Background: The prevalence of asthma indicates the importance of studying oral manifestations of inhalers as one of the indications of asthma. This study compares two methods of using inhalers, Metered Dose Inhaler (MDI) and Dry Powder Inhaler (DPI) in asthmatic patients. Methods: 100 asthmatic patients (50 MDI-treated, 50 DPI-treated) and 50 healthy individuals were selected by convincing sampling. The three sampled groups were gender- and age-matched. We performed a clinical examination, recorded the information, and analyzed the data by SPSS21 software using a t-test and one-way ANOVA for quantitative and Pearson’s chi-square test for qualitative indicators. Results: DMFT index (p-value 0.001), fissured tongue (p-value 0.005), xerostomia (p-value 0.001), and dental erosion (p-value: 0.011) in MDI-treated patients were significantly higher than the other two groups, while the geographic tongue (p-value 0.008) was significantly higher in DPI-treated patients than in the other two groups. It showed that periodontal disease and median rhomboid glossitis had no significant difference between the three groups. Conclusion: Due to the higher incidence of manifestations in MDI, it is expected that physicians give more attention to prescribing inhalers and give them the necessary training to maintain oral and dental hygiene.