Traditional prosthodontic workflows have long relied on adjustable articulators (AAs) to simulate occlusal relationships and temporomandibular joint (TMJ) movements. As defined in the Glossary of Prosthodontic Terms (Tenth Edition), an AA is “an articulator that allows some limited adjustment in the sagittal and horizontal planes to simulate recorded mandibular movements” [1]. However, the limitations of AAs have become increasingly apparent in the era of digital dentistry. Virtual articulators (VAs), first introduced in 2002 by Bisler et al. [2], are defined as “the articulator in the digital environment enables a user to see and interact with the related computerized files”. VAs can realistically reproduce TMJ and mandibular kinematics and have gradually been integrated into digital workflows, increasingly supplementing or replacing conventional AAs [1,[3], [4], [5]]. Comparative studies have demonstrated that VAs achieve comparable accuracy to that of AAs, in simulating dynamic mandibular movements, with most discrepancies remaining within clinically acceptable thresholds (<100 μm) [6,7]. Beyond simple movement simulation, VAs enable comprehensive digital arch modeling and provide unprecedented opportunities for precise occlusal analysis and treatment planning in a virtual environment [1,2]. Numerous digital workflows have emerged to support VA implementation, involving virtual facebows and digital occlusal records [[8], [9], [10]].

The successful clinical application of VA technology requires meticulous attention to two critical processes. First, virtual mounting procedures must precisely position maxillary and mandibular models within the virtual environment to accurately represent the patient-specific three-dimensional relationships between the jaws and temporomandibular joints [3,[8], [9], [10]]. Second, virtual programming requires careful determination of motion parameters to properly simulate individualized mandibular excursions and their associated occlusal contacts [11,12]. These processes fundamentally depend on two essential parameters for each temporomandibular joint: the sagittal condylar inclination (SCI) and the transverse condylar inclination (TCI, i.e., the Bennett angle) [13]. SCI describes the angulation between the condylar path and either the sagittal plane or an alternative horizontal reference plane [[13], [14], [15]], while TCI characterizes the angle formed by the nonworking condyle's movement path relative to the protrusive path during medial joint motion [13,16]. It has been demonstrated that a discrepancy of 9° in SCI can induce a compensatory error of approximately 0.2 mm in the occlusal scheme [17]. This magnitude of error exceeds the established sensory perception threshold for teeth, which ranges from 8 to 35 µm [15,18,19], and therefore likely to result in clinically significant occlusal interferences that require chairside adjustments.

Recent technological advances have introduced multiple digital approaches for SCI measurement, incorporating cone beam computed tomography (CBCT) imaging, facial scanning, intraoral scanning, and kinematic facebow recordings [11,12,[20], [21], [22], [23]]. Despite these advancements, the body of comparative research remains limited. A scoping review revealed fewer than 20 studies that directly address SCI measurements using digital or hybrid workflows [20,22,[24], [25], [26], [27], [28]]. Research on TCI is even more limited, with fewer than 10 studies directly comparing agreement among digital measurement techniques [[29], [30], [31], [32], [33]]. While previous studies have evaluated the accuracy of individual methods for measuring SCI or TCI in isolation, a significant gap exists in the concurrent assessment of both parameters within the same cohort. Furthermore, no previous study has benchmarked multiple digital workflows against a kinematic facebow reference for programming a VA.

This technical report was designed to systematically evaluate measurement variations in SCI and TCI obtained through 5 distinct methodologies including the AA, facial/intraoral scan integration, CBCT/intraoral scan fusion, direct CBCT measurement, and kinematic facebow with T-Scan analysis. The null hypothesis tested was that there would be no deviations in the measurement of sagittal and transverse condylar inclinations among the different techniques.