The consequence of Khat chewing habit on the periodontal conditions among adults in Sanaa city, Yemen Hussein M. Shoga al-deen (MSc, PhD) , Al-Kasem M. A. Abbas (MSc, PhD) , Hassan A. Al-Shamahy (MSc, PhD), Ali K. Al-Sharabi (MSc, PhD), Ibrahim Ghandour (MSc, PhD), Mohammed A. Al-Labani (MSc, PhD) , Ahmed M. Al-Haddad (MSc, PhD)