Expert Forum
Hong He, Li Ji
Precise torque expression and stable anchorage control are key points in orthodontic treatment. The concern of patients’ quality of life and oral health during orthodontic treatment is increasing. However, most orthodontic instruments cannot achieve the goals mentioned above. A spherical bracket exhibits advantages in these aspects and mitigates these problems to a certain extent. The spherical surface decreases the ulcer rate. Biofilm formation is inhibited, thereby reducing the probability of gum and periodontal disease occurrence. The bonding failure rate of the spherical bracket is lower than that of other self-ligating brackets by 95%. The lock-hook system is the most innovative aspect of the spherical bracket. The system contains thread, screw, and arch wire systems. The lock-hook system benefits torque expression because of its mitigating function. Furthermore, it improves the stability of anchorage when the lock screw is applied. The arch wire system containing three unique wires (0.152 4 mm×0.635 0 mm, 0.203 2 mm×0.584 2 mm, 0.254 0 mm×0.558 8 mm) can be used by orthodontist to control torque with light force during alignment. Therefore, the spherical bracket has gained increasing interest because of its outstanding performance such as comfort, low bonding failure rate, accurate torque expression, stable anchorage, and light force.