Periodontitis was assessed by aleolar bone loss measured from panoramic radiographs by one examiner blind to cancer status.Tongue cancer diagnoses came from the Roswell Park tumor registry.

• 牙周炎的是通过不知道患者已患癌症的X线照片检查人员确定诊断，舌癌诊断结果来源于罗斯威尔帕克癌症机构的肿瘤登记病案。