Almost all babies experience breathing through the mouth at least once in their lives. This is due to airway blockage caused by both mild and severe medical conditions.
The most prevalent reason is the common cold, which is why sometimes you see them sleeping with their mouths open.
While mouth breathing is necessary when nasal breathing is difficult, you should not allow your baby to do so for a prolonged period, as it may result in adverse effects in the future.
Here are some of them.