What are the implications of smoking traditional cigarettes on dental caries risk and oral cancer risk?

Implications of Smoking Traditional Cigarettes on Caries Risk and Oral Cancer Risk

Smoking traditional cigarettes significantly increases both dental caries risk and oral cancer risk, with oral cancer risk being particularly elevated with a relative risk of 2.0 or higher for oral cavity cancers.

Oral Cancer Risk

• Smoking is causally related to oral cavity cancer with convincing evidence of a large increase in risk (relative risk ≥2.0) 1
• Tobacco use is the single most significant cause of cancer, with 30% of all cancer deaths attributable to tobacco use 1
• A causal relationship exists between active smoking and oral cavity cancer, in addition to laryngeal and pharyngeal cancers 1
• The risk of oral cancer follows a clear dose-response relationship, increasing with the number of cigarettes smoked per day, deepness of inhalation, and duration of smoking 1
• Up to 75% of cases of oral cancer in the United States may be attributable to tobacco and alcohol use 1
• Smoking accounts for three-fourths of oral cancers in the United States 2

Risk Factors and Mechanisms

• Cigarette smoke contains many carcinogenic chemicals (e.g., nitrosamines, benzo[a]pyrene diol epoxide) that directly damage oral tissues 1
• The risk increases with pack-years of smoking history (number of cigarettes packs smoked per day multiplied by years of smoking) 1
• Even exposed nonsmokers have an increased risk of developing cancer from secondhand smoke 1
• The combination of tobacco and alcohol consumption creates a synergistic effect, substantially increasing oral cancer risk beyond either factor alone 3

Dental Caries Risk

• Tobacco use is a significant risk factor for dental caries, particularly coronal and root caries 2
• Recent research shows that both smoking and smokeless tobacco are significantly associated with high dental caries risk after adjusting for other factors 4
• Use of both smoking and smokeless tobacco creates the highest risk (adjusted odds ratio = 14.7), followed by smokeless tobacco only (aOR = 5.90) and smoking only (aOR = 2.18) 4
• Longer duration and higher frequency of daily tobacco use significantly increases the risk of high caries 4

Mechanisms of Caries Development

• Smoking affects saliva composition and flow, reducing its protective effects against caries 5
• Smoking can lead to decreased pH in the oral cavity, creating an environment favorable for cariogenic bacteria 5
• Tobacco use is associated with poor oral hygiene, which contributes to increased caries risk 5
• Smoking impairs immune responses in the oral cavity, potentially allowing greater proliferation of cariogenic bacteria 5

Additional Oral Health Implications

• Tobacco use is also a risk factor for periodontal disease, oral mucosal lesions, gingival recession, and impaired healing after periodontal treatment 2
• Smoking accounts for approximately half of all periodontal disease cases in the United States 2
• Daily brushing serves as a protective factor against oral cancer (OR = 0.41), highlighting the importance of oral hygiene 3
• Tobacco chewing particularly increases the risk of cancers of the gum and mouth (RR = 4.7), with risk increasing with higher daily frequencies and longer duration 6

Smoking Cessation Benefits

• Quitting smoking can result in decreased risk of oral diseases 2
• The risks of oral cancer and periodontal disease decline as time from cessation increases 2
• Some oral mucosal lesions may resolve with cessation of tobacco use 2
• Dental practices provide a uniquely effective setting for tobacco prevention and cessation interventions 2
• Smoking cessation interventions provided by oral healthcare providers can include brief educational, behavioral, and pharmacological interventions 5

Clinical Implications

• Comprehensive tobacco control policies are required to reduce the burden of tobacco-related oral diseases 2
• Dental professionals should routinely screen for oral cancer, particularly in patients with smoking history 1
• According to USPSTF guidelines, any abnormality that lasts for more than 2 weeks should be reevaluated and considered for biopsy 1
• Oncologists and dental professionals should encourage smoking cessation, especially in patients with cancer or oral disease 1
• Effective treatments to prevent tobacco use and increase cessation are available and need greater implementation in dental settings 2