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

Statement of problem: 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.

Purpose: 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.

Material and methods: 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.

Results: 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).

Conclusions: 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.