# A Comparative Accuracy Study of Nasal Soft Tissue Measurements Using a 3D Facial Scanner and Conventional Methods

## TL;DR

This study compares a 3D facial scanner with traditional methods for measuring nasal soft tissues and finds the scanner to be accurate and reliable.

## Contribution

The study provides empirical validation of a 3D facial scanner's accuracy for maxillofacial measurements compared to conventional methods.

## Key findings

- The 3D scanner showed high consistency with ICC values above 0.9 for all measurements.
- Most measurements were within 0.5 mm of conventional methods, with no significant systematic differences.
- 69.3% of measurements were within 0.3 mm and 86.1% within 0.5 mm of conventional methods.

## Abstract

Analysis of facial morphology is a critical component in craniomaxillofacial prosthetics and surgery, serving purposes such as preoperative diagnosis, postoperative evaluation, and symmetry analysis. This study evaluated the accuracy of a structured‐light 3D facial scanner for measuring facial soft tissues.

Twenty‐one adult participants were included in this study. A conventional alginate facial impression was obtained from each participant. 3D facial images were also captured using a digital face scanner. Six facial landmarks were identified and recorded on each 3D facial image. The 3D facial scanner and linear caliper measurements on facial casts were employed to measure the distances between landmarks. The accuracy of the 3D facial scanner was evaluated through reliability analysis and paired t‐tests.

The mean absolute error of the scanner ranged from 0.18 to 0.44 mm, and the mean relative error ranged from 0.00 to 0.02. Of all the measurements, 69.3% were reproduced within 0.3 mm, and 86.1% within 0.5 mm. The intraclass correlation coefficient (ICC) for all distances was greater than 0.9, demonstrating high consistency. Paired t‐test analysis indicated no systematic differences in mean measurements between the scanned images and the facial casts (p  > 0.05), except for one distance.

The findings suggest that the face scanner is a precise and reliable alternative for performing maxillofacial measurements.