Ghose L J, Baghdady V S, Enke H
Community Dent Oral Epidemiol. 1980 Oct;8(7):381-4. doi: 10.1111/j.1600-0528.1980.tb01312.x.
A comparative epidemiologic study on traumatized permanent anterior teeth was conducted on 6090 Iraqi and 3507 Sudanese primary schoolchildren. A significant relationship was found between the severity of trauma to protrusion of maxillary incisors and amount of lip coverage in Iraqis and a similar tendency was observed for the Sudanese. In a comparison between the two population groups the frequency of traumatized permanent maxillary incisors with greater tooth loss (types 3 + 4) were significantly higher in Iraqi than in Sudanese children with protrusion and inadequate lip coverage.
对6090名伊拉克和3507名苏丹小学生进行了一项关于外伤性恒前牙的比较流行病学研究。研究发现，伊拉克人上颌切牙前突的创伤严重程度与唇部覆盖量之间存在显著关系，苏丹人也观察到类似趋势。在两组人群的比较中，伊拉克儿童中牙齿缺失较多（3 + 4型）的外伤性恒上颌切牙的发生率显著高于苏丹有前突和唇部覆盖不足的儿童。
