The Accu-Liner

The Accu-Liner articulator as developed by Dr. James Carlson is the most advanced articulating/ diagnostic instrument available. It is the only articulating instrument that accurately relates the maxillary model to the cranial base and to the horizontal reference plane of the skull. These factors make this instrument invaluable to the practitioner who treats orthodontic cases, TMJ dysfunction, or does prosthetics in their practice. At Murdock Laboratory several appliances are fabricated exclusively on the Accu-Liner instrument.

The upper cast is mounted on the Accu-Liner by relating the hamular notches and the incisive papilla of the upper arch according to the level plane in the skull (the HIP plane). This assures that the plane of occlusion is parallel to the flat plane of the instrument. When lowering the upper cast to the flat plane occlusal, distortions can be readily identified. The lower cast is then mounted to the upper cast for appliance construction.

Tooth positioners at Murdock Laboratory are set-up on the Accu-Liner. No other instrument utilizes the flat plane so crucial to attaining the Jefferson Type I or Type II occlusion.

The teeth are set-up with the proper curve of Wilson and curve of Spee as prescribed by the practitioner. The tooth set-up on the Accu-Liner assures the practitioner that the plane of occlusion will be set to the level horizontal plane of the skull which results in a more stable finished case.

As the hamular notches are critical reference points, both sides must be visible on your working casts so they can be mounted on the Accu-Liner. When using a tooth positioner it is important that tooth movement must have taken place prior to using a tooth positioner for finishing your cases.

Indirect bracketing on the Accu-liner is made possible by first doing a tooth positioner- type set-up on the upper arch. Again the teeth are set-up in an ideal arrangement with the proper curve of Wilson and curve of Spee as prescribed by the doctor.

Indirect brackets are positioned on the teeth, in the laboratory, set exactly to a finishing arch wire according to the set-up.

The transfer tray is formed over the teeth and brackets. The teeth are cut individually with the brackets held in place by the transfer tray ready to be bonded to place.

The practitioner then goes through the regular course of light wires and round wires. When it is time for the finishing arch wire, the wire that the brackets were set to is used.