Current concepts in maxillofacial imaging

A global science mapping analysis on odontogenic infections

OBJECTIVES

Odontogenic infections are common and a topic of core interest for dentists, and maxillofacial surgeons. The aim of this study was to conduct a bibliometric analysis of the global literature on odontogenic infection and explore the top 100 most cited papers to identify the common causes, sequelae and management trends.

METHODS

Following a comprehensive literature search, a list of top 100 most cited papers was created. The VOSviewer software (Leiden University, The Netherlands) was used to create a graphical representation of the data, and statistical analyses were performed to analyze the characteristics of the top 100 most cited papers.

RESULTS

A total of 1,661 articles were retrieved with the first article published in 1947. There is an exponential upward trend on the number of publications (R2 = 0.919) and a majority of papers are in English language (n = 1,577, 94.94%). A total of 22,041 citations were found with a mean of 13.27 per article. The highest number of publications were recorded from developed countries. There was a male predilection in the reported cases and the most common sites included the submandibular and parapharyngeal spaces. Diabetes mellitus was identified as the commonest co-morbidity. Surgical drainage was ascertained to be the preferred method of management.

CONCLUSIONS

Odontogenic infections remain prevalent and have a global distribution. Although prevention of odontogenic infection through meticulous dental care is ideal, early diagnosis and prompt management of established odontogenic infections is important to avoid morbidities and mortality. Surgical drainage is the most effective management strategy. There is lack of consensus regarding the role of antibiotics in the management of odontogenic infections.

Computed tomography assessment of maxillary sinus hypoplasia and associated anatomical variations: a systematic review and meta-analysis of global evidence

OBJECTIVE

To summarize the scientific evidence on the prevalence of maxillary sinus hypoplasia (MSH) and associated anatomical variations as assessed by computed tomography scans.

STUDY DESIGN

This PROSPERO-registered systematic review followed the recommendations of the PRISMA guidelines. Search algorithms were constructed for each of the six databases and gray literature. After screening the references (Rayyan®), the extracted data were meta-analyzed according to a random-effects model. The joanna briggs critical appraisal tool assessed the methodological quality of the included studies. The GRADE approach was used to estimate the certainty of the evidence.

RESULTS

From a total of 2781 studies screened, 22 were considered for four meta-analysis. The prevalence of MSH in 7358 patients was 5.65% (CI95% = 4.07-7.47%) with significant heterogeneity between studies (p < 0.001, I2 = 89.30%). MSH was identified in 295 patients, of whom 82.38% (CI95% = 75.82-88.09%) had unilateral hypoplasia and 17.62% (CI95% = 11.91-24.18%) bilateral hypoplasia with moderate heterogeneity between studies (p < 0.0503, I2 = 42.87%). The prevalence of MSH in 9998 maxillary sinuses was 3.77% (95% CI = 2.44-5.38%), with significant heterogeneity between studies (p < 0.001, I2 = 92.84%). Hypoplastic/aplastic uncinate process, concha bullosa and paradoxical concha were the most reported anatomical variations. The studies presented a low-moderate methodological quality. The certainty of the evidence was very low to moderate.

CONCLUSION

The prevalence of maxillary sinus hypoplasia observed was 5.65%, with most cases being unilateral.

Performance of cone-beam computed tomography (CBCT) in comparison to conventional computed tomography (CT) and magnetic resonance imaging (MRI) for the detection of bone invasion in oral squamous cell cancer (OSCC): a prospective study

BACKGROUND

Oral squamous carcinoma (OSCC) is often diagnosed at late stages and bone erosion or invasion of the jawbone is frequently present. Computed tomography (CT) and magnetic resonance imaging (MRI) are known to have high diagnostic sensitivities, specificities, and accuracies in detecting these bone affections in patients suffering from OSCC. To date, the existing data regarding the impact of cone-beam computed tomography (CBCT) have been weak. Therefore, this study aimed to investigate whether CBCT is a suitable tool to detect bone erosion or invasion in patients with OSCC.

METHODS

We investigated in a prospective trial the impact of CBCT in the diagnosis of bone erosion or invasion in patients with OSCC who underwent surgery. Every participant received a CBCT, CT, and MRI scan during staging. Imaging modalities were evaluated by two specialists in oral and maxillofacial surgery (CBCT) and two specialists in radiology (CT and MRI) in a blinded way, to determine whether a bone affection was present or not. Reporting used the following 3-point system: no bony destruction ("0"), cortical bone erosion ("1"), or medullary bone invasion ("2"). Histological examination or a follow-up served to calculate the sensitivities, specificities, and accuracies of the imaging modalities.

RESULTS

Our results revealed high diagnostic sensitivities (95.6%, 84.4%, and 88.9%), specificities (87.0%, 91.7%, and 91.7%), and accuracies (89.5%, 89.5%, and 90.8%) for CBCT, CT, and MRI. A pairwise comparison found no statistical difference between CBCT, CT, and MRI.

CONCLUSION

Our data support the routine use of CBCT in the diagnosis of bone erosion and invasion in patients with OSCC as diagnostic accuracy is equal to CT and MRI, the procedure is cost-effective, and it can be performed during initial contact with the patient.

The Utility of Cone Beam Computed Tomography Scans in Diagnosing and Treating Anterior Lesions of the Maxilla and Mandible

BACKGROUND

The standard screening protocol for radiographic examination in dentistry as per the American Dental Association recommendations is a panoramic radiograph (PAN) and four horizontal bitewings. PAN inherently suffers from several shortcomings like the superimposition of anatomic structures, especially of the cervical spine that obscures a significant portion of the anterior maxilla and mandible. This region has a significant amount of pathology that is not adequately imaged. Three-dimensional (3D) imaging provides circumferential information on the area of interest and adds value to the diagnosis and treatment planning of pathology, especially in the anterior maxilla and mandible. However, there is not an adequate number of well-designed studies that articulate the true value addition of 3D imaging for the evaluation of this region.

OBJECTIVES

The objective of this study is to evaluate the value addition of 3D imaging in diagnosing pathologies in the anterior maxilla and mandible when compared to two-dimensional PAN.

MATERIALS AND METHODS

A total of 25 cases that had a diagnosis of anterior pathology and had both a PAN and a cone beam computed tomography (CBCT) scan were collected for this study. An institutional review board approval to retrospectively evaluate these data was obtained. The PAN and CBCT scans were randomly evaluated by a second-year dental student, an oral and maxillofacial radiology resident in training, and a board-certified oral radiologist. The scans were evaluated using a three-point modified Likert scale, where 1 represents "not visible or clear," 2 represents "visible but not clear," and 3 represents "visible and clear." The lesions were evaluated for characteristics like lesion location, size & shape, internal contents, borders of the lesion, cortical integrity, locularity, and effect on adjacent structures like root resorption. After the evaluation was completed, a comparison of the lesion diagnosis was done with histopathology to confirm the diagnosis. The evaluators were also asked to comment on the specific feature that 3D imaging provided that added value to the case. Kappa analysis was done to evaluate inter-operator reliability.

RESULTS

PAN demonstrated significantly lower efficacy in identifying and diagnosing lesions. Only 56% of cases were analyzed using PAN, with 44% deemed undetectable or poorly visualized. These challenging cases necessitated CBCT scans for accurate diagnosis, which successfully diagnosed all 25 cases. The p-value of 0.0002 for PAN implies a highly significant difference from histopathology, suggesting the distinctions are not due to chance. Conversely, the p-value of 0.3273 for CBCT implies that observed differences may be random, lacking sufficient evidence to reject the null hypothesis. CBCT scans consistently outperformed PAN in visualizing various lesion characteristics, underscoring their superior diagnostic capabilities.

CONCLUSIONS

In this study, with a small sample size, 3D imaging provided a significant value addition to the diagnosis and treatment planning by providing additional information regarding the location, extent, internal content, and effect on adjacent structures. The practical implications for clinical settings, along with comparisons to current literature, underscore the study's distinctiveness.

Importance of 3-dimensional imaging in the early diagnosis of chondroblastic osteosarcoma

The aim of this report is to present a case of chondroblastic osteosarcoma located in the right maxillary premolar region of a 17-year-old female patient. The initial clinical presentation and 2-dimensional (2D) radiographic methods proved inadequate for a definitive diagnosis. However, a cone-beam computed tomography scan revealed a hyperdense, heterogeneous lesion in the right maxillary premolar region, exhibiting a characteristic "sun-ray" appearance. To assess soft tissue involvement, a medical computed tomography scan was subsequently conducted. A positron emission tomography scan detected no metastasis or indications of secondary tumors. T1- and T2-weighted magnetic resonance imaging showed signal heterogeneity within the lesion, including areas of low signal intensity at the periphery. A histological examination conducted after an incisional biopsy confirmed the diagnosis of high-grade chondroblastic osteosarcoma. The patient was then referred to an oncology department for chemotherapy before surgery. In conclusion, these findings suggest that early diagnosis using 3-dimensional imaging can detect chondroblastic osteosarcoma in its early stages, such as before metastasis occurs, thereby improving the patient's prognosis.

Usefulness of preoperative computed tomography findings for airway management in patients with acute odontogenic infection: a retrospective study

Odontogenic infection is more likely to affect the airway and interfere with intubation than non-odontogenic causes. Although anesthesiologists predict the difficulty of intubation and determine the method, they may encounter unexpected cases of difficult intubation. An inappropriate intubation can cause airway obstruction due to bleeding and edema by damaging the pharynx and larynx. This study was performed to determine the most important imaging findings indicating preoperative selection of an appropriate intubation method. This retrospective study included 113 patients who underwent anti-inflammatory treatment for odontogenic infection. The patients were divided into two groups according to the intubation method: a Macintosh laryngoscope (45 patients) and others (video laryngoscope and fiberscope) (68 patients). The extent of inflammation in each causative tooth, the severity of inflammation (S1-4), and their influence on the airway were evaluated by computed tomography. The causative teeth were mandibular molars in more than 90%. As the severity of inflammation increased, anesthesiologists tended to choose intubation methods other than Macintosh laryngoscopy. In the most severe cases (S4), anesthesiologists significantly preferred other intubation methods (33 cases) over Macintosh laryngoscopy (9 cases). All patients with S4 showed inflammation in the parapharyngeal space, and the airway was affected in 41 patients. The mandibular molars were the causative teeth most likely to affect the airway and surrounding region. In addition to clinical findings, the presence or absence of inflammation that has spread to the parapharyngeal space on preoperative computed tomography was considered an important indicator of the difficulty of intubation.

Maxillofacial fracture detection and classification in computed tomography images using convolutional neural network-based models

The purpose of this study was to evaluate the performance of convolutional neural network-based models for the detection and classification of maxillofacial fractures in computed tomography (CT) maxillofacial bone window images. A total of 3407 CT images, 2407 of which contained maxillofacial fractures, were retrospectively obtained from the regional trauma center from 2016 to 2020. Multiclass image classification models were created by using DenseNet-169 and ResNet-152. Multiclass object detection models were created by using faster R-CNN and YOLOv5. DenseNet-169 and ResNet-152 were trained to classify maxillofacial fractures into frontal, midface, mandibular and no fracture classes. Faster R-CNN and YOLOv5 were trained to automate the placement of bounding boxes to specifically detect fracture lines in each fracture class. The performance of each model was evaluated on an independent test dataset. The overall accuracy of the best multiclass classification model, DenseNet-169, was 0.70. The mean average precision of the best multiclass detection model, faster R-CNN, was 0.78. In conclusion, DenseNet-169 and faster R-CNN have potential for the detection and classification of maxillofacial fractures in CT images.

Retrospective Evaluation of Maxillofacial Fractures With Cone-Beam Computed Tomography

ÖZ Amaç: Bu çalışmanın amacı maksillofasiyal bölgede meydana gelen fraktürlerin yaş ve cinsiyete göre dağılımlarını, lokalizasyonlarını, sayısını, deplasman varlığını, radyolojik özelliklerini Konik Işınlı Bilgisayarlı Tomografi (KIBT) ile retrospektif olarak değerlendirmektir. Gereç ve Yöntemler: Zonguldak Bülent Ecevit Üniversitesi Diş Hekimliği Fakültesi, Ağız Diş ve Çene Radyolojisi Anabilim Dalı’na 2019 ve 2021 yılları arasında travma nedeniyle başvuran 84 hastadan alınan KIBT görüntüleri retrospektif olarak incelenmiştir. Yaş, cinsiyet, fraktür lokalizasyonu, fraktürlerde deplasman varlığı kayıt altına alındı. İstatistiksel analiz için tüm hasta grubuna tanımlayıcı ve frekans analizleri uygulanırken, hastaların yaş ve cinsiyetlerini; fraktür hattı ve fraktür bölgesi ile karşılaştırırken ki-kare testi uygulandı. Bulgular: 60 erkek 24 kadın hasta (E/K, 2,5/1) olmak üzere toplam 84 hastanın maksillofasiyal travma nedeniyle KIBT görüntüsü incelendi. Çalışmada incelenen hasta grubunun yaşları 6 ve 72 arasında değişmekte olup yaş ortalaması 33.17±1.48 olarak belirlendi. Farklı etiyolojik nedenlerden kaynaklı çeşitli lokalizasyonlarda meydana gelen 116 fraktür hattı sayısı radyolojik olarak tespit edildi. İncelenen tüm fraktürlerin 73’ünde deplasman izlenirken kalan 43 fraktür hattında deplasman görülmedi. Meydana gelen fraktürler en sık angulus mandibulada (%22,61:n=19) tespit edildi. En az fraktür mandibula ramus (%3,57; n=3) ve koronoid proseste (%3,57; n=3) görüldü. Sonuçlar: Fraktür hatlarının varlığının, lokalizasyonlarının ve kırık parçalarının yer değişiminin doğru radyografik teknikler aracılığıyla tespit edilmesi, gerekli tedavi prosedürlerinin uygulanması açısından önem taşımaktadır. İki boyutlu radyografilerin kullanımının yetersiz kaldığı durumlarda KIBT gibi üç boyutlu görüntüleme yöntemleri tercih edilmelidir. Anahtar Kelimeler: Konik Işınlı Bilgisayarlı Tomografi, Fraktür, Mandibula, Teşhis

Osteosclerotic metaphyseal dysplasia, dysosteosclerosis or osteomyelitis? Paediatric case presentation with associated mandibular swelling and a review of the literature

Osteosclerotic metaphyseal dysplasia (OMD) is an extremely rare form of osteopetrosis, which bears significant clinical similarities to dysosteosclerosis (DSS). We aim to present a rare case of OMD with mandibular swelling and osteomyelitis infection including diagnosis journey as well as management in 7-year-old patient. Literature review completed for OMD cases. Case report investigative methods include genetic testing, CT facial bones and MRI scan, orthopantogram and bone biopsies. An initial suspected diagnosis of DSS with chronic osteomyelitis was made. However, following genetic testing, a diagnosis of OMD was confirmed. Our patient underwent a surgical debulking procedure and antibiotic treatment. Less than 10 patients with this condition have been reported within the international literature. There is a wide range of presentation. OMD, DSS and osteomyelitis are all within a similar spectrum of bone conditions. Our understanding, regarding OMD, remains limited and, hence, further research is required to elucidate a thorough clinical picture.

Radiological investigation of acute mandibular injury

This article focuses on the different imaging modalities used to evaluate acute mandibular fractures and explores important concepts relating to their diagnosis, investigation, and treatment. Significant focus will be given to exploring general management principles, considerations regarding first-line imaging, and recent technological advancement. Computed tomography (CT) is the preferred method when attempting to identify acute mandibular fractures, particularly in trauma patients, and has very high specificity and sensitivity. Multidetector CT now represents the standard of care, enabling fast scan times, reduced artifact, accurate reconstructed views, and three-dimensional (3D) reconstructions. Cone-beam CT is a newer advanced imaging modality that is increasingly being used worldwide, particularly in the ambulatory and intraoperative setting. It produces high-resolution images with submillimeter isotropic voxels, 3D and multiplanar reconstruction, and low radiation dose, however is less widely available and more expensive. Ultrasound is a valuable method in identifying a fracture in unstable patients, but is limited in its ability to detect nondisplaced fractures. Magnetic resonance imaging is useful in determining the presence of soft-tissue injury. CT angiography is invaluable in the assessment of potential vascular injury in condylar fracture dislocations.

[Dental imaging procedures in the Unified Health System and the expansion of secondary care: series between 2000-2016]

The scope of this paper was to analyze the time series of dental procedures performed between 2000 and 2016 in the Brazilian Unified Health System (SUS). The data were obtained from the Outpatient Information System of the SUS (SIA-SUS). The influence of the 2004 National Oral Health Policy of Ordinance No. 600/2006 (which instituted the financing of Dental Specialty Centers - CEOs), and Ordinance No. 1,234/2013 (Financial incentive for the Program for Enhancement of Quality and Access - PMAQ-CEO) were analyzed. Descriptive analyses of the initial and final years of the time series were presented, assessing trends and seasonality in seven types of imaging procedures. The time series of rates of periapical/bitewing radiographic exams revealed a trend of moderate increase and was the only area in which the impact of the financial implementation policy of the CEOs was observed, though not of the PMAQ-CEO. Extraoral imaging exams, such as panoramic radiography, facial CT/TMJ and TMJ MRI revealed a strong upward trend, despite the very low rates. The conclusion reached is that between 2000 and 2016, the policy of expansion of secondary care increased the use of periapical/bitewing imaging exams.

In vitro Comparison of Cone Beam Computed Tomography and Ultrasonography Imaging Methods in the Evaluation of Artificial Mandible Intraosseous Lesions

Statement of the Problem:

Intraosseous lesions of jaws can be imaged by cone beam computed tomography (CBCT) and ultrasonography (USG). The knowledge of imaging features of these two methods about intraosseous jaw lesions is important for dental radiology.

Purpose:

The aim of this study is to evaluate artificial mandible intraosseous lesions by using CBCT and USG.

Materials and Method:

In this in vitro study, intraosseous lesions containing water, milk, olive oil, and liver were evaluated in 60 artificial mandibles by using CBCT and USG. Lesion sizes were compared between CBCT and USG. Lesion sizes were measured on the anterior-posterior, bucco-lingual, and superior-inferior sides. Hounsfield unit (HU) values of the lesions in CBCT images were compared between different materials. Echogenicity of the lesions were evaluated in USG images. One sample t and one-way Anova tests were used for the statistical analysis of the study (p< 0.05).

Results:

In all size measurements of the lesions, mean CBCT values were statistically higher when compared with USG. In CBCT images, statistically difference was found between the HU values of lesions containing olive oil and other lesion contents. In USG images, echogenicity of water, milk and olive oil was found to be anechoic and the echogenicity of liver was found to be hypoechoic.

Conclusion:

CBCT was found to be more accurate than USG in measurement of the size of mandibular intraosseous lesions. According to the results of our study, it was thought that only oil content could be differentiated by using CBCT HU values. It was found that lesions with liquid and non-liquid contents could be differentiated with their echogenicity difference in USG images.

Radiobiological risks following dentomaxillofacial imaging: should we be concerned?

OBJECTIVES

This review aimed to present studies that prospectively investigated biological effects in patients following diagnostic dentomaxillofacial radiology (DMFR).

METHODS

Literature was systematically searched to retrieve all studies assessing radiobiological effects of using X-ray imaging in the dentomaxillofacial area, with reference to radiobiological outcomes for other imaging modalities and fields.

RESULTS

There is a lot of variability in the reported radiobiological assessment methods and radiation dose measures, making comparisons of radiobiological studies challenging. Most radiological DMFR studies are focusing on genotoxicity and cytotoxicity, data for 2D dentomaxillofacial radiographs, albeit with some methodological weakness biasing the results. For CBCT, available evidence is limited and few studies include comparative data on both adults and children.

CONCLUSIONS

In the future, one will have to strive towards patient-specific measures by considering age, gender and other individual radiation sensitivity-related factors. Ultimately, future radioprotection strategies should build further on the concept of personalized medicine, with patient-specific optimization of the imaging protocol, based on radiobiological variables.

Dental cone beam CT: An updated review

Cone beam computed tomography (CBCT) is a diverse 3D x-ray imaging technique that has gained significant popularity in dental radiology in the last two decades. CBCT overcomes the limitations of traditional two-dimensional dental imaging and enables accurate depiction of multiplanar details of maxillofacial bony structures and surrounding soft tissues. In this review article, we provide an updated status on dental CBCT imaging and summarise the technical features of currently used CBCT scanner models, extending to recent developments in scanner technology, clinical aspects, and regulatory perspectives on dose optimisation, dosimetry, and diagnostic reference levels. We also consider the outlook of potential techniques along with issues that should be resolved in providing clinically more effective CBCT examinations that are optimised for the benefit of the patient.

Hypoxia enhances basal autophagy of epithelial-derived ameloblastoma cells

Ameloblastoma is a locally aggressive odontogenic tumor. Etiopathogenesis and locally aggressive growth properties of ameloblastoma can be attributed to a hypoxic microenvironment conducive to tumor cell survival. Epithelial-derived follicular ameloblastoma cells (EP-AMCs) display enhanced basal autophagy, but the interplay of hypoxia and autophagy in EP-AMCs survival and ameloblastoma recurrence is unclear. We evaluated differential expression of autophagic markers in primary and recurrent ameloblastomas and hypothesized that hypoxia-induced autophagy supports EP-AMC survival. Primary and recurrent ameloblastomas were comparatively assessed for expression levels of pan-cytokeratin, Vimentin, and autophagic markers SQSTM1/p62, LC3, and pS6. EP-AMCs compared with human odontoma-derived cells (HODCs) were subjected to severe hypoxia to determine the interplay of hypoxia and autophagic process in posthypoxia survival. Pan-cytokeratin and SQSTM1/p62 were expressed by both primary and recurrent ameloblastoma epithelial cells while the ameloblastoma connective tissues displayed weak reactivity to vimentin. Under hypoxia, EP-AMC expression levels of hypoxia-inducible factor (HIF)-1α, p62, and LC3 were increased while pS6 was decreased posthypoxia. The combined decrease in pS6 and enhanced LC3 in EP-AMCs under hypoxia indicate that EP-AMCs re-establish basal autophagy under hypoxia. Taken together, these suggest a possible role of LC3-associated phagocytosis (LAP) in ameloblastoma cell survival.

Actual applications of magnetic resonance imaging in dentomaxillofacial region

Magnetic resonance imaging (MRI) is a versatile imaging modality utilized in various medical fields. Specifically used for evaluation of soft tissues, with non-ionizing radiation and multiplanar sections that has provided great guidance to diagnosis. Nowadays, use of MRI in dental practice is becoming more pervasive, especially for the evaluation of head-and-neck cancer, detection of salivary gland lesions, lymphadenopathy, and temporomandibular joint disorders. Understanding the basic principles, its recent advances, and multiple applications in dentomaxillofacial region helps significantly in the diagnostic decision making. In this article, the principle of MRI and its recent advances are reviewed, with further discussion on the appearance of various maxillofacial pathosis.

Study Between Panoramic Radiography and Cone Beam-Computed Tomography in the Diagnosis of Ameloblastoma, Odontogenic Keratocyst, and Dentigerous Cyst

OBJECTIVE

To determine how the diagnosis may or may not be influenced by cone-beam computed tomography (CBCT), comparing the diagnostic hypotheses obtained using images of panoramic radiographs and CBCT in cases of ameloblastoma, odontogenic keratocyst, and dentigerous cyst.

STUDY DESIGN

Five cases were selected for each lesion. Panoramic radiographs and CBCT scans were analyzed by 15 dentists for the formulation of the diagnostic hypotheses. Two observers performed the analyses and measurement of qualitative and quantitative features of the lesions evaluated in the CBCT.

RESULTS

There was no statistically significant difference in correct diagnostic average between panoramic radiography and CBCT, but there was a significant difference in correct diagnostic average in the diagnosis of ameloblastoma using CBCT compared to panoramic radiography. Master's and PhD-level observers had greater correct diagnostic average in the diagnosis of odontogenic keratocyst using panoramic radiograph compared to specialists, with a significant difference.

CONCLUSION

Cone-beam computed tomography images revealed that the ameloblastomas were greater in size and expansion compared to the odontogenic keratocyst and the dentigerous cysts. Ameloblastomas showed a higher incidence of multiloculated aspects compared to odontogenic keratocyst and dentigerous cysts. There were no differences between quantitative and qualitative features of odontogenic keratocyst and dentigerous cysts.

Evaluation of the snowing-like ultrasonographic features of intraosseous jaw pathologies

Aim of the study: Ultrasonographic examination of intraosseous jaw pathologies may reveal interesting incidental, mobile hyperechoic particles ("snowflakes") in anechoic areas. Purpose of this study is to explain and discuss this snowing-like ultrasonographic feature of intraosseous jaw pathologies. Material and methods: This study included 113 patients admitted to our clinic for examination: 43 (38.05%) males and 70 (61.9%) females with a mean age of 34.9 ± 17.2 years (range: 6-72 years). A total of 120 intraosseous lesions were evaluated prior to surgery using ultrasonography; these included non-neoplastic, odontogenic, and non-odontogenic lesions. Results: In total, 5 (4.1%) of the 120 lesions exhibited snowing-like feature on ultrasonography, including 2 (1.6% of total) of 3 incisive canal cysts, 2 (1.6% of total) of 7 dentigerous cysts, and 1 (0.8% of total) of 19 odontogenic keratocysts. Conclusions: Snowflakes evident on ultrasonography of intraosseous jaw lesions may be specific to certain pathologies. Future studies correlating radiologic and pathologic features of intraosseous jaw lesions should focus on ultrasonographic snowing-like appearance in different types of lesions and explore why they occur.

Validated image ordering guidelines for odontogenic infections

Overuse of computed tomography (CT) is a prevalent problem across multiple disciplines in healthcare and is common in the workup of odontogenic infections. To address this problem, an imaging pathway was created through collaboration of the oral maxillofacial surgery and emergency medicine departments to reduce unnecessary CT orders. A prospective study was implemented to assess the success of the imaging pathway to guide in the selection of the most appropriate radiological imaging modality when managing an odontogenic infection. Subjects included were adults, presenting through the emergency department for confirmed odontogenic infection. The primary outcome was the rate of unnecessary CT scans performed after the introduction of the pathway. Statistics were performed via the t-test, χ² test, and multiple regression analysis; P < 0.05 was considered significant. Between February 1 and December 15, 2019, 100 patients met the inclusion criteria and were enrolled. The rate of unnecessary CT scans was 25.6%, compared to 56.6% prior to the introduction of the imaging pathway. The pathway did not misclassify any patient to not receive a CT when it was medically necessary. Use of the imaging pathway has the potential to reduce unnecessary CT imaging for odontogenic infections, without negatively affecting patient outcomes.

High-resolution ultrasound imaging compared to magnetic resonance imaging for temporomandibular joint disorders: An in vivo study

PURPOSE

The study aims to determine the diagnostic value of high-resolution ultrasonography (US) compared with magnetic resonance imaging (MRI) for the evaluation of temporomandibular disorders (TMD).

METHODS

Fifty consecutive patients (42 female and 8 male) with signs and symptoms of TMD according to the Research Diagnostic Criteria for TMD were enrolled in the study. Each patient underwent US (13 and 20 MHz) and MRI examination of both TMJs, 1-7 days following clinical examination. All MRI examinations were performed by another radiologist using an 1.5 T MRI device. Sensitivity (Se), specificity (Sp), positive and negative predictive values (PPV, NPV) and diagnostic accuracy were computed along with 95% confidence intervals.

RESULTS

For overall disc displacements, 13 MHz US showed a Se of 72.58%, Sp of 86.84%, PPV of 90%, NPV of 66% and diagnostic accuracy of 78%, while 20 MHz US showed a Se of 75.81%, Sp of 86.84%, PPV of 90.38%, NPV of 68.75% and a diagnostic accuracy of 80%. For degenerative changes, 13 MHz US revealed a Se of 58.33%, Sp of 92.11%, PPV of 70%, NPV of 87.5% and a diagnostic accuracy of 84%, whereas 20 MHz US indicated the same Se of 58.33%, Sp of 93.42%, PPV of 73.68%, NPV of 87.65% and a diagnostic accuracy of 85%. The Cohen's Kappa coefficient for the intra- and inter-observer agreement was 0.822 and 0.836 for disc displacement, respectively 0.813 and 0.788 for degenerative disorders (p < 0.001).

CONCLUSIONS

High-resolution US could be a useful imaging technique in diagnosing TMJ disc displacements.

Direct Three-Dimensional Diagnosis of Ex Vivo Facial Fractures

The aim of the present study is to assess the reliability and accuracy of different 3-dimensional (3D) reconstruction algorithms in detecting undisplaced condylar, zygomatic arc, and orbital rim fractures based on cone-beam computed tomography data set. Twenty sheep heads were used in the present study. Sixty fractured and 60 nonfractured (control) zones were randomly allocated. Three groups consisting of nondisplaced fractures of condyle (CF, n = 20), orbital (OF, n = 20), and zygomatic arc (ZF, n = 20) were created by using a diamond cutting disc. Soft tissues were only dissected and no fractures were generated in the control group (n = 60). The 3D reconstructions were created by using multiplanar reconstruction (MPR), surface rendering (SR), volume rendering (VR), and maximum intensity projection (MIP) algorithms. Final 3D models were examined in Osirix software (Pixmeo SARL, Bernex, Switzerland) by 6 observers. Diagnostic accuracies of each algorithm were statistically compared by receiver operating characteristics (ROC) and area under the ROC curves (AUCs). For the detection of CF, AUC for VR algorithm was found to be statistically larger than that of MIP while AUCs for VR and MIP were larger than those of MPR and SR for OF detection. For the detection of ZF, AUCs for MPR and VR were significantly larger than those of MIP and SR (P < 0.05 for each). Within the limitations of this experimental study, it can be concluded that for maxillofacial surgeons, it is more likely to detect condylar, orbital, and zygomatic fractures by using VR algorithm in 3D reconstruction.

Gun-related eye injuries: A primer

Gun-related eye injuries are relatively common in the context of gunshot wounds to the head and neck. Many of the fundamental principles of gunshot wound management apply to the care of these patients, but the complex anatomy and functional relationships of the periocular region do pose special challenges. We provide a focused primer for physicians seeking a more in-depth understanding of gun-related eye injuries and present 3 representative cases outlining the spectrum of pathology, provide a focused review of the relevant ballistics concepts, and discuss the management of injuries to the periocular soft tissues, orbital structures, and globe. We found that good cosmetic and functional results can often be achieved with appropriate early intervention, but visual prognosis may remain guarded despite optimal treatment.

Common conditions associated with displacement of the inferior alveolar nerve canal: A radiographic diagnostic aid

Purpose

This study reviewed the common conditions associated with displacement of inferior alveolar nerve canal.

Materials and Methods

General search engines and specialized databases including Google Scholar, Pub Med, Pub Med Central, Science Direct, and Scopus were used to find relevant studies by using keywords such as “mandibular canal”, “alveolar canal”, “inferior alveolar nerve canal”, “inferior dental canal”, “inferior mandibular canal” and “displacement”.

Results

About 120 articles were found, of which approximately 70 were broadly relevant to the topic. We ultimately included 37 articles that were closely related to the topic of interest. When the data were compiled, the following 8 lesions were found to have a relationship with displacement of mandibular canal: radicular/residual cysts, dentigerous cyst, odontogenic keratocyst, aneurysmal bone cyst, ameloblastoma, central giant cell granuloma, fibrous dysplasis, and cementossifying fibroma.

Conclusion

When clinicians encounter a lesion associated with displaced mandibular canal, they should first consider these entities in the differential diagnosis. This review would help dentists make more accurate diagnoses and develop better treatment plans according to patients' radiographs.

Cone-beam computed tomography imaging of dentoalveolar and mandibular fractures

Three-dimensional imaging methods have an important role in the diagnosis of dentomaxillofacial fractures that can not be seen on the plain films. Cone-beam computed tomography (CBCT) is one of the three-dimensional imaging methods and has facilitated dental professionals' access to cross-sectional imaging. CBCT units allow different technical parameters and the data acquired by CBCT, can be reformatted. Osseous structures are correctly examined with this technique but the technique is not useful for the examination of soft tissues. Therefore, the purpose of its use should be based on the expected diagnostic gain. The aim of this review is to present the use of CBCT with different multi-planar reformatted sections and three-dimensional reconstructions of dentoalveolar and mandibular fractures.

Evaluation of Odontogenic Maxillary Sinusitis with Cone Beam Computed Tomography: A Retrospective Study with Review of Literature

Aim and Objectives:

The purpose of this study was to describe the radiographic characteristics of odontogenic maxillary sinusitis as seen on cone beam computed tomography (CBCT) scans and determine whether any tooth or any tooth root, was more frequently associated with this disease.

Materials and Methods:

The present study included 500 CBCT images that included the entire maxillary sinus of both the sides in all the three planes. The modified classification of Abrahams and Glassberg was used to assess maxillary sinusitis of odontogenic origin. Furthermore, the proximity of the tooth root to the sinus floor, periapical pathology, and the septae within the maxillary sinus were also assessed.

Results:

In the present study, 1000 hemimaxillas were analyzed. Majority of the cases (74.9%) the apex of either tooth was touching the floor of the sinus. While 16.9% were in close relationship to the sinus while 8.2% of the cases, the apices were present within the sinus. Furthermore, in the present study, 38 of the total cases had an odontogenic cause of maxillary sinusitis, whereas 273 of them had a nonodontogenic cause, 96 have an undetermined cause, and the rest 593 cases had healthy sinus.

Conclusion:

The incidence of odontogenic sinusitis is likely under-reported in the available literature. The introduction of low-dose CBCT is particularly useful to establish a definitive diagnosis to augment in the treatment of chronic maxillary sinusitis of odontogenic origin.

Re-exposure in cone beam CT of the dentomaxillofacial region: a retrospective study

METHODS:

In a retrospective cohort study CBCT images of 4986 patients from the patient database from the Department of Oral Radiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany were included and the rate of re-exposures was counted. Patients were stratified into those who received a scan with the small field-of-view CBCT or the large field-of-view CBCT. The effect of patient-related parameters as age and gender was implicated. As a further device-specific parameter, the statistical analysis included whether the selection of the field of view due to the device type had a significant influence on the occurrence of re-exposures. Furthermore, the rescans were analyzed with regard to their causes.

RESULTS:

In total, CBCT images of 82 (1.6%) patients had to be repeated. Looking at the two different devices, in 42 (1.3%) patients that received a scan with the large field-of-view CBCT and in 40 (2.3%) patients that received a scan with the small field-of-view CBCT respectively needed a retake. There was no statistically significant correlation between age and gender to retakes. For the small field-of-view-size significantly more retakes were observed than for the large one. With 46% motion artifacts were the most frequent causes for a re-exposure of the patient.

CONCLUSIONS:

Gender and age did not have an impact on the occurrence of re-exposures. Patients who received a scan with the small field-of-view CBCT were significantly more often rescanned than those with the large field-of-view CBCT.

Evaluation of Size and Location of a Mental Foramen in the Polish Population Using Cone-Beam Computed Tomography

Introduction

The mental foramen (MF) is a bilateral opening localized on an anterior surface of the mandible. A precise location as well as well-defined shape, size, and number of the MF is crucial for different clinical dental procedures. The aim of this study was to determine a size and location of the MF in relation to the lower teeth using the cone-beam computed tomography (CBCT) study.

Material and Methods

In a group of 201 patients (106 males and 95 females) the CBCT images were performed using the GX CB-500 device (Gendex, USA).

Results

No significant differences in values of the horizontal (H) and vertical (V) diameters as well as the H:V ratio on both sides in relation to the age of participants were found. In males both average values of a horizontal diameter (p=0.031) and vertical diameter (p=0.001) were significantly higher on the right side than in the female subgroup, whereas on the left side only an average value of a vertical diameter was significantly higher in men (p=0.006) in comparison to women. Moreover, the H:V ratio was significantly lower in males on the left side (p=0.032). There were no significant relationships between age and gender of the patients (p>0.05) and the type of mental foramen on the right and left sides.

Conclusions

The application of the CBCT study enabled a precise determination of the shape, size, and position of the mental foramen in relation to the neighboring anatomical structures on a representative group of the Polish patients. The results obtained may contribute to guidelines for dental procedures including anesthesia of the mental nerve and endodontic, implantology, and dental surgery with regard to the location of mental foramen depending on the sex and age of patients.

Contribution of cone-beam computed tomography in the decision of surgical management for bone lesions of the maxillofacial region

The aim of this study was to evaluate the contribution of cone-beam computed tomography (CBCT) in the decision of surgical management for bone lesions of the maxillofacial region. It is a retrospective cross-sectional observational study that includes a sample of panoramic radiography (PR) and CBCT from patients with some type of bone lesion in the maxillofacial region. PR and CBCT images were evaluated by three previously assessed examiners, specialists in oral and maxillofacial surgery. Each image was evaluated randomly, and a surgical procedure was suggested, initially in PR and then in CBCT. The obtained results were submitted to the McNemar test to evaluate the frequencies of changes in the surgical management between the first and the second evaluation in PR and CBCT, and intra-examiner and inter-examiner agreements were analyzed by the Cohen's kappa test. The level of significance was set at 5% (p < 0.05). Intra-examiner agreement increases when CBCT is used. Inter-examiner agreement was low, independently of the evaluated exam, which shows that the choice of treatment plan is examiner-dependent and not exam-dependent. CBCT increases the certainty of the professional in the evaluation of the bone lesions of the maxillofacial region; however, it does not change the indication of the treatment type.

Radiographic predictors of bone exposure in patients with stage 0 medication-related osteonecrosis of the jaws

OBJECTIVE

The aim of this study was to explore the radiographic appearance of stage 0 medication-related osteonecrosis of the jaws (MRONJ) and examine 5 radiographic parameters (trabecular sclerosis, cortical erosion, periosteal reaction, sequestration, and crater-like defect) as predictors of progression to bone exposure.

STUDY DESIGN

Twenty-three patients with a history of antiresorptive therapy, no bone exposure, and nonspecific signs and symptoms were included. Intraoral photographs, panoramic and cone beam computed tomography (CBCT) images at initial visit, and follow-up intraoral photographs were reviewed. Three patients had dental disease (DD), 10 patients with stage 0 MRONJ did not progress to bone exposure (NBE), and 10 patients progressed to bone exposure (BE). Radiographic parameters were scored as absent (0), localized (1), or extensive (2), and their sum formed the composite radiographic index (CRI).

RESULTS

DD patients demonstrated minimal radiographic findings, and their CRI was significantly lower than that of NBE and BE patients. Additionally, BE patients demonstrated a higher radiographic index compared with NBE patients. Intriguingly, sequestration was observed in the initial CBCT of 9 (90%) of 10 BE patients, whereas 80% of NBE patients showed absence of sequestration at initial CBCT examination.

CONCLUSIONS

CBCT imaging can aid in the differentiation of stage 0 MRONJ from dental disease. Radiographic sequestration at initial presentation can serve as a predictor of future bone exposure in patients with stage 0 MRONJ.

Evaluation of mandibular odontogenic keratocyst and ameloblastoma by panoramic radiograph and computed tomography

OBJECTIVES:

The purpose of this study was to describe and compare the main imagenological features of mandibular ameloblastomas and odontogenic keratocyst (OKC) using panoramic radiograph (PR) and CT.

METHODS:

The sample consisted of nine cases of ameloblastomas and nine cases of OKC. PR and CT images were analyzed according to shape, internal structure, borders, associated unerupted tooth, root resorption, expansion and perforation of cortical bones.

RESULTS:

PR evaluation allowed the identification of the lesion's location, presence of sclerosis in the periphery, presence of associated non-erupted tooth and expansion of the mandible's lower border cortical bone. CT was more accurate than PR in the assessment of the lesion shape, presence of inner bone septa, root resorption, buccolingual expansion and rupture of cortical bone. Most cases of ameloblastoma and OKC presented buccolingual expansion and erosion of cortical bone. Only ameloblastomas showed tooth root resorption.

CONCLUSIONS:

Although PR is very helpful and widely used, CT provides more precise information on buccolingual expansion, calcification, bone septa, perforation of cortical bones and tooth resorption, features that are frequently underdescribed in the literature, particularly in OKC.

3D reconstruction images of cone beam computed tomography applied to maxillofacial fractures: A case study and mini review

Maxillofacial injuries can be complex and are clinically important due to their functional and cosmetic significance. Maltreated and missed fractures might cause deformity of the face; thus, accurate evaluation of the fracture provided by X-ray images is critical. In this study, we explore the application of cone-beam computed tomography (CBCT) for diagnosis of severe maxillofacial traumas. A patient with a complex fracture that affects the maxilla, mandible, wall of the maxillary sinus, zygoma, zygomatic arch and nasal bone was diagnosed using 3D reconstruction of CBCT images. This diagnostic approach provides detailed information obtained by static images and a systematic model with unique advantages for the following pre-surgical evaluation, surgical treatment and prognostic assessment of complex maxillofacial fractures.

Does CBCT alter the diagnostic thinking efficacy, management and prognosis of patients with suspected Stage 0 medication-related osteonecrosis of the jaws?

OBJECTIVES

To evaluate the impact of cone beam CT (CBCT) in the diagnostic thinking efficacy, management and prognosis of patients with suspected Stage 0 medication-related osteonecrosis of the jaw (MRONJ).

METHODS

For 15 patients with suspected Stage 0 MRONJ, clinical photographs, a panoramic radiograph and selected CBCT sections were identified. 13 oral surgeons reviewed the material and answered 10 questions in two different sessions. First session included clinical photographs and panoramic radiographs, while second session also included CBCT images. Questions (Qs) referred to dental disease and bone abnormalities (Qs 1, 2 and 3), differential diagnosis (Qs 4 and 5), patient management (Qs 6 and 7) and prognosis (Qs 8 and 9). Q 10 queried indication (first session) and usefulness (second session) of CBCT images.

RESULTS

Qs 2, 3, 5, 7 and 9 scores increased between sessions, with statistical differences for Qs 2, 3, 5 and 7 (<0.05). Patients 2, 8 and 11 showed a significant increase in the average score of all Qs between sessions, while scores for patient 10 nearly reached statistical significance (p = 0.055). For Q 10, 57.4% of answers reported that CBCT was needed (first session) and was beneficial (second session).

CONCLUSIONS

CBCT had a significant impact in differential diagnosis and management of patients with suspected Stage 0 MRONJ.

Cone beam computed tomography and ultrasonography imaging of benign intraosseous jaw lesion: a prospective radiopathological study

OBJECTIVE

We assessed whether ultrasonography (US) can be used in combination with cone beam computed tomography (CBCT) to image intraosseous jaw lesions.

MATERIAL AND METHODS

Using CBCT and US, we evaluated 123 lytic intraosseous jaw lesions diagnosed in 121 patients with guidance from the CBCT findings. The lesions were classified into two groups based on histopathological evaluation: (1) cysts and (2) tumors and tumor-like lesions. US and histopathological findings on the lesions of the two groups and their relationships with each other were also assessed. Results are reported as means ± standard errors, and p < 0.001 was accepted as indicating statistical significance.

RESULT

In total, 123 lesions were evaluated; 74 (60.2%) were cysts and 49 (39.8%) were tumors or tumor-like lesions. The CBCT and US findings were compatible as far as dimensional measurements of the lesions in the three planes (p < 0.001). The US and histopathological findings on the content of the lesions correlated (p < 0.001).

CONCLUSION

CBCT provides useful information for diagnosing intraosseous jaw lesions. Because it offers no valid Hounsfield unit (HU) value, it does not differentiate between solid and cystic masses. Thus, US can be used with CBCT to image intraosseous jaw lesions caused by buccal cortical thinning or perforation.

CLINICAL RELEVANCE

US provides useful information about intraosseous jaw lesions and can be used with CBCT to image such lesions caused by buccal cortical thinning or perforation. Clinicians can take this information into consideration when evaluating intraosseous jaw pathology.

Multidetector CT of Mandibular Fractures, Reductions, and Complications: A Clinically Relevant Primer for the Radiologist

After the nasal bones, the mandible is the second most common site of facial fractures, and mandibular fractures frequently require open reduction. In the trauma injury setting, multidetector computed tomography (CT) has become the cornerstone imaging modality for determining the most appropriate treatment management, fixation method, and surgical approach. Multidetector CT is also used to assess the adequacy of the reduction and evaluate potential complications in the postoperative period. For successful restoration of the mandible's form and function, as well as management of posttraumatic and postoperative complications, reconstructive surgeons are required to have a detailed understanding of mandibular biomechanics, occlusion, and anatomy. To provide added value in the diagnosis, treatment planning, and follow-up of mandibular fractures, radiologists should be aware of these concepts. Knowledge of the techniques commonly used to achieve occlusal and anatomic reduction and of the rationale behind the range of available treatment options for different injury patterns-from isolated and nondisplaced fractures to multisite and comminuted fractures-also is essential. This article focuses on the use of multidetector CT for pre- and postoperative evaluation of mandibular fractures and outlines fundamental concepts of diagnosis and management-beginning with an explanation of common fracture patterns and their biomechanical underpinnings, and followed by a review of the common postoperative appearances of these fractures after semirigid and rigid fixation procedures. Specific considerations regarding fractures in different regions of the tooth-bearing and non-tooth-bearing mandible and the unique issues pertaining to the edentulous atrophic mandible are reviewed, and key features that distinguish major from minor complications are described. (©)RSNA, 2016.

The Reliability of Panoramic Radiography Versus Cone Beam Computed Tomography when Evaluating the Distance to the Alveolar Nerve in the Site of Lateral Teeth

BACKGROUND The aim of this study was to compare the reliability of panoramic radiography (PR) and cone beam computed tomography (CBCT) in the evaluation of the distance of the roots of lateral teeth to the inferior alveolar nerve canal (IANC). MATERIAL AND METHODS 100 PR and 100 CBCT images that met the selection criteria were selected from the database. In PR images, the distances were measured using an electronic caliper with 0.01 mm accuracy and white light x-ray film reviewer. Actual values of the measurements were calculated taking into consideration the magnification used in PR images (130%). Measurements on CBCT images were performed using i-CAT Vision software. Statistical data analysis was performed using R software and applying Welch's t-test and the Wilcoxon test. RESULTS There was no statistically significant difference in the mean distance from the root of the second premolar and the mesial and distal roots of the first molar to the IANC between PR and CBCT images. The difference in the mean distance from the mesial and distal roots of the second and the third molars to the IANC measured in PR and CBCT images was statistically significant. CONCLUSIONS PR may be uninformative or misleading when measuring the distance from the mesial and distal roots of the second and the third molars to the IANC.

Imaging modalities for midfacial fractures

The middle third of the facial skeleton is one of the most complex areas of the human body. A critical factor determining the successful treatment of midfacial fractures is an early and correct diagnosis. Assessment and management of the traumatized patient requires rapid evaluation and decision making. Imaging for the evaluation of patients with midfacial fractures has contributed to achieving an accurate diagnosis and a subsequent successful management. It requires a knowledge of those imaging modalities and projections that provide the most information with the least exposure of radiation to the patient. Conventional radiography has been used successfully for many years although advanced imaging methods such as—three-dimensional computed tomography, magnetic resonance imaging, and cone beam computed tomography have been applied more recently. In this article, we will take a relook at various modalities to image midfacial fractures, and discuss the rationale for selection of those procedures that offer the greatest diagnostic information.

Reliability and accuracy of cone-beam computed tomography voxel density and linear distance measurement at different voxel sizes: A study on sheep head cadaver

Background/purpose

The reliability and accuracy of linear distance and voxel density (VD) measurements are very important in dentistry. The purpose of this study was to assess the accuracy and reliability of linear distances and VD measurements of cone-beam computed tomography (CBCT) at different voxel sizes.

Materials and methods

Eighteen-millimeter linears of size 40 gutta-percha were prepared in fresh sheep head. The head was scanned using CBCT with 0.25, 0.3, and 0.40 voxel sizes. Standard linear distances of gutta-percha were measured in panoramic CBCT images at 0.25, 0.3, and 0.4 voxel sizes. VD measurements were made separately on spongeous bone of palatal surfaces of the roots of teeth 4, 5, and 6 of maxilla and on cortical bone of teeth 4, 5, and 6 regions of the left and right hemimandibles through cross-sectional imaging.

Results

We found that linear distance measurements on panoramic image of CBCT were slightly lower than physical measurements. A significant difference was not found for the gutta-percha linear distances and cortical VD measurements at different voxel sizes (P ≥ 0.05). The correlation between measurements of VD at different voxels in cortical bone was greater than 0.85 (P = 0.000).

Conclusion

Linear distance measurements on the sheep head cadaver of 0.25, 0.3, and 0.4 voxel sizes were similar and reliable when compared with physical measurements. In minimizing radiation exposure, VD measurement of cortical bone at 0.4 voxel-based CBCT could be used to estimate cortical bone density. However, studies should be performed on the human head cadaver.

Delayed diagnosis in the maxillofacial region: Two case reports

While conventional CT scan has historically been used for maxillofacial bone imaging. The introduction of cone beam CT (CBCT) in the new millennium has revolutionized the use of CT for dental and maxillofacial diagnoses. This paper presents two clinical examples of delayed diagnoses associated with maxillofacial imaging, describes the reasons for the delays and offers potential preventive measures. The first case involves a delay in the diagnosis of non-Hodgkin's lymphoma in a 49-year-old female who was being treated for an odontogenic problem. In the second case, a 9-year-old female who presented with a limited ability to open her mouth was mistakenly diagnosed with muscles spasm. Subsequently, she was found to have an elongation of the right lateral pterygoid plate that interfered with her right mandibular body, which restricted the degree to which she could open her mouth. A thorough clinical examination and accurate radiographic interpretation combined with a complete medical history can minimize these types of diagnostic delays. If the dentist is unable to conclusively reach a diagnosis, the patient should be referred immediately to a specialist who can better manage the specific medical problem.

Cone-beam volumetric imaging in craniofacial medicine

With the development of X-ray computed tomography (CT) in the 1960s and its first use for clinical studies in 1972 by Sir Godfrey Hounsfield, radiological tomography attained widespread use and today is one of the essential imaging techniques in medical radiology. It is a technically mature and clinically widely accepted method and complements classical X-ray panoramic radiography in many areas. The technology is frequently used in craniofacial radiology, because of its characteristic low radiation dose, high spatial resolution and lower cost compared with CT. The aim of this work was to describe the principles of cone beam computed tomography, to make a brief description of the existing devices, to present briefly the use of 3D diagnosis in craniofacial medicine.

CT sinus and facial bones reporting by radiographers: findings of an accredited postgraduate programme

OBJECTIVES

The aim of this study was to compare the observer performance of a cohort of radiographers in reporting CT sinus and facial bone investigations against a reference standard and alternative comparator of summary data from peer-reviewed literature.

METHODS

The participants (n = 6) completed a 9-month part-time distance learning training programme prior to reporting an examination bank (n = 25 cases) from a retrospectively collected and anonymized digital imaging and communications in medicine archive of CT examinations with referral histories and clinical reports. A literature search was performed to identify an additional alternative comparison reference standard from studies reporting observer performance data in CT sinus and facial bone investigations of both trauma and sinus pathology (target conditions). The data analyses used to measure observer performance and determine differences between the cohort and the reference standards used statistical assessment models including accuracy, sensitivity, specificity, kappa (κ) and summary receiver-operating characteristic curves with estimated area under the curve (AUC).

RESULTS

The cohort of radiographer sensitivity was 97.5%, specificity 93.6% and accuracy 95%, with p < 0.000, and a κ = 0.9121 score of agreement. The mean radiographer AUC was 0.9822. The summary reported data of the alternative literature reference standard comparator were AUC 0.9533 for sinus and 0.9374 for trauma.

CONCLUSIONS

The results suggest that this cohort of radiographers at the end of a period training in CT sinus and facial bones are able to clinically report comparably high standards.

Trends in maxillofacial imaging

Maxillofacial imaging encompasses radiology of the teeth and jaws, including the temporomandibular joints. Modalities used include intra-oral radiographs, panoramic tomography, cephalograms, cone-beam computed tomography, computed tomography, magnetic resonance imaging, ultrasound, and radionuclide imaging. Common indications for imaging are impacted and supernumerary teeth, dental implants, inflammatory dental disease, and fibro-osseous lesions, cysts, and masses of the jaws. Osteonecrosis of the jaws may follow radiotherapy or the use of bisphosphonates and other drugs. Imaging of the temporomandibular joints and the potential role of imaging in obstructive sleep apnoea are also discussed.

The effect of ameloblastoma and keratocystic odontogenic tumor on the displacement pattern of inferior alveolar canal in CBCT examinations

Background. The inferior alveolar canal should be examined as a significant anatomical landmark, particularly in the posterior body and ramus of the mandible, for dental and surgical procedures. In the present study, the effects of two pathological lesions, ameloblastoma and keratocystic odontogenic tumor, on canal displacement were investigated.

Methods. This study had a single-blinded design. Twenty-six patients with lesions in the mandible referred to Imam Reza Hospital, Tabriz, Iran, were studied in two equal groups (13 patients with a histopathological diagnosis of ameloblastoma and 13 with a histopathological diagnosis of odontogenic keratocyst). After confirming the initial incisional biopsy and pathological report, cone beam computed tomography (CBCT) of lesions larger than 3 cm mesiodistaly and those involving the mandibular posterior body and ramus were included in the study. Two maxillofacial surgeons in association with an oral and maxillofacial radiologist examined three points on CBCT images to determine the mandibular canal position relative to the lesions from the lingual and buccal aspects.

Results. The results of statistical analyses showed that in ameloblastoma, the inferior alveolar canal had been displaced more buccally in the ramus area (point A) (84.6%) but in the distal region (point C), the displacement was less buccal (41.6%). The canal was displaced buccally in 53.8% of cases at point A and in 46.2% of cases at point C in KOT lesions. Finally chi-squared test did not show any statistically significant differences between these two lesions.

Conclusion. The results of this study showed no relationship between these lesions and the displacement of the mandibular canal.