This study aims to assess the effect of first premolars extraction during orthodontic treatment bite force during the excursive mandibular movements using a digital occlusal analysis system.

The study sample consists of 16 patients, aged 14-25 years-old, who will be presented at the outpatient dental clinics and are seeking orthodontic treatment to relief crowding or to treat their proclined teeth. A written consent will be signed by them or their parents or caregivers after their approval to participate in this research study. The inclusion criteria are : age group from14 to 25 years, full complement of permanent teeth (excluding third molars) and the case analysis revealed extraction of their first premolars to relieve the malocclusion problem. As for the exclusion criteria; they include patients with previous Orthodontic/ Orthopedic/ Orthognathic surgical treatment, patients with history of trauma or obvious/ gross facial asymmetry.

Patients sampling:

Patients will be divided into two groups , each group includes eight patients according to the proposed treatment plan:

• Group I : Patients who will be treated with the extraction of their upper and lower first premolars .
• Group II : Patients who will be treated with extraction of their upper first premolars.

Methods:

Records will be taken on patients selected before initiating any orthodontic treatment to register the occlusal force distribution on teeth during the different excursive mandibular movements (right, left and protrusive mandibular movements) using the T-scan III system before orthodontic treatment and extraction of teeth .

• Orthodontic treatment of patients will be undertaken.
• After finishing the patients' treatment , the T-scan III system is used to measure the bite force distribution during mandibular excursive movements immediately after brackets debonding .
• The bite force measurements taken before and after treatment will be compared with each other .

Statistical Analysis:

In the current study, observations and all numerical data will be collected for statistical analysis using SPSS version 29 for Windows.

Inclusion Criteria:

• Age group from14 to 25 years
• Full complement of permanent teeth (excluding third molars)
• The case analysis revealed extraction of their first premolars to relieve the malocclusion problem

Exclusion Criteria:

• Patients with previous Orthodontic/ Orthopedic/ Orthognathic surgical treatment
• Patients with history of trauma or obvious/ gross facial asymmetry.