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

摘要： 下颌第二磨牙是牙周炎的好发部位，还常因第三磨牙等因素影响牙周支持组织，更易发生进行性破坏而出现患牙松动乃至脱落。对于此类患牙缺失，种植修复是首选治疗方案；但缺牙区常存在软硬组织缺陷，并可能伴有对颌牙过长、邻牙倾斜等现象。这些因素不仅增加了种植体植入与上部结构修复的难度，也会影响种植修复体长期稳定性，需要针对性处理，使缺牙区满足种植修复的基本需求。文章报告1例双侧下颌第二磨牙缺失伴广泛型Ⅱ期B级牙周炎患者的诊疗过程，系统阐述其病情分析、多学科联合治疗方案的制定与实施，以及种植修复后随访效果，以期为此类磨牙区游离端缺牙伴牙周炎病例的综合诊治提供参考。

关键词: 牙周炎, 牙列缺损, 种植治疗, 正畸治疗, 多学科治疗