An epidemiologic examination on the prevalence of the periodontal diseases and oral pigmentation in Yusho patients in 2002.

An epidemiologic examination was carried out to reveal the prevalence of the periodontal diseases and oral pigmentation in patients with Yusho. The results obtained were as follows. 1) 95 patients out of 110 patients, who were examined periodontal pocket depth using Ramfjord' methods, had at least one tooth with periodontal pocket deeper than 3 mm. Similarly, 276 teeth out of a total 495 examined teeth showed periodontal pockets with more than 3 mm depth. However, the ratio of the teeth with periodontal pockets deeper than 4 mm to total examined teeth in each age fell to less than 25%. 2) Oral pigmentation was observed in 75 patients out of 121 patients with Yusho. In this examination, gingival pigmentation was most predominant among oral pigmentation. It is of particular interest that severe pigmentation tended to be observed at a much higher frequency in younger patients with Yusho. Taken these findings into consideration, it was suggested that PCBs and related compounds might play an important role in the development of both periodontal diseases and oral pigmentation.