Australopithecus
You have normal cavities in your body: chest cavity, pelvic cavity, brain cavity. If you mean teeth, those are caused by disease.
The teeth are located in the oral cavity ( the Latin terminology is stomodeum).
faster transmission of nutrients thoughout the body
The oral cavity
The oral cavity is located in the head and neck region of the human body. It is the space inside the mouth where food is ingested and begins the process of digestion. The oral cavity includes structures such as the lips, tongue, teeth, and salivary glands.
The "Wisdom teeth" are technically called the 3rd molars.
An alternative name for the mouth or oral cavity is the buccal cavity.
the enamel or the cavity
The frenulum, a small fold of mucous membrane, acts as the boundary between the buccal cavity (cheek area) and the lingual cavity (tongue area) in the mouth.
By the cavity size inside the skull based off a human skull cavity size today. Different material wears down the teeth at different rates. So depending on where the body was found and what plant matter grew there or animals grazed there would determine the food sources.
The oral cavity contains the teeth and tongue. It is the opening through which food enters the body and where the process of digestion begins.