Digital design and manufacturing of the Lingualcare bracket system.

duced in the early 1970s, used conventional labial brackets that were modified by the clinician and bonded directly to the lingual surfaces. Brackets designed specifically for lingual usage1-4 were initially prone to technical problems that made them difficult to use in everyday practice. The development of indirect bonding permitted more precise lingual bracket positioning and reduced the chairtime and labor required for bonding procedures.5-9 The next technological advance was the customization of lingual brackets with composite, which compensated for the gaps between standardized bracket bases and the variable morphology of the lingual tooth surfaces. This allowed the laboratory to incorporate much of the biomechanical plan into the brackets and their positioning, thus reducing the need for wire bending. The Torque Angulation Reference Guide* (TARG) developed in 1984 by Ormco further improved the precision of bracket placement. Fillion added a thickness-measuring device to this system in 1987.6 Today, the most commonly used indirect laboratory procedures are: • The Custom Lingual Appliance Setup Service** (CLASS).7 The lingual brackets are positioned on a target setup. To prevent having to use more than one transfer tray, the brackets are transferred to the working cast before the transfer tray is made. • The Hiro System from Japan (named for its inventor).10 The brackets are positioned on a setup model, using an ideal archwire, and then transferred to the mouth using an individual mini-tray for each tooth. • Fillion’s Bonding with Equal Specific Thickness*** (BEST) system. The brackets are directly positioned on the working cast, using the modified TARG.6 • The German Transfer Optimized Positioning**** (TOP) System.11-14 The setup is used for three-dimensional orientation of each tooth. Every bracket has at least a one-point contact with the teeth to minimize the volume of the appliance in the mouth. The brackets are positioned on the working cast, and a customized archwire is fabricated using computer technology. Although the demand for lingual orthodontic treatment in Europe and Asia has boomed in recent years, there are still relatively few orthodontists in the United States providing lingual therapy. Clinicians seem to be discouraged by problems in three areas: • Patient adaptation to the lingual appliances, especially in speech. • Difficulty of precise finishing.