Text V. Development of the oral cavity as a whole

By the time of birth the oral cavity of the foetus is formed of three parts:

- the vestibule of the mouth (vestibulum oris),

- the cavity of the mouth proper (cavum oris proprium),

- the fauces (isthumus faucium).

The cavity of the mouth communicates with the external surroundings by way of the oral fissure. The vestibule is bounded in front by the lips and cheeks, and at the back by the alveolar processes of the upper and lower jaws. These processes are powerfully developed and each has 18 dental follicles, ten of the follicular period in the formation of the tooth coincides in time with its eruption.

The periodontal ligament produces the cementum that covers the root dentin. It also produces the lamina dura of the tooth socket. The attachment of the periodontal ligament fibers in the lamina dura and in the cementum holds the tooth securely in the socket.

The upper jaw of a newborn consists mainly of the alveolar process, while the body of the lower jaw is much smaller in height than its alveolar process.

The oral cavity proper is bounded above by the hard and soft palate, below by the floor of the mouth and the uvula, in front and on the sides by the inner surface of the alveolar processes; at the back the cavity of the mouth communicates with the pharynx and larynx. Numerous salivary and mucous glands are found under the oral mucosa.

With growth and development the functions of the organs situated in the maxillofacial region become more complicated.

Speaking

1. Try to guess what teeth are spoken about. Prove your point of view.

1. These teeth are four in number. They erupt from 7 to 9 months after birth.

2. This tooth is in the lower jaw. It has two roots. It erupts at the age of ten.

3. These teeth have each two roots. They are in the lower jaw. These teeth have no predecessors. Their function is to crush and grind food.

4. The function of these teeth is intermediate between the cuspids and molars. They erupt from 11 to 12.

5. These teeth are used to cut food. They are four in number. They usually erupt at the age of 6 years.

2. Choose any of the tooth structures (root, dentin, enamel) and describe the process of its development.

3. Imagine that you are a pedodontist. Tell a child’s mother about the eruption of teeth and possible alterations or abnormalities. Try to explain a significant role of the process.

Unit VI. Physiology of digestion and the role of the oral cavity structures.

Lead-in

Some centuries ago it was commonly thought that digestion begins somewhere in the stomach. But physiologists proved that the initial and the most important processes of digestion occur already in the oral cavity. Do you agree? Do you have any idea about how the food is processed in the oral cavity? Read the texts and evaluate the role of the oral cavity structures in human digestion.

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