Is photogrammetry of the face reliable?

Area of Science:

• Anthropometry
• Medical Imaging
• Biometrics

Background:

• Photogrammetry is increasingly used for non-invasive anatomical assessments.
• Accurate facial measurements are crucial in fields like plastic surgery and orthodontics.
• Assessing the reliability of photogrammetric techniques is essential for their clinical application.

Purpose of the Study:

• To evaluate the reliability of photogrammetry for obtaining facial surface measurements.
• To determine which types of facial measurements are most accurately reproduced using photogrammetry.
• To compare the accuracy of measurements from frontal versus lateral photographic views.

Main Methods:

• 18 healthy young Canadian adults (equal sex distribution) participated.
• Facial landmarks were identified before direct measurements and standardized photography.
• 104 direct surface measurements were compared to those reproducible from frontal and lateral photographs.

Main Results:

• 26 out of 62 reproducible measurements (41.9%) met reliability criteria (≤1 mm or 2° difference).
• Lips and mouth measurements showed the highest reliability (7/13), while ear measurements were unreliable.
• Inclination measurements (9/26) were frequently reliable; frontal views yielded more reliable measurements than lateral views.

Conclusions:

• Photogrammetry can reliably measure certain facial features, particularly around the lips and mouth.
• Frontal photographic views are generally more reliable for anthropometric measurements than lateral views.
• Further research is needed to optimize photogrammetric protocols for comprehensive facial anthropometry.