This study has employed CPITN to investigate the prevalence of periodontal diseases in the Kurdish population of Sulaimani; additionally, the impacts on periodontal condition of other confounders such as age, sex, location, visit to dentist, tooth brushing, use of mouth wash and interdental aids, systemic disease, smoking status and missing teeth were examined. It is important to acknowledge that prevalence of periodontal diseases amongst the Kurdish population had not previously been examined using any criteria for determining periodontal diseases. As a first attempt to determine periodontal disease in this population, this study employed CPITN as it is extensively used in epidemiological studies for periodontal diseases and would therefore allow comparative assessment of the data of this study. Although CPITN has been criticized for inaccuracy in gingivitis and calculus detection and for generally underestimating periodontitis, this index is still widely accepted as a simple, quick to implement and reproducible assessment tool (16).
Among the subjects examined, calculus (score 2) was the most common highest score (62.2%), which is in line with other studies (3,17,18). Severe periodontitis, as represented by score 4, was found in only 6.1% of the examined population (Figure 3), which is in accordance with the data reported in Hungary (19) and Norway (20). Whereas, Pilot & Miyazaki (21) in a European population found higher (10% to 15%) prevalence of periodontitis. These differences can be explained by the fact that periodontal diseases are multifactorial diseases, meaning that factors such as genetics, medication, systemic diseases, habit (such as smoking) and frequency of tooth brushing have an impact on the extent and severity of this disease and these confounders vary from one place to another.
At sextant level, calculus is most prevalent at lower anterior sextant, which is obviously related to the presence of the Wharton’s duct, and this is in agreement with other studies (22, 23). Meanwhile, both shallow and deep pockets are most prevalent at upper posterior sextants and this is again similar to the result of other research (23) (Figure 4).
Logistic regression showed that only age, sex (male), brushing and smoking status have impact on periodontal condition (P< 0.05, Table 3). Periodontal condition was poorer in males than females and this is similar to the data reported by other studies (19, 24, 25). Age is another factor found to have impact on periodontal condition, with the present study showing a steady increase in prevalence and severity of periodontal disease with age (Table 2) which is in accordance with the WHO data bank and results of other studies (26, 27). Smoking is well-known as a risk factor that contributes to poor periodontal condition, and the present study found both current and former smoking to be associated with poor periodontal condition (odd ratio = 1.8 and 1.4, respectively), which is in accordance with previous studies (28, 29). Brushing is another factor shown to have impact on periodontal condition (odd ratio = 2.1), while at population level, other factors such as interdental aids, mouth wash, residence place, visit to dentist frequency and systemic diseases such diabetes and hypertension showed no effect on periodontal condition, which is not in agreement with other studies (28, 30, 31). This can be related to factors such as small sample size and the limitations of the CPITN index mentioned earlier.