Why it is harmful to respire through mouth than through nasal openings?

Respiring through the mouth can be harmful because it bypasses the natural filtration and humidification functions of the nasal passages. The nose filters out dust, allergens, and pathogens, reducing the risk of respiratory infections. Additionally, nasal breathing helps regulate airflow and maintain optimal oxygen exchange, while mouth breathing can lead to dry air entering the lungs, potentially causing irritation and increasing the risk of respiratory issues. Long-term mouth breathing may also contribute to dental problems and altered facial development.