Measurement properties of CADIAX computerized axiography for hinge axis and condylar path assessment: A systematic review of technical accuracy, reliability, agreement with optical and ultrasonic jaw tracking systems, and diagnostic validity

INTRODUCTION. Computerized axiography with the CADIAX family of devices (Gamma Dental, Austria) is widely used to locate the kinematic transverse horizontal axis and to derive sagittal condylar inclination (SCI) and Bennett angle (BA) for articulator programming and temporomandibular joint diagnostics. This review appraised the measurement properties of CADIAX devices: technical accuracy, reliability, agreement with alternative recording methods, and diagnostic or discriminative validity.

Materials And Methods

The review followed PRISMA 2020. PubMed (four search strings), Consensus and Google Scholar were searched from 1 January 2000 to 2 September 2026, supplemented by citation searching. Eligible studies used any CADIAX-family axiograph (Cadiax III, Compact, Compact 2, Diagnostic, Cadiax 4) and reported at least one measurement property. Risk of bias was assessed with QUADAS-2 for diagnostic accuracy studies, the COSMIN reliability and criterion validity standards for reliability and agreement studies, and a QUIN-adapted checklist for in vitro studies. Findings were synthesized narratively because of heterogeneity in designs, parameters and reference standards.

Results

Of 562 records, 29 studies (30 reports) were included: 4 in vitro accuracy studies, 8 reliability studies, 9 agreement studies and 8 diagnostic or known-groups validity studies. On articulators with preset values the mean error of Cadiax Compact devices was about 1.2° (maximum 2.5° to 3.4°). Test-retest reliability of SCI was consistently excellent (ICC 0.97 to 0.98 at 3 and 5 mm), BA reliability was lower but still above 0.90 in recent studies, whereas transverse parameters showed poor reliability in one multilevel analysis. Mounting method changed mean SCI by up to 10°. Compared with MODJAW, SCI recorded by CADIAX was systematically lower (mean difference 5.9°, 95% CI 3.9 to 8.2), with wider discrepancies at 3 mm than at 5 mm. Compared with Zebris JMA, SCI was comparable once the reference plane was harmonized, whereas BA differed. Against MRI, the sensitivity for disc displacement ranged from 27% to 85% and specificity was 95% in the only study with a prospective reference standard. Case-control studies showed that qualitative kinematic abnormalities, not ranges of motion, separated patients with myogenous TMD or migraine from controls.

Conclusion

CADIAX axiography is a technically accurate and highly repeatable method for recording SCI and the kinematic hinge axis, provided a paraocclusal mounting is used. Its numerical outputs are not interchangeable with those of optical or ultrasonic systems without device-specific correction, and its diagnostic accuracy for internal derangement is insufficient to replace MRI. The evidence base consists of small single-center studies with heterogeneous protocols; multicenter studies with blinded reference standards and standardized reference planes are needed.