Effect of the lower premolar extraction on third molar eruption
10.3969/j.issn.1001-3733.2010.01.025
- VernacularTitle:正畸拔除下颌前磨牙对第三磨牙萌出影响的测量研究
- Author:
Quan YU
;
Xin GONG
;
Guoping JI
;
Jing LU
- Publication Type:Journal Article
- Keywords:
Third molar;
Premolar;
Extraction
- From:
Journal of Practical Stomatology
2010;26(1):103-107
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To evaluate the eruption of mandible third molar in orthodontic patients with non-extraction or extraction of the lower premolars. Methods: We selected 3 group of the orthodontic patients. One group consisted of 23 subjects (12 males, 11 females, average age 13.5 years) with non-extraction. One group consisted of 23 subjects (12 males, 11 females, average age 13 years) with lower first premolar extraction. One group consisted of 21 subjects (11 males, 10 females, average age 14.07 years) with lower second premolar extraction. The panoramic radiography was taken. The lower third molar angulation and eruption space were measured before and after the orthodontic treatment. The comparison of treatment changes in 3 groups were performed by means of a paired-sample t test using SPSS 17.0 software package. Results: The RS, LS, Rratio and Lratio increased significantly after treatment in patients with lower first premolar extraction(P<0.01). The RM3 and LM3 increased(P<0.05) and RS, LS, Rratio and Lratio increased significantly(P<0.01) after treatment in patients with lower second premolar extraction(P<0.05). Conclusion: The mandibular third molars show improvement in eruption space and inclination in the orthodontic patients with lower premolar extraction.
