American Board of Orthodontics (ABO) Practice Exam

An ankylosed primary tooth is typically diagnosed through a combination of clinical examination findings and radiographic analysis, with a particular emphasis on the presence of angular bone defect and infraocclusion. In cases of ankylosis, the tooth is fused to the jawbone, which can often be visually assessed when there’s an intraoral examination revealing signs of infraocclusion, meaning the tooth does not erupt normally due to its fusing with the alveolar bone.

The angular bone defect associated with an ankylosed tooth might be observable on radiographs, indicating that the surrounding bone morphology has changed due to the absence of the normal eruption pattern of the tooth. This results in the angular appearance of the bone around the tooth.

Visual inspection alone is inadequate for a definitive diagnosis, as it does not provide comprehensive information about the tooth's relationship to the surrounding bone and its eruption status. Similarly, patient history can provide useful context, but it cannot replace the physical signs and radiographic evidence needed to make an accurate diagnosis. Thus, the combination of the angular bone defect and infraocclusion is essential in diagnosing an ankylosed primary tooth.