Question 187 · LDEK · Crowding and dental anomalies
Which of the following statements concerning extractions in orthodontics is true?
1) teeth with large restorations and teeth treated endodontically are preferred for extraction;
2) extractions in the upper arch are contraindicated in the maxillary buccal crossbite;
3) extractions are preferred when the nasolabial angle is decreased;
4) extractions are preferred when the interincisal angle is decreased;
5) premature loss of a primary canine on one side in an indication for the extraction of the primary canine on the same side of the other arch.
The correct answer is:
2) extractions in the upper arch are contraindicated in the maxillary buccal crossbite;
3) extractions are preferred when the nasolabial angle is decreased;
4) extractions are preferred when the interincisal angle is decreased;
5) premature loss of a primary canine on one side in an indication for the extraction of the primary canine on the same side of the other arch.
The correct answer is:
- A. only 1.
- B. 1,2.
- C. 1,2,3.
- D. 1,3,4.
- E. 1,4,5.
Hint
Consider what decreased nasolabial and interincisal angles reveal about incisor protrusion, and how a midline shift is prevented after unilateral canine loss.
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