American Board of Orthodontics (ABO) Practice Exam 2025 - Free Orthodontics Practice Questions and Study Guide

Severe infraocclusion is a critical condition that necessitates the extraction of ankylosed primary molars. When a primary molar becomes ankylosed, it fuses to the underlying bone, preventing it from erupting to the proper occlusal plane. As a result, the affected tooth may become significantly submerged relative to adjacent teeth. This infraocclusion can lead to several issues, including disruption of normal occlusion, difficulties in oral hygiene, potential for caries in adjacent teeth, and impacting the eruption of nearby permanent teeth.

In such cases, if the ankylosed primary molar is not extracted, it can hinder the proper alignment and positioning of permanent successors, potentially leading to longer-term orthodontic complications. The extraction of the ankylosed tooth can create space for the permanent teeth to erupt into their intended positions and can help establish a more functional and aesthetic occlusion.

While other factors like the absence of symptoms or minor mobility might suggest that extraction is unnecessary, the presence of severe infraocclusion poses a clear indication for intervention. Thus, addressing severe infraocclusion through extraction is essential for maintaining the integrity of the dental arch and promoting healthy dental development.