This study evaluated the periodontal effects of mandibular second premolar extraction compared to first premolar extraction in orthodontic patients. Participants (ages 16–31) were assessed at least two years post-treatment for periodontal health indicators. Patients with second premolars extracted exhibited significantly worse outcomes, including greater probing depth, attachment loss, bleeding, plaque accumulation, and food impaction (p<0.05). In contrast, first premolar extraction patients remained periodontally healthy. The findings suggest that contact between the mandibular first premolar and first molar following second premolar extraction may increase the risk of localized periodontal breakdown.
