Martin, Domingo

This article examines the innovative Stop and Go concept in aligner treatment planning, an important aspect of the Functional and Cosmetic Excellence Aligner System (Forestadent, Pforzheim, Germany). This approach sets a predetermined control point during treatment at which to reassess the patient’s progress as a reference for fabricating the following phase of aligners. It offers several benefits, namely the need for fewer aligners, shorter treatment time, improved tracking and more predictable finishing, and is also environmentally friendly. Guidelines for planning the Stop and Go phase during treatment are based on intra-treatment analysis of the evolution of the planned treatment design. In cases where it is necessary to modify the original treatment plan, change the aligner material, improve tracking, modify attachments and place or remove occlusal stops, Stop and Go is highly advantageous. Its use is suggested by the treatment planner based on the complexity and type of correction required; if necessary, however, the orthodontist has the freedom to decide the optimal time at which to introduce the Stop and Go phase based on treatment progress. In conclusion, Stop and Go is an important concept in both moderate and complex cases, for improved efficiency and treatment outcomes. Keywords: aligners, Functional and Cosmetic Excellence Aligner System, occlusion, predictability, tracking

Objective: To compare the influence of outer bow length difference and unilateral outer bow expansion on the 'asymmetric effect' of the headgear. Methods: Twelve 3D finite element models of a headgear with two tubes were designed, which were similar except for the outer bow length or the degree of unilateral expansion in Solid-Works 2011. A 3N force was applied to the outer bow ends in ANSYS Workbench 12.1 and the distalising, lateral forces to molars, moments and the energy of the system were evaluated. Results: As the degree of unilateral expansion increased, the net differences in all findings were increased up to a point, and then changed. There was an increasing pattern in the length difference group. Buccal movement was observed in the intact/shorter side molar. Conclusion: Unilateral shortened outer bow asymmetric headgears are more efficient and more predictable in clinical application than the unilateral outer bow expansion. Keywords: asymmetric cervical headgear, finite element method, unilateral expanded, unilateral shortened