关键词: Ⅳ期牙周炎, 牙周-正畸联合治疗, 治疗时机

Abstract: Patients with stage Ⅳ periodontitis often suffer from severe destruction of periodontal supporting tissues，which is frequently accompanied by tooth displacement，occlusal disorders，and functional loss. The treatment requires multidisciplinary collaboration to achieve functional reconstruction and periodontal health maintenance. During this process，orthodontic treatment，as one of the core components，not only shoulders the crucial responsibilities of correcting pathological tooth displacement and reconstructing stable occlusal relationships but also requires dynamic adaptation of precise biomechanical control  to periodontal supporting tissues. This approach aims to minimize damage to periodontal tissues while creating favorable conditions for periodontal regeneration and functional recovery. Given the great difficulty and complexity of orthodontic treatment for stage Ⅳ periodontitis，this article will elaborate on the key considerations in combined periodontal-orthodontic treatment，aiming to ensure the safety and effectiveness of the treatment.

Key words: stage Ⅳ periodontitis, combined periodontal-orthodontic treatment, treatment timing