The muscles that form the walls of the oral cavity are simpler than those that form the walls of the pharynx. The orbicularis oris, which circles the opening of the mouth, and functions as a sphincter to close it, is the anterior boundary of the oral cavity.
http://www.nature.com/gimo/contents/pt1/full/gimo5.html
In some cases, changes to cells in the oral cavity can cause cancer. Most often, oral cavity cancer starts in flat, thin cells called squamous cells. These cells make up the squamous epithelium, which is a layer of the mucous membrane. This type of cancer is called squamous cell carcinoma of the oral cavity.
http://www.cancer.ca/en/cancer-information/cancer-type/oral/oral-cancer/?region=on
1 Functionally, the oral cavity and oropharynx are the pathway that food takes, their boundaries are the muscles that move food.  Comprehension of oropharyngeal anatomy is the basis of modern clinical practice.
http://www.nature.com/gimo/contents/pt1/full/gimo5.html
1 The oral cavity and oropharynx are spaces defined by both hard and soft tissue structures. 2  The oral cavity has muscle and bony boundaries, but the pharynx is a muscular tube.  An embryologic/evolutionary definition is useful for understanding the impact of birth defects.
http://www.nature.com/gimo/contents/pt1/full/gimo5.html
The oral cavity begins at the lips and extends back to the beginning of the tonsils. The bones of the lower jaw (mandible) and upper jaw (hard palate) are included in this region. The oral cavity also includes: The floor of the mouth, situated directly behind the lower teeth in what looks like a smooth gutter.
http://www.mountsinai.org/patient-care/service-areas/ent/areas-of-care/head-and-neck-cancer/oral-cancer
The oral cavity begins at the lips and extends back to the beginning of the tonsils. The bones of the lower jaw (mandible) and upper jaw (hard palate) are included in this region. The oral cavity also includes: 1  The floor of the mouth, situated directly behind the lower teeth in what looks like a smooth gutter.  The front two-thirds of the tongue.
http://www.mountsinai.org/patient-care/service-areas/ent/areas-of-care/head-and-neck-cancer/oral-cancer
Figure 1: Views of the oral cavity and pharynx. a: Midline sagittal view. b: Posterior view of the oral cavity and pharynx. In this view, the spinal column has been removed, so that the view is into the pharynx. The esophagus and pharynx have been opened to show the connections of the nasal cavity, oral cavity, larynx, and esophagus into the pharynx.
http://www.nature.com/gimo/contents/pt1/full/gimo5.html
The oral cavity begins at the lips and extends back to the beginning of the tonsils. The bones of the lower jaw (mandible) and upper jaw (hard palate) are included in this region. The oral cavity has numerous functions. One is to hold food and saliva in the mouth without drooling.
http://www.mountsinai.org/patient-care/service-areas/ent/areas-of-care/head-and-neck-cancer/oral-cancer
Sometimes changes to cells in the oral cavity can cause precancerous conditions. This means that the cells are not yet cancer but there is a higher chance these abnormal changes will become cancer. The most common precancerous conditions of the oral cavity are leukoplakia and erythroplakia.
http://www.cancer.ca/en/cancer-information/cancer-type/oral/oral-cancer/?region=on
Oral cavity cancer is a malignant tumour that starts in cells of the mouth. Malignant means that it can spread, or metastasize, to other parts of the body. The oral cavity is part of the digestive system. The structures in the oral cavity help you speak, taste and chew.
http://www.cancer.ca/en/cancer-information/cancer-type/oral/oral-cancer/?region=on
what is the oral cavity
The oral cavity is the space defined by both hard and soft tissue structures. The oral cavity is the spaces defined by both hard and soft tissue structures.