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Synchronous Straight-Wire (SSW) is the trademark of the authors Charles Cole and Jon Hammond. In part one the SSW technique was introduced, the reasons for its development were explained and the theory outlined. The aim of this second paper is to demonstrate the SSW technique. A case is presented to demonstrate the technique, all aspects of the malocclusion being addressed concurrently. The case is then treated in 11 visits, reducing the PAR score from 38 to 0, giving a Treatment Efficiency Index (TEI) of 3.45. The conclusions that can be drawn are that the technique offers a more efficient means of undertaking fixed appliance treatments and highlights the advantages of pre-programming the entire appliance and using a coherent mechanism to facilitate 3-dimensional movements.
Clinical Relevance: This paper demonstrates a means of organizing simultaneous treatment events by synchronizing, rather than sequencing, tooth movement, thereby giving greater efficiency than other techniques. It requires a radically different approach to treatment mechanics and a fundamental shift in thinking.
Article
A male patient aged 14 years, 8 months with average oral hygiene with a Class I malocclusion on a Class I base, increased MMPA and vertical lower facial dimension, had moderate crowding in both arches and lateral incisor crossbites. The upper and lower left first molars had a poor prognosis while the third molars presented good form and position.
The treatment plan was as follows:
The required movements were as follows:
The required movements are charted on the ACT (Figure 2).
The forces required for configuration are shown in Figure 3. In the lower arch, elastic traction from molar to canine will give a good balance of movement of canine retraction and molar advancement. Asymmetrical movement of the lower incisors can be facilitated by coil spring, and elastic traction from the wire to the lower right lateral incisor will advance the incisor into the space as it becomes available. In the upper arch, elastic chain can be used in the same way but space loss will be much more rapid in the upper molar region. Therefore, it is important to ensure that the balance of forces is applied so that the canines retract well before the molar space is lost. Coil spring is therefore used to distalize the canines and is supplemented with inter-arch traction to retract the upper canine reciprocally and advance the slower moving lower second molar. Elastic traction to the upper lateral incisors will advance them into their final positions as their space opens and counteract any anterior movement of the upper incisors under the influence of the coil spring.
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