Comparing Direct Measurements and Three-Dimensional (3D) Scans for Evaluating Facial Soft Tissue.

Area of Science:

• Dentistry
• Medical Imaging
• Anthropometry

Background:

• Assessing soft tissue changes and facial physiognomy after dental procedures is challenging.
• Manual measurements can be uncomfortable and time-consuming for patients.

Purpose of the Study:

• To evaluate the accuracy and repeatability of 3D facial scanning for measuring soft tissue changes.
• To compare 3D scan measurements with direct manual measurements.

Main Methods:

• Utilized a low-cost RGBD 3D scanner to capture facial images of 39 participants for repeatability testing.
• Scanned 10 participants before and after mandibular advancement to assess treatment outcomes.
• Employed Iterative Closest Point (ICP) registration and exact distance algorithms for 3D image analysis.

Main Results:

• 3D facial scans demonstrated high reproducibility (mean difference <1%) between repeated scans.
• Computational measurements were accurate, repeatable, and comparable to direct manual measurements.
• Direct manual measurements showed excellent repeatability only for the tragus-pogonion line.

Conclusions:

• 3D facial scanning is a faster, more comfortable, and accurate technique for quantifying facial soft tissue changes.
• This method can be effectively used to monitor outcomes of dental procedures affecting facial structure.