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Dentigerous cyst is an odontogenic developmental cyst arising from the pericoronal tissue of an impacted tooth, and that may exhibit various radiological aspects. The aim of this article is to present four cases of histologically confirmed mandibular dentigerous cysts to highlight diverse radiological presentations: one of classical appearance (well-limited unilocular radiolucent lesion surrounding the crown) and three which have shown radiological peculiarities (one cyst displacing the adjacent tooth, with bone but no root resorption, one cyst presenting hallmarks of infection and one multilocular cyst with thin septa). Such radiologic diversity may, on occasion, suggest a clinical aggressive lesion such as an odontogenic keratocyst or ameloblastoma. The diagnosis of dentigerous cyst requires a thorough evaluation of the clinical presentation and accurate radiological studies.

A healthy man in his 40s was referred to the Oral Surgery and Implantology Unit of Geneva University Hospital for diagnosis and management of facial swelling affecting the right side of his lower jaw. The patient’s history revealed that the patient had been hit by several punches to the face a few months earlier. To investigate the swelling, an intra-oral radiograph, an orthopantomographic radiograph, and computed tomography were performed, which revealed no fracture of the lower jaw but the presence of a partly impacted fractured wisdom tooth (third molar). This finding, together with the clinical status, indicated cellulitis most likely related to the presence of a fractured wisdom tooth. The decision was made to proceed with tooth extraction, and follow-up at 3 weeks showed good healing and complete resolution of facial swelling. This case highlights that odontogenic infection can also occur as a result of necrosis following the fracture of an impacted wisdom tooth.

The purpose of this study was to report a rare case of an aggressive nasopalatine cyst with nasal involvement in an edentulous patient. A 61-year-old edentulous Caucasian male presented with an anterior maxillary lesion that prevented him from wearing his complete upper denture. Clinical examination showed vestibular and palatal swelling around the edentulous sites of teeth #11, 12 and 13. Radiological examination revealed a well-limited cyst of the anterior maxilla that was aggressive in nature because of its size, erosion of the palatal and buccal cortical bone, and extension to the nasal floor. The provisional diagnosis was an aggressive nasopalatine duct cyst, but because the patient had been edentulous for years, the differential diagnosis also included a residual cyst. To remove the lesion, we used a slightly modified surgical procedure compared with the conventional approach: a flap was raised on the palatal side and another on the vestibular side instead of the classical palatal approach. The diagnosis of a nasopalatine duct cyst was confirmed after a histopathological examination. Large destructive nasopalatine duct cysts involving the nasal cavity are rare. In an edentulous patient, this lesion may be misdiagnosed as a residual cyst. In this case, the surgical risk was the inadvertent creation of a naso-antral communication. The lesion was completely enucleated without complications and healing was uneventful.

Purpose We evaluated the clinical significance of magnetic resonance imaging (MRI) findings and their prognostic value for initial hearing loss and recovery in patients with sudden sensorineural hearing loss (SSNHL). Materials and Methods This retrospective study included consecutive adult patients with unilateral SSNHL, contrast‐enhanced MRI and audiometric testing evaluated in our institution between 2005 and 2017. MRI reports, patient data, treatment, and audiometric tests were reviewed, with the relationship between MRI findings and hearing loss/recovery analyzed. Results Overall, 266 patients were included. Additional symptoms comprised tinnitus (114/266; 43%), vertigo (45/266; 17%), ear pain (26/266; 10%), and ear pressure (6/266; 2%). At least one cardiovascular risk factor (hypertension, diabetes, hypercholesterolemia, cardiopathy, and active smoking) existed in 167/266 (63%) patients. Corticosteroid treatment was followed by 198/266 (74%) patients while contraindications/refusal/compliance precluded treatment in 68/266(26%). Complete, partial or slight hearing recovery occurred in 167/266 (63%) patients. Three MRI patient groups were identified: a group with normal MRI examinations or incidentalomas (128/266; 48%), a group with peripheral auditory system (PAS) lesions (95/266; 36%), and a group with central nervous system (CNS) lesions (43/266; 16%). PAS lesions included lesions from the cochlea to the brain stem (e.g., schwannoma, meningioma, labyrinthitis, intracochlear hemorrhage, vestibulocochlear neuritis), whereas CNS lesions corresponded in 42/43(98%) of cases to leukoaraiosis and other vascular lesions (e.g., stroke, hemorrhage, aneurysm, venous sinus thrombosis, and cavernoma). Belonging to one of the three MRI groups did not influence the degree of initial hearing loss, affected frequencies or treatment, p > .05. Gender and cardiovascular risk factors did neither affect initial hearing loss nor recovery. However, age > 70 years negatively affected initial hearing loss in all frequencies, as well as recovery in all frequencies except 1000 Hz. Also, poor recovery of initial high‐frequency hearing loss (>1000 Hz) was significantly associated with CNS lesions. Conclusion Age > 70 years and CNS lesions depicted by MRI independently predicted poor auditory recovery, albeit in different frequencies. Lay Summary In patients with sudden hearing loss, older age (above 70 years) predicts poorer hearing recovery than in younger patients in most hearing frequencies. In addition, abnormalities of brain tissue revealed by MRI predict poorer hearing recovery at high frequencies. Level of Evidence Level III. This retrospective study included 266 consecutive patients with unilateral sudden sensorineural hearing loss evaluated by magnetic resonance imaging (MRI) and audiometric tests. Cardiovascular risk factors and gender did neither influence initial hearing loss nor recovery. However, age >70 years was a negative prognosticator of auditory recovery for all frequencies excepting 1000 Hz while leukaraiosis and central nervous system lesions of vascular origin depicted by MRI negatively influenced auditory recovery in high frequencies (>1000 Hz).

PurposeThis prospective study aimed to compare the diagnostic performance of [18]FDG PET/MRI and PET/CT for the detection of distant metastases and distant second primary cancers in patients with head and neck squamous cell carcinoma (HNSCC). MethodsA total of 103 [18F]FDG PET/MRI examinations immediately followed by PET/CT were obtained in 82 consecutive patients for staging of primary HNSCC (n = 38), suspected loco-regional recurrence/follow-up (n = 41) or unknown primary HNSCC (n = 3). Histology and follow-up > 2 years formed the standard of reference. Blinded readers evaluated the anonymized PET/MRI and PET/CT examinations separately using a 5-point Likert score. Statistical analysis included: receiver operating characteristic (ROC) analysis, jackknife alternative free-response ROC (JAFROC) and region-of-interest (ROI)-based ROC to account for data clustering and sensitivity/specificity/accuracy comparisons for a score ≥ 3. ResultsDistant metastases and distant second primary cancers were present in 23/103 (22%) examinations in 16/82 (19.5%) patients, and they were more common in the post-treatment group (11/41, 27%) than in the primary HNSCC group (3/38, 8%), p = 0.039. The area under the curve (AUC) per patient/examination/lesion was 0.947 [0.927–1]/0.965 [0.917–1]/0.957 [0.928–0.987] for PET/MRI and 0.975 [0.950–1]/0.968 [0.920–1]/0.944 [0.910–0.979] for PET/CT, respectively (p > 0.05). The diagnostic performance of PET/MRI and PET/CT was similar according to JAFROC (p = 0.919) and ROI-based ROC analysis (p = 0.574). Sensitivity/specificity/accuracy for PET/MRI and PET/CT for a score ≥ 3 was 94%/88%/89% and 94%/91%/91% per patient, 96%/90%/91% and 96%/93%/93% per examination and 95%/85%/90% and 90%/86%/88% per lesion, respectively, p > 0.05.ConclusionsIn HNSCC patients, PET/MRI and PET/CT had a high and similar diagnostic performance for detecting distant metastases and distant second primary cancers.

Although rare, masses and mass-like lesions of developmental and genetic origin may affect the paediatric craniofacial skeleton. They represent a major challenge in clinical practice because they can lead to functional impairment, facial deformation and disfigurement. The most common lesions include fibrous dysplasia, dermoid cysts, vascular malformations and plexiform neurofibromas. Less common lesions include torus mandibularis and torus palatinus, cherubism, nevoid basal cell carcinoma syndrome, meningoencephalocele and nasal sinus tract. This article provides a comprehensive approach for the evaluation of children with masses or mass-like lesions of developmental and genetic origin affecting the craniofacial skeleton. Typical findings are illustrated and the respective roles of computed tomography (CT), cone beam CT (CBCT), magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) sequences and ultrasonography (US) are discussed for the pre-therapeutic assessment, complex treatment planning and post-treatment surveillance. Key imaging findings and characteristic clinical manifestations are reviewed. Pitfalls of image interpretation are addressed and how to avoid them.Teaching points• Masses of developmental and genetic origin may severely impair the craniofacial skeleton.• Although rare, these lesions have characteristic imaging features.• CT, MRI and ultrasonography play a key role in their work-up.• Recognition of pivotal imaging pearls and diagnostic pitfalls avoids interpretation errors.

Pleomorphic adenoma directly arising in the neck is thought to originate from heterotopic salivary gland tissue. In this article, we present the case of a 55-year-old female patient with a histologically proven pleomorphic adenoma located at the left mandibular angle, anteriorly to the sternocleidomastoid muscle and posteroinferiorly to the submandibular gland. As the patient also had an ipsilateral thyroid nodule with coarse calcifications, clinical and radiological features suggested a possible level II metastatic lymph node. However, ultrasound-guided fine needle aspiration cytology and postsurgery histopathological examination revealed a pleomorphic adenoma arising from heterotopic salivary gland tissue unrelated to a benign thyroid nodule. In this article, we provide a review of the existing literature on heterotopic salivary gland tissue and related neoplasms and discuss their imaging presentation.

Mesiodens is the most common type of supernumerary tooth, located between the maxillary central incisors. A young man was referred by his orthodontist for management of a supernumerary tooth located in quadrant I, superposed to the bottom of the right maxillary sinus, distally orientated with the crown in contact with the apex of the palatal root of the maxillary first molar. The tooth was found on a panoramic radiography before starting his orthodontic treatment. To remove it and in order to study, its relationship to the anatomical structures a cone-beam CT examination was performed. This revealed the presence of a mesiodens located on the right paramedian maxillary area. Pericoronal tissue submitted for histopathological examination showed an uninflamed dental follicle. Healing was uneventful. This case shows that mesiodens outside the arch, located in the posterior palate, may be not discovered in a panoramic radiograph.

ObjectiveTo evaluate the value of synthetic magnetic resonance imaging (MRI) and T2 mapping in distinguishing between different types of fillers in soft tissues.Materials and methodsEx vivo fillers of buttock soft tissues (silicone, collagen, and different types of hyaluronic acid) were scanned using a synthetic MRI sequence at 1.5 and 3 T and an optimized T2 mapping sequence to measure the T2 relaxation times of the fillers ex vivo. Three patients addressed to assess complications with buttock fillers underwent MRI with the standard morphological sequences and an additional synthetic MRI sequence; T2 mapping was not performed for the patients. Two patients had silicone fillers, whereas the exact filler composition for the third patient was unknown.ResultsMeasurements of T1 and T2 relaxation times of ex vivo fillers at 1.5 and 3 T using synthetic MRI showed that the silicone, collagen, and hyaluronic acid had distinct relaxation time characteristics. In vivo, the synthetic MRI correctly identified silicone in the two patients with known silicone fillers, showing low T1 and T2 values, whereas in the third patient with an unknown filler type, the synthetic MRI suggested a collagen filler, with intermediate relaxation time values.ConclusionQuantitative sequences have the potential to differentiate between filler types in a noninvasive fashion.