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

The reproducibility of positioning the maxillary occlusal plane in an articulator with a facebow remains debated. Its clinical use is widespread, yet its reliability and clinical outcomes compared to other transfer methods under standardized conditions remain uncertain.

The purpose of this in vitro study was to compare the intra-operator reproducibility of maxillary positioning on an articulator using a facebow compared to a standardized transfer table.

Sixty identical maxillary replicas from a single patient were mounted by a single operator (30 using a facebow and 30 using a 10-degree inclined transfer table). Each articulator was scanned, and frontal and sagittal occlusal plane angulations were measured using a validated mesh-based method. Statistical analyses included Shapiro-Wilk test to assess normality, Fligner-Killeen and Wilcoxon rank-sum tests to compare the groups, and Cliff δ to estimate effect size.

The mesh-based analysis was validated with perfect intra-observer agreement. The reproducibility significantly differed for both frontal and sagittal inclinations between the facebow record and the standardized method (P<.05). Angular values also differed significantly between groups (P<.05), with a large effect size in sagittal directions (Cliff δ=1.00) and a small effect size in frontal directions (Cliff δ=0.32).

The facebow transfer technique exhibited low reproducibility. The mesh-based protocol offered a reproducibility baseline for assessing emerging maxillary transfer techniques with a reliable measurement method.