Final answer:
A 13-year-old typically has 28 teeth. This includes the eight incisors, four canines, eight premolars, and eight molars, as the wisdom teeth generally emerge later.
Step-by-step explanation:
The number of teeth that should be present in the mouth of a 13-year-old is typically 28.
During middle childhood and pre-adolescence, there is a significant change in the dentition. Moving from the center of the mouth to the side, the teeth consist of the eight incisors, four top and four bottom, which are the front teeth used for biting into food. The four canines (or cuspids) have a pointed edge to tear up food. By 13 years, most children have lost their deciduous (baby) teeth and have had most of their permanent teeth emerge. This includes the eight incisors, four canines, eight premolars, and up to eight molars (excluding the third molars or wisdom teeth), hence the total is around 28.
While adults typically have a total of 32 permanent teeth, the last four (the wisdom teeth) usually do not appear until later in adolescence or early adulthood.