II. Работа над грамматикой – 40 мин Продолжение темы Continuous Tenses. Разница употребления времён Indefinite и Continuous. Выолнение упражнений раздела

III. Перевод текста со словарём. (40 мин) Направлено на формирование компетенции ок-6 Tooth structures formation

Dentinogenes is the name given to the origin and formation of dentin. Dentin is the 1^st mineralized tissue to appear in any developing tooth. It is composed of a fibrillar matrix, which mineralizes, and odontoblastic processes which remain unmineralized.

The 1^st dentin is formed at the incisal or cusp area of a tooth, and formation progresses in a rootward direction. Several cytoplasmic extensions of each odontoblast join to make a single dentinal process. The cells remain connected with their point of origin by the cytoplasmic extension, which are branched at their peripheral ends.

Dentin matrix mineralizes progressively. The newest nonmineralized dentin is called predentin. Dentin may be produced along the pulpal wall in a tooth of any age as long as the pulp is intact.

Amelogenesis is the name given to the process of enamel formation. The ameloblasts produce an organic matrix in which mineral salts later crystallize out of solution thereby making enamel a hard tissue. The formation of enamel is completed when submicroscopic crystals develop. Tooth enamel, being about 96% mineral substance, is the hardest of all body tissues.

As the root dentin starts to form, the already formed crown moves occlusally. If the tooth has a single root, the dentin wall encloses a single pulp canal. If the tooth is multirooted, the division of the pulp cavity into 2 pulp canals is apparent after the completion of the crown.

Root length is not complete until 1 or 4 years after the tooth emerges into the oral cavity. A newly emerged tooth has a short root and a large apical opening. As teeth become older, the root length is completed.

IV. Устная речь (40 мин). Направлено на формирование компетенции ок-6.

Задание 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.

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

Задание 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.

V. Ознакомление с вариантом Лексико-грамматической итоговой работы №2 – 15 мин (см. Раздел Контрольные задания)

Тема 2.3. Аномалии развития структур ротовой полости

Занятие 7

Этапы занятия:

I. Выполнение Лексико-грамматической итоговой работы №2 по Теме 2.2- 45 мин

II. Изучающее чтение. Направлено на формирование компетенции ОК-5

Remember the pronunciation and the meaning of the words and word combinations.

Inherited наследственный, унаследованный

acquired приобретенный

fusion слияние, сочленение

congenital врожденный

cleft lip расщелина губы

cleft palate расщелина нёба

unsightliness уродство

malocclusion неправильный прикус

hypoplasia гипоплазия (врожденное недоразвитие органа и т.п.)

Anomalies of the oral cavity structures

Disorders of oral structures may be prenatal or postnatal in origin, and may be inherited or acquired. A congenital disease is one which occurs before or at birth but is not necessarily inherited, while a number of hereditary states are found at birth or become evident over a number of years.

Facial malformations result from fusion of maxillary and premaxillary processes between 5^th and 8^th weeks of fetal life. The incidence in general populations is 1 in 800 births. If a history of the abnormality exists in one parent there is about a 4% chance that the first child will have the defect.

Severe congenital abnormalities, such as cleft lip or cleft palate arise because of the failure of the facial processes to unite. Statistically cleft lip and cleft palate develop rather oftener than other abnormalities. It is more common in males. This condition is a serious handicap to the child and to the adult that he will become.

The treatment of cleft lip is a problem not for dentist alone. He is only one member of a team that work together for maximum results. The plastic surgeon, the dentist, the speech therapist and psychotherapist must work together, each in his special field, to give the child with a cleft palate not only normal appearance but also the possibility of normal functioning.

Babies with a cleft palate may have a great deal of difficulty in swallowing and are often severely undernourished. Besides, this condition is accompanied by unsightliness and functional disturbances especially in mastication and phonation. It is more common in girls. Cleft palate may involve the soft and hard palate and may extend into the nose, forming an oronasal passageway. This abnormality produces malocclusion from displacement of the maxillary arch.

The size and form of teeth are subjected to genetic, developmental and posteruptive factors, of which heredity is probably the most important.

Disturbances in tooth structure involve enamel and dentine. Hypoplasia or defective enamel structure may ensue from the matrix formation. If the mineralizing mechanism is disrupted, hypomineralization will result.