Epidemical Study of the Natural History of Periodontitis

Abstract

Several studies have been undertaken on the natural history of periodontal disease, but the exact nature of its progress are still unclear. The purpose of this study was to determine how periodontal conditions in the population with poor oral hygiene would change without treatment during an interval of two years. A total of 486 subjects (211 males and 275 females, aged from 14 to 44 on initial examination) in a rural area of Chengde, China, were monitored for 2 years. They have very few chances to visit dentists because of the lack of dental facilities. All subjects agreed that their dental diseases would not be treated over 2 years. Two quadrants in each subject randomly selected (right upper and left lower, or left upper and right lower), and 6 sites of each tooth in both quadrants were examined by using an NIDR probe. Two years of changes of Pocket Depth (PD) and Attachment Level (AL) were analyzed site by site, and the following results were obtained. Mean PD was gradually increased by age (male 2.37, female 2.34 at age 14-19, 2.88 and 2.44 at age 40-44). Shallow pockets of less than 4 mm at the baseline showed mostly no remarkable change during 2 years in all age groups. However, pockets over 4 mm tended to deepen in 2 years. The young group had very few deep pockets, but it was noteworthy that the deepening in two years of these pockets were greater than in those of older people. Mean AL also receded by age, but the rate was higher (0.66 and 0.64 at age 14-19, 3.24 and 2.51 at age 40-44) than that of PD. Pockets of which AL was less than 3 mm at the baseline showed mostly no change during 2 years in each group. However, AL over 3 mm at the baseline tended to recede in all age groups. The results indicate that most shallow pockets have shown no noticeable change in PD and AL at least for 2 years; however, the sites where PD is over 4 mm and/or AL is over 3 mm have more potential for further periodontal breakdown.