Abstract: Objective: This article reported a case of combined periodontal-orthodontic treatment in a patient with Angle class I malocclusion with gingivitis. Diagnosis and treatment: The patient came to the clinic with misaligned teeth, and after a clear diagnosis and the patient’s informed consent, the patient was treated with a combination of basic periodontal treatment and fixed orthodontic techniques. Basic periodontal treatment was carried out before orthodontic treatment, and after the periodontal condition was improved, the patient was treated with fixed orthodontic appliances after subtractive extractions based on multifactorial considerations, and attention was paid to the control of the support resistance during the orthodontic process. Results: After nearly two years of periodontal, orthodontic, and combined periodontal-orthodontic treatment, the patient’s teeth were aligned and occlusal relationship was significantly improved, while gingivitis was effectively controlled. Conclusion: Combined periodontal-orthodontic treatment can reduce the periodontal risk in orthodontic treatment and improve the stability of periodontal treatment, while taking into account the aesthetics of the teeth, occlusal balance, and periodontal tissue health in the diagnosis and treatment.

Key words: combined periodontal-orthodontic treatment, Angle class I malocclusion, gingivitis, periodontal initial therapy, fixed appliances