In one embodiment, a method includes: accessing a bite register with a post, upper and lower dental models, and a fixture having upper and lower plates and a clamp; coupling the register post to the fixture, such that the register post has a first orientation; coupling the upper and lower models to the register; coupling the upper and lower models to the upper and lower plates; uncoupling the register; coupling an appliance post to the fixture, such that the appliance post has a second orientation the same as the first orientation; and forming a custom oral appliance coupled to the appliance post and maintaining the second orientation of the appliance post. In one embodiment, a device is configured to couple to an articulator and to position and retain a bite register post. The device includes a lower member, first and second couplers, an upper member, and an adjustor.