Comparison of Periodontal Inflammatory Disease in Young Adults With and Without Pericoronitis Involving Mandibular Third Molars

Abstract

To compare the prevalence and severity of periodontal inflammatory disease in subjects with pericoronitis involving a mandibular third molar and those without pericoronitis. Data obtained from healthy adults consecutively enrolled in an institutional review board-approved trial with pericoronitis affecting at least 1 mandibular third molar (study group) were compared with data obtained during the same time frame from subjects without pericoronitis enrolled in a longitudinal third molar monitoring study (comparison group). The periodontal status of each subject was classified based on periodontal probing depths (PD): all PD <4 mm, no disease; 1 to 3 PD >or=4 mm, incipient disease; at least 4 PD >or=4 mm, early disease. Full mouth periodontal probing data were obtained as clinical measures of periodontal status. Data were aggregated to the subject level for the third molar region, the 6 third molar probing sites and the 2 second molar distal probing sites, the non-third molar region, and all remaining probing sites. The prevalence of disease in the study and comparison groups were compared with the Fisher's exact test. As an indicator of disease severity, the number of PD >or=4 mm in the 2 groups were compared by the Kruskal-Wallis test. Level of significance was set at P values less than .05. Median age of the 56 subjects with pericoronitis was 23.3 years (IQR 21.3-26.0 years). Fifty-five percent were Caucasian, 16% African American, and 22% Asian. Males and females were almost equally represented in the study group and in the comparison group. The 194 subjects enrolled without pericoronitis were significantly older (32.8 years; IQR 27.2-40.0 years; P < .001). Eighty-four percent were Caucasian, 10% African American, and 4% Asian. The proportion of subjects with periodontal inflammatory disease in the third molar region was significantly different between the study and comparison groups. Thirty-one percent of the subjects with pericoronitis had incipient and 55% early disease in the third molar region compared with 25% with incipient and 38% with early disease among subjects without pericoronitis (P = .003). The pattern was similar, but the proportion of subjects was not significantly different between the groups for the non-third molar region. In the study group, 32% had incipient disease and 32% early disease compared with 27% with incipient disease and 22% with early disease in the comparison group (P = .09). The median number of PD >or=4 mm for all teeth differed significantly for subjects with and without pericoronitis (median 5 [IQR 3-9] vs 3 [IQR 0-8], respectively; P = .03). Pericoronitis involving mandibular third molars may reflect more underlying periodontal inflammatory disease in affected young adults than might be found in young adults with retained third molars and no pericoronitis.