Evaluation of Trueness and Precision in Extraoral 3D Facial Scanning Systems Using a 3D-Printed Head Model: An In...

Area of Science:

• Biomedical Engineering
• Dental Technology
• 3D Imaging

Background:

• Extraoral 3D facial scanning systems are increasingly used in dentistry and digital workflows.
• Evaluating the accuracy (trueness) and repeatability (precision) of these systems is crucial for clinical application.
• Standardized laboratory assessments are needed to compare different scanning technologies.

Purpose of the Study:

• To evaluate and compare the trueness and precision of four extraoral 3D facial scanning systems.
• To assess the suitability of handheld, desktop, and mobile-based scanners for clinical use.
• To provide quantitative data on the accuracy of commonly available facial scanning technologies.

Main Methods:

• A 3D-printed human head model with defined landmarks and distances was used as a reference.
• Four systems (MetiSmile handheld scanner, RAYFace desktop scanner, Heges mobile app, Polycam mobile app) were used to scan the model 15 times each.
• Caliper measurements served as the ground truth; digital measurements were analyzed for trueness and precision using statistical tests.

Main Results:

• Polycam achieved the highest trueness (0.49 ± 0.32 mm), followed by MetiSmile (0.51 ± 0.36 mm).
• MetiSmile demonstrated the highest precision (0.12 ± 0.07 mm), with Polycam also showing good precision (0.15 ± 0.06 mm).
• All systems showed mean deviations under 1 mm, with three systems achieving less than 0.6 mm accuracy.

Conclusions:

• Polycam and MetiSmile offer high trueness and precision, respectively, indicating clinical acceptability for educational and preliminary digital workflows.
• Both professional and mobile-based scanners can capture facial morphology with clinically acceptable deviations.
• Further validation in real clinical settings is recommended due to potential variations in motion, lighting, and soft tissues.