Accuracy of Different Modalities to Record Natural Head Position in 3 Dimensions: A Systematic Review

Area of Science:

• Medical Imaging
• Craniofacial Surgery
• 3D Imaging Technology

Background:

• Three-dimensional (3D) imaging requires patient stabilization, often resulting in random head orientation.
• Reorientation to the natural head position (NHP) is essential for accurate dentofacial deformity assessment and surgical planning.

Purpose of the Study:

• To systematically review and evaluate modalities for recording the NHP in 3 dimensions.
• To compare the accuracy of different NHP recording methods.

Main Methods:

• Systematic literature search of PubMed, Cochrane Library, and Embase databases (July 2015).
• Evaluation of methodologies, accuracies, advantages, and limitations of identified NHP recording modalities.
• Inclusion of eight articles in the final review.

Main Results:

• Six NHP recording modalities identified: stereophotogrammetry, facial markings with laser lines, clinical photographs with POSIT algorithm, digital orientation sensing, handheld 3D camera system, and laser scanning.
• Digital orientation sensing and laser scanning demonstrated good accuracy (within 1°).
• Stereophotogrammetry showed highest reliability (within 0.1°), and the POSIT algorithm method also reported good accuracy.

Conclusions:

• Digital orientation sensing provides accurate 3D NHP recording.
• Laser scanning offers comparable accuracy but faces limitations in cost and portability.
• Stereophotogrammetry and the POSIT algorithm method are potential alternatives, requiring further clinical validation.