Lingual orthodontics--its renaissance.

Lingual treatment has obvious advantages over labial treatment for the patient: no damage to labial or buccal surfaces of the teeth, no labial or buccal gingival hypertrophy or gingivitis, and better visualization of tooth alignment and facial contours. By the same token, lingual treatment has inherent disadvantages over labial treatment. Brackets are attached to very irregular and inconsistent lingual surfaces, which are not the surfaces to be aligned. Furthermore, lingual brackets are cantilevered a substantial distance from the labial surfaces, making the vertical height of the brackets vary with the torque angle of the labial surfaces and also making torquing adjustments affect not only the torque of the labial surfaces but also their heights. These factors make direct placement of preangulated, pretorqued brackets very inaccurate, especially on maxillary anterior teeth; mandibular anterior teeth are not so variable. More accurate indirect bracket placement with predictable and accurate indirect bonding procedures is resolving these disadvantages. It has been shown that a lingual appliance can have the same capacity to align the teeth as a labial appliance. The mere lingual placement of labial brackets, tubes, and arch wires with minor modifications has not proved to be a satisfactory solution. Rather, the designing of a completely new appliance system has been necessary to meet the mechanical requirements inherent in the lingual environment. This engineering challenge has basically been met with the Conceal occlusal-slot lingual system. Undoubtedly, refinements in the appliance system will be made as experience in its use expands ultimately to make lingual treatment as common as labial treatment.