Facial motor function monitored by hand held calipers versus computer-assisted photography

Area of Science:

• Medical imaging and analysis
• Biomechanical assessment of facial function

Background:

• Reliable tools are needed for assessing and comparing facial function in clinical settings.
• Two techniques, hand-held calipers (HHC) and computerised analysis of digital photographs (CAOP), were evaluated.
• The study aimed to compare the reliability and interchangeability of HHC and CAOP.

Purpose of the Study:

• To determine the agreement between two operators using HHC for facial landmark measurements.
• To determine the agreement between two operators using CAOP for facial landmark measurements.
• To explore if HHC and CAOP can be used interchangeably for assessing facial function.

Main Methods:

• Measurements of facial landmarks were taken at rest and during four facial expressions.
• Measurements were repeated after one week to assess inter/intra-rater reliability.
• Nine female volunteers with normal facial function participated.

Main Results:

• Computerised analysis of digital photographs (CAOP) demonstrated high intra- and inter-rater agreement.
• Hand-held calipers (HHC) showed low intra- and inter-rater agreement.
• CAOP proved to be a reliable method for objective measurement.

Conclusions:

• Hand-held calipers (HHC) are unreliable for monitoring facial function.
• Digital photography with Adobe Photoshop 7 offers a reliable, objective measurement tool.
• CAOP is simple, low-cost, and suitable for clinical application.