Comparison of a 3D Scanning-Based Semiautomatic Measurement With the Direct Measurement for Auricle Anthropometry

To compare the stability and accuracy of semiautomated measurements (SM) based on 3-dimensional scanning technology and Rhinoceros 8 software with direct measurements (DM) of auricular morphologic parameters and explore the clinical application value of the semiautomated measurement method.

A self-controlled study design was used. Two plastic surgeons independently performed 3 repeated measurements of 11 key auricular parameters on 20 healthy volunteers (40 ears) using both SM and DM.

For intermethod reliability, SM yielded significantly higher intraclass correlation coefficient (ICC) values than DM for both physicians ( P <0.001). When the same method was used, no significant difference in ICC was observed between the 2 physicians ( P >0.05). The SM demonstrated significantly lower coefficient of repeatability (CR) values across all 11 parameters ( P <0.001), indicating superior accuracy. Bland-Altman analysis revealed that SM produced narrower limits of agreement, confirming its higher stability and lower variability. Repeated-measures ANOVA showed no significant differences across the 3 time points for 9 of the 11 parameters (81.8%). Statistically significant within-group differences were observed in earlobe length and auricular inclination angle.

The SM approach demonstrated significantly superior reproducibility and accuracy compared with the DM approach in the complex 3D morphometric assessment of the human auricle. These findings provide objective evidence supporting the integration of this 3D-based SM technique into clinical practice for auricular evaluation, surgical planning, outcome assessment, and related research.