Position change of upper incisors and molars after extraction of first premolars in cases with Angle class I malocclusion and crowding
- VernacularTitle:安氏Ⅰ类拥挤拔牙矫治后磨牙及切牙位置变化的研究
- Author:
Xiaoping YUAN
- Publication Type:Journal Article
- Keywords:
Angle class I malocclusion;
Crowding;
Cephalometry;
Molars;
Incisors;
Changes in position
- From:
Journal of Practical Stomatology
2001;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To observe the position change of the upper mol ar s and incisors in cases with Angle class I malocclusion and crowding treated by extraction of four first premolars. Methods: 20 patients with An gle class I malocclusion and crowding aged 14-16 years old, 8 male and 12 femal e, were treated by extraction of the four first premolars, and Edgewise applianc e. Two X-ray cephalometry films were taken for every patient before and after t reatment, cephalometry measurements were obtained and the position of the upper molars and incisors were analyzed. Results:The treatment was co mpleted in 18 month on average in all patients. After treatment, the crown of th e upper first molars showed mesial displacement of 3.15 mm on average, the crown of the upper incisors distal displacement of 2.55 mm, the crown of the lowe r first molars mesial displacement of 4.3 mm, the crown of the lower incisors d istal displacement of 1.77 mm. Conclusion: With of dental anchor age, the position changes of the upper molars and incisors in the cases with Ang le class I malocclusion and crowding after extraction treatment may be achived.I n relation to RL line,the mesial displacement of molars are larger than the dist ally displacement of incisors.
