Which device is a caliper-like instrument used to record the spatial relationship of the maxillary arch?

Which device is a caliper-like instrument used to record the spatial relationship of the maxillary arch?

• A. Facebow
• B. Articulator
• C. Caliper
• D. Goniometer

Answer: (A)

The main idea is capturing how the upper jaw sits in relation to the skull so you can mount the models accurately on an articulator. A facebow is used because it records the spatial relationship between the maxillary dentition and the temporomandibular joints (condyles) or their reference hinge axis, then transfers that orientation to the articulator. This allows the dental team to reproduce the patient’s true jaw relationships when evaluating occlusion or planning restorations. The other devices don’t serve this purpose: an articulator reproduces jaw movement once the casts are mounted but doesn’t capture the skull-to-arch relationship by itself; a caliper is just a general measuring tool without cranial reference; a goniometer measures angles between body parts and isn’t used to transfer skull–arch positioning for mounting.

The main idea is capturing how the upper jaw sits in relation to the skull so you can mount the models accurately on an articulator. A facebow is used because it records the spatial relationship between the maxillary dentition and the temporomandibular joints (condyles) or their reference hinge axis, then transfers that orientation to the articulator. This allows the dental team to reproduce the patient’s true jaw relationships when evaluating occlusion or planning restorations.

The other devices don’t serve this purpose: an articulator reproduces jaw movement once the casts are mounted but doesn’t capture the skull-to-arch relationship by itself; a caliper is just a general measuring tool without cranial reference; a goniometer measures angles between body parts and isn’t used to transfer skull–arch positioning for mounting.