Light-elastics Use In The Early-phase Of Passive Self-Ligating Orthodontic Treatment

Objectives: to summarize some general remarks about the use of light-elastics during the initial phase of straight-wire orthodontic treatment. Methods: PubMed research of articles containing the terms "elastomer"and"orthodontic". Results: elastomers are materials characterized by the property of returning to their original size immediately after undergoing a distortion; their "Limit of Elasticity" is the stress at which the material stop to return to its original shape when the applied stress is removed; the "Maximum Elastic Force" is equivalent to a distortion corresponding to three-times its initial size. Benefits: self-managed by a properly-trained patient, disposable, no orthodontic activation required, effects enhanced by mandibular movements. Disadvantages: deterioration due to loss of elastic memory, variability of the forces exerted if prescription is not properly implemented and not regularly monitored, unwanted movements in the event of misuse by the patient, non-constant forces, patient's cooperation is required. Conclusions: the employment of light-elastics as an auxiliary procedure in the early-phase of a straight-wire orthodontic treatment can be extremely useful in obtaining dental movements not otherwise attainable with a simple interaction arch-bracket. Factors to be considered are: clinical objective; magnitude of the force in relation to the type of movement; distribution of forces in relation to the point of application(bracket arm or bow pin); use of other auxiliary devices, in particular the parallel use of occlusal-rises; type of elastic(diameter and overall strength); interval between check-ups depending on type of movement, estimated time of response to therapy, integration and interaction with other auxiliary devices; risks and errors due to inadequate control. However, for such a technique to be successful, it must be conducted following a precise criteria of programming and treatment planning, with goals articulated over intermediate stages, involving not only procedural implementations, but also a check-up schedule aimed at monitoring the expression of the clinical outcome.