Why is an ankylotic primary second molar in the mandible not always a good space maintainer?

An ankylotic primary second molar in the mandible may not be an effective space maintainer primarily because it does not adapt to changes in occlusion. As the rest of the dentition continues to erupt and move into the occlusal plane, the ankylotic molar remains fixed in position due to its fusion with the bone. This results in a situation where the primary molar fails to maintain the proper space for the emerging permanent molar, leading to potential alignment and spacing issues. The presence of an ankylotic tooth can ultimately hinder proper occlusal function and spacing for the permanent dentition, making it less than ideal as a space maintainer.

The ankylotic tooth impacts the alignment and function of surrounding teeth, and as the eruption of other teeth continues, it may create further complications in maintaining a healthy bite and oral health.