facebow

A facebow is a dental instrument used to record the spatial relationship of the maxillary arch to a reference point on the skull and to transfer that relationship to an articulator. This enables the clinician to reproduce the patient’s occlusion on a dental laboratory setup by orienting the maxillary cast on the articulator with respect to a defined reference axis or plane, improving occlusal accuracy, vertical dimension, and jaw relations.

There are two primary types of facebows. Arbitrary (non-kinematic) facebows establish a recording that approximates the hinge axis using external landmarks such as the external auditory meatus and a bite fork. Kinematic (true hinge axis) facebows locate the actual functional hinge axis by recording mandibular rotation, providing a more precise mounting for procedures that demand exact jaw relation.

Procedure typically involves seating the patient, positioning and securing the facebow to the head, recording the maxillary occlusion with a bite registration, and transferring this information to the articulator. The maxillary cast is mounted on the articulator so that the recorded reference points align with the articulator’s hinge or reference plane, after which the mandibular cast can be mounted using an interocclusal record or equivalent jaw relation method.

Uses and limitations: Facebows are commonly employed in complete and partial denture fabrication and certain fixed prosthodontic workflows to improve occlusal accuracy. With advances in digital dentistry, intraoral scanning and virtual articulation offer alternatives or supplements. The accuracy of a facebow depends on landmark reliability, technique, and patient anatomy, and not all cases require its use.