Straightening Iron & Hair Pattern ChangeQ: I took my four year old child to a salon to get a haircut. They used a straightening iron on her hair. She had naturally curly hair and ever since they used the iron on her, her curls have been virtually non-existent. Is this possible? Her hair is quite thin but it was very curly before. Will it come back or do curls fall out?
A: I can honestly tell you that the use of the flat iron will not have made more than a temporary change in the wave pattern of your daughter's hair. Heated styling appliances add or remove curl by changing the physical side bonds in the hair. These are broken by the application of heat or moisture and reform - when the hair cools or dries - into the new configuration. This transformation lasts only until the hair is again warmed or becomes wet - generally until the next shampoo. This is why women who curl their hair with curling irons have to re-curl the hair after shampooing.
What you have probably encountered is this: your child's hair has been changing as she has grown. While her hair may have been growing in a very curly pattern initially, as she has continued to grow, this may be changing. The lack of curl in the new growth may not have been apparent since the ends of the hair (which grew curly) were still present until the haircut.
This haircut likely removed enough of the curly hair that the remaining, newer growth is now distinctly less curly (although I expect there is at least some wave). In order for the change in the hair caused by the flat iron to be permanent, the hair would have had to undergo some significant damage in the process. You would not be able to miss such an occurrence, especially since I suspect you were there to supervise the whole styling process anyway.
I would chalk this up to her natural transition in growth pattern. If curly hair is commonplace in your family, there is a good chance that her hair follicles will mature into the kind that produce curly hair.
Kids hair and hairstyles
Will trimming encourage the growth of a child's hair?
Is it save to straighten a child's hair with a flat iron?