2Offenbacher S, Katz V, Fertik G, et al. Periodontal infection as a possible risk factor for preterm low birth weight[J]. J Periodontol, 1996,67 : 1103-1113.
3Lopez N J, Smith PC, Gutierrez J. periodontal therapy may reduce the risk of preterm low birth weight in women with periodontal disease: a randomized controlled trial [ J ]. J Periodontol, 2002, 73:911-924.
4Jin LJ, Chiu GKC, Corbet EF. Are periodontal diseases risk factors for certain systemic disorders? - What matters to medical practitioners? [ J]. Hong Kong Med J ,2003,9:31-37.