Bracket position is extremely important as otherwise the teeth will NOT be correctly aligned.
Modern brackets are based on the 'straight wire' technique. This means the brackets have the torque, tip, inset/offset built into the bracket, which reduces the need for bending archwires at the chairside. However, it means each tooth requires an individual bracket correctly placed on the buccal surface.
The brackets are positioned on the tooth at the Facial Axis (FA) point, with the plane of the archwire slot placed at a specific angle relative to the Facial Axis of the Clinical Crown (FACC).
To sight the bracket to ensure its correct placement it is important to view the bracket correctly.
This means viewing the bracket directly as illustrated in the above diagrams, a mirror may be used to view the upper brackets and teeth from the occlusal surface.
If the bracket is not positioned properly mesio-distally, unwanted rotation of the tooth occurs. If the bracket is placed too far gingivally or occlusally unwanted inclination, cusp height or prominence may result.