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Harmful habits

Habits are generally considered repeated acts of unspecified motivation. They will be treated as consciously repeated acts here. As such they fall into two classes; (1) occupational and (2) nonspecific.

In the case of occupational habits, many callings require the use of the teeth and mouth in an active or passive role. Musicians who play wind instruments, glass blowers, furriers, and many others use the mouth or teeth or both, either by necessity or for convenience. The type of breakdown will vary with the type of abuse inflicted.

The habits of sucking the thumb, lip, or tongue, so frequently formed by young children will, if persisted, cause marked malocclusion.

Fortunately, the habit of thumb-sucking is usually broken before any evil effects result, so that cases are easily recognized. The upper incisors and canines are drawn forward and to one side, according as the thumb of the right or left hand has bean used, while pressure from the back of the thumb upon the lower incisors causes their displacement.

The habit of biting the lower lip will move the upper central incisors. This habit is more common than seems.

The habit of sucking the lower lip, though quite rare, may produce marked malocclusion. The upper lip becomes short and contracted, the gums highly colored, and the lower lip becomes larger than normal.

Third National Health and Nutrition Examination Survey was conducted in the USA in 1988 to 1994. Participants were interviewed about tobacco use and examined by dentists trained to use standardized clinical criteria. It was calculated that 41.9% of periodontitis cases (6.4 million cases) in the U.S. adult population were attributable to current cigarette smoking and 10.9% (1.7 million cases) to former smoking. Among current smokers, 74.8% of their periodontitis was attributable to smoking. According to the findings of this study and numerous other reports, it is possible to conclude that smoking is a major risk factor for periodontitis and may be responsible for more than half of periodontitis cases.

Grammar

1. Find the examples of the Infinitive and Gerund in the text, explain the reasons for their use.

2. Complete the sentences with the correct form of the verb – Infinitive or Gerund.

1. As we don't agree about politics we generally avoid ……. (discuss) the subject.

2. He doesn't get on with the new boss, so he's asked ……. (transfer) to another

branch of the company.

3. Please stop ....... (interrupt) me when I'm explaining something to you.

4. We had arranged ....... (meet) in my office for him to check the documents.

5. He admits ....... (enter) the house but he says he didn't take anything.

6. I've apologised to her but she still refuses ……. (speak) to me

7. What a dreadful man! Can you imagine ……. (live) with him?

8. I'll help you, as long as it doesn't involve ….... (lift) anything heavy.

9. Oh no! I've forgotten …… (bring) my briefcase. I'll have …….(go back) for it.

10. I don't mind ....... (work) late, if it will help at all.

11. I simply can't afford ……. (support) you any longer

12. We had hoped to finish the project by the end of the month but we keep …….

(work) because of the changed situation.

13. You'd better go and see the boss and say what you've done. If you put off …….

(explain) it to her, she'll only be more annoyed.

Summary

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