Questionnaire survey on oral function during growth periods throughout Japan after the coronavirus disease 2019 pandemic

Objectives: Systemic and local problems may lead to the disruption of craniofacial growth and development during growth periods. However, no studies have demonstrated the negative effects of the coronavirus disease 2019 (COVID-19) on the development of oral function in children. In this study, we aimed to investigate whether the COVID-19 pandemic has influenced the development of oral function in children. Materials and methods: The study participants comprised children who visited public or 58 private dental clinics after the COVID-19 pandemic. The questionnaire comprised 66 items regarding current medical conditions and lifestyle habits that are linked to oral function. The survey was a self-administered questionnaire or a web-based questionnaire using Google Forms. Results: Compared to our 2014 survey (Nogami et al., 2014), the results of 599 children (282 boys and 317 girls; aged 3-12 years; mean age, 7.8 years, standard deviation, 2.4 years) who were included in the study showed a remarkable increase in their responses for the following questions: "Difficulty maintaining nasal breathing for more than a minute with one's mouth closed," "incompetent lip seal," "round shoulders," "thick lips," "dry lips," "chapped lips," "morning breath," "inverted V-shaped upper lip," "loose lips," and "frequent dry mouth." Conclusion: Systemic and local problems can be categorized into four factors, namely (1) poor sleep habits, (2) commonly observed eating habits, (3) nasal disorders, and (4) general motor functions. Evident from the current study, the COVID-19 pandemic has negatively affected the systemic and oral health of children.