Oral Cavity Generalities

The oral cavity represents the entrance to the upper aerodigestive tract:
- Which begins at the lips and ends at the anterior surface of the faucial arch
- It is lined by:
  - Squamous epithelium with interspersed minor salivary glands
The oral cavity also contains the:
- Dentoalveolar structures:
  - With the upper and lower dentition
The oral cavity is continuously exposed to inhaled and ingested carcinogens:
- Thus it is the most common site for the origin of malignant epithelial neoplasms in the head and neck region
- Known carcinogens for oral cavity carcinoma include:
  - Those present in tobacco, alcohol, and betel nuts
  - The association of human papilloma virus with oral cancer is not as well established as in oropharyngeal cancers
Primary tumors of the oral cavity may arise from the:
- Surface epithelium
- Minor salivary glands
- Submucosal soft tissues
- Lesions of dentoalveolar origin:
  - Representing a unique group of neoplasms and cysts
The various anatomic sites within the oral cavity as described by the American Joint Committee on Cancer (AJCC) and International Union Against Cancer (UICC) staging system are shown below:

More than 90% of malignant tumors in the oral cavity are:
- Squamous cell carcinomas:
  - The remainder are:
    - Minor salivary gland carcinomas and other rare tumors
Most patients with cancer in the oral cavity are men:
- Although the incidence of tongue cancer in women in the United States has progressively increased over the past several decades
  - In the Western world:
    - The tongue and floor of the mouth:
      - Are the most common sites of origin for primary squamous cell carcinomas in the oral cavity:
        
        However, the retromolar trigone and buccal mucosa are the most frequently encountered primary sites in areas of the world where chewing of tobacco and / or betel nuts is common
The site distribution of various primary cancers in the oral cavity in the United States is shown bowls: