Diagnosis of tooth ankylosis using panoramic views, cone beam computed tomography, and histological data: a retrospective observational case series study

Objectives: The aim of this study was to determine whether cone beam computed tomography is a reliable radiological method to diagnose tooth ankylosis. Materials and methods: A series of teeth clinically diagnosed as ankylosed were collected after extraction in a private practice from 2009 to 2015 and analyzed retrospectively. Inclusion criteria comprised permanent molars extracted due to failed tooth eruption in the absence of any visible mechanical obstruction, existing panoramic view (PV), and cone beam computed tomography (CBCT) and histological sections of sufficient quality. The CBCT scans and PVs were evaluated twice for signs of ankylosis by two independent observers using the following score: clear signs, possible signs, and no signs. The histological sections were evaluated and graded similarly to the radiographs by a specialist blinded to the radiographs and treatment. Results: Out of an initial group of 22 patients, 9 subjects with 10 affected teeth were included for final evaluation. The age ranged from 8.3 to 17 years. No agreement was seen in comparing the PV scores to the histological sections. Fair to moderate agreement was seen in comparing the CBCT scores to the histological sections. All histologically confirmed ankylosis were detected in CBCT by both observers but some false positive results were found. Limitation: Only a small sample size was available as the disorder is rare. It is difficult to distinguish ankylosis from primary failure of eruption. Conclusion: CBCT images can be a useful adjunctive diagnostic tool to diagnose ankylosed teeth, but cannot be recommended as a single diagnostic modality as false positive results were found.