Medical definition of oral cavity is the cavity of the mouth; especially the part of the mouth behind the gums & teeth that is bounded above by the hard & soft palates & below by the tongue & by the mucous membrane connecting it with the inner part of the mandible.
Bacteria & viruses usually cause oral infections. They can affect the teeth, gums, palate, tongue, lips & inside of the cheeks. Simple oral infections are limited to the mouth & are different from oral lesions, which are non-infectious & may be a sign of an illness that involves other parts of the body.
Oral infections are very common. Tooth decay is the second most common infectious condition after the common cold.
1. Abdur-Rahman Bin Abu Atiq رضي الله عنه says: "My father told me: 'I heard A’isha رضي الله عنها saying, (narrating) from Nabi ﷺ: "Siwak is a means of purification for the mouth & is pleasing to the Lord.&qu