key: cord-0693825-e15xzf9d authors: Fontenele, Rocharles Cavalcante; Gomes, Amanda Farias; Ruiz, Débora Costa; Oliveira, Matheus L; Freitas, Deborah Queiroz title: Is it possible to obtain extraoral X-ray images of patients wearing face masks? A new infection control measure during the COVID-19 pandemic date: 2021-09-20 journal: Acad Radiol DOI: 10.1016/j.acra.2021.08.029 sha: f00e529fba6e2393cb32fa9a4d932a332cc05b37 doc_id: 693825 cord_uid: e15xzf9d nan Recently published guidelines on measures to perform extraoral examinations in oral radiology centers during the COVID-19 pandemic suggest that patients diagnosed with COVID-19 and those with suspected COVID-19 wear a face mask during these imaging examinations (5, 6) . Accordingly, a chin rest must be used instead of a bite block and the canine prominence must be used as reference to correctly position the patient's head. However, since many individuals infected with SARS-CoV2 are asymptomatic or have mild symptoms similar to those of seasonal flu, all patients should wear a face mask (3, 4) . Because most of the face masks include a nose wire with metal components, it is advisable to remove it from the mask before image acquisition to avoid the superposition of its image on the nasal cavity and maxilla. Figure 1 shows panoramic radiographs of an anthropomorphic phantom covered with a soft tissue simulator (Mix-D) (7) acquired with the use of a face mask with the nose wire ( Fig 1A) and with the use of a face mask without the nose wire ( Fig 1B) . Also, one may assume that the presence of a nose metal wire during cone-beam computed tomography (CBCT) acquisition can lead to the generation of metal artifacts, which may decrease image quality. Figure 2 shows sagittal images of CBCT of an anthropomorphic phantom acquired under the same conditions as the panoramic radiographs. Subjectively, the quality of both types of extraoral images is unaffected by the face mask without the nose wire. However, imaging professionals should be aware that the effect of the nose wire may vary according to the thickness of the metal. Another option for developing countries, where access to surgical face masks may be limited, is the use of cloth masks. Importantly, the acquisition of extraoral examinations with the patient wearing a face mask requires extra positioning adjustments (Fig 3) . As previously explained, the bite block must be replaced with the chin rest to acquire extraoral images from edentulous patients. It is also essential to place protective barriers on surfaces that will be in contact with the patient. After positioning the patient's chin on the chin rest, the professional should instruct the patient to bite a disposable item such as a wood stick to promote disocclusion and avoid the overlap of the crowns of the upper and lower teeth (Fig 3A) . Then, the midsagittal plane and the patient's canine prominence, which can be palpated without the need to remove the mask, must be aligned with the laser lights of the X-ray device. The protective barriers must be removed from the device surfaces after exposure and the device must be properly disinfected in accordance with the local protocols for infection control (5, 6) . Therefore, the use of a face mask without nose wire during extraoral imaging examinations may be considered a new infection control measure to control the exposure to oral secretions containing viral particles in oral radiology centers, preventing the contamination of professionals and patients and the spread of the COVID-19 disease. Second wave of COVID-19 in Brazil: younger at higher risk About Variants of the Virus that Causes COVID-19 Oral radiology center as a potential source of COVID-19 transmission; points to consider Oral radiology practice in dental schools during the COVID-19 pandemic: What will be the new normal? Guidelines for oral and maxillofacial imaging: COVID-19 considerations. Oral Surg Oral Med Oral Pathol Oral Radiol 2021 Recommendations for Diagnostic Imaging during COVID-19 pandemic DIMITRA paediatric skull phantoms: development of age-specific paediatric models for dentomaxillofacial radiology research The authors deny any conflicts of interest related to this study.