2020-09-24
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SETS OF TEETH
During his life each human has two sets of teeth. Those teeth that erupt in early childhood are called the temporary teeth or deciduous teeth. The second or permanent teeth erupt later and are intended to serve during the adult years.
Temporary teeth. There are twenty teeth in the temporary dentition, ten in each jaw.
The first of those teeth usually erupts about six months, and this process continues, one temporary tooth after another pushing its way through the gums until about the second year. Between the ages of six and twelve or thirteen, these teeth loosen and drop out (exfoliate), and are promptly replaced by the permanent ones.
The temporary dentition in each jaw consists of: two central incisors, two lateral incisors, two cuspids or canine teeth, four molar teeth. While the temporary teeth are still in place in the mouth, the permanent teeth are commencing to form inside the jawbone. As they grow, they press against the roots of the temporary teeth, which wear away, until there is not enough root structure remaining to support them and, one by one, they are lost. As each temporary tooth is exfoliated, a permanent tooth, usually just beneath the surface of the gum, is waiting to push through and take its place.
Permanent teeth. The normal permanent dentition of a man consists of 32 teeth. The first of these usually erupts at about the age of 6. This is the first permanent molar or six-year molar. It erupts behind the second temporary molar, and does not replace a temporary tooth. This first permanent molar tooth acts as a keystone, determining the position of all the other permanent teeth, which are to erupt later. Because this important tooth comes through at such an early date and doesn’t replace a temporary tooth, it is often overlooked and permitted to decay. Its early loss may result in irregularities in the dental arch and damage of the teeth.
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Exercise 5. Answer the questions to the text:
1. How many sets of teeth does each man have?
2. When do the temporary teeth erupt?
3. When are teeth called temporary?
4. How many teeth are there in dentition? How many are there in each jaw?
5. Until what age does the process of eruption of deciduous teeth continue?
6. What are the deciduous teeth replaced by?
7. What is the function of the permanent teeth?
Exercise 6. Make sentences from the following words and word combinations:
1. to call, which, early, the temporary teeth, to erupt, childhood, those teeth.
1. to erupt, the age, between, six, to loose, these teeth, of, twelve or thirteen.
- to press, of, the roots, against, the permanent teeth, the temporary teeth.
- normal, a man, consists of, permanent dentition, 32 teeth.
- a key-stone, acts, first molar, this, tooth, as, permanent.
Exercise 7. Find synonyms to the following words in the text:
Gingiva, to lead to, milk teeth, dentition, to replace, canine, to drop out, to allow, injury.
Exercise 8. Make questions to the underlined words:
1. The deciduous teeth start erupting at six months.
2. All deciduous teeth were replaced by the permanent ones between the ages of 6 and 12 years.
3. Permanent teeth are the second and final set.
4. All teeth start developing inside the jaw before the birth.
5. All temporary teeth have already erupted.
6. The last wisdom tooth erupted at the age of 20.
7. The eruption of all permanent teeth will be completed at the age of 25.
8. The second or permanent teeth are intended to serve during the adult years.
Exercise 9. Translate into English:
1. Перші зуби прорізуються в дітей у ранньому дитинстві.
2. Напртязі двох років один за другим молочні зуби пробиваються через ясна.
3. Тимчасових зубів по 10 на кожній щелепі.
4. Постійні зуби, починаючи формуватися у щелеповій кістці, тиснуть на корені тимчасових зубів.
5. 32 зуба – нормальна кількість зубів у людини.
6. Перший постійний моляр прорізується в 6 років.
7. Рання втрата першого моляра може привести до зміни зубної дуги.
Exercise 10. Fill in the missing remarks. Reproduce the dialogues:
a) - What does every tooth consist of? - …
- What are the neck and apex? - …
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- What is every tooth composed of? - …
b) - What do you know about enamel? - …
- I’d like to know what cementum is? - …
- What does dentine occupy? - …
- What is pulp? - …
- What can you tell me about the alveolar process? - …
- By what is a tooth attached to its socket in the jaw? - …
c) - How are the low and the upper jaw also called? - …
- What is the hard palate? - …
- And what jaw is immovable? - …
