It is a condition where the upper jaw is significantly narrower than the lower.
Signs of a narrow jaw include crowding on the upper front teeth or the side and back teeth biting inside of the lower teeth.
A smile in a narrow jaw appears narrow rather than broad. Spaces may also be seen on the side of the smile, instead of where teeth should be.
Another sign is where the upper adult canine teeth are high and very slow to erupt.
If you or your child has a narrow jaw, this can also be seen in the leaning in of the lower side and back teeth.
The upper jaws are connected with the nose and in children with narrow upper jaws, the nose passage is smaller. This may cause a child to breathe through their mouth, snore at night or wake up with a dry mouth due to mouth breathing.
Heavy mouth breathing can change the way a child’s jaw grows, also causing a smaller lower jaw and an overbite naturally worsening. It is also one of the main reasons why the upper teeth appear crowded.
There is a time frame where the upper jaw bones and their connections have not hardened in a child and early teen, where the upper jaw can widened effectively without surgery.Below 2 rows of images are of an 8 year old girl where the upper jaw was successfully widened with a conventional upper expander and followed up over a 6 year period
Between the ages of 9-11 years, your child’s side baby teeth get looser and would no longer be able to effectively support an upper expander. If the simplest form of a conventional expander is chosen, it would need to wait before the key adult 1st premolar teeth erupt. This may be too late in girls who often have their mid pubertal growth spurt characterized by the onset of their first period, sometimes as young as 10-11 years.While an upper expander may still work in these instances, if it is accompanied by moderate to severe upper crowding, it may result in less ideal outcomes and more forward positioned upper front teeth. This is because less upper jaw widening would occur, so less space would be available to straighten the teeth. As a side effect, the upper front teeth lean forwards.