Parijat Chakraborty

Fixed functional appliances form a useful addition to the clinician's orthodontic armamentarium. But many of these appliances need further studies to substantiate the claims made by their respective originators. With this in mind, clinicians must take great care in selecting the right patient and also pay attention to every detail in the manipulation, to attain successful results with these appliances.

Extraction therapy is followed by the closure of spaces. Though some amount of space is spent to alleviate the crowding, the remaining space opens a new window in orthodontics. Space closure mechanics is either friction or frictionless. Irrespective of the mechanics employed, due consideration must be given to the force applied, anchorage, and other biologic factors. Most approaches of space closure describe the technical features of the appliance, such as loops or spring shape, the wire/bracket interaction, or the placement and size of elastics. The technique for their use follows a cookbook approach rather than an analytical assessment of the specific needs of the individual patient. Orthodontic space closure must be individually tailor based on the diagnosis and treatment plan. The selection of any treatment, whether a technique, stage, spring, or appliance design should be based on the desired tooth movement.