Comparison of Chinese Orthodontic Experts' Subjective and Objective Evaluations of Post-Orthodontic Treatment Profile Photos and Lateral Cephalograms.

Objective: This study aims to analyse and compare the subjective evaluations of post-orthodontic treatment profile photos and cephalometric radiographs by Chinese orthodontic experts, along with their correlation to objective measurements.

Materials and methods: A total of 216 cases treated at Peking University School of Stomatology (2016-2021) were included. Sixty-five Chinese orthodontic experts conducted subjective ranking and grading of post-treatment profile photos and lateral cephalograms, while three doctoral students performed objective cephalometric analyses. Statistical analyses were used to identify and compare objective indices correlated with expert assessments, determine their weightings, and establish thresholds distinguishing 'harmony' from 'disharmony'.

Results: Experts' subjective evaluations of profile photos and cephalograms showed moderate agreement. Five objective indices correlated with facial photograph evaluations (two skeletal: ANB, MP/SN; three soft tissue: Sn-GPos, UL-E, Bs-GPos), while eight indices were associated with cephalogram assessments (including additional skeletal and dental indices: ANB, MPA, Pog-NB, U1/PP, L1/MP, Sn-GPos, UL-GPos, Bs-GPos). ROC analysis determined that a threshold of 3.30 points could differentiate 'harmony' from 'disharmony' for both modalities.

Conclusion: Experts' subjective assessments are significantly associated with multiple objective cephalometric parameters, particularly those related to incisor inclination, skeletal relationships, and labiomental morphology. Regression analysis suggests that a combination of these indices can reasonably predict expert evaluations. Compared to facial photographs, cephalogram assessments place greater emphasis on incisor inclination and chin morphology.