Ruptured silicone cheek implant mimicking odontogenic infection: A diagnostic pitfall

Facial swelling adjacent to the dentition is frequently attributed to odontogenic infection; however, non-odontogenic causes should also be considered in the differential diagnosis.

A 60-year-old female presented with left cheek swelling extending toward the pharyngeal region. The patient had no fever, pain, or systemic symptoms at presentation or prior evaluation. She initially consulted the otolaryngology clinic and was referred to the oral surgery clinic within the same hospital, where incision and drainage were performed, and a tentative diagnosis of apical periodontitis was made despite the absence of typical inflammatory findings. The swelling persisted despite the administration of antibiotics. Extraction or endodontic treatment was considered. The patient was subsequently referred to our department for further evaluation.

Referral computed tomography (CT) images obtained at the referring hospital (original slice thickness: 5.0 mm; reconstructed at 3.0 mm for visualization) (Fig. 1A) suggested a subtle periapical radiolucency in the left maxillary molar region. However, the clinical presentation was atypical for odontogenic infection, as the patient had no pain, fever, or clear inflammatory signs. Intraoral periapical radiography at our department revealed a continuous periodontal ligament space without periapical radiolucency (Fig. 1B), and the cause of the swelling remained unclear.

Figure 1.

Computed tomography (CT) images and intraoral radiograph of a ruptured silicone cheek implant mimicking odontogenic infection. Images were processed and reviewed using Onis 2.5 Viewer (Onis Solutions, Seoul, South Korea). (A) Coronal CT image obtained at the referring hospital (original slice thickness: 5.0 mm, bone window setting) and reconstructed at 3.0 mm for improved visualization (left), with a magnified view of the left maxillary molar region (right). The dashed square indicates the area shown at higher magnification in the right panel. The image was initially interpreted as suggesting possible periapical pathology (arrow). (B) Intraoral periapical radiograph demonstrating continuity of the periodontal ligament space (arrow) without evidence of periapical radiolucency. (C) Coronal CT image (left), magnified view of the left maxillary molar region (center), and axial CT image (right) obtained at our department (original slice thickness: 2.5 mm, bone reconstruction) and reconstructed at 0.625 mm. The dashed square indicates the area shown at higher magnification in the center panel, demonstrating only minimal periapical changes. Careful review reveals radiopaque materials within the bilateral buccal soft tissues (yellow arrows), spatially separated from the maxillary molar apices, with no substantial periapical lesion to account for the marked purulent discharge. (D) Ruptured silicone cheek implant surgically removed at the referring hospital.

Because the clinical findings were inconsistent with odontogenic infection, CT data obtained at our department (original slice thickness: 2.5 mm) were re-evaluated after reconstruction at a 0.625 mm slice thickness. No periapical pathology sufficient to explain the clinical findings was identified. However, careful review revealed radiopaque material within the buccal soft tissues, spatially separated from the tooth apices (Fig. 1C), raising suspicion of a non-odontogenic process. This case highlights how a foreign body may be overlooked on thick-slice CT yet become apparent after thin-slice reconstruction and careful reevaluation.

Retrospective history taking revealed bilateral silicone cheek implants placed 20 years previously, which had not been recognized during the initial evaluation. These findings suggested a non-odontogenic origin. An odontogenic cause was excluded, thereby avoiding unnecessary dental intervention. This diagnostic reassessment was communicated to the referring hospital, and the patient subsequently underwent surgical removal of the lesion (Fig. 1D). The surgical findings were consistent with rupture of a silicone cheek implant. The patient subsequently developed contralateral implant rupture, which was promptly recognized and surgically treated without diagnostic delay.

This case illustrates how diagnostic anchoring toward odontogenic infection, together with limited imaging resolution, may contribute to misinterpretation of facial swelling and diagnostic delay. Thick-slice CT may obscure subtle soft tissue abnormalities or foreign bodies. Thin-slice CT provides improved spatial resolution and may facilitate accurate diagnosis. Awareness of such diagnostic pitfalls may help prevent misdiagnosis and unnecessary invasive dental procedures.1 Clinicians should consider cosmetic implants in the differential diagnosis of atypical facial swelling.

Written informed consent was obtained from the patient for publication of this case report and accompanying images, including clinical photographs obtained at another institution and provided by the patient.