PREVENTION OF WHITE SPOT LESIONS (WSLs): Background: Incidence & Prevalence -- Detection -- Treatment -- Prevention -- Clinical Recommendations. MAINTENANCE OF PERIODONTAL HEALTH AND PREVENTION OF PERIODONTAL DETERIORATION: Extraction vs. non-extraction treatment -- Functional appliances vs. headgear -- Diagnosis and treatment of anterior open bite -- The importance of chin projection -- Stability and Post-treatment retention -- Clinical Recommendations. PREVENTION OF EXTERNAL APICAL ROOT RESORPTION (EARR): Etiologic Factors - Controversies -- Genetic predisposition - Evidence -- Root-Sparing Treatment Strategies -- Clinical recommendations.