title: Incidental occurrence of an unusually large mastoid foramen on cone-beam computed tomography and review of the literature.
abstract: The incidental finding of an enlarged mastoid foramen on the right posterior mastoid region of temporal bone is reported, together with a discussion of its clinical significance. A 67-year-old female underwent the pre-implant assessment of a maxillary left edentulous region. A cone-beam computed tomographic (CBCT) image was acquired and referred for consultation. Axial CBCT slices revealed a unilateral, well-defined, noncorticated, low-attenuation, transosseous defect posterior to the mastoid air cells in the right temporal bone. The borders of the osseous defect were smooth and continuous. No other radiographic signs suggestive of erosion or sclerosis were noted in the vicinity. The density within the defect was homogenous and consistent with a foramen and/or soft tissue. The patient's history and physical examination revealed no significant medical issues, and she was referred to a neuroradiologist for a second opinion. The diagnosis of an enlarged mastoid foramen was made and the patient was reassured.
authors.affiliation: Department of Oral and Maxillofacial Medicine and Diagnostic Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH, USA.
authors.forename: Ali Z
authors.initials: AZ
authors.lastname: Syed
authors.affiliation: Department of Oral and Maxillofacial Medicine and Diagnostic Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH, USA.
authors.forename: Cleo
authors.initials: C
authors.lastname: Sin
authors.affiliation: Department of Oral and Maxillofacial Medicine and Diagnostic Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH, USA.
authors.forename: Raquel
authors.initials: R
authors.lastname: Rios
authors.affiliation: Division of Radiology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA.
authors.forename: Mel
authors.initials: M
authors.lastname: Mupparapu
keywords: Cone-Beam Computed Tomography; Cortical Defect; Mastoid; Temporal Bone