Respiratory disease occurs frequently in children. The nasal cavity, trachea, and oral cavity are considered the primary routes of infection. We aimed to investigate the types of microbial pathogens present in the oral cavities of children with respiratory disease. In addition, we compared the detection rates of different pathogens between the oral cavity and the nasopharynx according to Hellman dental age. We included 32 children who were hospitalized for respiratory disease and classified them according to Hellman dental age. Specimens were collected using 2 palate swabs: one taken at hospital admission and the other at discharge. The culture results of the samples were compared with those of nasopharyngeal cultures. The following 6 bacterial strains were detected in both the palate and nasopharynx: α-Streptococcus, Corynebacterium, Haemophilus influenzae, Haemophilus parainfluenzae, MRSA, and Neisseria. In the comparison of the detection rates, Neisseria were significantly more frequently detected in the palate. MRSA was detected at a significantly higher rate in the nasopharynx. When the detection rates of different bacteria were compared according to Hellman dental age, significant differences were observed in the detection rates of α- Streptococcus in stage IA and Neisseria in stages IC and IIA. We noted that the bacterial load of specific bacteria in the palate increased with Hellman dental age.