After 9/11, airlines security got into a tizz-wozz about electrical items, and these all had to be carried in hand luggage so's they could be inspected.
They've got over that now with improved x-ray equipment, and my latest experience is that your electrical stuff can be in either or both, hold or cabin luggage.
Take the batteries out of your toothbrush before you pack it. I didn't on a trip to Oz and when the porters brought my luggage to my room, there was a buzzing noise coming from my case. The expressions on the porters faces suggested that they thought I had a vibrator in there! They left before I could get my case open and show them the buzzing toothbrush. I got funny looks off them for days after :-/