Characteristic features of the odontogenic myxoma on cone beam computed tomography

Objectives: To illustrate the characteristic features of odontogenic myxoma (OM) on CBCT. Methods: From 52 subjects with histopathologically diagnosed OMs, 18 subjects who underwent a CBCT examination were retrieved between May 2009 and April 2016. Features on CBCT images and clinical records were carefully observed and analyzed. Results: Characteristic features include: (1) fine and straight septa that were recognized to separate the tumour into triangular, square or rectangular spaces, which appeared as "tennis racket" or "honeycomb" patterns; (2) septa that frequently scattered to the borders of lesions and appeared perpendicular to the margins; (3) tooth displacement and resorption that were seen in most of the OM lesions; (4) OMs that were noted to have a tendency to involve the alveolar process, scallop between the roots and affect the integrity of the alveolar ridge; (5) the cortex of OMs that appeared normally perforated and the edge of the cortex expanded into the soft tissue. Conclusions: CBCT is highly effective in demonstrating the comprehensive internal structures of the lesions precisely and providing detailed information for the diagnosis of OM.