In general, most cases for interdisciplinary treatment often demonstrate a poor periodontal health, moderate dental caries requiring multiple extractions, or a missing tooth status. Missing teeth or a poor periodontal heath can cause tooth movement over time, which leads to the collapse of teeth alignment and therefore requires a space redistribution when establishing a treatment plan. In case when the existing periodontal health is poor, however, one should be careful for initiating orthodontic treatment, which should be applied to a proper case only. Once a treatment initiation is decided, the periodontal inflammation control - the most crucial factor - should be considered with caution over three stages: pre-treatment, mid-treatment, and post-treatment stage.