How many posterior teeth are in an arch, in addition to the 6 anteriors?

In a complete adult dentition, there are typically 8 posterior teeth in each quadrant of the mouth. The posterior teeth consist of premolars and molars. Given that there are 4 quadrants in the mouth, this calculates to a total of 8 posterior teeth in the entire arch.

To clarify, the anterior teeth typically include the incisors and canines, totaling 6 teeth (2 central incisors, 2 lateral incisors, and 2 canines). Since the question specifies that there are already 6 anterior teeth accounted for, when moving to consider the posterior teeth, it is important to identify the number of these teeth that accompany them in each arch.

Thus, following the standard dental anatomy, there are 8 posterior teeth in addition to the previously mentioned 6 anterior teeth, leading to a conclusion that the total in question reflects accurate dental anatomy.