This patient's crowded teeth were posing a few different risks including plaque and tartar buildup which can harbor harmful periodontal bacteria. After one year of Invisalign the patient's teeth have aligned properly and are healthy! Crowding-- Some potential issues: Buildup of plaque and tartar, harbors harmful periodontal bacteria, risk of periodontal disease, tooth, and bone loss. After one year of Invisalign treatment, teeth have aligned properly for a healthier mouth.