Methods The age, sex, time and frequence of chewing betel nut, clinical features as well as the mouth opening width were studied among 2,749 physical check-up subjects in Changsha area.

• 方法对长沙地区2749例体检者的年龄、性别、咀嚼槟榔时间、频率、口腔粘膜主要症状、张口度等临床资料进行分析。