Epidemiologic examination on the prevalence of the periodontal diseases and oral pigmentation in Yusho patients in 2006

An epidemiologic examination was carried out to reveal the prevalence of the periodontal diseases and oral pigmentation in patients with Yusho in 2006. The results obtained were as follows. (1) 98 patients out of 106 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, 343 teeth out of a total 494 examined teeth showed periodontal pocket with more than 3 mm depth. (2) Oral pigmentation was observed in 61 patients out of 116 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, this examination revealed that the patients below the age of sixty had a high prevalence of oral pigmentation. These results indicated that PCB-related compounds may be responsible for the higher prevalence of both periodontal diseases and oral pigmentation.