What is the purpose of the arbitrary facebow and how accurate can it be?

The purpose of an arbitrary facebow is to record and transfer the maxillary relationship in relation to the temporomandibular joint (TMJ) for prosthodontic procedures. It allows the dentist to accurately establish the spatial orientation of the maxilla to the anatomical axis of the skull, which is crucial for the proper alignment and function of dental prosthetics.

When using an arbitrary facebow, it is designed to have a maximum error of about 5 mm. This level of accuracy is generally sufficient for clinical practice, as it balances the need for precision with the practical aspects of dental procedures. Ensuring that the maxillary relationship is captured accurately within this range helps facilitate the proper positioning of dental restorations or appliances.

This understanding of the facebow's function and its accuracy is essential for prosthodontic work, as it contributes to the overall fit and function of dental prosthetics, ensuring better treatment outcomes for patients.