Radiolucent lesions of the mandible: a pattern-based approach to diagnosis

Abstract

ObjectivesRadiolucent mandibular lesions seen on panoramic radiographs develop from both odontogenic and non-odontogenic structures. They represent a broad spectrum of lesions with a varying degree of malignant potential. The purpose of this review is to illustrate the characteristic imaging findings—as well as the clinical and histological features—of common and uncommon radiolucent lesions of the mandible.MethodsThis review article is based on the retrospective evaluation of 11,725 panoramic radiographs seen in our institution during the past 6 years. It provides a comprehensive, practical approach to the radiological interpretation of radiolucent lesions of the mandible. To facilitate the diagnostic approach, we have classified radiolucent lesions into two groups: lesions with well-defined borders and those with ill-defined borders.ResultsLesion prevalence, age of manifestation, location within the mandible, relationship to dental structures, effect on adjacent structures and characteristic findings at computed tomography (CT), cone beam CT (CBCT) and magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) are discussed. Pitfalls including malignant lesions mimicking benign disease and pseudo-lesions are equally addressed.ConclusionKnowledge of the characteristic imaging features of radiolucent mandibular lesions narrows the differential diagnosis and is crucial for the identification of those lesions, where biopsy is indicated for definitive histology.Teaching points• Panoramic X-rays, CT and MRI are essential for the work-up of radiolucent mandibular lesions.• Lesion borders, location within the mandible, relationship to dental structures and tissue characteristics on cross-sectional imaging are indispensable to narrow the differential diagnosis.• High-resolution CT and CBCT play a major role for the assessment of lesion margins and their relationship to important anatomic structures, such as the inferior alveolar nerve.• Although most radiolucent lesions with well-defined sclerotic borders are benign, MRI may reveal clinically unsuspected malignant disease.

Solid Multicystic Ameloblastoma Misdiagnosed Radiographically as a Periapical Cyst: A Case Report

“…[3][4][5] The occurrence of ameloblastoma at the apex of teeth is rare and can be often misleading in a definitive diagnosis, as illustrated in this case, which can lead to the initiation of endodontic therapy with the assumption that the lesion is pulpo-periapical in origin, although the pretreatment panoramic radiograph in the current case did not reveal any features suggesting pulp or periodontal pathology. This initial misdiagnosis was reported previously in similar cases where the definitive diagnosis of ameloblastoma was reached after histological examination.…”

Diagnostic d’un lymphome non hodgkinien mandibulaire primitif pour mobilités dentaires multiples : un cas

“…Les diagnostics différentiels à évoquer sont les autres processus infiltrants tels que le myélome multiple, les carcinomes primitifs intra-osseux, les leucémies, et les métastases osseuses, ou avec un processus infectieux tel que l'ostéomyé-lite chronique [3]. La localisation du lymphome peut s'effectuer dans l'ensemble des niveaux de la mandibule.…”

“…D'autres suggèrent que le scanner et l'IRM ne montrent que peu ou pas d'érosion corticale malgré la confirmation de l'envahissement médullaire et des tissus mous péri-mandibulaires [3]. Imaizumi et al [5] ont montré la supériorité de l'IRM sur le scanner ou le cone-beam pour évaluer l'envahissement médullaire et des tissus mous des LMNH.…”

Bisphosphonate-related osteonecrosis of the jaw: from the sine qua non condition of bone exposure to a non-exposed BRONJ entity

“…46 Consequently, the assessment of osteolytic lesions of BRONJ beyond the limits of the jaws (extraosseous structures) is not allowed, where it would lead to underestimation of disease extent. 56 CT, in turn, even though having a lower spatial resolution with some magnification of the images, provides better contrast resolution, where the soft-tissue window allows detailed information on the soft-tissue alterations, based on X-ray attenuation degrees (Hounsfield units) correlated to greyscale shades. Considering these properties in BRONJ evaluation, it seems that CBCT gives a precise analysis of bone lesion extent within the jaws and its relationship with structures such as the inferior alveolar nerve and teeth, whereas CT can give more information about the soft tissues involved, including cervical lymphadenopathy, and also the involvement of nasal and maxillary sinus cavities.…”

“…45 MRI helps in detecting early signs of BRONJ 43 and in establishing a differential diagnosis, including clinically unsuspected malignancy. 56 Meanwhile, this examination is not able to show the destruction of the cortical bone 37,45 and can overestimate the dimension of the necrotic lesion, where it is not recommended to determine BRONJ extent. 43,55 Another limitation in MRI is the artefact generated from the dental casting alloys.…”