Abstract

The aims of this study were to determine the prevalence of periodontal disease for two clinical parameters: probing pocket depth (PPD) and attachment loss (AL) among twins, and to compare between mono zygote (MZ) and dizygote (DZ) twins, in addition to the evaluation of the degree to which MZ and DZ twins are concordant for four clinical parameters. The sample consisted of 75 pairs of twins reared together, with an age range of 16-45 years. They were selected from different cities of Iraq. The examination was carried out using a graduated Williams’s periodontal probe, on a portable chair, using artificial light. The clinical examination included recording of PPD and AL. Results of the present study have shown significant difference in periodontal pocket depth between MZ and DZ group; which was higher in MZ were higher than in DZ twins. No significance difference was found between MZ and DZ twins in attachment loss. Results from this study have demonstrated that the degrees of concordance for MZ were higher than in DZ twins for PPD and AL and there were significant differences between MZ and DZ twins. These findings provide evidence that genetic factors play an important role in the etiology of periodontal disease.

Key words: Periodontal disease, probing pocket depth, attachment loss among mono zygote, dizygote.