The oral and maxillofacial region is the site of numerous cancer forms. The most frequent cancer, which accounts for more than 90% of these tumors, is squamous cell carcinoma. Genetic changes caused by malignant transformation later result in phenotypic changes in cells. Potentially malignant disorders and circumstances can lead to the development of some malignancies, such as oral squamous cell carcinomas (OSCCs). Because OSCC and precursor lesions cannot be detected early, the 5-year survival rate for OSCC is still only about 50%. Early detection of oral cancer, particularly in the premalignant stage, can greatly reduce death and morbidity. The clinical, histological revelations and etiopathogenesis of a few potentially malignant disorders of the oral and maxillofacial region are reviewed in this chapter.