Nicholas Bean, a $12-$year$-$old who is your first patient of the day, is going right from his prophylaxis appointment to the orthodontist's office, where they will be placing fullmouth bands and brackets on his teeth. You know that the best toothbrush to recommend for him to use is a bi$-$level orthodontic toothbrush, but you do not happen to have a sample to give him. You decide to tell his mother what it looks like so she can get one. Using terminology that describes the parts of a toothbrush from Figure $26-1$ in the textbook and the pictures from Figure $26-2$ in the textbook, develop a brief description of this type of toothbrush trim profile.