group had flatter profile, while ACV group had more convex profile compared with the norms. AN and ACC groups had more protruded upper lip and retruded lower lip, while ACV group had similar upper and lower lip position compared with Thai norms. ACC group had protruded chin, AN group had normal chin position, while ACV group had retruded chin. Prominent nose and more competent lip were presented in all groups when compared with the norms.

Conclusion: All three esthetically acceptable profile groups had some different skeletal, dental, and soft tissue characteristics from the present norms. For AN patients, orthodontic treatment could be planned based on previous Thai norms. Skeletal open bite tendency were acceptable in all groups. For the other profiles, orthodontic treatment could be performed with more protruded and proclined upper incisors and more retruded and retroclined lower incisors than the norms in ACC patients, and on the contrary treatment plan in ACV patients. In summary, different treatment goal based on cephalometric values for each lateral facial profile should be applied to achieve the esthetically acceptable facial profiles.