الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Globally, oral cancer is a major health hazard. It is one of the ten most common cancers worldwide. Nearly 3% of all cancer cases are oral cancers, and two thirds of oral cancer cases occur in developing countries. (1, 2)
Oral squamous cell carcinoma disease, tobacco use is universally regarded as the single biggest risk factor. About 80% of OSCC patients have a history of smoking tobacco, and a person’s risk of developing OSCC increases with heavier daily use and longer duration of use.(5) Smokeless tobacco (chewing tobacco, moist snuff and dry snuff) has also been implicated in OSCC. Recent epidemiologic studies have found that smokeless tobacco users are about twice as likely to develop OSCC as those who have never used. (6)
Other factors include frequent alcohol consumption, previous family history, poor oral hygiene, irritation caused by ill-fitting dentures and other rough surfaces on the teeth, poor nutrition, and some chronic infections caused by bacteria or viruses. (5)
In Yemen, there is a quite high relative frequency of oral cancer among Yemeni, when compared to populations of neighboring countries. (7)The frequency of OSCC is high among young Yemeni people, and it is diagnosed mostly at advanced stages. (8)
Globally, oral cancer is a major health hazard. It is one of the ten most common cancers worldwide. Nearly 3% of all cancer cases are oral cancers, and two thirds of oral cancer cases occur in developing countries. (1, 2)