Which factor does NOT influence the location of the center of resistance?

The center of resistance in orthodontics is primarily determined by the properties of the teeth and their supporting structures. It is the point within a tooth or a group of teeth where forces can be applied without causing movement in that specific direction.

The quality of periodontal structures, root structure, and amount of bone support are all critical factors in influencing the center of resistance. The quality of periodontal tissues supports the tooth and affects how force is transmitted, while the root structure plays a significant role in anchoring the tooth within the alveolar bone. Additionally, the amount of bone support directly impacts the stability of the tooth and its movement in response to applied forces.

Crown shape, however, does not significantly influence the center of resistance. While crown shape may affect the overall aesthetics and functionality of the teeth, it does not play a role in how forces are distributed or the resulting movement of the tooth within its socket. Thus, it can be considered as an element that does not directly affect the center of resistance, making it the correct answer to this question.