NASOPALATINE DUCT CYSTS: A SPECTRUM OF IMAGING PRESENTATIONS

Abstract

<h3>Background</h3> Nasopalatine duct cysts are the most common nonodontogenic cysts of the oral cavity. These cysts are classified as being developmental in nature because they most likely develop after spontaneous cystic degeneration of the epithelial remnants of the nasopalatine duct. Imaging plays a vital role in the diagnosis and management of these cysts. <h3>Discussion/Conclusions</h3> We present 5 cases consisting of 3 males and 2 females seen in the Oral and Maxillofacial Radiology clinic at University of Toronto Faculty of Dentistry (Toronto, Canada). The ages of the patients ranged from 40 to 65 years. These cases all exhibited unusual imaging features that posed difficulties in interpretation. One potential difficulty in the radiologic interpretation of these entities was that these cysts exhibited a range of growth patterns that were unconventional; for example, some were asymmetric, and their epicenters were not located in the midlines of the anterior maxillae. Furthermore, some entities demonstrated benign-appearing expansile characteristics, whereas others had more aggressive features. Because of their positions and their proximities to the maxillary anterior teeth, the lesions appeared to resorb or displace teeth. Therefore, the possibility that these entities could be interpreted as rarefying osteitis (e.g., radicular cysts) or odontogenic keratocysts could not be ruled out on the basis of plain film imaging alone. Although there is value in planar film imaging as the preliminary imaging modality, atypical features, such as asymmetric location and loss of normal anatomic structures, made routine interpretation difficult. As a result, we undertook advanced imaging of these patients which enabled us to identify additional key features that enabled us to make a more definitive interpretation. This presentation aims to demonstrate the range of atypical presentations of the nasopalatine duct cysts. A clear understanding of this range of imaging features will improve the interpretive skill of oral and maxillofacial radiologists.