Treatment progress
The patient was referred to the surgeon to extract wisdom teeth before the start of treatment. The ClinCheck virtual set up dictated 44 steps for each arch (Fig. 2). In the upper arch, sequential distalisation was planned to gain space for retraction of incisors, achieving optimal overjet and class I canine and molar relationships bilaterally. Attachments were planned on most of the teeth to guide their movement and control their axes. Vertical attachments were planned for molars and premolars to avoid tipping and aid in bodily movement. The paired vertical root control attachments on the canines bilaterally to help achieve bodily movement and control their long axes during distalization. Horizontal attachments were planned on upper incisors for extra retention and firmer grip of the aligner.
Class II elastics (3/16inch, heavy force 4.5 oz) were used to augment the movement. The elastics extended from the upper premolars to lower molars. The benefit of using short class II elastics is to prevent any clockwise rotation and bite deepening that might happen due to extrusion of anterior teeth. Intermaxillary elastics were hooked from notches in the upper aligners at first premolar to buttons that were bonded on the lower molars. The lower arch crowding was relieved by the expansion effect of the aligners and the proclination of the lower incisors. The patient was instructed to wear each aligner for 22 h per day and to move on to the next one in the series after 14 days. Mid treatment records are presented in (Fig. 3).