Adverse effects of E-cigarettes on head, neck, and oral cells: A systematic review.

Background: E-cigarette sales in the United States (US) are projected to reach 16.5 billion by 2024 according to market analysis. Six deaths and 450 lung illnesses have been linked to e-cigarette use. To our knowledge, a systematic review of the adverse effects of e-cigarettes on head, neck, and oral cells does not exist. This review aimed to conduct a systematic review of current literature to determine whether e-cigarettes caused adverse effects on cells of the head, neck, and oral cavity.

Methods: Five databases including Medline, Dentistry and Oral Sciences, CINAHL, CAPLUS, Web of Science, and gray literature were searched for articles any time up to December 2020. Using Rayyan software, two-independent researchers screened 233 articles and extracted 41 for further investigation. Based on the inclusion criteria, 18 articles were eligible for this review.

Results: Aberrant morphology, cytotoxicity, oxidative stress, reduced viability, delayed fibroblast migration, and genotoxicity were statistically significant when the head, neck, and oral cells were exposed to e-cigarettes. Of note, most articles in this systematic review found cigarette smoke to be significantly more toxic to head, neck, and oral cells than e-cigarettes.

Conclusions: E-cigarettes are implicated in adverse effects on head, neck, and oral cells, yet very few have been tested against these cells. More longitudinal studies using a wider variety of e-cigarettes are necessary before we can determine their total adverse effects. Future research must also investigate chronic e-cigarette use and if it leads to periodontal disease and/or head, neck, or oral cancer.