Is there any recomendation of chewing exercices for children? duration, frequency and a chewing "device" (it could be a specially tough vegetable too). I gues

Is there any recomendation of chewing exercices for children? duration, frequency and a chewing "device" (it could be a specially tough vegetable too). I guess a couple of minutes of strong chewing before each meal could improve the growth of the jaw in small kids.