Two-dimensional versus three-dimensional Frӓnkel Manoeuvre: a reproducibility study

Area of Science:

• Orthodontics
• Dental Imaging
• Biomedical Engineering

Background:

• Skeletal Class II malocclusion is a common dental anomaly.
• The Frӓnkel Manoeuvre (FM) is a diagnostic tool used in orthodontics.
• Reproducibility of diagnostic methods is crucial for effective treatment planning.

Purpose of the Study:

• To evaluate the intra- and inter-observer reproducibility of the Frӓnkel Manoeuvre (FM) assessment.
• To compare the reproducibility of FM evaluation between 3D scans and 2D pictures.
• To determine the impact of imaging modality on the reliability of FM assessment.

Main Methods:

• 44 patients with skeletal Class II malocclusion were included.
• The Frӓnkel Manoeuvre (FM) was recorded using both 2D photography and 3D scanning.
• Six orthodontists and one gold standard evaluated the FM twice, with reproducibility assessed using Cohen's Kappa.

Main Results:

• Intra-observer agreement for FM assessment ranged from 0.36 to 1 on 2D pictures and 0.22 to 0.69 on 3D scans.
• Overall agreement was higher for 2D analysis (0.63) compared to 3D analysis (0.5).
• The reproducibility of the FM assessment was significantly lower when using 3D records.

Conclusions:

• The Frӓnkel Manoeuvre (FM) assessment demonstrates lower reproducibility with 3D scan data than with 2D photographic images.
• The choice of imaging modality influences the reliability of FM evaluation in orthodontic diagnosis.
• Further research may be needed to optimize 3D imaging techniques for orthodontic assessments.