Why are small toothed combs a no-no, but Denman Brushes a yes-yes?

[lashannasmall]

All I know is that the Denman is the only thing that defines my babies 4A curls. There is always little to no hair in the brush. It is probably your technique and the conditioner you use.

 

[justnotsure]

So these brushes are pretty much for use on natural hair? Is that correct? Does anyone with relaxed hair use them?