Park Kitae, Jung Da-Woon, Kim Ji-Yeon
Department of Pediatric Dentistry, The Institute of Oral Health Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea 135-710.
Int J Paediatr Dent. 2009 Nov;19(6):383-9. doi: 10.1111/j.1365-263X.2009.00990.x. Epub 2009 Apr 16.
A space maintainer is generally preferred when a primary first molar is lost before or during active eruption of the first permanent molars in order to prevent space loss. However, controversy prevails regarding the space loss after eruption of the permanent first molars.
The purpose of this study was to examine spatial changes subsequent to premature loss of a maxillary primary first molar after the eruption of the permanent first molars.
Thirteen children, five girls and eight boys, expecting premature extraction of a maxillary primary first molar because of caries and/or failed pulp therapy, were selected. Spatial changes were investigated using a three-dimensional laser scanner by comparing the primary molar space, arch width, arch length, and arch perimeter before and after the extraction of a maxillary primary first molar. Also, the inclination and angulation changes in the maxillary primary canines, primary second molars, and permanent first molars adjacent to the extraction site were investigated before and after the extraction of the maxillary primary first molar in order to examine the source of space loss.
There was no statistically significant space loss on the extraction side compared to the control side (P = 0.33). No consistent findings were seen on the inclination and angulation changes on the extraction side.
The premature loss of a maxillary primary first molar, in cases with class I molar relationship, has limited influence on the space in permanent dentition.
当第一恒磨牙萌出前或萌出过程中乳磨牙早失时,通常会使用间隙保持器以防止间隙丧失。然而,关于恒磨牙萌出后的间隙丧失存在争议。
本研究的目的是检查上颌乳磨牙早失后恒磨牙萌出后的空间变化。
选择13名儿童,5名女孩和8名男孩,因龋齿和/或牙髓治疗失败而预计上颌乳磨牙早失。通过比较上颌乳磨牙拔除前后的乳磨牙间隙、牙弓宽度、牙弓长度和牙弓周长,使用三维激光扫描仪研究空间变化。此外,在拔除上颌乳磨牙前后,研究拔除部位相邻的上颌乳尖牙、乳第二磨牙和恒第一磨牙的倾斜度和角度变化,以检查间隙丧失的来源。
与对照侧相比,拔除侧无统计学意义的间隙丧失(P = 0.33)。拔除侧的倾斜度和角度变化未见一致结果。
在I类磨牙关系的病例中,上颌乳磨牙早失对恒牙列间隙的影响有限。