A caliper‐like instrument used to record the spatial relationship of the maxillary arch to some anatomic reference point or points and then transfer this relationship to an articulator; it orients the dental cast in the same relationship to the opening axis of the articulator. Customarily, the anatomic references are the mandibular condyles transverse horizontal axis and one other selected anterior point. Called also hinge bow.
In orthodontics, an appliance that maintains the position of the posterior molars or moves the molars distally. A metal archwire (a metal wire fitting the dental or alveolar arch) is attached to a molar tooth in each arch. External attachments connect to an elastic strap that fits behind the head. The force for this active appliance is supplied by the neck strap.