Dense bone islands in orthodontic patients: a cross-sectional imaging (CBCT) study of location and interactions with teeth

Abstract

Aim: To use CBCT imaging taken before and after orthodontic treatment to evaluate the interactions between dense bone island (DBI) lesions and teeth. Specific aims were to evaluate 1) where dense bone islands reside in the buccal-lingual dimension of the jaw bones, 2) if DBIs tend to occur in areas of potential orthodontic tooth movement, 3) presence of root resorption on teeth adjacent to DBIs, and 4) presence of hindered orthodontic tooth movement of teeth adjacent to DBIs.Methods: This project reviewed 2243 CBCT radiology reports on patients undergoing treatment at the University of Minnesota Graduate Orthodontics Program between the years of 2018 and 2022. Patients were included in this study if at least one of their CBCT radiology reports contained one of the following words: dense bone island, idiopathic osteosclerosis, or enostosis. For the 87 dense bone islands included in the study, the pre- and post-orthodontic CBCT images were analyzed using the linear measurement tool in Dolphin Software to identify changes to the dense bone islands and adjacent teeth over time. Information related to dense bone island location, shape, size, evidence of root resorption, evidence of hindered root movement, and the patient demographics were recorded. Prevalence of root resorption and root movement hindrance and prevalence of DBIs in various buccal-lingual locations were reported. Results: Of the 87 DBIs included in the study, 65 of them (74.7%) were deemed to be located in areas of potential orthodontic tooth movement. Of the 65 DBIs located in areas of potential orthodontic tooth movement, 8 of them (12.3%) showed evidence of root resorption and 6 of them (9.2%) exhibited signs of hindered tooth movement. In the post-orthodontic scans, 39.1% of the DBIs were connected to the lingual plate alone, 31.0% of the DBIs were bi-cortical, 17.2% were connected to the buccal plate alone, and 12.6% were intracortical without evidence of contact with either cortical plate.