Assessing the reproducibility of facebow transfers: A mesh-based intra-observer study

Area of Science:

• Dental prosthetics
• Occlusion and articulation
• Laboratory techniques

Background:

• The reproducibility of maxillary occlusal plane positioning using a facebow in dental articulators is debated.
• Despite widespread clinical use, its reliability compared to other transfer methods is uncertain.

Purpose of the Study:

• To compare the intra-operator reproducibility of maxillary positioning on an articulator using a facebow versus a standardized transfer table.
• To evaluate the accuracy of different maxillary transfer techniques in a controlled in vitro setting.

Main Methods:

• Sixty maxillary replicas were mounted by one operator, 30 with a facebow and 30 with a 10-degree inclined transfer table.
• Articulators were scanned, and frontal/sagittal occlusal plane angulations were measured using a validated mesh-based method.
• Statistical analyses included Shapiro-Wilk, Fligner-Killeen, Wilcoxon rank-sum tests, and Cliff δ for effect size.

Main Results:

• The mesh-based analysis demonstrated high intra-observer agreement.
• Significant differences in reproducibility were found between the facebow and standardized transfer table methods for both frontal and sagittal inclinations (P<.05).
• Angular values differed significantly between groups, with large effect size for sagittal (Cliff δ=1.00) and small for frontal (Cliff δ=0.32) directions.

Conclusions:

• The facebow transfer technique exhibits low intra-operator reproducibility for maxillary positioning.
• The standardized transfer table offers a more reproducible method for articulator mounting.
• The mesh-based protocol provides a reliable baseline for evaluating new maxillary transfer techniques.