Lindsten R, Ogaard B, Larsson E
Department of Orthodontics, The Institute for Postgraduate Dental Education, Jönköping, Sweden.
Angle Orthod. 2001 Feb;71(1):36-43. doi: 10.1043/0003-3219(2001)071<0036:ASRALI>2.0.CO;2.
The anterior arch spaces and the effect of early loss of deciduous canines have been studied in 2 different cohorts of 9-year-old children. One group of 119 children was from Norway and consisted of 56 girls and 63 boys, and 1 group of 133 children was from Sweden and consisted of 72 girls and 61 boys. Within these cohorts, half of the children were born in the 1960s and half in the 1980s. The 1960s group has been compared with the 1980s group to look for anterior arch changes occurring during this period of time. The children who had lost a lost deciduous canine at the age of 9 years were also compared with the children with all deciduous canines remaining. Groups were compared with analysis of variance. It was found that children with a lost deciduous canine at the age of 9 years belong to a group with less available arch space and are a crowded group when compared with an earlier study. For the girls, this was also associated with larger teeth. Anterior arch space did not differ between the 1960s and the 1980s groups except for the Swedish boys, where there was less available mandibular arch space in the 1980s group. The irregularity index for the 4 mandibular incisors was increased in the 1980s group compared with the 1960s group. This could indicate a secular trend toward an increased prevalence of malocclusion in the present population.
在两组不同的9岁儿童队列中，研究了前牙弓间隙以及乳牙早失的影响。一组119名儿童来自挪威，其中有56名女孩和63名男孩；另一组133名儿童来自瑞典，其中有72名女孩和61名男孩。在这些队列中，一半儿童出生于20世纪60年代，另一半出生于20世纪80年代。将20世纪60年代组与20世纪80年代组进行比较，以寻找这一时期发生的前牙弓变化。还将9岁时乳牙犬齿已缺失的儿童与乳牙犬齿全部保留的儿童进行了比较。采用方差分析对各组进行比较。结果发现，9岁时乳牙犬齿已缺失的儿童所属组的牙弓间隙较小，与早期研究相比是拥挤组。对于女孩来说，这也与牙齿较大有关。除了瑞典男孩外，20世纪60年代组和20世纪80年代组的前牙弓间隙没有差异，20世纪80年代组的瑞典男孩下颌牙弓间隙较小。与20世纪60年代组相比，20世纪80年代组4颗下颌切牙的不整齐指数增加。这可能表明当前人群中错牙合患病率增加的长期趋势。
