Environmental Research 93 (2003) 131–137 Neonatal and childhood teeth in relation to perinatal exposure to polychlorinated biphenyls and dibenzofurans: observations of the Yucheng children in Taiwan $ Shu-Li Wang, a,b Tzung-Tarng Chen, c Jing-Fang Hsu, a Chen-Chin Hsu, d Louis W. Chang, a John J. Ryan, e Yueliang Leon Guo, a,f, and George H. Lambert g a Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Taiwan b Department of Public Health, Chung Shan Medical University, Taiwan c Department of Dentistry, College of Medicine, National Cheng Kung University, Taiwan d En-Chu Kong Hospital, San Shia, Taipei, Taiwan e Food Research Division, Health Protection Branch, Health Canada, Ottawa Canada K1A OL2 f Department of Occupational and Environmental Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan g Department of Pediatrics, Center for Child and Reproductive Environmental Health, Environmental and Occupational Health Service Institute, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, NJ, USA Received 12 August 2002; received in revised form 13 February 2003; accepted 26 February 2003 Abstract In order to determine the effect of perinatal polychlorinated biphenyls and dibenzofurans (PCBs/PCDFs) exposure on neonatal and childhood teeth in Yucheng children, we carried out complete dental examinations on 73 Yucheng children born to mothers who ingested high levels of PCBs/PCDFs and 75 matched controls, aged 7–11 years, in 1992. Ten of 73 (10%) exposed children were reported to have borne teeth during the neonatal period, while none of the controls did. The exposed group also had a significantly higher percentage of teeth with congenitally missing tooth germ compared to the controls (29 vs 2.7%) or rotation (19 vs 2.7%). The percentages of developmental defects increased significantly with increasing maternal serum PCB levels, childhood PCB and PCDF levels, and the duration of breast feeding. The maternal PCB level clearly played a more important role in an increased risk of neonatal teeth and developmental defects. The defects were apparent from the lowest tertile, with a total PCB level of o10 ppb in maternal serum measured nearest to childbirth. The number of permanent teeth tended to be less in exposed children than in the control group from the age of 11years onwards. Our present study has demonstrated for the first time a dose-response relationship between perinatal PCBs/PCDFs exposure and dental defects. r 2003 Elsevier Inc. All rights reserved. Keywords: Polychlorinated biphenyles; Polychlorinated dibenzofurans; Tooth abnormalities; maternal exposure; Breast feeding 1. Introduction Polychlorinated biphenyls and dibenzofurans (PCBs/ PCDFs) are highly lipophilic, bioaccumulative, and are transferred to the fetus and infants transplacentally and lactationally (Robbins, 1974). Children who experienced in utero exposure to PCBs from maternal ingestion of PCB-contaminated oil in the Japanese Yusho episode were reported to bear abnormally-shaped tooth roots, retarded eruption, and reduced numbers of permanent teeth (Fukuyama et al., 1979). Periodical examinations of permanent teeth for the Yusho patients revealed consistent results of prevalent periodontal diseases and ARTICLE IN PRESS $ This study was funded by The National Science Council of Taiwan, Grant No. NSC90-2621-Z-006-005 (Y.L.G), and the United States Environmental Protection Agency, STAR Grant No. R038759 (G.H.L). The Human Subject Review Board of the National Cheng Kung University Medical Center approved this study. Informed consent was obtained from each of the subjects and their parents/ guardians after detailed explanation of the nature and possible consequences of the study by the interviewer on the day of the dental examination.  Corresponding author. Department of Occupational and Environ- mental Health, College of Medicine, National Cheng Kung University, 61 Shiao Tong Road, Tainan 704, Taiwan. Fax: +866-6-2743748. E-mail address: leonguo@mail.ncku.edu.tw (Y.L. Guo). 0013-9351/03/$ - see front matter r 2003 Elsevier Inc. All rights reserved. doi:10.1016/S0013-9351(03)00040-9