Invisible orthodontics part 2: lingual appliance treatment

A review of the literature1 suggests that, as far back as 1726, Fauchard introduced using appliances on the lingual surfaces of teeth. However, it was Fujita2 in the 1970s who is credited with pioneering modern lingual treatment with lingual brackets and ‘mushroom-shaped’ archwires. Interestingly, this came about to address the demands of martial artists undertaking orthodontic treatment. The poor outcome of completed cases triggered a drop in interest in the 1990s, but with technological advances there has been a recent resurgence in the use of lingual appliances.

Since the initial suggestion that brackets could be placed behind the teeth in the 70s, several American orthodontists formed the Lingual Task Force to promote the use of lingual appliances. This has led to the development of numerous lingual appliance systems. Table 1 gives a breakdown of the brackets currently available. Ormco Corporation (Orange, CA, USA) produced one of the first bracket systems following work undertaken by Kurz et al;5 this was placed as an edgewise appliance. As access is difficult and there is a lack of direct visualization of the lingual surfaces, numerous indirect bonding set-up systems have developed as an alternative to direct bonding. Published research has suggested significant improvement in bracket position with reduced torque and rotational errors using an indirect bonding system.6 A high degree of accuracy can therefore be achieved using these techniques in bracket positioning. The chairside bond-up time is also reduced. Table 2 lists some of the main bracket set-up systems and outlines their main features. Actual bonding protocols have also advanced over the last decade. Previous problems relating to the increased debonding of brackets negatively influenced the lingual technique in the US during the 1980s.9 The standard technique was difficult to employ with bracket positional discrepancies and inaccuracies in finishing.