To explain in layman term, these are lesions and/or condition may have chances of transforming into oral cancer. Average age for occurrence of PMD's is 50–69 years, which is 5 years before occurrence of oral cancer. Unfortunately, in recent years 5% of PMDs has been observed in persons under 30.
PMD's are usually found on the buccal mucosa, followed by gingivae, tongue and floor of the mouth. World Health Organisation has classified PMDs into two types:
- Premalignant Lesions: a benign lesion with morphologically altered tissue, which has a greater than normal risk of transforming into malignancy. These include:
Proliferative verrucous leukoplakia(PVL)
Reverse smokings’ palate
Oral verrucous carcinoma
Oral submucous fibrosis
- Premalignant Conditions: a disease or patients’ habit that does not necessarily alter the clinical appearance of local tissues but is associated with a greater than normal risk of precancerous lesion or cancer development in that tissue. These include:
Discoid lupus erythematosus
Plummer Vinson Syndrome
Syphilis (third stage)
Vitamin A, B, C deficiency
Immunosuppressive disease (AIDS)
Oral PMD's are usually misdiagnosed due to lack of adequate knowledge among the general population and even medical professionals.
Many oral cancers develop from PMDs, hence early diagnosis of these lesions and associated risk factors can help save many lives form claws of cancer.