Otani Nobuko, Hamasaki Tomoko, Soh Inho, Yoshida Akihiro, Awano Shuji, Ansai Toshihiro, Hanada Nobuhiro, Miyazaki Hideo, Takehara Tadamichi
Division of Community Oral Health Science, Department of Health Promotion, Kyushu Dental College, Japan.
Arch Oral Biol. 2009 Feb;54(2):192-200. doi: 10.1016/j.archoralbio.2008.09.010. Epub 2008 Oct 30.
The people of the Yayoi period (5th C b.c.-3rd C a.d.), who were the first wet-rice agriculturalists in ancient Japan, had carious lesions that were most frequently located on the root surfaces of their teeth. Root surface exposure is a prerequisite for this type of decay, and alveolar bone loss is the main cause of such exposure. Therefore, we identify the factors associated with root caries, and examine the relationship between root caries and alveolar bone loss in the people of the Yayoi period.
This study was performed using 263 sets of ancient skeletal remains that are believed to be from the Yayoi period and that were excavated at 49 archaeological sites in western Japan. Using 5010 teeth found among the remains, we analysed the relationship between the prevalence of root caries and the cemento-enamel junction-alveolar crest (CEJ-AC) distance.
The prevalence of root caries and the mean number of teeth with root caries per person were significantly correlated with age, the presence of coronal caries and the mean CEJ-AC distance per person. We also found that as the mean CEJ-AC distance per tooth surface increased, the percentage of the root surface affected by caries increased. Moreover, after excluding the lingual (palatal) side, the mean CEJ-AC distance per surface was significantly greater for those tooth surfaces with root caries.
We present the first evidence that the occurrence of root caries correlated with the CEJ-AC distance in the Yayoi people of Japan.
弥生时代（公元前5世纪 - 公元3世纪）的人们是古代日本最早的水稻种植者，他们的龋齿病变最常位于牙齿的根面。根面暴露是这种龋齿类型的先决条件，而牙槽骨吸收是根面暴露的主要原因。因此，我们确定与根龋相关的因素，并研究弥生时代人群中根龋与牙槽骨吸收之间的关系。
本研究使用了263套据信来自弥生时代的古代骨骼遗骸，这些遗骸是在日本西部的49个考古遗址发掘的。利用遗骸中发现的5010颗牙齿，我们分析了根龋患病率与牙骨质 - 釉质界 - 牙槽嵴（CEJ - AC）距离之间的关系。
根龋患病率和每人患根龋的平均牙齿数与年龄、冠龋的存在以及每人的平均CEJ - AC距离显著相关。我们还发现，随着每个牙面的平均CEJ - AC距离增加，受龋齿影响的根面百分比增加。此外，排除舌（腭）侧后，有根龋的牙面每个表面的平均CEJ - AC距离明显更大。
我们首次提供证据表明，日本弥生时代人群中根龋的发生与CEJ - AC距离相关。
