Unexpected metallic foreign bodies on panoramic scans - a narrative review

The digital panoramic radiograph (orthopantomogram, OPG) is the standard radiographic technique for basic diagnostics in dental practice. A correctly taken image provides a good overview of teeth and jaw, whereas radiopaque foreign materials, e. g. metal, can obscure relevant findings.

A literature review on unexpected metallic foreign bodies in OPG was performed to determine the spectrum of metallic foreign bodies that may cause radiopaque areas on panoramic radiographs in routine clinical use.

A total of 37 different unexpected metallic foreign bodies were found. They can be categorized as jewelry, clothing, personal protective equipment, medical devices, iatrogenic foreign bodies, and rare incidental findings. Radiopaque foreign materials in the OPG are often relatively easy to recognize as artifacts because of their location, and they are avoidable in most cases. If unclear, a three-dimensional radiograph was helpful for determining the location. Radiopaque areas caused by foreign bodies can lead to misinterpretation or partial or complete non-evaluability and should therefore be avoided.

· The OPG is the standard radiograph for dentists, oral surgeons, and oral and maxillofacial surgeons.. · Foreign bodies made of metal can lead to non-evaluability of panoramic radiographs. Based on a review of the literature and exemplary radiographs, this article provides an overview of rare but typical metallic foreign bodies in OPG, thus addressing the problem of the subfield of radiography by making radiologists more familiar with these images.. · The spectrum of unexpected metallic foreign bodies includes unremoved earrings with the typical ghost images on the contralateral side, piercings, hearing aids, acupuncture needles, rare iatrogenic foreign bodies, incidental findings in infants in the nose and external auditory canal, vascular clips after surgical interventions, and ritual subcutaneous foreign materials..

· Brauer HU, Bartols A, Hellmann D et al. Unexpected metallic foreign bodies on panoramic scans - a narrative review. Fortschr Röntgenstr 2023; 195: 809 - 818.