my child is very freequently doing fingers and wrist sucking ( mouthing) . how can i prevent her from thumbsucking ?? can i use teethers ..does they really useful ? i know mouthing has benificial effects lyk soothing ,parasympathetic activities etc and helps in chewing further . but as my child grows it can develop in to thumbsucking which leads to dental anomalies after chronic habitiual activity at 2_3 years.shall i start teethers at 4months age?? any side effects with teethers .?