<prompt> Which of these structures appears radiopaque?Maxillary sinusNasal fossaNasal septumMental foramen  <response>: Radiopaque refers to that portion of the radiograph that appears light or white. Radiopaque structures are dense and absorb or resist the passage of the X-ray beam, E.g., Enamel, dentin and bone.Nasal septumOn the panoramic radiograph, it appears as a vertical radiopaque partition that divides the nasal cavity.Reference: Freny R Karjodkar Oral Radiology Principles and Interpretation 2nd edition page no 251 