Effect of orthodontic removal of mandibular first molar on the position change of third molar
10.12016/j.issn.2096-1456.2017.07.011
- Author:
HAN Xiaoli
1
;
XIAO Danna
2
;
YIN Shuo
1
Author Information
1. Graduate School, Tianjin Medical University
2. Department of Orthodontics, Tianjin Stomatological Hosptial
- Publication Type:Journal Article
- Keywords:
Panoramic radiograph;
First molar;
Extraction treatment;
Eruption space;
Eruption angle
- From:
Journal of Prevention and Treatment for Stomatological Diseases
2017;25(7):458-461
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effects of the first molar on the eruption of the third molar by comparing the changes of the third molar position after orthodontic treatment in different tooth extraction modes.
Methods:39 cases of adolescent patients were selected and divided into three groups:the first molar extraction, first premolar extraction and non-extraction.The pretreatment, posttreatment panoramic radiographs were measured to analyze the change of the third molar position among these groups.
Results: There were significant differences (P< 0.05) in the average annual variation of the third molar eruption space and angle. The changes in first molar extraction group were larger than that in premolar extraction group and non-extraction group. The average annual variation of the third molar eruption space, three groups were (2.38 ± 1.62) mm, (1.61 ± 0.90) mm and (1.08 ± 1.49) mm; the average annual variation of eruption angle, the three were 1.89° ± 1.93°, 1.37° ± 1.16° and 0.83° ± 1.74°.
Conclusion :Compared with conventional treatment, mandibular first molar extraction can significantly increase the third molar eruption space and improve its eruption angle, which is beneficial to the eruption of the third molar.
- Full text:正畸拔除下颌第一磨牙对第三磨牙位置变化的影响.pdf
