关键词: 牙周炎, 牙列缺损, 种植治疗, 正畸治疗, 多学科治疗

Abstract: The mandibular second molars are highly susceptible to periodontitis，often exhibiting progressive destruction of periodontal tissues due to factors such as third molars，and leading to tooth mobility and even loss. For such dentition defects，implant restoration has become the preferred treatment option. However，the edentulous area often presents with soft and hard tissue deficiencies and may be accompanied by issues such as overeruption of opposing teeth and tilting of adjacent teeth. These factors not only increase the difficulty of implant placement and restoration but also affect the long-term stability of the implant prosthesis. Targeted treatment is required to make the edentulous area meet the basic requirements for implant restoration. This article shows the whole process of a case with bilateral missing mandibular second molars and periodontitis（Stage Ⅱ，Grade B），including condition analysis，multidisciplinary treatment design，specific implementation steps，and the follow-up outcomes after implant restoration. The aim is to provide a reference for the comprehensive management of similar cases involving free-end partial edentulism in the molar region accompanied by periodontitis.

Key words: periodontitis, dentition defect, dental implant therapy, orthodontic treatment, multidisciplinary therapy