Abstract: Objective: This article aims to provide treatment plans for patients with severe periodontitis of stageⅣ grade C, which combined periodontal, endodontic treatment, alveolar surgery, orthodontics, and restorative treatment. Diagnosis and treatment: The patient suffered from severe periodontitis, resulting in anterior teeth displacement, multiple teeth loosening, and individual posterior teeth loss, accompanied by individual tooth decay and mandibular impacted wisdom teeth. After adequate communication, the clinical treatment process includes periodontal basic therapy, filling and root canal treatment of decayed teeth, extraction of severely loose teeth and impacted wisdom teeth, periodontal surgery, orthodontic treatment, implant restoration, and periodontal maintenance treatment. Results: Through these comprehensive oral treatment, the patient's periodontal condition returned to health, the anterior interdental space was closed, the occlusal relationship was improved, and the dentition integrity was restored. Conclusion: The diagnosis and treatment of patients with severe periodontitis requires comprehensive consideration, and good treatment results can be achieved through multidisciplinary cooperation.

Key words: periodontitis, periodontal surgery, orthodontic treatment, comprehensive dental care