What does the facebow NOT help with?

A facebow records the three-dimensional spatial relationship of the maxillary arch to the temporomandibular joints (hinge axis) and transfers this relationship to an articulator. It helps establish the horizontal plane (via the Frankfort horizontal or axis-orbital plane), the vertical plane, and the positional relationship of the maxilla to the condylar joints. However, the facebow does NOT assist in determining midline alignment — that is established separately using clinical landmarks on the maxillary occlusal rim (e.g., the philtrum, facial midline) and is not a function of the facebow.