When the jaw and airway don’t fully develop, the airway can become easily obstructed during sleep. During the complete muscle relaxation of deep stage sleep, the muscles around the airway also relax and collapse. The airway is a tight space, often made tighter by large tonsils and adenoids in both children and infants.
If the airway becomes obstructed, the brain must bounce out of deep sleep and into a lighter stage of sleep in order to grind and clench to push the jaw forward to allow for breathing again. Grinding and clenching are the body’s way of reopening a collapsed airway during sleep to start breathing again. This is why grinding and clenching are the new red flag for catching sleep apnoea early.
Mouth breathing can also impact on behaviour and personality. Deprived sleep due to mouth breathing in children can cause hyperactivity as a result of adrenaline used to compensate for sleepiness. They are poor achievers in their academic pursuits because their brains and bodies aren’t at their best in this damaged, deep sleep-deprived state. These children are often diagnosed with ADHD and other behavioural issues. They have lowered immune systems, poor health and can also be overweight.