ACCURACY OF ORTHODONTIC BRACKETS POSITIONING WITH OR WITHOUT DENTAL LOUPES

Interventions

This was a two-arm parallel, singe-centre randomised study where the patients that have been treatment planned were randomised into two groups according to the block pattern:

Group NL: Bonding of the orthodontic brackets without dental loupe Group L: Bonding of the orthodontic brackets with dental loupe After extraction procedure was performed according to treatment plan. Within a week, the patient's teeth were dried before taking an intraoral scan with an intraoral scanner 3Shape TRIOS, Copenhagen, Denmark. After scanning the upper and lower arches, the teeth images were stored in STL file. STL file is a format commonly used for 3D printing and computer-aided design (CAD).

The STL file of each patient upper and lower arches were exported and printed into model by the 3D printer by digital dental laboratory to allow extraoral bracket positioning. The extraoral bracket positioning on the twenty 3D printed models were the gold standard for the eighteen patients respectively.

Once the gold standard for individual patient was generated, the bond up session was scheduled within a week time, a new set of brackets were placed by MJHS on the patient's maxillary and mandibular right to left premolars. Bonding of the brackets was performed according to the manufacturer's instructions. Dental loupes Zumax DFK Angled Loupe with a magnification of x3.0 and focus depth of 42cm was used. For the patients bond up by direct eye vision or using dental loupes, the brackets were positioned in the centre of mesial-distal dimension and aligned with the long axis of the crown. No over-correction of the bracket positioning was done to correct specific malocclusions, rotation, or tipping problems. After 40s light-curing of the composite according to manufacturer instructions. The bracket bonding was performed by MJHS in all patients to avoid inter-operator errors.