CT and MR anatomy of the larynx and hypopharynx.

Imaging of the larynx and hypopharynx is frequently requested to assess the extent of neoplasms beyond the field of view of endoscopic evaluation. The combination of optical and cross-sectional imaging allows tumors to be classified according to AJCC/UICC guidelines. A thorough understanding of laryngeal and hypopharyngeal anatomy is crucial to guide the radiological eye along the possible pathways of the spread of diseases and to guide differential diagnoses. Computed tomography (CT) has been the first cross-sectional imaging technique used to evaluate the larynx and hypopharynx; its spatial resolution combined with volumetric capability and the use of injectable contrast medium made CT the working horse in the assessment of neoplastic and inflammatory diseases. In the last two decades, magnetic resonance (MR) supported CT in the most challenging cases, when the optimal contrast resolution due to the multisequence portfolio is needed to assess the neoplastic involvement of laryngeal cartilages, paraglottic space(s), and extra laryngeal spread. The aim of this paper is to give a comprehensive radiological overview of larynx and hypopharynx complex anatomy, combining in vivo images, anatomical sections, and images of ex vivo specimens.

Computer-aided designed 3D-printed polymeric scaffolds for personalized reconstruction of maxillary and mandibular defects: a proof-of-concept study.

PURPOSE: To investigate the potential reconstruction of complex maxillofacial defects using computer-aided design 3D-printed polymeric scaffolds by defining the production process, simulating the surgical procedure, and explore the feasibility and reproducibility of the whole algorithm. METHODS: This a preclinical study to investigate feasibility, reproducibility and efficacy of the reconstruction algorithm proposed. It encompassed 3 phases: (1) scaffold production (CAD and 3D-printing in polylactic acid); (2) surgical simulation on cadaver heads (navigation-guided osteotomies and scaffold fixation); (3) assessment of reconstruction (bone and occlusal morphological conformance, symmetry, and mechanical stress tests). RESULTS: Six cadaver heads were dissected. Six types of defects (3 mandibular and 3 maxillary) with different degree of complexity were tested. In all case the reconstruction algorithm could be successfully completed. Bone morphological conformance was optimal while the occlusal one was slightly higher. Mechanical stress tests were good (mean value, 318.6 and 286.4 N for maxillary and mandibular defects, respectively). CONCLUSIONS: Our reconstructive algorithm was feasible and reproducible in a preclinical setting. Functional and aesthetic outcomes were satisfactory independently of the complexity of the defect.

Microsurgical transcranial approaches to the posterior surface of petrosal portion of the temporal bone: quantitative analysis of surgical volumes and exposed areas.

Different microsurgical transcranial approaches (MTAs) have been described to expose the posterior surface of the petrous bone (PPB). A quantitative, anatomical comparison of the most used MTAs, for specific areas of the PPB, is not available. Anatomical dissections were performed on five formalin-fixed, latex-injected cadaver heads (10 sides). Six MTAs were analyzed: Kawase approach (KWA), retrosigmoid approach (RSA), retrosigmoid approach with suprameatal extension (RSAS), retrolabyrinthine approach (RLA), translabyrinthine approach (TLA), and transcochlear approach (TCA). Surgical volumes and exposed areas of each approach were quantified with a dedicated neuronavigation system (ApproachViewer, part of GTx-Eyes II, University Health Network, Toronto, Canada) and adjuvant software (ITK-SNAP and Autodesk Meshmixer 3.5). Areas and volumes were compared using linear mixed models. TCA provided the best exposure of Trautmann's triangle and the retromeatal, suprameatal, meatal, and premeatal regions. RSAs provided the best exposure of the inframeatal region, with RSAS gaining significant exposure of the suprameatal region. KWA had the highest surgical volume, and RLA the lowest. Transpetrosal approaches offer the widest exposure of PPB proportionally to their invasiveness. Retrosigmoid approaches, which get to the studied region through a postero-lateral path, are paramount for the exposure of the inframeatal and suprameatal region and, given the adequate exposure of the remaining PPB, represent an effective approach for the cerebellopontine angle (CPA). These anatomical findings must be considered with approach-related morbidity and the pathological features in order to choose the most appropriate approach in clinical practice.

AI-Based Automated Lipomatous Tumor Segmentation in MR Images: Ensemble Solution to Heterogeneous Data.

Deep learning (DL) has been proposed to automate image segmentation and provide accuracy, consistency, and efficiency. Accurate segmentation of lipomatous tumors (LTs) is critical for correct tumor radiomics analysis and localization. The major challenge of this task is data heterogeneity, including tumor morphological characteristics and multicenter scanning protocols. To mitigate the issue, we aimed to develop a DL-based Super Learner (SL) ensemble framework with different data correction and normalization methods. Pathologically proven LTs on pre-operative T1-weighted/proton-density MR images of 185 patients were manually segmented. The LTs were categorized by tumor locations as distal upper limb (DUL), distal lower limb (DLL), proximal upper limb (PUL), proximal lower limb (PLL), or Trunk (T) and grouped by 80%/9%/11% for training, validation and testing. Six configurations of correction/normalization were applied to data for fivefold-cross-validation trainings, resulting in 30 base learners (BLs). A SL was obtained from the BLs by optimizing SL weights. The performance was evaluated by dice-similarity-coefficient (DSC), sensitivity, specificity, and Hausdorff distance (HD95). For predictions of the BLs, the average DSC, sensitivity, and specificity from the testing data were 0.72 [Formula: see text] 0.16, 0.73 [Formula: see text] 0.168, and 0.99 [Formula: see text] 0.012, respectively, while for SL predictions were 0.80 [Formula: see text] 0.184, 0.78 [Formula: see text] 0.193, and 1.00 [Formula: see text] 0.010. The average HD95 of the BLs were 11.5 (DUL), 23.2 (DLL), 25.9 (PUL), 32.1 (PLL), and 47.9 (T) mm, whereas of SL were 1.7, 8.4, 15.9, 2.2, and 36.6 mm, respectively. The proposed method could improve the segmentation accuracy and mitigate the performance instability and data heterogeneity aiding the differential diagnosis of LTs in real clinical situations.

Chest X-ray versus chest computed tomography for outcome prediction in hospitalized patients with COVID-19.

The purpose of this study was to compare the prognostic value of chest X-ray (CXR) and chest computed tomography (CT) in a group of hospitalized patients with COVID-19. For this study, we retrospectively selected a cohort of 106 hospitalized patients with COVID-19 who underwent both CXR and chest CT at admission. For each patient, the pulmonary involvement was ranked by applying the Brixia score for CXR and the percentage of well-aerated lung (WAL) for CT. The Brixia score was assigned at admission (A-Brixia score) and during hospitalization. During hospitalization, only the highest score (H-Brixia score) was considered. At admission, the percentage of WAL (A-CT%WAL) was quantified using a dedicated software. On logistic regression analyses, H-Brixia score was the most effective radiological marker for predicting in-hospital mortality and invasive mechanical ventilation. Additionally, A-CT%WAL did not provide substantial advantages in the risk stratification of hospitalized patients with COVID-19 compared to A-Brixia score.

An approach to evaluate the quality of radiological reports in Head and Neck cancer loco-regional staging: experience of two Academic Hospitals.

OBJECTIVES: To evaluate the quality of the reports of loco-regional staging computed tomography (CT) or magnetic resonance imaging (MRI) in head and neck (H&N) cancer. METHODS: Consecutive reports of staging CT and MRI of all H&N cancer cases from 2018 to 2020 were collected. We created lists of quality indicators for tumor (T) for each district and for node (N). We marked these as 0 or 1 in the report calculating a report score (RS) and a maximum sum (MS) of each list. Two radiologists and two otolaryngologists in consensus classified reports as low quality (LQ) if the RS fell in the percentage range 0-59% of MS and as high quality (HQ) if it fell in the range 60-100%, annotating technique and district. We evaluated the distribution of reports in these categories. RESULTS: Two hundred thirty-seven reports (97 CT and 140 MRI) of 95 oral cavity, 52 laryngeal, 47 oropharyngeal, 19 hypo-pharyngeal, 14 parotid, and 10 nasopharyngeal cancers were included. Sixty-six percent of all the reports were LQ for T, 66% out of all the MRI reports, and 65% out of all CT reports were LQ. Eight-five percent of reports were HQ for N, 85% out of all the MRI reports, and 82% out of all CT reports were HQ. Reports of oral cavity, oro-nasopharynx, and parotid were LQ, respectively, in 76%, 73%, 100% and 92 out of cases. CONCLUSION: Reports of staging CT/MRI in H&N cancer were LQ for T description and HQ for N description.

Which role for chest x-ray score in predicting the outcome in COVID-19 pneumonia?

OBJECTIVE: We aim to demonstrate that a chest X-ray (CXR) scoring system for COVID-19 patients correlates with patient outcome and has a prognostic value. METHODS: This retrospective study included CXRs of COVID-19 patients that reported the Brixia score, a semi-quantitative scoring system rating lung involvement from 0 to 18. The highest (H) and lowest (L) values were registered along with scores on admission (A) and end of hospitalization (E). The Brixia score was correlated with the outcome (death or discharge). RESULTS: A total of 953 patients met inclusion criteria. In total, 677/953 were discharged and 276/953 died during hospitalization. A total of 524/953 had one CXR and 429/953 had more than one CXR. H-score was significantly higher in deceased (median, 12; IQR 9-14) compared to that in discharged patients (median, 8; IQR 5-11) (p < 0.0001). In 429/953 patients with multiple CXR, A-score, L-score, and E-score were higher in deceased than in discharged patients (A-score 9 vs 8; p = 0.039; L-score 7 vs 5; p < 0.0003; E-score 12 vs 7; p < 0.0001). In the entire cohort, logistic regression showed a significant predictive value for age (p < 0.0001, OR 1.13), H-score (p < 0.0001, OR 1.25), and gender (p = 0.01, male OR 1.67). AUC was 0.863. In patients with ≥ 2 CXR, A-, L-, and E-scores correlated significantly with the outcome. Cox proportional hazards regression indicated age (p < 0.0001, HR 4.17), H-score (< 9, HR 0.36, p = 0.0012), and worsening of H-score vs A score > 3 (HR 1.57, p = 0.0227) as associated with worse outcome. CONCLUSIONS: The Brixia score correlates strongly with disease severity and outcome; it may support the clinical decision-making, particularly in patients with moderate-to-severe signs and symptoms. The Brixia score should be incorporated in a prognostic model, which would be desirable, particularly in resource-constraint scenarios. KEY POINTS: • To demonstrate the importance of the Brixia score in assessing and monitoring COVID-19 lung involvement. • The Brixia score strongly correlates with patient outcome and can be easily implemented in the routine reporting of CXR.

Skull base osteomyelitis: clinical and radiologic analysis of a rare and multifaceted pathological entity.

Skull base osteomyelitis (SBO) is a potentially life-threatening inflammation of cranial base bony structures of variable origin. Criteria for diagnosis and treatment are still controversial. Demographics, predisposing factors, symptoms, imaging, and clinical, laboratory, histological, and microbiological data of patients managed for SBO at the University Hospital of Brescia (ASST Spedali Civili) between 2002 and 2017 were retrospectively reviewed. Patients were included in different etiological groups. The topographic distribution of magnetic resonance (MR) abnormalities was recorded on a bi-dimensional model of skull base, on which three different patterns of inflammatory changes (edematous, solid, or necrotic) were reported. In patients with a history of radiotherapy, the spatial distribution of SBO was compared with irradiation fields. The association between variables and etiological groups was verified with appropriate statistical tests. A classification tree analysis was performed with the aim of inferring a clinical-radiological diagnostic algorithm for SBO. The study included 47 patients, divided into 5 etiological groups: otogenic (n = 5), radio-induced (n = 16), fungal (n = 14), immune-mediated (n = 6), and idiopathic (n = 6). At MR, five types of topographical distribution were identified (central symmetric, central asymmetric, orbital apex, sinonasal, maxillary). In patients with a history of radiotherapy, the probability to develop SBO was significantly increased in areas receiving the highest radiation dosage. The analysis of patients allowed for design of a classification tree for the diagnosis of SBO. The integration of clinical and radiologic information is an efficient strategy to categorize SBO and potentially guide its complex management.

Characteristics and outcomes of patients hospitalized for COVID-19 and cardiac disease in Northern Italy.

AIMS: To compare demographic characteristics, clinical presentation, and outcomes of patients with and without concomitant cardiac disease, hospitalized for COVID-19 in Brescia, Lombardy, Italy. METHODS AND RESULTS: The study population includes 99 consecutive patients with COVID-19 pneumonia admitted to our hospital between 4 March and 25 March 2020. Fifty-three patients with a history of cardiac disease were compared with 46 without cardiac disease. Among cardiac patients, 40% had a history of heart failure, 36% had atrial fibrillation, and 30% had coronary artery disease. Mean age was 67 ± 12 years, and 80 (81%) patients were males. No differences were found between cardiac and non-cardiac patients except for higher values of serum creatinine, N-terminal probrain natriuretic peptide, and high sensitivity troponin T in cardiac patients. During hospitalization, 26% patients died, 15% developed thrombo-embolic events, 19% had acute respiratory distress syndrome, and 6% had septic shock. Mortality was higher in patients with cardiac disease compared with the others (36% vs. 15%, log-rank P = 0.019; relative risk 2.35; 95% confidence interval 1.08-5.09). The rate of thrombo-embolic events and septic shock during the hospitalization was also higher in cardiac patients (23% vs. 6% and 11% vs. 0%, respectively). CONCLUSIONS: Hospitalized patients with concomitant cardiac disease and COVID-19 have an extremely poor prognosis compared with subjects without a history of cardiac disease, with higher mortality, thrombo-embolic events, and septic shock rates.

CT texture analysis for prediction of EGFR mutational status and ALK rearrangement in patients with non-small cell lung cancer.

PURPOSE: To develop a CT texture-based model able to predict epidermal growth factor receptor (EGFR)-mutated, anaplastic lymphoma kinase (ALK)-rearranged lung adenocarcinomas and distinguish them from wild-type tumors on pre-treatment CT scans. MATERIALS AND METHODS: Texture analysis was performed using proprietary software TexRAD (TexRAD Ltd, Cambridge, UK) on pre-treatment contrast-enhanced CT scans of 84 patients with metastatic primary lung adenocarcinoma. Textural features were quantified using the filtration-histogram approach with different spatial scale filters on a single 5-mm-thick central slice considered representative of the whole tumor. In order to deal with class imbalance regarding mutational status percentages in our population, the dataset was optimized using the synthetic minority over-sampling technique (SMOTE) and correlations with textural features were investigated using a generalized boosted regression model (GBM) with a nested cross-validation approach (performance averaged over 1000 resampling episodes). RESULTS: ALK rearrangements, EGFR mutations and wild-type tumors were observed in 19, 28 and 37 patients, respectively, in the original dataset. The balanced dataset was composed of 171 observations. Among the 29 original texture variables, 17 were employed for model building. Skewness on unfiltered images and on fine texture was the most important features. EGFR-mutated tumors showed the highest skewness while ALK-rearranged tumors had the lowest values with wild-type tumors showing intermediate values. The average accuracy of the model calculated on the independent nested validation set was 81.76% (95% CI 81.45-82.06). CONCLUSION: Texture analysis, in particular skewness values, could be promising for noninvasive characterization of lung adenocarcinoma with respect to EGFR and ALK mutations.

Qualitative evaluation of MRI features of lipoma and atypical lipomatous tumor: results from a multicenter study.

OBJECTIVES: The objectives of the study are (1) to distinguish lipoma (L) from atypical lipomatous tumor (ALT) using MRI qualitative features, (2) to assess the value of contrast enhancement, and (3) to evaluate the reproducibility and confidence level of radiological readings. MATERIALS AND METHODS: Patients with pathologically proven L or ALT, who underwent MRI within 3 months from surgical excision were included in this retrospective multicenter international study. Two radiologists independently reviewed MRI centrally. Impressions were recorded as L or ALT. A third radiologist was consulted for discordant readings. The two radiologists re-read all non-contrast sequences; impression was recorded; then post-contrast images were reviewed and any changes were recorded. RESULTS: A total of 246 patients (135 females; median age, 59 years) were included. ALT was histopathologically confirmed in 70/246 patients. In multivariable analysis, in addition to the lesion size, deep location, proximal lower limb lesions, demonstrating incomplete fat suppression, or increased architectural complexity were the independent predictive features of ALT; but not the contrast enhancement. Post-contrast MRI changed the impression in a total of 5 studies (3 for R1 and 4 for R2; 2 studies are common); all of them were incorrectly changed from Ls to ALTs. Overall, inter-reader kappa agreement was 0.42 (95% CI 0.39-0.56). Discordance between the two readers was statistically significant for both pathologically proven L (p < 0.001) and ALT (p = 0.003). CONCLUSION: Most qualitative MR imaging features can help distinguish ALTs from BLs. However, contrast enhancement may be limited and occasionally misleading. Substantial discordance on MRI readings exists between radiologists with a relatively high false positive and negative rates.

Quantitative anatomical comparison of transnasal and transcranial approaches to the clivus.

BACKGROUND AND OBJECTIVE: The clivus was defined as "no man's land" in the early 1990s, but since then, multiple approaches have been described to access it. This study is aimed at quantitatively comparing endoscopic transnasal and microsurgical transcranial approaches to the clivus in a preclinical setting, using a recently developed research method. METHODS: Multiple approaches were performed in 5 head and neck specimens that underwent high-resolution computed tomography (CT): endoscopic transnasal (transclival, with hypophysiopexy and with far-medial extension), microsurgical anterolateral (supraorbital, mini-pterional, pterional, pterional transzygomatic, fronto-temporal-orbito-zygomatic), lateral (subtemporal and subtemporal transzygomatic), and posterolateral (retrosigmoid, far-lateral, retrolabyrinthine, translabyrinthine, and transcochlear). An optic neuronavigation system and dedicated software were used to quantify the working volume of each approach and calculate the exposure of different clival regions. Mixed linear models with random intersections were used for statistical analyses. RESULTS: Endoscopic transnasal approaches showed higher working volume and larger exposure compared with microsurgical transcranial approaches. Increased exposure of the upper clivus was achieved by the transnasal endoscopic transclival approach with intradural hypophysiopexy. Anterolateral microsurgical transcranial approaches provided a direct route to the anterior surface of the posterior clinoid process. The transnasal endoscopic approach with far-medial extension ensured a statistically larger exposure of jugular tubercles as compared with other approaches. Presigmoid approaches provided a relatively limited exposure of the ipsilateral clivus, which increased in proportion to their invasiveness. CONCLUSIONS: This is the first anatomical study that quantitatively compares in a holistic way exposure and working volumes offered by the most used modern approaches to the clivus.

COVID-19 outbreak in Italy: experimental chest X-ray scoring system for quantifying and monitoring disease progression.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a new virus recently isolated from humans. SARS-CoV-2 was discovered to be the pathogen responsible for a cluster of pneumonia cases associated with severe respiratory disease that occurred in December 2019 in China. This novel pulmonary infection, formally called Coronavirus Disease 2019 (COVID-19), has spread rapidly in China and beyond. On 8 March 2020, the number of Italians with SARS-CoV-2 infection was 7375 with a 48% hospitalization rate. At present, chest-computed tomography imaging is considered the most effective method for the detection of lung abnormalities in early-stage disease and quantitative assessment of severity and progression of COVID-19 pneumonia. Although chest X-ray (CXR) is considered not sensitive for the detection of pulmonary involvement in the early stage of the disease, we believe that, in the current emergency setting, CXR can be a useful diagnostic tool for monitoring the rapid progression of lung abnormalities in infected patients, particularly in intensive care units. In this short communication, we present our experimental CXR scoring system that we are applying to hospitalized patients with COVID-19 pneumonia to quantify and monitor the severity and progression of this new infectious disease. We also present the results of our preliminary validation study on a sample of 100 hospitalized patients with SARS-CoV-2 infection for whom the final outcome (recovery or death) was available.

Radiographic severity index in COVID-19 pneumonia: relationship to age and sex in 783 Italian patients.

PURPOSE: To improve the risk stratification of patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an experimental chest X-ray (CXR) scoring system for quantifying lung abnormalities was introduced in our Diagnostic Imaging Department. The purpose of this study was to retrospectively evaluate correlations between the CXR score and the age or sex of Italian patients infected with SARS-CoV-2. MATERIALS AND METHODS: Between March 4, 2020, and March 18, 2020, all CXR reports containing the new scoring system were retrieved. Only hospitalized patients with SARS-CoV-2 infection were enrolled. For each patient, age, sex, and the CXR report containing the highest score were considered for the analysis. Patients were also divided into seven groups according to age. Nonparametric statistical tests were used to examine the relationship between the severity of lung disease and the age or sex. RESULTS: 783 Italian patients (532 males and 251 females) with SARS-CoV-2 infection were enrolled. The CXR score was significantly higher in males than in females only in groups aged 50 to 79 years. A significant correlation was observed between the CXR score and age in both males and females. Males aged 50 years or older and females aged 80 years or older with coronavirus disease 2019 showed the highest CXR score (median ≥ 8). CONCLUSIONS: Males aged 50 years or older and females aged 80 years or older showed the highest risk of developing severe lung disease. Our results may help to identify the highest-risk patients and those who require specific treatment strategies.

Non-typhoidal Salmonella aortitis.

Non-typhoidal Salmonella (NTS) spp. causes about 40% of all infective aortitis and it is characterized by high morbidity and mortality. Human infection occurs by fecal-oral transmission through ingestion of contaminated food, milk, or water (inter-human or zoonotic transmission). Approximately 5% of patients with NTS gastroenteritis develop bacteremia and the incidence of extra-intestinal focal infection in NTS bacteremia is about 40%. The organism can reach an extra-intestinal focus through blood dissemination, direct extension from the surrounding organs and direct bacterial inoculation (e.g. invasive medical procedures). Medical and surgical interventions are both needed to successfully control the infection. Here, we report a case of abdominal sub-renal aortitis caused by Salmonella enterica serovar Enteritidis in an 80-year-old man.

Texture features of colorectal liver metastases on pretreatment contrast-enhanced CT may predict response and prognosis in patients treated with bevacizumab-containing chemotherapy: a pilot study including comparison with standard chemotherapy.

PURPOSE: Bevacizumab added to chemotherapy can improve survival in patients with metastatic colorectal cancer, but no predictive factors of efficacy are available in clinical practice. The aim of this study is to assess the predictive and prognostic value of texture analysis on pretreatment contrast-enhanced CT in patients affected by colorectal liver metastases. MATERIALS AND METHODS: Forty-three patients with colorectal liver metastases were retrospectively included in the study: 23 treated with bevacizumab-containing chemotherapy (group A), and 20 with standard chemotherapy (group B). Target liver lesions were analyzed by texture analysis of pretreatment contrast-enhanced CT. Texture analysis produced the parameter uniformity, describing lesion heterogeneity. Radiological response was classified after 3 months according to RECIST-1.1. Overall survival (OS) and progression-free survival (PFS) were considered to be outcome indicators. Multivariable logistic regression and survival analysis were performed. RESULTS: Uniformity was lower in responders than in nonresponders (p < 0.001) in group A but not in group B. Lesion CT density was lower in nonresponders in both groups (p = 0.03 and 0.02, respectively). In group A, uniformity was independently correlated with radiological response (odds ratio = 20, p = 0.01), OS and PFS (relative risks 6.94 and 5.05, respectively; p = 0.005 and p = 0.004, respectively). In group B, no variables were correlated with radiological response, OS or PFS. CONCLUSION: Texture analysis on contrast-enhanced CT stratified response probability and prognosis in patients with colorectal liver metastases treated with bevacizumab-containing therapy. This result was specific for the bevacizumab group.

Three-rooted maxillary first premolars incidentally detected on cone beam CT: an in vivo study.

PURPOSE: To explore the incidence and analyze the morphology of three-rooted maxillary first premolars (MFPs) incidentally detected on cone beam computed tomography (CBCT) scans. METHODS: Of 1328 patients who underwent CBCT scans of the maxilla, only patients with three-rooted MFPs were selected. Morphological features, including the lengths and diameters of palatal, mesiobuccal (MB) and distobuccal (DB) roots, the positions of bucco-palatal (B-P) bifurcations, the distances between root canal bifurcations and cementoenamel junctions (CEJs) and the distances between the apical thirds of the roots, were measured. The canal configuration and the visibility of root canals were also evaluated. RESULTS: A total of 16/1328 (1.2%) patients had one or two three-rooted MFPs, and a total of 22/2656 (0.8%) three-rooted MFPs were enrolled. The lengths and diameters of palatal roots were significantly greater than those of other roots. The positions of B-P bifurcations were located mainly at the middle third of the root. The median distances between root canal bifurcations and CEJs were 3 mm for B-P bifurcations and 5.2 mm for MB-DB bifurcations. The distance between MB and DB roots was significantly shorter than the distances between other root pairs. All teeth had a type VIII canal configuration. Palatal roots exhibited the best visibility of root canals, whereas the worst visibility was observed within DB roots. A gender-related relationship was observed only for the lengths of the roots. CONCLUSIONS: The occurrence of three-rooted MFPs is not unusual; therefore, preoperative CBCT evaluation could be suggested whenever endodontic procedures are planned on an MFP.

Five mental foramina in the same mandible: CBCT findings of an unusual anatomical variant.

The mental foramen is an important anatomic landmark located on the buccal aspect of the mandible, typically near the apex of the second premolar. Mental foramina exhibit many anatomical variations, including differences in size, shape, position, and number. The most frequent type of variation in number is the presence of double mental foramen, which has a reported incidence ranging from 1.4 to 12.5%. The incidence of triple mental foramen ranges from 0.7 to 1.2%. The frequency of accessory mental foramina varies among ethnic groups, with a low incidence in white Caucasian populations. At present, cone beam computed tomography (CBCT) is the diagnostic tool of choice for examining the maxillofacial region, and the high spatial resolution of CBCT allows accurate three-dimensional analysis of mental foramen variations. The present report describes an unusual case of five mental foramina in a 24-year-old white European male diagnosed by CBCT.