Study of Chinese periodontal patients at National Taiwan University Hospital. Part I: Basic periodontal information and oral hygiene status.

A cross-sectional study of 288 subjects with complete periodontal documentation was evaluated to determine the clinical status of periodontal disease. The patients were divided into age group intervals of ten years. The conditions of oral hygiene and their association with the clinical status of periodontal disease were compared and analyzed. Chronological features of the disease and its background development among Chinese patients is also explored. Our results indicated that in the mind of Chinese patients the loss of teeth was considered to be a natural fate of aging, and dental and periodontal problems were viewed merely as a symptom of pain, but not as disease entity. Most patients were completely ignorant of both the importance of oral hygiene care and prevention of periodontal diseases. A high incidence of ill-fitted restorations, lack of motivations, and insufficient knowledge on prevention were common in our subjects. In this study, the oral hygiene index (OHI) in females was found to be lower than that of males. The OHI dropped abruptly after 20 years of age in females and after 30 years of age in males. The lowest gingival index (GI) was found in the 31-40 age group in both sexes. During the later periods of life, the OHI again rose, and this increase appeared earlier in females than in males. The GI corresponded to chronological changes in OHI. There was no statistical difference in GI between the corresponding age groups of males and females. The periodontal disease index (PDI) increased progressively with age in both sexes. However, no significant difference was noted between males and females. The progression of the PDI appeared stationary in the 31-40 age group, which corresponded to the period of lowest GI. In conclusion, our Chinese subjects exhibited poor oral hygiene and had an associated high incidence of periodontal disease. Irrespective of sex, OHI showed a positive correlation with GI. However, there was no obvious correlation between OHI and PDI. In contrast, GI was highly correlated to PDI in the 21-30 and 31-40 age groups in the present study. In addition, the paroxysmal nature of clinical periodontal parameters supports the recently held concept that the onset and progression of periodontal disease is intermittent.