The Lingual Orthodontics

The lingual appliance was developed simultaneously in two countries during the 1970s. Although not fully recognized by the orthodontic mainstream, lingual treatment has steadily expanded, with increased numbers of lingual orthodontists and patients. Because lingual appliance do not influences patients delight, so it is also called "adelomorphic orthodontic treatment".Lingual appliance includes lingual bracket and special "mushroom shape" arch wire. The design of lingual bracket is based on the special anatomy structure of lingual face of every tooth and its morphological characteristics. Every bracket has its different thickness, inclination and torque. Compared with labial bracket, the brackets of superoanterior teeth have more typical characteristics. Because the anatomy structure of lingual face of every tooth is particular, the standard arch form of lingual orthodontic is "mushroom shape".As is known, accurate bracket position is very important for treatment outcome. Different with labial orthotherapy, because the effect of posture, it is very difficult to lay the lingual bracket on accurate position, so orthodontic doctor can not obtain ideal treatment easily. In the world at present, orthodontics doctors all use indirect bonding system to bond lingual brackets. There are three major indirect bonding system: Customized Lingual Appliance Set-up Service, Torque / Angulation Reference Guide system and HIRO system. The procedure of lingual orthodonticsinclude indirect bonding of lingual bracket, extraction(case that needs extraction), bonding of bands, alignment and leveling dentition, closure space, completion phase and retain after orthodontic treatment. The advantages of lingual appliance are delight, maximum anchorage and easy to open bite. The disadvantages of lingual appliance are long manipulation time, high treatment cost and the effect to pronunciation.Currently, there are few contraindications for treatment with the lingual appliance. Cephalometric measurements do not reveal statistically significant differences in treatment results between labial and lingual treatment; however, more clinical trial studies are needed to compare the efficiency and outcome of lingual appliances with those of labial appliances. The standard arch form of lingual orthodontics is "mushroom arch wire". I believe that lingual orthodontics must become a mature orthodontic technique in the future.This article reviews the history of development, advantages and disadvantages, the characteristics of lingual bracket, lingual bracket positioning system, indirect bonding techniques, treatment procedures, biomechanics, key point of successful and prospect of the lingual appliance.