What kinds of occlusion are predominantly distributed in chronic periodontitis?

Objectives: To investigate the characteristics of occlusion types in patients with chronic periodontitis by comparing them with those from university students. Methods: Group A was one hundred chronic periodontitis patients who had an average disease period of 3.05+/-4.03 years (3 months – 30 years), aged 41.30+/-11.26 years old . Group B consisted of 277 university students. The diagnostic casts were obtained from all participants and panoramic radiograph was taken for each patient. The frequencies of Angle's Classes, impinging bite and large horizontal overlap of anterior teeth, cross-bite of anterior and posterior occlusion, reversal cross-bite of posterior occlusion in the two groups were compared. Results: 1.Three kinds of occlusions in patient group were found more than in student group and 51% of the patients had at least one kind of them. They were Angle's Class II (19/95 in patients and 19/277 in students), impinging bite of anterior teeth (21/98 in patients and 34/277 in patients), and the cross-bite of the third molar (24/72 pairs of the third molars in patients and 3/65 in students). 2.The diseased teeth which were assessed clinically and the teeth with lower bone level on the panoramic radiograph distributed in similarities, both of them were higher in first and second molars, incisors, but lower in cupids, premolars and the third molars . Conclusions: Comparing with the nature population, the university students, Angle's Class II, impinging bite of anterior occlusion, and cross-bite of the third molar are predominantly distributed in patients with chronic periodontitis.