PDF(Pubmed)
Abstract：
OBJECTIVE: To assess the success rate of spontaneous space closure after extraction of the first permanent molar (FPM) in the maxilla and the mandible, and to identify the factors that make spontaneous space closure most favorable in each.
METHODS: A retrospective records-based cohort study was conducted through a search of the database of the Public Dental Service, Stockholm County Council, Stockholm, for young adults born between 2000 and 2001, who underwent extraction of one or more FPM between 2006 and 2016. A total of 995 extracted teeth were identified, of which 203 teeth in 155 patients met the inclusion criteria.
RESULTS: Of the 203 extracted teeth, 166 (81.8%) did not receive any orthodontic treatment. The success rate for space closure in orthodontically treated patients was 91.9%. The success rate for spontaneous space closure was 84.3%. All unsuccessful spontaneous space closure in the maxilla occurred in patients older than 12 years. The dental developmental stage of the second permanent molar (SPM) had a statistically significant association with spontaneous space closure in the mandible (P < .001).
CONCLUSIONS: The success rate of spontaneous space closure was high (84.3%) and was higher in the maxilla (94.1%) than the mandible (74.1%). Age at time of extraction and dental developmental stage of the SPM were significant factors for successful spontaneous space closure in the maxilla and mandible, respectively.
METHODS: A retrospective records-based cohort study was conducted through a search of the database of the Public Dental Service, Stockholm County Council, Stockholm, for young adults born between 2000 and 2001, who underwent extraction of one or more FPM between 2006 and 2016. A total of 995 extracted teeth were identified, of which 203 teeth in 155 patients met the inclusion criteria.
RESULTS: Of the 203 extracted teeth, 166 (81.8%) did not receive any orthodontic treatment. The success rate for space closure in orthodontically treated patients was 91.9%. The success rate for spontaneous space closure was 84.3%. All unsuccessful spontaneous space closure in the maxilla occurred in patients older than 12 years. The dental developmental stage of the second permanent molar (SPM) had a statistically significant association with spontaneous space closure in the mandible (P < .001).
CONCLUSIONS: The success rate of spontaneous space closure was high (84.3%) and was higher in the maxilla (94.1%) than the mandible (74.1%). Age at time of extraction and dental developmental stage of the SPM were significant factors for successful spontaneous space closure in the maxilla and mandible, respectively.
摘要：
目的：评估上颌骨和下颌骨第一恒磨牙（FPM）拔除后自发间隙闭合的成功率，并确定使自发空间闭合最有利的因素。
方法：通过搜索公共牙科服务数据库，进行了一项基于记录的回顾性队列研究，斯德哥尔摩县议会,斯德哥尔摩,对于在2000年至2001年之间出生的年轻人，他们在2006年至2016年期间接受了一个或多个FPM的提取。共识别出995颗拔牙,其中155例患者中的203颗牙齿符合纳入标准。
结果：在203颗拔除的牙齿中，166例(81.8%)未接受任何正畸治疗。正畸治疗患者的空间闭合成功率为91.9％。自发性空间闭合成功率为84.3%。上颌骨所有不成功的自发性间隙闭合均发生在12岁以上的患者中。第二恒磨牙（SPM）的牙齿发育阶段与下颌骨的自发性间隙闭合有统计学意义（P<.001）。
结论：自发性空间闭合成功率高（84.3%），上颌骨（94.1%）高于下颌骨（74.1%）。拔牙时的年龄和SPM的牙齿发育阶段是上颌骨和下颌骨成功自发闭合的重要因素，分别。
方法：通过搜索公共牙科服务数据库，进行了一项基于记录的回顾性队列研究，斯德哥尔摩县议会,斯德哥尔摩,对于在2000年至2001年之间出生的年轻人，他们在2006年至2016年期间接受了一个或多个FPM的提取。共识别出995颗拔牙,其中155例患者中的203颗牙齿符合纳入标准。
结果：在203颗拔除的牙齿中，166例(81.8%)未接受任何正畸治疗。正畸治疗患者的空间闭合成功率为91.9％。自发性空间闭合成功率为84.3%。上颌骨所有不成功的自发性间隙闭合均发生在12岁以上的患者中。第二恒磨牙（SPM）的牙齿发育阶段与下颌骨的自发性间隙闭合有统计学意义（P<.001）。
结论：自发性空间闭合成功率高（84.3%），上颌骨（94.1%）高于下颌骨（74.1%）。拔牙时的年龄和SPM的牙齿发育阶段是上颌骨和下颌骨成功自发闭合的重要因素，分别。
