An epidemiologic examination on the prevalence of the periodontal diseases and oral pigmentation in Yusho patients in 2008

An epidemiologic examination was carried out to reveal the prevalence of the periodontal diseases and oral pigmentation in patients with Yusho in 2008. The results obtained were as follows. 1) Yusho patients complained of tooth pain and periodontal diseases such as gingival swelling, gingival bleeding, but not of oral pigmentation. 2) 116 patients out of 148 patients with Yusho, who were measured periodontal pocket depth according to Ramfjord' methods, had at least one tooth with periodontal pocket deeper than 3 mm. Similarly, 399 teeth out of a total 710 examined teeth showed a periodontal pocket with more than 3 mm in depth. However, it was determined that 74 teeth had a periodontal pocket deeper than 4 mm. 3) Oral pigmentation was observed in 91 patients out of 155 patients with Yusho. In this study, gingival pigmentation was most predominant among oral pigmentation. The prevalence of oral pigmentation in male patients seemed to be somewhat higher than that in female patients. In addition, the prevalence of oral pigmentation tended to be higher in younger patients than in elder patients. Pigmentation of the buccal mucosa, lip or palate, however, was observed only in patients beyond the age of fifty. These results indicated that PCB-related compounds may be responsible for the higher prevalence of both periodontal diseases and oral pigmentation.