High Parity Is an Independent Risk Factor for Tooth Loss in Women: A Community-Based Takahata Study in Japan

High Parity Is an Independent Risk Factor for Tooth Loss in Women: A Community-Based Takahata Study in Japan

Shigeo Ishikawa,¹ Tsuneo Konta,² Shinji Susa,³ Kaoru Edamatsu,¹ Kenichi Ishizawa,^3,4 Hitoshi Togashi,⁵ Satoru Nagase,⁶ Yoshiyuki Ueno,⁴ Isao Kubota,⁴ Hidetoshi Yamashita,⁴ Takamasa Kayama⁴ and Mitsuyoshi Iino¹

¹Department of Dentistry, Oral and Maxillofacial Plastic and Reconstructive Surgery, Faculty of Medicine, Yamagata University, Yamagata, Yamagata, Japan
²Department of Public Health and Hygiene, Yamagata University Graduate School of Medicine, Yamagata, Yamagata, Japan
³Department of Neurology, Hematology, Metabolism, Endocrinology, and Diabetology, Yamagata University Faculty of Medicine, Yamagata, Yamagata, Japan
⁴Global Center of Excellence Program Study Group, Yamagata University School of Medicine, Yamagata, Yamagata, Japan
⁵Yamagata University Health Administration Center, Yamagata, Yamagata, Japan
⁶Department of Obstetrics and Gynecology, Yamagata University Faculty of Medicine, Yamagata, Yamagata, Japan

Risk factors for tooth loss have been widely examined previously. However, no previous study has comprehensively investigated the risk factors, including lifestyle-related specific factors (parity, oral health habits, and socioeconomic status), for fewer than 20 teeth among women in the general population in Japan. This cross-sectional study explored the association of these risk factors, especially parity, with having fewer than 20 teeth among Japanese women. A self-reported questionnaire including items on lifestyle-related risk factors (parity, oral health, diet [e.g., alcohol and sucrose consumption]) and socioeconomic status was sent by post to female residents (age 40 years) of Takahata town, Yamagata Prefecture, in 2005. Multivariate logistic regression analysis including 3,854 eligible participants was performed to investigate the association between various factors (including parity) and having fewer than 20 teeth. The results indicated that, compared with nulliparous women, women with two, three, and four completed pregnancies had 2.485-, 2.844-, and 4.305-fold increased risk of having fewer than 20 teeth, respectively. Our study is the largest-scale study of the general female population in Japan and the first study to comprehensively investigate risk factors (parity, oral health status, and socioeconomic status) for fewer than 20 teeth. We thus found that higher parity, especially, two or more, was independent risk factors for having less than 20 teeth among Japanese women. In conclusion, the present study emphasizes the importance of good oral health habits in women, especially, during pregnancy and in the postpartum period, to maintain 20 or more teeth.

Keywords —— cross-sectional study; multivariate logistic regression analysis; number of teeth; oral health; parity

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Tohoku J. Exp. Med 2021 253, 77-84.

Correspondence: Shigeo Ishikawa, Department of Dentistry, Oral and Maxillofacial Plastic and Reconstructive Surgery, Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, Yamagata 990-9585, Japan.

e-mail: shigeo_ishikawa2011@yahoo.co.jp