Using computed tomography, photogrammetry & structured light scanning for measuring human mandibles: a comparison of...

Area of Science:

• Medical Imaging
• Anthropometry
• Biomechanical Engineering

Background:

• Computed tomography (CT) is a reliable method for mandibular metric assessments but faces limitations in cost, portability, and ease of use.
• Accessible and user-friendly imaging alternatives are needed to overcome CT's accessibility challenges.

Purpose of the Study:

• To evaluate photogrammetry and structured light scanning (SLS) as viable alternatives to CT for quantitative analysis of human mandibles.
• To compare the accuracy and reliability of measurements obtained via CT, photogrammetry, and SLS.

Main Methods:

• Thirty-three human mandibles were imaged using CT, photogrammetry, and SLS.
• Intra-observer and inter-observer reliability were assessed using the Intraclass Correlation Coefficient (ICC).
• Inter-modality agreement was evaluated using the Total Absolute Error (TEM).

Main Results:

• Intra-observer ICC results ranged from 0.37 to 1, indicating variable measurement reliability.
• While inter-observer results were unreliable, inter-modality TEM assessments were within acceptable thresholds (<5 TEM).
• Photogrammetry demonstrated the highest consistency with CT (ICC 0.37-0.88), followed closely by SLS (ICC 0.47-0.87), with all methods proving interchangeable.

Conclusions:

• Photogrammetry and SLS are effective, interchangeable alternatives to CT for mandibular metric assessments.
• These techniques offer practical solutions in clinical and research settings where CT access is limited.
• Further refinement of protocols is needed to improve inter-observer reliability for these alternative methods.