Background & Aim: Tobacco smoking exerts a harmful effect on the periodontal tissues manifested by periodontal pockets, attachment loss and periodontal bone loss. Current evidences on the effects of tobacco on periodontal health mainly concern cigarette smoking. In view of the increasing popularity of water pipe smoking in Arabian countries and reports confirming that water pipe smoking has health effects similar to those of cigarette smoking, there is a need for a better understanding of the potential harm of this smoking habit. The present thesis was carried out in order to explore whether water pipe smoking is associated with periodontal health in a manner similar to cigarette smoking.

An association between tobacco smoking and periodontal bone height reduction is observed. The impact of water pipe smoking is of the same magnitude as that of cigarette smoking.

The present observations indicate a significant long-term influence of smoking on vertical periodontal bone loss, yielding additional evidence that smoking is a risk factor for periodontal bone loss.

The observations suggest that smoking is associated with increased levels of prevalence as well as severity of vertical bone loss. Smoking is considered a potential risk factor for vertical periodontal bone loss.

A vertical (angular) defect is a radiographic diagnostic phenomenon of severe periodontal destruction. The objective of the present study was to investigate the prevalence and severity of vertical defects in a population of dentally aware individuals at 2 different points in time, 1982 and 1992. Intra-oral radiographs of 251 individuals in 1982 and 247 individuals in 1992 in the age range 21-70 years were assessed with regard to presence or absence of vertical defects adjacent to a maximum of 28 teeth per person. A vertical bone defect was defined as a one-sided bone resorption of the interdental marginal bone > or = 2 mm that had a typical angulation towards either the mesial or distal aspect of the root. 'The prevalence of vertical defects in 1982 was 38% increasing from 11% in age 21-30 years to 64% in age 51-70 years, and 27% in 1992 increasing from 7% to 47% in the same age groups, respectively. The number of defects per person increased with age. The majority of affected individuals had 1-2 defects and only about 5% were severely affected. Vertical defects were more common in the posterior as compared to the anterior region of the dentition and the distribution of defects within the maxilla as well as the mandible typically revealed a right-hand to left-hand side symmetry. Vertical defects seem to be a rare phenomenon in dentally aware individuals. In particular, multiple defects were observed only in a minor proportion. Both prevalence and severity increased with age.