Odontogenic Tumors: Imaging-Based Review of the Fourth Edition of World Health Organization Classification

[Use of current imaging tools for the study of odontogenic myxoma. A review of the literature]

Odontogenic myxoma (OM) is currently classified as a benign tumor of ectomesenchymal origin, observed between the second and fourth decade of age, with a predilection in women and predominance in the mandibular region, composed of rounded and angular cells embedded in an abundant myxoid stroma, of aggressive biological behavior, having the characteristic of being locally infiltrative. Tumor cells spread in the intratrabecular space beyond the bone limit, making it difficult to determine the edge of the tumor, even without cortical continuity, presenting intermittent direct contact with soft tissue; the appearance can be unilocular (small lesions), or commonly the typical image is that of a destructive lesion with poorly defined borders with a multilocular growth pattern, for which the use of advanced medical images such as Cone Beam Computed Tomography (CTHC), Computed Tomography (CT), Magnetic Resonance Imaging (MRI), are useful to establish an adequate diagnosis with the ability to point out the characteristics of OM with precision and three-dimensional perspective. This review presents a systematic analysis of the types of imaging tools currently used for the study of OM.

Central odontogenic fibroma of simple type: An original observation

Central odontogenic fibroma is an uncommon, benign, slow-growing intraosseous mesenchymal odontogenic tumour. It presents a diagnostic dilemma to the clinician and the pathologist because its clinical and radiological features resemble other odontogenic and/or non-odontogenic tumours, and the differential diagnosis is based on histological examination. In this report, we describe our experience with a case of a 23-year-old female patient with central odontogenic fibroma of the mandible that was diagnosed as 'simple type'. Highlighting a subtype that was dropped from the last World Health Organization classification of head and neck tumours is important to accumulate more information about this lesion and to show its different features. Despite its rarity, central odontogenic fibroma should be included in the differential diagnosis of intrabony tumours of the jaws. These findings can better educate oral and maxillofacial surgeons about the unusual nature of this lesion, help establish a correct diagnosis and give the appropriate therapeutic management.

Bone-related disorders of the jaw: A clinico-radiological diagnostic algorithm

Bone-related disorders of the jaw (BRDJ) include a spectrum of non-neoplastic and neoplastic lesions of the maxillofacial region that have been recently classified into fibro-osseous lesions, giant cell lesions and osseous tumours. The histopathological features of BRDJ can be similar and overlie each other. Imaging is important in order to reach a specific diagnosis. However, the appearance of BRDJ on imaging is non-specific in some cases. Computed tomography (CT) and magnetic resonance imaging (MRI) are used for accurate localisation, characterisation of the tumour matrix, delineation of the lesion extension and establishment of the relation of BRDJ to the surrounding structures. Imaging is usually done to detect the relationship with the adjacent surrounding vital structures and to diagnose aggressive forms, malignant transformation and associated syndromes. The correlation of the demographic findings, the location and the clinical presentations with the imaging features are important for the diagnosis of BRDJ. The proposed clinico-radiological diagnostic algorithm with CT and MRI helps a specific diagnosis to be reached in some cases.

Usefulness of MR imaging for odontogenic tumors

MRI has become an invaluable diagnostic tool in all areas of the body. However, it has not been widely used to image odontogenic tumors of the jaw. Major advantages of MRI include excellent soft tissue contrast in the absence of ionizing radiation. Furthermore, diffusion-weighted MRI and dynamic contrast-enhanced MRI can be used as functional imaging techniques for assessing tissue biology. In this review article, we present representative MR images of several types of odontogenic tumors, and discuss MR imaging characteristics useful for differential diagnosis.

Stylohyoid complex syndrome: A report of two cases and review of the literature

This article reports two patients with stylohyoid complex syndrome.

Cone beam computed tomography examination of the 37-year-old Caucasian woman with hemifacial pain, radiating to the left ear which intensified in response to opening the mouth revealed the ossified distal part of the left stylohyoid ligament, 23.85 mm long, which had a contact with the lesser horn of the hyoid.

A 43-year-old man with a 5-month history of pain in the anterolateral surface of the neck and temporomandibular joint on the right side when swallowing and yawning had the styloid process elongation with a “bayonet-like” deformity on the same side.

Ossification of the stylohyoid ligament, elongation and bending of the slyloid process, as a reason of the lateral neck and/or facial pain is not commonly suspected in clinical practice where diagnosis is often first made radiologically.

Primordial odontogenic tumour: A systematic review of the common but also unusual features of this novel entity

BACKGROUND

Primordial odontogenic tumour (POT) is a novel entity that was described in 2014 and that is included in the group of benign mixed epithelial and mesenchymal odontogenic tumours. In recent years, several papers have added new cases with some clinical and histopathological aspects that slightly differ from those described in the original report. The aim of this systematic review is to update all available data on POT published in the literature and to identify those features of the neoplasm that require further investigation.

MATERIALS AND METHODS

A systematic review of literature was conducted using PubMed, Embase, Web of Science and Scopus. Additional sources were also checked. Publications reporting cases with enough clinicopathological information were included, without any time or language restrictions. Histopathological or radiological studies were considered for qualitative analysis.

RESULTS

A total of 30 publications were included. Seventeen papers were used for quantitative analysis while 13 papers were used only for qualitative analysis. A total of 18 cases of POT were identified. Some clinical, radiographic, histopathological and therapeutic features were common in all reported cases, while other aspects of the neoplasm were inconsistent through published cases. This inconsistency was particularly remarkable when dealing with the histopathological features of the neoplasm.

DISCUSSION

Some issues about POT remain unclear and deserve to be clarified by future reports. The description of the odontogenic epithelium covering the ectomesenchyme is often contradictory, while it remains debatable whether peripheral ameloblastic epithelial islands or hard dental tissue deposition can occasionally occur within the tumour.