Efficiency of clear aligner treatment in orthodontic patient requiring premolar teeth extraction

INTERVENTION: Participants who met the inclusion criteria underwent orthodontic treatment using in‐house clear aligners appliance. A split mouth randomisation technique is used to allocate the side of the maxillary canine teeth (left or right), the experimental canine with power arm attached or without power arm on the other side. Bilateral symmetrical extraction of the upper left and right first premolar teeth were carried out. Canine teeth on both sides were to be moved through the extraction site. Both canine teeth receive pushing force from the clear aligners. However, The experimental canine tooth is subjected to another retracting force on the palatal side using power chain from 1st molar tooth. According to the principle of orthodontic biomechanics, the power arm helps lower the retracting force toward more apical level which hypothetically may help creating bodily tooth movement. The control side of the mouth does not have this power arm extension. Incisors teeth movement will also be concomittantly carried out although at a smaller distance. The trial cannot be double blinded due to the visibilty of power arm attached on the experimental canine tooth. Total duration of treatment and follow‐up: 4 years CONDITION: Orthodontic treatment using in‐house clear aligners appliance in the first premolar extraction patient ; Oral Health PRIMARY OUTCOME: ; Tooth movement measured using 3D inspection software at pretreatment, at various set up stages which are: the 6th clear aligners, at 12th clear aligners and at completion:; 1. Mesial/distal teeth movement (distance change in millimeters); 2. Extrusion/ intrusion teeth movement (distance change in millimeters); 3. Rotation / tip/ torque (angulation change in degree); 4. Canine teeth retraction; 5. Incisor teeth retraction; SECONDARY OUTCOME: ; 1. Pain level will be measured using visual analogue scale (VAS) at baseline, day 1, day 3 and day 7; 2. Teeth off track from clear aligners will be evaluated at pretreatment, at 12th clear aligners, at 24th clear aligners and at completion by observation.; 3. Root resorption will be evaluated using periapical radiograph at completion of treatment; INCLUSION CRITERIA: 1. Aged 18 years or older 2. Angle Class I or II, with upper anterior teeth proclination/protrusion 3. Crowding less than 6 mm 4. Requiring full therapy of all permanent teeth, with bilateral symmetrical extraction of the upper first premolar teeth.