Anomalies of color

Abnormal tooth color is any color other than the white to yellowish-white of normal teeth. The change in color may affect the entire tooth, or just appear as spots or lines in the tooth enamel. Your genes influence your tooth color. Other things that can affect tooth color include: congenital diseases, environmental factors, infections. Inherited diseases may affect the thickness of enamel or the calcium or protein content of the enamel, which can cause color changes. Metabolic diseases may cause changes in tooth color and shape. Drugs and medications either taken by the mother while pregnant or by the child during the time of tooth development can cause changes in both the color and hardness of the enamel.

Ex. 16. Find in the text the equivalents for the following words and word-combinations:

Формування зубного ряду, рідкісне генетичне захворювання, суміжні зуби, скупченість зубів, поверхня кореня, один корінь, більша кількість коренів, гострі кути, недостатня кількість, зовнішні шари зубів, зміни кольору.

Ex. 17. Answer the following questions:

1. What is tooth development? 2. What are the causes of tooth development? 3. What categories can all developmental abnormalities of teeth be classified into? 4. What disease is characterized by the congenital absence of all teeth? 5. What is the difference between hypodontia and hyperdontia? 6. What is the difference between microdontia and macrodontia? 7. What anomalies of enamel structure can you name? 8. What is the difference between germination and fusion? 9. What factors can affect tooth color?

Ex. 18. Insert the missing prepositions (at, in, of):

Disorders ___ development of teeth may be due to abnormalities ___ the differentiation of the dental lamina and the tooth germs, causing anomalies __ the number, size, and form ___ teeth (abnormalities of morphodifferentiation) or to abnormalities __ the formation ___ the dental hard tissues resulting in disturbances ___ tooth structure (abnormalities of histodifferentiation). Abnormalities of histodifferentiation occur ___ a later stage in development than abnormalities of morphodifferentiation; in some disorders both stages ___ differentiation are abnormal.

Ex. 19. Insert the missing words given below:

A disruption during tooth ________ may affect the enamel. Generally such a __________ is referred to as hypoplasia (insufficient and/or irregular quantity of ________). Tetracycline can _____ enamel hypoplasia when taken during _________ or by an infant or young _______ during tooth development. Tetracycline should not be _____ during pregnancy or by children ages 8 and under. In addition, Vitamin D _______ during tooth development and calcification results in enamel and ________ hypoplasia. The enamel is poorly calcified and may fail to ______ at all in some areas.

Disruption, development, cause, enamel, used, pregnancy, child, deficiency, dentin, form

Ex.20. Read and retell the following text:

Дата добавления: 2015-07-11