Abstract: Objective    To explore the correlation between the Fusobacterium nucleatum（Fn） and inflammatory reaction of gum in the process of orthodontic treatment；to analyse the role of Fn in the development of gingivitis during orthodontic treatment. Methods    Totally 128 patients were randomly chosen from the orthodontic and oral medicine departments in Jinan Stomatological Hospital，separatively，constituting orthodontic group（A），normal control group（B）and periodontitis group（C）. A variety of clinical indicators were recorded and the gingival crevicular fluid（GCF）was collected from the deepest periodontal pocket. 16S rDNA PCR technique was used to detect Fn. The relationship between detection rate and clinical indicators was analyzed. Results    Eighty-seven cases showed Fn positive，of which 44 （69.84%） were from group A，14（46.67%）from group B and 29（82.85%） from group C. The higher detection rate was noticed in the orthodontic group in comparison with the control group，while the periodontitis group showed highest detection rate. Thus the significant variance was displayed among them（χ2 = 9.843，P < 0.05）. Significant positive correlation（rs =1.000，P < 0.01）was observed between GI（Gingival index）and detection rate of  Fn in the orthodontic group by using spearman rank correlation analysis. Conclusion    Fn is closely related to occurrence and development of gingivitis reaction during orthodontic treatment. Therefore，orthodontists should pay more attention to the oral hygiene instruction and supervision during orthodontic treatment.

Key words: Fusobacterium nucleatum, orthodontic treatment, gingiva inflammatory reaction, 16S rDNA PCR technique

摘要： 目的    探讨具核梭杆菌（Fusobacterium nucleatum，Fn）在正畸牙龈炎性反应发生发展中的作用。方法    收集2011年8月至2012年2月在济南市口腔医院正畸科接受固定矫治并伴有不同程度牙龈炎性反应的牙颌畸形患者63例组成正畸治疗组；正畸治疗前未戴用矫治器的牙周健康者30例组成正常对照组；牙周科就诊的慢性牙周炎患者35例组成牙周炎组。记录患者牙龈指数（GI），分别采集牙周袋最深处或龈沟液标本，采用16S rDNA PCR技术对Fn进行检测，分析Fn的检出率与GI之间的关系。结果    128例患者临床标本中，共扩增出Fn 87例，检出率67.97%。其中正畸治疗组检出率为69.84%（44/63）；正常对照组检出率为46.67%（14/30）；牙周炎组检出率为82.86%（29/35）。正畸治疗组的Fn检出率明显高于正常对照组，牙周炎组高于正畸治疗组和正常对照组，三者之间差异有统计学意义（χ2 = 9.843，P < 0.05）。Spearman等级相关分析显示，Fn的检出率与牙龈指数之间存在明显的正相关关系（rs =1.000，P < 0.01）。结论    Fn与正畸治疗中牙龈炎性反应的发生发展密切相关，正畸医生应高度重视正畸治疗前与治疗过程中的口腔卫生指导和监督。

关键词: 具核梭杆菌, 正畸治疗, 牙龈炎性反应, 16S rDNA PCR技术