An evaluation and validation study on oral cancer screening methods will be carried out, and two different methods will be used for oral cancer screening among the population. The two different methods are: (1) clinical observation (including inspection and palpation) combined with pathological biopsy. (2) Clinical observation (including inspection and palpation), in vivo staining (toluidine blue) combined with pathological biopsy. By evaluating and comparing the sensitivity and specificity of the two screening methods, the more effective oral cancer screening method will be selected.

An evaluation and validation study on oral cancer screening methods will be carried out, and two different methods will be used for oral cancer screening among the population. The two different methods are: (1) clinical observation (including inspection and palpation) combined with pathological biopsy. That is, inspecting and palpating the oral cavity and neck of the screened object. If positive lesions are found, then further pathological biopsy will be performed. This is also the commonly used screening method for oral cancer now; (2) Clinical observation (including inspection and palpation), in vivo staining (toluidine blue) combined with pathological biopsy. That is, toluidine blue staining is performed at the same time as the inspection and palpation of the oral cavity and neck of the screening object. As long as the screening subjects found positive lesions or abnormal living body staining, pathological biopsy was performed. By evaluating and comparing the sensitivity and specificity of the two screening methods, the more effective oral cancer screening method will be selected. Finally, we will carry out prospective controlled population studies in high-risk areas and non-high-risk areas to further evaluate the effectiveness and feasibility of screening method after selection.

Inclusion Criteria:

• aged 40-69 years old.

Exclusion Criteria:

• No.