<prompt> On average, approximately what is the dimension of the permanent maxillary canine at the widest mesiodistal diameter of the crown?5.5 mm.6.5 mm.7.5 mm.8.5 mm.  <response>: The dimension of the permanent maxillary canine at the widest MD diameter is 7.5 mm 7.5 mm Ash and Nelson, 2003; 7.6 mm . 