gap-toothed (adj): having gaps between the teeth
Some people were born with gaps between / in their teeth. It is not a condition or an illness or whatsoever, it is just a body feature, just like some people are tall while others are short.
Now similarly, some people were born with low hair density while others have high hair density. It is not a bald thing or a hair loss condition. It is just the way it is, a body feature. I don't know how to express this feature.
I asked this question because when I look at my child's hair I can see he has less hair than other children, his hair grows slower and is not as dense as others. There are blur gaps in his hair.
"gaps between / in one's teeth" and "gap-toothed" are idiomatic.
We can say "you are gap-toothed or have gaps between / in your teeth"
Do you say "gaps between your hair" or "gap-haired" the same way you say "gaps between your teeth" or "gap-toothed" respectively?