Orthodontic treatment aims to realign teeth in a functional and esthetic manner. When applied on an unhealthy periodontium, this may lead to advanced periodontal tissue breakdown. The present 12-year follow-up report describes the multidisciplinary management of a severe, iatrogenic, generalized periodontitis case that was caused/aggravated by orthodontic therapy on unhealthy periodontal tissues. Prompt therapy was applied through nonsurgical and surgical approaches, including soft and hard tissue grafting procedures combined with corrective orthodontic treatment on healthy tissues. This report is a clear demonstration that early disease detection and proper diagnosis combined with appropriate therapeutic approaches concomitant with strict supportive periodontal therapy could lead to long-term successful and maintainable outcomes, even in hopeless cases.