## 4 Discussion
Similarfindings were also reported by [PERSON] in 2015, who found greater prevalence of CAC in the age groups older than 50 years [61]. Diabetes and hypertension are acknowledged factors for arteriosclerosis. When the correlation with systemic diseases was studied, this study did not show any correlation with diabetes and hypertension. [PERSON] et al. and [PERSON] did not find any correlation with systemic diseases either [65; 66]. However, studies by [PERSON] et al. found that CAC was correlated with hypertension but not with diabetes, whereas [PERSON] et al. reported a correlation between diabetes and CAC as well [67; 68]. [PERSON] et al. (\(n=15\)) also showed positive correlation of hypertension with CAC [69]. The difference in results could be due to the difference in the sample size. A significant difference was found in age with respect to diabetes and hypertension. More patients with systemic diseases were reported with increasing age. Smoking is one of the factors which affects the cardiovascular disease morbidity and mortality. Smoking results in a two- to fourfold increase in the risk of coronary heart disease. This risk increases in the presence of hypertension and diabetes, due to the symbiotic effect with smoking [70]. In this study we investigated the association of smoking with CAC. The results of this study showed no significant relationship between CAC and smoking. This is in agreement with the findings of [PERSON] et al. [3], [PERSON] et al. [71] and [PERSON] et al. [72] who did not find any association between smoking and CAC either. However, [PERSON] et al. showed that CAC was two times worse in smokers than in nonsmokers [66]. This difference could be due to the sample size. [PERSON] et al. also showed a positive correlation between smoking duration and CAC. The difference between their results and the results of our study could be due to the lack of information about the duration of smoking and the study sample population [67]. Alveolar bone loss is an import factor that determines the periodontal support. Greater periodontal destruction is seen with increased periodontal disease or the severity of periodontitis resulting in tooth loss if not controlled. In the present study, increased bone loss was seen more in the CAC (+) than in the CAC (-) group. This is an accordance with other studies which showed greater bone loss associated with carotid artery calcification [39; 40; 73]. However, such findings were not significant in a study by [PERSON] [74] who reported no correlation between the alveolar bone loss and CAC. This could be attributed to the differences in the sample size and the method of assessment. However, [PERSON] showed a significant association between bone loss and CAC [73]. Tooth loss is a quick and reliable feature to determine the periodontal disease comparable to the clinical periodontal parameters of periodontitis such as pocket dept, clinical attachment loss and alveolar bone loss [75]. A higher number of missing teeth was seen in the CAC (+) group compared to the CAC (-) group. [PERSON] et al., 2006, and [PERSON], 2015, also showed increased tooth loss in the presence of carotid artery calcification. Increased tooth loss was also seen associated with the increase in age [56; 75]. Using the number of missing teeth and the bone loss, periodontal risk was assessed as per [PERSON] and [PERSON]'s procedure [46]. A significant correlation was found between CAC (+) and periodontal risk. A similar positive association between periodontal risk and CAC was reported by another study [53]. This study showed that panoramic radiography is an effective tool in determining the CAC. However, it is important to make careful differential diagnosis while assessing CAC in the panoramic radiographs.