Effect of Upper first premolars extraction During Orthodontic Treatment on Distribution of Bite Force.

Introduction: Improving masticatory and postural function is one of the primary goals of orthodontic treatment. The assessment of the patient’s occlusion throughout the treatment permits the orthodontist to improve the functional occlusion through interventional tooth movements when necessary, rendering the overall treatment to be more efficient and decreasing the patient’s discomfort. Aim: An in-vivo cross-sectional study to evaluate the effect of upper first premolars extraction during orthodontic treatment on bite force distribution. Methods: Ten patients (mean age=16.13±2.17 years), who would be treated orthodontically with upper first premolars extraction to treat their upper anterior teeth proclination, were selected for this study. The T-scan III system was utilized to measure the occlusal bite force of the patients before and after treatment, and the findings were compared. Results: There was a statistically significant increase in the occlusal bite force’s mean in the arch’s anterior segment from 5.96% (±6.57) to 14.48% (±8.81) after the orthodontic treatment. A non-statistically significant increase in the occlusal bite force in the posterior right segment of the arch from 36.94% (±15.60) to 42.36 % (±11.14) was found after the treatment. The occlusal bite force in the posterior left segment of the arch decreased insignificantly from 56.45% (±15.72) to 40.15% (±13.59). It was found that there was an increase in the distribution of occlusal bite force on the right side and a subsequent decrease on the left side after treatment. There was an even distribution of bite force on both sides of the arch by the end of the treatment. Conclusions: Extraction of upper first premolar teeth does not negatively impact the functional aspect of occlusion. The T-scan III system is a key diagnostic tool utilized during orthodontic treatment to monitor occlusal changes.