CT findings for dental disease.

Traumatic and especially inflammatory-infectious dental lesions are very prevalent in our context. Inflammatory-infectious disease is usually discovered incidentally on imaging studies that include the orofacial region. Moreover, these conditions can result in potentially severe complications, so early diagnosis and treatment are important. Multidetector computed tomography offers good diagnostic performance for dental lesions, although the radiological findings can be subtle and can go undetected if the radiologist is not familiar with them. Likewise, invasive dental procedures are becoming increasingly common, and these can also result in complications. On the other hand, in daily practice a variety of radiolucent mandibular lesions or developmental anomalies can lead to erroneous interpretations. For these reasons, radiologists should be familiar with possible findings related with dental conditions.

A meta-review of effective doses in dental and maxillofacial cone beam CT using the ROBIS tool.

OBJECTIVES: To apply the ROBIS tool for assessment of risk of bias (RoB) in systematic reviews (SRs) in a meta-review on effective doses (EDs) in dental and maxillofacial cone beam CT. METHODS: Three electronic databases and reference lists of included SRs were searched. Eligible SRs were classified as having low, high or unclear RoB. Findings of SRs were synthesised and data from primary studies combined to relate ED to field of view (FOV) and operating potential (kV). RESULTS: Seven SRs were included: three displayed low RoB, three high and one had unclear RoB. Only one SR related ED to image quality. Deficiencies in reporting of eligibility criteria, study selection and synthesis of results in SRs were identified. FOV height had a significant relationship with ED, explaining 27.2% of its variability. Median ED for three FOV categories differed significantly. Operating potential had a weak relationship with ED, with no significant difference in median ED between three operating potential groups. CONCLUSION: The ROBIS tool should have a role for meta-reviews of different aspects of radiology. The disappointing results for RoB might be remedied by developing standards to improve the quality of reporting of primary dosimetry studies and of SRs. Future dosimetry studies should always relate ED to image quality or diagnostic accuracy. ADVANCES IN KNOWLEDGE: This meta-review is the first to implement ROBIS for SRs of ED and identified that trustworthiness of some SRs is questionable. The percentage change in average ED per cm increase in FOV height could be calculated, emphasizing the importance of FOV as a determinant of ED in CBCT.

Dental disease detection on periapical radiographs based on deep convolutional neural networks.

OBJECTIVES: It is with a great prospect to develop an auxiliary diagnosis system for dental periapical radiographs based on deep convolutional neural networks (CNNs), and the indications and performances should be investigated. The aim of this study is to train CNNs for lesion detections on dental periapical radiographs, to evaluate performances across disease categories, severity levels, and train strategies. METHODS: Deep CNNs with region proposal techniques were constructed for disease detections on clinical dental periapical radiographs, including decay, periapical periodontitis, and periodontitis, leveled as mild, moderate, and severe. Four strategies were carried out to train corresponding networks with all disease and level categories (baseline), all disease categories (Net A), each disease category (Net B), and each level category (Net C) and validated by a fivefold cross-validation method afterward. Metrics, including intersection over union (IoU), precision, recall, and average precision (AP), were compared across diseases, severity levels, and train strategies by analysis of variance. RESULTS: Lesions were detected with precision and recall generally between 0.5 and 0.6 on each kind of disease. The influence of train strategy, disease category, and severity level were all statistically significant on performances (P < .001). Decay and periapical periodontitis lesions were detected with precision, recall, and AP values less than 0.25 for mild level, while 0.2-0.3 for moderate level and 0.5-0.6 for severe level. Net A performed similar to baseline (P > 0.05 for IoU, precision, and recall), while Net B and Net C performed slightly better than baseline under certain circumstances (P < 0.05), but Net C failed to predict mild decay. CONCLUSIONS: The deep CNNs are able to detect diseases on clinical dental periapical radiographs. This study reveals that the CNNs prefer to detect lesions with severe levels, and it is better to train the CNNs with customized strategy for each disease.

Facial swelling for the emergency radiologist-typical and atypical causes.

There are a wide variety of inflammatory, infectious, and cystic lesions which may lead patients to seek acute care for facial swelling. Computed tomography (CT) has become the mainstay for imaging in the urgent/emergent setting. However, magnetic resonance imaging (MRI) can also serve as a powerful problem solving tool in the modern era. As volume continues to increase, a wide variety of facial pathology will be encountered by the emergency radiologist. Recognition of both common and uncommon pathology will assist in diagnosis and value-based care. This article serves as an image-rich review of the many causes of facial swelling with an emphasis on key imaging findings and possible complications.

Dental Radiography and Radiographic Signs of Equine Dental Disease.

Radiography is an important imaging modality and is available to most equine veterinarians providing primary care. Diagnostic radiographic imaging of the equine skull and dentition requires careful positioning and technique. This article is aimed at providing the veterinarian with instructions and guidelines for obtaining diagnostic skull and dental radiographs and a discussion of the radiographic signs of dental disease with case-based examples. The limitations of radiography are discussed with regard to determining the need for adjunct diagnostic techniques and more advanced imaging techniques, such as computed tomography.

Equine Imaging: Computed Tomography Interpretation.

Computed tomography (CT) has revolutionized the veterinarian's ability to image the equine skull and led to improved diagnostic accuracy and clarity for surgical planning. The increased cost for this evaluation is offset by more accurate diagnosis and targeted therapy. As novel technology is developed that allows for increased availability of equine head, the price will continue to decrease and more examinations will be performed. New skills are needed for the veterinarian to accurately interpret this modality. This article reviews the normal CT appearance of the equine skull and presents examples and key features of several common diseases.

Dentomaxillofacial CBCT: Clinical Challenges for Indication-oriented Imaging.

This critical review discusses the clinical challenges for patient-specific and indication-oriented dentomaxillofacial cone beam computed tomography (CBCT). Large variations among units and protocols may lead to variable degrees of diagnostic and three-dimensional model accuracy, impacting both specific diagnostic tasks and treatment planning. Particular indications, whether diagnostic or therapeutic, may give rise to very specific challenges with regard to CBCT unit and parameter setup, considering the required image quality, segmentation accuracy, and artifact level. Considering that dental materials are in the field of view needed for diagnosis or treatment planning, artifact expression is a dominant factor in proper CBCT selection. The heterogeneity of dental CBCT units and performances may highly impact the scientific results. Thus research findings cannot be simply generalized as published evidence, and a demonstrated clinical applicability for a specific indication should not be simply extrapolated from one CBCT unit to another.

Imaging Anatomy of the Jaw and Dentition with Cone Beam Computed Tomography.

Knowledge of dental, maxillary, and mandibular anatomy and the use of correct nomenclature is critical in the evaluation of a mandibulofacial and/or maxillofacial imaging data set. The use of the correct diagnostic imaging tool tailored to the patient's needs is of equal importance. This article highlights imaging anatomy and cross-sectional imaging modalities mainly focusing on cone beam computed tomography of the mandibulofacial and maxillofacial region.

Computed tomographic findings of dental disease in domestic rabbits (Oryctolagus cuniculus): 100 cases (2009-2017).

OBJECTIVE: To characterize the CT findings and epidemiological features of acquired dental disease in rabbits. ANIMALS: 100 client-owned rabbits (Oryctolagus cuniculus). PROCEDURES: Medical records were searched to identify rabbits that underwent skull CT for any reason from 2009 to 2017. History, signalment, and physical examination findings were recorded. The CT images were reevaluated retrospectively for evidence of dental disease and graded according to a previously described system (from 1 [no evidence of disease] to 5 [severe dental disease]) for acquired dental disease in rabbits, and an overall (mean) grade was assigned. Descriptive analyses were performed. Factors were assessed for associations between dental disease grade and malocclusion stage. RESULTS: Common findings included premolar or molar tooth curvature in transverse (n = 100 rabbits) and sagittal (95) planes, apical elongation of premolar or molar teeth (99), sharp dental points (93), deformation of the mandibular canal (82), and periodontal ligament space widening (76). Acquired dental disease was classified as grade 1 (n = 2 rabbits), 2 (60), 3 (14), 4 (4), or 5 (20). Most CT findings were significantly correlated with each other. Agreement of grades was fair between left- and right-sided quadrants and between maxillary and mandibular quadrants. Age was associated with increasing dental disease grade and malocclusion stage (proportional ORs, 1.21 and 1.32/y, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Fair agreement in disease grades between dental quadrant pairs indicated a degree of asynchrony in the development of dental disease. Findings suggested premolar or molar tooth curvature in a sagittal plane, subtle elongation at premolar or molar tooth apices, and mandibular canal deformation should be added to the grading system.

Recent Advances in Cone-beam CT in Oral Medicine.

BACKGROUND: The cone-beam computed tomography (CBCT) technology has continuously evolved since its appearance in oral medicine in the early 2000s. OBJECTIVES: To present recent advances in CBCT in oral medicine: i) selection of recent and consensual evidence-based sources, ii) structured summary of the information based on an iterative framework and iii) compliance with ethical, public health and patient-centered concerns. MAIN FINDINGS: We will focus on technological advances, such as sensors and reconstruction algorithms used to improve the constant quality of the image and dosimetry. CBCT examination is now performed in almost all disciplines of oral medicine: currently, the main clinical disciplines that use CBCT acquisitions are endodontics and oral surgery, with clearly defined indications. Periodontology and ear, nose and throat medicine are more recent fields of application. For a given application and indication, the smallest possible field of view must be used. One of the major challenges in contemporary healthcare is ensuring that technological developments do not take precedence over admitted standards of care. The entire volume should be reviewed in full, with a systematic approach. All findings are noted in the patient's record and explained to the patient, including incidental findings. This presupposes the person reviewing the images is sufficiently trained to interpret such images, inform the patient and organize the clinical pathway, with referrals to other medical or oral medicine specialties as needed. CONCLUSION: A close collaboration between dentists, medical physicists, radiologists, radiographers and engineers is critical for all aspects of CBCT technology.

Radiographic review of anatomy and pathology of the masticator space: what the emergency radiologist needs to know.

The differential diagnosis of a masticator space (MS) lesion is broad, owing in part to the multiple structures contained within such a small region. It is also because the MS is adjacent to many of the other deep spaces within the head and neck, which can act as gateways for disease spread. Therefore, emergency radiologists must be familiar with anatomy of the MS, as well as adjacent spaces in order to provide an accurate diagnosis to the referring clinician. This article illustrates the anatomy and common pathologies within the MS using a case-based multimodality approach. Common masticator space pathologies can be categorized into inflammatory/infectious, neoplastic, and vasoformative lesions. Important imaging features of MS lesions and patterns of disease spread will be discussed, with the aim of making this complex deep space more approachable in the emergent setting.

Dental Emergencies: A Practical Guide.

Dental disease is a frequent finding on head and neck images, especially in the context of emergencies, and can be a challenge for radiologists who are inexperienced with findings of dental trauma or disease. Dental abnormalities can be subtle and therefore must be included in the systematic approach to these images. Although dedicated dental images are not acquired in most emergency cases, the teeth are included on many different images of the head and neck, and their initial evaluation seldom requires a specific protocol. The high prevalence of craniofacial trauma, sinus infection, and maxillomandibular procedures, among other conditions, frequently requires interpretation of dental images in daily emergency practice. The imaging findings can be categorized into infection, trauma, and complications of procedures, although sometimes these categories can overlap. Such categories can help the radiologist decide which imaging protocol and dynamic maneuvers should be used and are also useful when reading images and proposing differential diagnoses. Familiarity with the imaging findings of dental emergencies improves the radiologist's diagnostic confidence and role in guiding patient care, avoiding progression to life-threatening conditions, and reducing aesthetic problems, dental loss, and related conditions. Information about the imaging protocols is provided, the relevant anatomy of the teeth and related structures is reviewed, and the key imaging findings of dental emergencies are presented.©RSNA, 2019.

Odontogenic sinusitis is a common cause of unilateral sinus disease with maxillary sinus opacification.

BACKGROUND: Unilateral sinus disease (USD) carries a broader differential diagnosis than bilateral sinus disease, including various inflammatory and neoplastic conditions. Odontogenic sinusitis (ODS) is a common cause of unilateral maxillary sinusitis, but few studies have examined its incidence among all USD etiologies. The main purposes of this prospective study were to determine the incidences of ODS and other etiologies causing USD with complete maxillary sinus opacification on computed tomography (CT), and to compare CT features of ODS and non-odontogenic USD patients. In addition, clinical features of the ODS cohort are described. METHODS: A prospective case series of 134 patients with USD with complete maxillary sinus opacification on CT was conducted from August 2015 to November 2018. Based on nasal endoscopy, sinus CT, and dental examination and imaging, patients were categorized as having unilateral ODS or non-odontogenic USD. Patients with non-odontogenic USD were categorized as inflammatory or neoplastic. Demographic and clinical data were reported for ODS patients. RESULTS: Of the 134 patients, 45% had ODS, 36% had non-odontogenic inflammatory conditions, 17% had inverted papilloma, and 2% had malignancies. Of the 60 ODS cases, 86.7% were associated with middle meatal purulence on nasal endoscopy. On CT, 88.3% had extramaxillary sinus disease extension, and 65.5% of CT reports made no mention of dental pathology. CONCLUSION: ODS caused nearly 50% of all USD cases with maxillary sinus opacification on CT, and was the most common individual etiology. ODS was frequently associated with anterior ethmoid and frontal sinus disease on CT, and middle meatal purulence on nasal endoscopy.

Sphenopalatine Neuralgia: An Independent Neuralgia Entity. Pooled Analysis of a Case Series and Literature Review.

BACKGROUND: Structural damage or demyelization of the sphenopalatine ganglion may cause sphenopalatine neuralgia (SN). The current International Classification of Headache Disorders, third edition (ICHD-3) regards SN as a phenotype of cluster headache. Whether SN is an independent neuralgia entity has been debated for years. METHODS: This article presents a case series of SN, a review of all published cases, and a pooled data analysis of the identified cases. RESULTS: Seven patients were identified, with a median age at symptom onset of 59 years. Six cases were secondary to structural lesions surrounding the ipsilateral sphenopalatine ganglion, and all of them experienced significant clinical improvements after removing the primary causes. In the seventh patient, no evidence of underlying disease was found. The literature review showed that SN affected patients spanning a wide range of ages and both sexes. The clinical characteristics of SN might mimic cluster headache with the exception of cluster pattern and treatment response to oxygen. The typical duration of pain episodes in SN was several hours to several days; and in some cases, pain was persistent. Sixty-seven percent (59/88) of patients with SN had structural lesions around the sphenopalatine ganglion. CONCLUSION: SN could possibly be regarded as a different clinical entity from cluster headache. Based on our patients and literature review, SN can be categorized as idiopathic SN and secondary SN. Craniofacial structural lesions should be highly rating and taken into account when SN is suspected.

Doses, Benefits, Safety, and Risks in Oral and Maxillofacial Diagnostic Imaging.

Diagnostic imaging is essential in dentistry. Doses range from low to very low, benefits to patients can be immense, and safe techniques are well known but widely ignored. Doses range from very low with properly executed intraoral, cephalometric, and panoramic imaging to higher than multidetector computed tomography with cone-beam computed tomography. Benefits are substantial: imaged dental disease, often obscured from direct vision by size and anatomy, can pose a mortal threat to the patient. Additionally, imaging is often central in planning complex dental procedures. Safe imaging in dental environments is straightforward; the means for minimizing dose and maximizing diagnostic efficacy have been widely and inexpensively available for decades. Such techniques reduce patient dose by some 80% over traditional techniques but are infrequently used. Digital panoramic equipment reduces doses markedly. For cone-beam computed tomography imaging, selection criteria are critical in defining appropriate fields of view and presets; several publications address this. It is treacherous to discuss risk in oral and maxillofacial radiology. There are more than 330 million dental x-ray examinations annually, the majority being intraoral examinations, with steady increases in panoramic and cone-beam computed tomography. Radiation carcinogenesis from conventional imaging is unlikely, while large field-of-view, high-resolution preset cone-beam computed tomography can be comparable in carcinogenesis risk to craniofacial multidetector computed tomography. Uncertainties in risk estimation from low doses coupled with the huge numbers of dental images taken annually and the rapid growth of cone-beam computed tomography dictate that safe oral and maxillofacial imaging is in the interests of patients, staff, and the public. As low as reasonably achievable (ALARA) practices and linear no-threshold risk modeling continue to be prudent and appropriate.

US of Pediatric Superficial Masses of the Head and Neck.

Superficial palpable masses of the head and neck are common in the pediatric population, with the vast majority of the lesions ultimately proven to be benign. Duplex ultrasonography (US) has emerged as the first-line imaging modality for the evaluation of superficial pediatric masses. Without utilizing radiation, iodinated contrast material, or sedation and/or anesthesia, US provides a means for quick and cost-effective acquisition of information, including the location, size, shape, internal content, and vascularity of the mass. In this review, the US findings are described for a variety of common and uncommon pediatric head and neck masses diagnosed in our practice. Specifically, the entities covered include neonatal scalp hematoma, craniosynostosis, dermoid and epidermoid cysts, Langerhans cell histiocytosis, lymph nodes and their complications, fibromatosis colli, thyroglossal duct cyst, branchial cleft cyst, cervical thymus, congenital goiter, thyroid papillary carcinoma, parathyroid adenoma, hemangioma, lymphangioma, jugular vein phlebectasia, Lemierre syndrome, acute parotitis and parotid abscess, leukemia and/or lymphoma, neurogenic tumor, and rhabdomyosarcoma. Ultimately, in situations in which the head or neck mass is too large, deep, or hyperechoic to be fully assessed within the US field of view, or if malignancy or a high-flow vascular lesion is suspected, then further evaluation with cross-sectional imaging is warranted. Online supplemental material is available for this article. ©RSNA, 2018.