Objective: This article reports a case of severe generalized aggressive periodontitis and subsequent collapse of the occlusion in a psychiatric patient, treated by an extremely conservative orthodontic-periodontal-prosthodontic treatment. Summary: A woman presented with severe anterior proclination caused by severe periodontal disease and Angle's class II molar malocclusion. The patient wanted to preserve her teeth and rejected the idea of implant treatment. This case report demonstrates that combining periodontal therapy, orthodontic treatment, and prosthodontics (through a decision-making system with a proper interdisciplinary coordination) can greatly improve function and the esthetic result. Comprehensive periodontal treatment took place before other intervention, and periodontal maintenance and follow-up throughout the treatment and after played a crucial role. Keywords: dental protrusion, depressive disorders, generalized aggressive periodontitis, intracoronary occlusal retention, orthodontic treatment, periodontal treatment