Which type of contact, when missing, can cause migration of a tooth?

Proximal contacts, which are the points where adjacent teeth touch each other, play a crucial role in maintaining the position of teeth within the dental arch. When these contacts are missing, it creates a gap that can allow for the movement of teeth. This migration can occur because the supporting forces that typically keep teeth in alignment are compromised, leading to a shift toward the space created by the missing proximal contact.

In contrast, anterior canine guided contacts, facial contacts, and lingual contacts have specific functions, such as guiding occlusion and providing stability during movements like chewing or speaking. However, their absence does not directly lead to the same type of tooth migration that missing proximal contacts would, as they do not influence the positioning of adjacent teeth in the same direct manner as proximal contacts do. Hence, the stability of the dental arch relies heavily on the presence of intact proximal contacts to prevent unwanted tooth movement.