Space closure using aligners

Abstract

Introduction: Due to the search for more aesthetic and comfortable alternatives to perform orthodontic treatments and to the great technological development, orthodontic aligners have assumed great importance. More and more complex treatments have been carried out with these appliances without, however, having all aspects involved in their use being studied in depth. Its biomechanical planning requires different approaches than those used in fixed orthodontics, as the force systems involved in movements, responses and side effects are distinct, and the professional must be prepared when opting for the technique. Objective: The objective of this article is to perform an evaluation of the force systems created on the space closure with aligners, its characteristics, and problems, as well as make some suggestions to overcome the difficulties inherent to its use. Conclusion: Space closure with aligners is possible, but depends on the correct selection of the patient, in addition to requiring the proper planning of the applied forces. The use of auxiliary resources and overcorrections to address the deficiencies of the aligner systems should always be considered. Digital planning should be used as a map of the force systems that will be applied, and not just as a marketing tool, keeping in mind that determining the objectives and the way to achieve them is the responsibility of the orthodontist, and that treatment plans must be individualized for each situation, following appropriate biomechanical precepts.

Essential Attributes of Clear Aligner Therapy in terms of Appliance Configuration, Hygiene, and Pain Levels during the Pandemic: A Brief Review

“…Since the anterior and posterior teeth are covered on all surfaces, there is a better control over anterior proclination or reciprocal lingual or distal tipping of the molars as side effects. So, the patient can continue active treatment without having to worry much about side effects of unmitigated forces [ 29 ].…”

“…With aligners, however, tooth movements must be small, and lesser teeth must be moved at the same time to ensure there are minimal side effects. Most aligners offer the option to use a virtual power chain for space closure, allowing spaces to be closed, but the orthodontist needs to plan the placement of attachments carefully so that the teeth do not tip instead of undergoing bodily movement [ 14 , 29 ].…”

Biomechanical analysis of effective mandibular en-masse retraction using Class II elastics with a clear aligner: a finite element study

“…That is why the auxiliary forces are so vital. Many researchers proposed to use Class II elastics via CA to reinforce anchorage and achieve Class I relationship, even in Class I extraction cases [ 8 , 9 ] (Fig. 1 a).…”

“…Aside from better anchorage control and the avoidance of mesial movement of the maxillary posterior teeth, Class II elastics may also produce the bowing effects in the maxillary arch. It is reported that the sagittal force component of Class II elastics improved the distalization of the maxillary canine, while the vertical force component of Class II elastics extruded the maxillary incisors [ 9 , 10 ]. However, the role of Class II elastics in extraction cases on mandibular dentition has not yet been investigated.…”

“…Dai et al [ 8 ] reported unfavorable outcomes of the treatment with CA for four first premolar extraction cases which presented insufficient retraction of anterior teeth and excessive mesial displacements of the maxillary first molars. Machado [ 9 ] also concluded that an undesirable Class II relationship was found in the final occlusion in many CA cases with the involvement of tooth extraction. This was likely due to the minor loss in maxillary anchorage during anterior retraction.…”