Imaging of maxillofacial trauma: Evolutions and emerging revolutions

Evaluation of calcium hydroxide root canal filling materials by cone beam computed tomography and three-dimensional modeling

AIM

The aim of this study was to compare the effectiveness of filling pastes in resin prototype primary molars by cone beam computed tomography (CBCT) and 3D modeling.

The Application of Cone Beam Computed Tomography (CBCT) on the Diagnosis and Management of Maxillofacial Trauma

The assessment and management of facial trauma in an acute setting is one of the core services provided by oral and maxillofacial units in the United Kingdom. Imaging is a pre-requisite for appropriate diagnosis and treatment planning, with a combination of plain radiographs and medical-grade CT being the mainstay. However, the emergence of cone beam CT in recent years has led to its wider applications, including facial trauma assessment. It can offer multi-planar reformats and three-dimensional reconstruction at a much lower radiation dose and financial cost than conventional CT. The purpose of this review is to appraise its potential indications in all anatomical areas of maxillofacial trauma and provide our experience at a level 1 trauma centre.

The role of implants and implant prostheses on the accuracy and artifacts of cone-beam computed tomography: an in-vitro study

To assess the accuracy of CBCT in implant-supported prostheses and to evaluate metal artifacts with and without implants or implant prostheses. Accuracy and artifacts were assessed in the dried mandible at three points on the buccal and lingual cortical plates on the mandible's body near the crest and the base. On the buccal cortical plate, these points were labelled as A, B and C near the crest and D, E and F near the base of the body of the mandible. Similarly, points a to f were marked on the lingual cortical plate corresponding to points A to F. The study had two control groups, C0 for physical linear measurement (PLM) and C1 for radiographic linear measurement (RLM) and artifact assessment. There were seven test groups, TG 1 to 7, progressing from a single implant to implant full-arch prosthesis. For accuracy assessment, PLM was compared to RLM. CBCT artifacts were investigated in images integrated at 0.25 mm, 10 mm, and 20 mm at regions of interest on concentric circles at different intersecting angles by comparing grayscale values at C1 and TG1 to 7. The data were collected and statistically analyzed. A significant difference was observed between C0 and C1, and RLM in test groups at the superior axial plane. Similarly, PLM and test RLM in the sagittal plane at A-B, B-C, and D-E were statistically significant. A significant difference between PLM and RLM was also observed in the vertical plane at A-D, B-E, and C-F. Quantification of CBCT artifacts in the presence of implants or prostheses revealed that full-arch prostheses had the highest mean grayscale value, whereas single implants with a prosthesis had the lowest. The mean grayscale change was greatest around the implant and implant prosthesis. The mean grayscale value was maximum at 20 mm voxel integration scales (VIS) and lowest at 0.25 mm. CBCT is a clinically reliable device. Metal in implants or implant-supported prostheses prevents true assessment of the peri-implant area; therefore, lower VIS is suggested in the presence of implants or implant prostheses.

A review on artificial intelligence for the diagnosis of fractures in facial trauma imaging

Patients with facial trauma may suffer from injuries such as broken bones, bleeding, swelling, bruising, lacerations, burns, and deformity in the face. Common causes of facial-bone fractures are the results of road accidents, violence, and sports injuries. Surgery is needed if the trauma patient would be deprived of normal functioning or subject to facial deformity based on findings from radiology. Although the image reading by radiologists is useful for evaluating suspected facial fractures, there are certain challenges in human-based diagnostics. Artificial intelligence (AI) is making a quantum leap in radiology, producing significant improvements of reports and workflows. Here, an updated literature review is presented on the impact of AI in facial trauma with a special reference to fracture detection in radiology. The purpose is to gain insights into the current development and demand for future research in facial trauma. This review also discusses limitations to be overcome and current important issues for investigation in order to make AI applications to the trauma more effective and realistic in practical settings. The publications selected for review were based on their clinical significance, journal metrics, and journal indexing.

Micro computed tomography (Micro-CT) characterization of root and root canal morphology of mandibular first premolars: a systematic review and meta-analysis

INTRODUCTION

Mandibular first premolars are familiar with their varied root canal morphology, causing difficulties and challenges for successful endodontic procedures. This systematic review and meta-analysis aim to study the characterization of root and canal morphology of the first mandibular premolar using micro-computed tomography.

METHODOLOGY

The literature search was conducted using electronic web databases like PubMed, Scopus, ScienceDirect and Cochrane with the chosen MeSH key words and data was retrieved until May 2023. Further to perform the statistical analysis, R v 4.3.1 software with "meta", 'metafor" "metaviz" " ggplot2" package was used, and results were represented by odds ratios (OR) and the percentage of forest plots along a 95 per cent confidence interval (CI).

RESULTS

The total number of studies meeting the inclusion criteria was 13; these studies were conducted on mandibular first premolar using Micro-CT; the total sample size was 1817. To scan the sample, an X-ray micro-focus CT system (Siemens Inveon CT, Erlangen, Germany) was used in four studies and seven different machines were used in the respective studies. Mimics 10.01 software (Materialize, Leuven, Belgium) and NRecon v.1.6.9 software (Bruker, Kontich, Belgium) were commonly operated. The minimum and maximum voxel size ranges between 11.94 and 50 μm. Vertucci's classification was frequently used (9), while one study applied Ahmed et al. and Vertucci's classification.

CONCLUSION

This systematic review provides essential information about the root and canal configurations, radicular grooves, accessory canals, and apical foramina through Micro-CT, aiming to improve the accuracy of endodontic treatment and help practitioners.

A Study to Evaluate the Efficacy of Ultrasonography as a Diagnostic Screening Tool in Maxillofacial Fractures: A Prospective Study

AIM

The aim of the study was to estimate the diagnostic efficacy of high-resolution ultrasonography (USG) in the diagnosis of maxillofacial fractures.

MATERIALS AND METHODS

A descriptive diagnostic evaluation study was carried out on 30 patients with suspected maxillofacial fractures, out of which 26 were male (86.7%) and 4 were female (13.3%). After initial management, detailed clinical examinations were carried out and significant findings were noted. Computed tomography (CT) scans were performed in fracture-suspecting patients followed by USG examination which was done in a standardized pattern on both sides of the face. The result of USG was compared with the CT scan report.

RESULT

Based on CT findings, 65 sites were found to be fractured, and this was considered the gold standard. Ultrasonography detected 58 fractures at these 780 sites, of which 54 were true fractures, while 4 were false-positive results. However, USG was not able to detect eleven fractures. The overall sensitivity and specificity of USG were 83.1% and 99%, respectively. The positive and negative predictive values were 93% and 98%, respectively.

CONCLUSION

According to our study, it may be concluded that USG may be recommended as a diagnostic screening tool to detect superficial maxillofacial fractures.

CLINICAL SIGNIFICANCE

Ultrasonography provides a safe, cost-effective, reliable, non-invasive, easily available, and portable imaging modality to screen for maxillofacial fractures.

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

Relationship between the condyle morphology and clinical findings in terms of gender, age, and remaining teeth on cone beam computed tomography images

Aim: This study aimed to evaluate the relationship between clinical findings and some factors such as age, gender, and remaining teeth on the anatomy of the temporomandibular joint in order to diagnose normal variations from abnormal cases. Methods: In this cross-sectional study, cone-beam computed tomography (CBCT) images of 144 patients referring to Tabriz Dental School for various reasons were selected and evaluated. The different aspects of the clinical parameters and the morphology of the condyle were evaluated on coronal, axial, and sagittal views. The CBCT prepared using the axial cross-sections had been 0.5 mm in thickness. The sagittal cross-sections had been evaluated perpendicular to the lengthy axis of the condyle at a thickness of 1 mm and the coronal cross-sections had been evaluated parallel to the lengthy axis of the condyle at a thickness of 1 mm. Data were analyzed with descriptive statistical methods and t-test, chi-squared test, using SPSS 20. The significance level of the study was p < 0.05. Results: There was a significant relationship between the condyle morphology, number of the teeth, and mastication side (p = 0.040). There were significant relationships between the condyle morphology, age between 20-40, and occlusion class I on the all the three views (coronal, axial, sagittal) (p = 0.04), (p = 0.006), (p = 0.006). Also, significant relationships were found in the condyle morphology and location of pain according to age, the number of remaining teeth, and gender. (p = 0.046) (p = 0.027) (p = 0.035). Conclusion: There are significant relationships between the clinical symptoms and condyle morphology based on age, gender, and the number of remaining teeth. The clinical finding that has the most significant relationship between the condyle morphology, remaining teeth (9-16 teeth), all of the age range (20-80 year), and gender was mastication side.

Head Computed Tomography Versus Maxillofacial Computed Tomography: An Evaluation of the Efficacy of Facial Imaging in the Detection of Facial Fractures

BACKGROUND

In an initial trauma evaluation, computed tomography of the head (CTH) is performed to assess for life-threatening intracranial injury. Given the high incidence of concomitant facial injuries, many facial fractures are diagnosed incidentally during this evaluation. Although maxillofacial CT (CTMF) is widely accepted as the most sensitive method for evaluating facial fractures, it is often excluded from the initial survey. Failure to obtain dedicated imaging can lead to increased costs related to a missed or delayed facial fracture diagnosis. Our study investigates the location and type of missed facial fractures on CTH by reviewing imaging data from patients who presented at a level 1 trauma center and underwent both CTH and CTMF.

METHODS

A retrospective review of all facial fractures diagnosed at a single institution from 2002 through 2016 was conducted. Inclusion criteria included adults aged 18 years or older who received CTH and then subsequent CTMF. Patients who had either CTH or CTMF only or combined CTH/CTMF were excluded. The facial fractures were further subdivided by location.

RESULTS

There were 501 patients with 1743 total facial fractures. CTH successfully identified 788 (45.21%) fractures, versus 1743 (100%) for CTMF. The most common fractures, in both cohorts, were nasal bone (15.7%) and orbital floor (12.8%) fractures. Using CTMF to identify missed fractures on CTH, significant differences were noted in the following locations: anterior table frontal sinus, medial/lateral pterygoid, maxillary sinus, lateral orbital wall, zygomatic arch, palate, and all types of mandible fractures excluding the mandibular condyle.

CONCLUSIONS

CTH for initial trauma evaluation often misses facial fractures. CTH alone was only sufficient in detecting posterior frontal sinus, orbital (excluding lateral wall), and mandibular condyle fractures. In patients with suspected facial injury, dedicated imaging should be performed to detect the location and extent of injury because CTH inadequately identifies most facial fractures.

ACR Appropriateness Criteria® Imaging of Facial Trauma Following Primary Survey

Maxillofacial trauma patients comprise a significant subset of patients presenting to emergency departments. Before evaluating for facial trauma, an emergency or trauma physician must perform a primary survey to ensure patient stabilization. Following this primary survey, this document discusses the following clinical scenarios for facial trauma: tenderness to palpation or contusion or edema over frontal bone (suspected frontal bone injury); pain with upper jaw manipulation or pain overlying zygoma or zygomatic deformity or facial elongation or malocclusion or infraorbital nerve paresthesia (suspected midface injury); visible nasal deformity or palpable nasal deformity or tenderness to palpation of the nose or epistaxis (suspected nasal bone injury); and trismus or malocclusion or gingival hemorrhage or mucosal hemorrhage or loose teeth or fractured teeth or displaced teeth (suspected mandibular injury). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

A comparative study on mandibular premolar root canal morphology employing cone-beam computed tomography and microcomputed tomography imaging

Aim:

The present study was to investigate the root canal morphology of mandibular premolars in Malaysian population using cone-beam computed tomography (CBCT) and microcomputed tomography (micro-CT) scanned images.

Materials and Methods:

Sixty selected mandibular premolars were evaluated in vitro and the root canal morphologies of the samples were categorized based on Vertucci's classification. The position of apical foramen, presence, and location of lateral canal, as well as prevalence of apical delta, were also determined.

Results:

Invariably, Type I variety (Vertucci's classification) was the most frequent root canal morphology followed by Type V and Type III after micro-CT imaging. CBCT investigation also revealed Type I as the most numerous; however, the second most common configuration was Type III followed closely by others. There was a moderate agreement in Vertucci's classification of root canal configuration and also prevalence of apical delta (kappa: 0.516 and 0.550, respectively). However, only a fair agreement (kappa: 0.289) was observed between CBCT and micro-CT on the prevalence of lateral canal.

Conclusion:

CBCT should be cautiously used in determining root canal configuration as deficiencies were evident and revealed during micro-CT imaging.

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.

Long-term evaluation of treatment protocols for isolated midfacial fractures in a German nation-wide craniomaxillofacial trauma center 2007-2017

An update on the trends in maxillofacial traumatology provides additional information on the actual and changing needs. This retrospective study aimed to review all patient records of patients treated for isolated midface fractures in the Department of Cranial- and Maxillofacial Surgery at the Dortmund General Hospital between 2007 and 2017. The patient radiographs and patient files were reviewed. The safety and efficacy of the applied methods were controlled by assessing complications based on the Clavien-Dindo classification system. The statistical analysis included descriptive methods including regression analysis and χ2-test. In eleven years, 3474 isolated midface fracture sites have been identified in 2868 patients. The yearly trend is slightly increasing, in elderly clearly worsening, in children and youth decreasing. The male-to-female ratio was 2.16:1 for the whole study population, in the age group 18-25 y.o. 6.95:1 while in elderly above 80 y.o. 1:2.51, the age group specific incidence reflects this result, too. The most common fractures were nasal bone fractures (1405), zygomatic fractures (832) and orbital floor fractures (700). The average hospital stay was 2.7 days, the most fractures were operated within 24 h. The complication rate was 2.02% (Clavien-Dindo class II-V). The incidence of midfacial fractures is increasing in the total population and especially in elderly, but decreasing in children. Development of injury prevention measures is needed in this population. The diagnostic and therapeutic procedures are appropriate, as there is a low complication rate and short inpatient stay observed.

The panoramic dental radiograph for emergency physicians

Dental emergencies are common reasons for presenting to hospital emergency departments. Here, we discuss the panoramic radiograph (orthopantomogram (OPG, OPT) as a diagnostic tool for the assessment of mandibular trauma and odontogenic infections. In this article, we review the radiographic principles of image acquisition, and how to conduct a systematic interpretation of represented maxillofacial anatomy. The aim is to equip the emergency physician with the skills to use the OPG radiograph when available, and to rapidly assess the image to expedite patient management. Included is a discussion of a number of cases seen in the emergency setting and some common errors in diagnosis.

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.

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.

"Radiological morphometric analysis of the zygomatic arch: Application of osteosynthesis on the upper arch border for rigid fixation"

BACKGROUND

This study was designed to introduce a novel method of applying osteosynthetic materials to the upper zygomatic arch border for fracture fixation through a temporal incision, and analyze the radiologic morphometric dimensions of the arch to verify its validity.

METHODS

Radiological morphometry was analyzed in 51 adult patients with unilateral isolated zygomatic arch fractures. Frequent fracture sites, sites of minimal thickness and height, and their correlation were evaluated, as were the locations and dimensions of fixation vantage points. The novel surgical method based on the results was implemented in 17 clinical cases.

RESULTS

Frequent fracture sites, occurring 4.40, 16.47 and 30.48 mm posterior to the arch origin, did not correlate to sites of minimal height and thickness. Arch minimal thickness and height locations were 12.23 and 27.09 mm behind its origin, respectively. Fixation vantage point dimensions varied from point to point, with upper thickness ranging from 1.67 to 4.86 mm and mid-portion thickness ranging from 2.06 to 7.36 mm, and height ranging from 8.99 to 22.53 mm. Arch vertical axis inclination ranged from 6.51° to 16.47°, which increased as the arch stretches posteriorly. These results suggested the use of 1.5 mm-wide plates and 1 mm-diameter screws with 6-8 mm length. Patients received surgery based on these morphometry results for satisfactory stabilization.

CONCLUSIONS

This study introduces a new method for open reduction and internal fixation of arch fractures, with morphometric analysis of the arch verifying the validity of tangential plate application to the upper border.

Endodontic Management of Mandibular Second Premolar with Type IX Canal Configuration Using Cone-Beam Computed Tomography as a Diagnostic Aid: A Rare Case Report

Successful endodontic treatment requires knowledge of the root canal anatomy, cleaning, and shaping followed by three-dimensional filling of the root canals. With the advent of newer diagnostic aids such as cone-beam computed tomography (CBCT) and magnifying tools such as dental operating microscope and loupes, it has become easier for an operator to identify the root canal anatomy of teeth and reduce the risk of procedural accidents and failures. Variations in root canal configuration require modification in access cavity preparation, disinfection, and obturation of the canals. Mandibular premolars are identified to have unusual root and canal anatomy which increases the risk of endodontic failure when additional canals remain undiagnosed. The present case report elaborates successful endodontic management of a mandibular second premolar with Type IX root canal configuration using CBCT as a diagnostic tool.

New and emerging patient-centered CT imaging and image-guided treatment paradigms for maxillofacial trauma

This article reviews the conceptual framework, available evidence, and practical considerations pertaining to nascent and emerging advances in patient-centered CT-imaging and CT-guided surgery for maxillofacial trauma. These include cinematic rendering-a novel method for advanced 3D visualization, incorporation of quantitative CT imaging into the assessment of orbital fractures, low-dose CT imaging protocols made possible with contemporary scanners and reconstruction techniques, the rapidly growing use of cone-beam CT, virtual fracture reduction with design software for surgical pre-planning, the use of 3D printing for fabricating models and implants, and new avenues in CT-guided computer-aided surgery.

A simple method to locate mandibular foramen with cone-beam computed tomography and its relevance to oral and maxillofacial surgery: a radio-anatomical study

PURPOSE

The mandibular foramen (MF) cannot be palpated clinically and its location is variable at the medial surface of mandibular ramus. Nevertheless, determining its exact location is very important to the oral and maxillofacial surgeon for the relevant anesthetic and surgical ramus procedures. The aim of this study was to analyze the position of MF using cone-beam computed tomography (CBCT) to help the surgeon in identifying reliable 'target area' for the inferior alveolar nerve (IAN) block and 'safety zone' for mandibular ramus osteotomies approached extra-orally.

MATERIALS AND METHODS

This radio-anatomical study examined all CBCT radiographs for patients treated over 2 years. Distances from MF to the anterior (A) and posterior (P) borders of the ramus, mandibular incisura (MI), mandibular notch (MN), and mandibular occlusal plane (O) were measured by a reliable examiner, followed by calculation of ratios to determine the horizontal and vertical position of MF. Patients' details were then recorded. Student's t test and One-Way-ANOVA test were used to analyze data.

RESULTS

A total of 210 CBCT radiographs were included and belonged to 210 subjects; 91 males (43.3%) and 119 (56.7%) females, with mean age (± SD) of 43.70 ± 19.08 years. The horizontal and vertical positions of MF differed significantly (P < 0.001) according to age, but generally calculated at least 40% of AP and MIMN distances from P and MI, respectively.

CONCLUSION

This study suggested the '40% rule' to locate the 'target area' for IAN block and 'safety zone' for ramus osteotomies approached extra-orally.

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.

A comparative study between traditional fixation with miniplates and modified lag screws for the treatment of mandibular fractures

OBJECTIVES

The objective of this study is to investigate two internal fixation surgical techniques for mandibular fractures in order to compare modified lag screw techniques with standard miniplates.

MATERIALS AND METHODS

This is an observational prospective study. Three hundred eighteen patients were operated on for mandibular fractures. The patients were divided into two groups according to the type of surgical technique used: modified lag screws (155 patients) and traditional miniplates (163 patients). Analyses were made of sociodemographic and preoperative variables, the parameters related to the fracture type and postoperative data.

RESULTS

There were no differences between the two groups regarding their sociodemographic characteristics. The modified lag screws were primarily used with double fractures, while conventional miniplates were more often used with simple fractures. The number of complications was higher with the miniplate technique. The unfavorable fractures had an OR of 5.75 due to postoperative complications; double fractures had an OR of 8.87 and simple fractures an OR of 19.53, which, in both cases, were lower with conventional miniplates than with modified lag screws.

CONCLUSION

Modified lag screws provide a rigid fixation system that is as secure as miniplates, but with greater compression between the fragments, less postsurgical gap, faster ossification, and fewer postoperative complications.

CLINICAL RELEVANCE

The modified screw technique is a safe tool that does not require any specific osteosynthesis materials not found in a basic traumatology kit and has a lower cost, due to the reduced amount of material used.

Association between demographic and radiographic characteristics of the schneiderian membrane and periapical and periodontal diseases using cone-beam computed tomography scanning: A retrospective study

Background. This study was undertaken to assess the pathological and spatial associations between periapical and periodontal diseases of the maxillary first molars and thickening of maxillary sinus mucosa with cone-beam computed tomography.

Methods. A total of 132 CBCT images of subjects 20‒60 years of age were evaluated retrospectively. The patients' sex and age and demographic and pathologic findings of the maxillary sinus in the first molar area were recorded, graded and analyzed.

Results. Approximately 59% of patients were male and 41% were female, with no significant difference in the thickness of schneiderian membrane between males and females. Based on the periapical index scoring, the highest frequency was detected in group 1. Based on the results of ANOVA, there were no significant differences in the frequencies of endodontic‒periodontal lesions and an increase in schneiderian membrane thickness. There were significant relationships between periapical and periodontal infections (P<0.001) and schneiderian membrane thickness. Furthermore, a significant relationship was detected between the thickness of the schneiderian membrane and the distance between the sinus floor and the root apices (P=0.38).

Conclusion. A retrospective inspection of CBCT imaging revealed that periapical lesions and periodontal infections in the posterior area of the maxilla were associated with thickening of the schneiderian membrane. In addition, there was a significant relationship between the location of maxillary posterior teeth, i.e. the thickness of bone from the root apex to the maxillary sinus floor, and schneiderian membrane thickness.

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.

Cone Beam Computed Tomography Study of Root Canal Morphology of Permanent Mandibular Incisors in Indian Subpopulation

Background

The aim of the study was to determine the root canal morphology of permanent mandibular incisor teeth in the Indian subpopulation with the use of cone beam computed tomography (CBCT).

Material/Methods

CBCT images of 200 patients with 800 permanent mandibular incisors, fulfilling necessary inclusion criteria and aged 18 to 60 years were evaluated. The number of roots, number of root canals and canal configuration were investigated and then classified according to Vertucci’s classification of root canals. The effect of gender on the incidence of root canal morphology was also investigated.

Results

All the permanent mandibular incisors had a single root. The majority of mandibular incisors (66.5%) had a single root with a single canal. The prevalence of second canals was as follows: right central incisor – 33.5%, left central incisor – 30%, right lateral incisors – 33.5% and left lateral incisor – 36.5%. According to gender, 15.2% of men and 20.4% of women had a second root canal. Type 1 Vertucci configuration was most prevalent, followed by type 3, type 2, type 5 and type 4 in that order.

Conclusions

Type 1 Vertucci’s classification (64.5%) was the most prevalent canal configuration in the mandibular anterior teeth in the Indian population. Type 5 Vertucci’s classification was the most frequently observed canal configuration of the two-canalled teeth. CBCT is an excellent imaging modality for detection of different canal configurations of mandibular incisors.

Computer-aided diagnosis of periapical cyst and keratocystic odontogenic tumor on cone beam computed tomography

BACKGROUND AND OBJECTIVES

In this article, we propose a decision support system for effective classification of dental periapical cyst and keratocystic odontogenic tumor (KCOT) lesions obtained via cone beam computed tomography (CBCT). CBCT has been effectively used in recent years for diagnosing dental pathologies and determining their boundaries and content. Unlike other imaging techniques, CBCT provides detailed and distinctive information about the pathologies by enabling a three-dimensional (3D) image of the region to be displayed.

METHODS

We employed 50 CBCT 3D image dataset files as the full dataset of our study. These datasets were identified by experts as periapical cyst and KCOT lesions according to the clinical, radiographic and histopathologic features. Segmentation operations were performed on the CBCT images using viewer software that we developed. Using the tools of this software, we marked the lesional volume of interest and calculated and applied the order statistics and 3D gray-level co-occurrence matrix for each CBCT dataset. A feature vector of the lesional region, including 636 different feature items, was created from those statistics. Six classifiers were used for the classification experiments.

RESULTS

The Support Vector Machine (SVM) classifier achieved the best classification performance with 100% accuracy, and 100% F-score (F1) scores as a result of the experiments in which a ten-fold cross validation method was used with a forward feature selection algorithm. SVM achieved the best classification performance with 96.00% accuracy, and 96.00% F1 scores in the experiments in which a split sample validation method was used with a forward feature selection algorithm. SVM additionally achieved the best performance of 94.00% accuracy, and 93.88% F1 in which a leave-one-out (LOOCV) method was used with a forward feature selection algorithm.

CONCLUSIONS

Based on the results, we determined that periapical cyst and KCOT lesions can be classified with a high accuracy with the models that we built using the new dataset selected for this study. The studies mentioned in this article, along with the selected 3D dataset, 3D statistics calculated from the dataset, and performance results of the different classifiers, comprise an important contribution to the field of computer-aided diagnosis of dental apical lesions.

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.

Alternative methods to visual and radiographic examinations for approximal caries detection

A shift in caries prevalence from occlusal surfaces to approximal surfaces has been demonstrated by epidemiological studies. Two recent meta-analyses evaluated the performance of visual examination and radiography for carious lesion detection, and reported low sensitivity but high specificity for early approximal caries detection. This suggests that the conventional methods have a higher risk of failing to detect approximal lesions. Consequently, in caries susceptible populations, there is a risk of progression of non-cavitated lesions to irreversible tooth destruction before the lesions are detected. This paper aims to review the performance of unconventional and novel methods for approximal caries detection. In vitro and in vivo studies identified through a MEDLINE search using keywords such as caries detection, approximal caries detection, light fluorescence and dental caries, and transillumination and dental caries were reviewed. The unconventional methods known to be used for approximal caries detection and included in this review are: cone beam computed tomography, fiber-optic trans-illumination, digital imaging fiber optic trans-illumination, near-infrared digital imaging transillumination, optical coherence tomography, laser fluorescence, ultrasound, and LED reflection and refraction.

Contemporary imaging for the diagnosis and treatment of traumatic dental injuries: A review

Traumatic dental injuries (TDI) have an array of presentations. Diagnostic challenges are common and clinicians' ability to correctly identify specific injuries dictates the optimal course of treatment(s). The aim of this review was to outline and assess all dental imaging techniques and their applications to traumatic dental injuries. A particular interest is given to the advancement of 3D imaging techniques and their role in diagnosis and treatment planning. The benefits of achieving a more accurate diagnosis are paramount to perfecting clinical judgments and outcomes.

Root and canal morphology of maxillary second molars by cone-beam computed tomography in a native Chinese population

Objective

To evaluate the root and root canal morphology of the maxillary second molars (MSMs) in a native Chinese population by cone-beam computed tomography.

Methods

Cone-beam computed tomography images of 2412 MSMs from 1294 Chinese patients were analyzed to determine the number and morphology of the roots, the root canal morphology, the bilateral symmetry, and the correlations of these parameters with sex and age.

Results

The percentage of fused roots increased with age, while the percentage of fused roots in women was higher than that in men. The percentage of second mesiobuccal (MB2) canals in MSMs with three separate roots was higher in men than women. Patients aged 31 to 40 years showed a higher prevalence of MB2 canals, while those aged ≥51 years showed the lowest prevalence of MB2 canals among both men and women. There was a significant difference in bilateral symmetry of MSMs between men and women.

Conclusion

Root fusion of MSMs increased with age, while the root canal morphology was more complex in patients of intermediate ages.

Assessment of slice thickness effect on visibility of inferior alveolar canal in cone beam computed tomography images

Objective:

The aim of this study is to evaluate the effect of slice thickness on the visibility of inferior alveolar canal (IAC) in cone-beam computed tomography (CBCT) images.

Materials and Methods:

CBCT images of thirty patients (15 male and 15 female) with an age range between 40–50 years old were used. Cross-sectional images were obtained with 0.5, 1, and 2 mm slice thickness and 2 mm interval. Two oral radiologists with at least 5 years' of experience observed all of the 90 images and rated the images based on the visibility of IAC in a 4-score classification (highly visible, visible, nearly visible, nearly invisible). Friedman test was used for the comparison of visibility of IAC in different slice thicknesses. To do the above test, the average of the scores of two examiners was calculated. A P. value below 0.05 was considered significant.

Results:

Visibility of IAC in different slice thicknesses of both raters showed no significant difference (P = 0.20).

Conclusion:

Within the limitations of this study the slice thickness has no effect on visibility of IAC in cross-sectional images. Future studies on other multiplanar images are recommended.

CBCT Assessment of Root Dentine Removal by Gates-Glidden Drills and Two Engine-Driven Root Preparation Systems

Introduction:

The aim of this study was to compare the dentine removing efficacy of Gates-Glidden drills with hand files, ProTaper and OneShape single-instrument system using cone-beam computed tomography (CBCT).

Methods and Materials:

A total of 39 extracted bifurcated maxillary first premolars were divided into 3 groups (n=13) and were prepared using either Gates-Glidden drills and hand instruments, ProTaper and OneShape systems. Pre- and post-instrumentation CBCT images were obtained. The dentin thickness of canals was measured at furcation, and 1 and 2 mm from the furcation area in buccal, palatal, mesial and distal walls. Data were analyzed using one-way ANOVA test. Tukey’s post hoc tests were used for two-by-two comparisons.

Results:

Gates-Glidden drills with hand files removed significantly more (P<0.001) dentine than the engine-driven systems in all canal walls (buccal, palatal, mesial and distal). There were no significant differences between OneShape and ProTaper rotary systems (P>0.05).

Conclusion:

The total cervical dentine removal during canal instrumentation was significantly less with engine-driven file systems compared to Gates-Glidden drills. There were no significant differences between residual dentine thicknesses left between the various canal walls.

Maxillofacial injuries among trauma patients undergoing head computerized tomography; A Ugandan experience

Aim:

The aim of this study was to investigate epidemiological features of maxillofacial fractures within trauma patients who had head and neck computed tomography (CT) scan at the Mulago National referral hospital.

Methods:

CT scan records of trauma patients who had head scans at the Department of Radiology over 1-year period were accessed. Data collected included sociodemographic factors, type and etiology of injury, and concomitant maxillofacial injuries.

Results:

A total of 1330 trauma patients underwent head and neck CT scan in the 1-year study period. Out of these, 130 were excluded due to incomplete or unclear records and no evidence of injury. Of the remaining 1200, 32% (387) had maxillofacial fractures. The median age of the patients with maxillofacial fractures was 28 (range = 18–80) years and 18–27 age group was most common at 47.5%. Road traffic accidents constituted 49.1% of fractures. The single most affected isolated bone was the frontal bone (23%). The number of maxillofacial bones fractured was predicted by age group (df = 3 F = 5.358, P = 0.001), association with other fractures (df = 1 F = 5.317, P = 0.03).

Conclusions:

Good matched case–control prospective studies are needed to enable us tease out the finer difference in the circumstances and pattern of injury if we are to design appropriate preventive measures.

Monoscopic photogrammetry to obtain 3D models by a mobile device: a method for making facial prostheses

Purpose

The aim of this study is to present the development of a new technique to obtain 3D models using photogrammetry by a mobile device and free software, as a method for making digital facial impressions of patients with maxillofacial defects for the final purpose of 3D printing of facial prostheses.

Methods

With the use of a mobile device, free software and a photo capture protocol, 2D captures of the anatomy of a patient with a facial defect were transformed into a 3D model. The resultant digital models were evaluated for visual and technical integrity. The technical process and resultant models were described and analyzed for technical and clinical usability.

Results

Generating 3D models to make digital face impressions was possible by the use of photogrammetry with photos taken by a mobile device. The facial anatomy of the patient was reproduced by a *.3dp and a *.stl file with no major irregularities. 3D printing was possible.

Conclusions

An alternative method for capturing facial anatomy is possible using a mobile device for the purpose of obtaining and designing 3D models for facial rehabilitation. Further studies must be realized to compare 3D modeling among different techniques and systems.

Clinical implication

Free software and low cost equipment could be a feasible solution to obtain 3D models for making digital face impressions for maxillofacial prostheses, improving access for clinical centers that do not have high cost technology considered as a prior acquisition.

Diagnosis and imaging of orbital roof fractures: a review of the current literature

Isolated adult orbital roof fractures are uncommon, and the majority of them are typically associated with extensive craniofacial, ophthalmologic, and other body injuries. It is crucial to make an appropriate diagnosis of orbital roof fracture if present. Therefore, the aim of this article was to review the current literature about diagnosis and imaging of orbital roof fracture to obtain current indications. A systematic review of articles published between January 1990 and August 2013 was performed. Early diagnosis of orbital roof fractures can reduce the incidences of intracranial and ocular complications. CT scan still plays a major role in the assessment of acute orbital trauma. Careful assessment and reporting of the CT scan findings are important. In fact, the clinicians managing the patient with acute head and facial trauma should be familiar with the common findings of CT scan in case of an orbital roof fracture.

Treatment of multiple traumatized anterior teeth associated with an alveolar bone fracture in a 20-year-old patient: A 3-year follow up

Intrusive luxation is a type of recognizable luxation injury represented by a deeper axial displacement of the tooth toward the alveolar bone. Treatment strategies include waiting for the tooth to return to its position, immediate surgical repositioning, and repositioning through dental traction by orthodontic devices. The aim of this case report was to present the management of severe dental trauma and later restoration following IADT. A 20-year-old patient was presented after fainting at home four hours before, resulting in a dento-alveolar trauma. Clinical examinations revealed a traumatic intrusion, in 1.2, 1.1 and 2.1, uncomplicated crown fractures in 1.1 and 2.1 and a complicated crown-root fracture in 2.2. The diagnosis was confirmed with CBCT. Following IADT protocol, the emergency treatment consisted of the surgical repositioning and semi-rigid splinting using orthodontic wire-composite, replacing the buccal bone plate, and postoperative instructions to the patient regarding oral hygiene. After 2 weeks the root canal treated and filled with fiberglass posts in 1.2, 1.1, 2.1 and 2.2. Splint was removed after 4 weeks and the IADT reassessment protocol followed, with revisions at 6-8 weeks, 6 months, a year and annual reviews for 5 years. A year after the treatment, the traumatized teeth were restored with minimally invasive preparations of feldspathic ceramic. Esthetics and function were recorded with a 3-year follow-up period.

Key words:Intrusive luxation, dental trauma, crown-root fracture, dento-alveolar trauma, permanent tooth, CBCT.

The Comprehensive AOCMF Classification System: Radiological Issues and Systematic Approach

The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial (CMF) classification system with increasing level of complexity and details. The basic level 1 system differentiates fracture location in the mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94); the levels 2 and 3 focus on defining fracture location and morphology within more detailed regions and subregions. Correct imaging acquisition, systematic analysis, and interpretation according to the anatomic and surgical relevant structures in the CMF regions are essential for an accurate, reproducible, and comprehensive diagnosis of CMF fractures using that system. Basic principles for radiographic diagnosis are based on conventional plain films, multidetector computed tomography, and magnetic resonance imaging. In this tutorial, the radiological issues according to each level of the classification are described.

Recent advances in imaging technologies in dentistry

Dentistry has witnessed tremendous advances in all its branches over the past three decades. With these advances, the need for more precise diagnostic tools, specially imaging methods, have become mandatory. From the simple intra-oral periapical X-rays, advanced imaging techniques like computed tomography, cone beam computed tomography, magnetic resonance imaging and ultrasound have also found place in modern dentistry. Changing from analogue to digital radiography has not only made the process simpler and faster but also made image storage, manipulation (brightness/contrast, image cropping, etc.) and retrieval easier. The three-dimensional imaging has made the complex cranio-facial structures more accessible for examination and early and accurate diagnosis of deep seated lesions. This paper is to review current advances in imaging technology and their uses in different disciplines of dentistry.

A cone-beam computed tomography study of the root canal morphology of anterior teeth in a Turkish population

Objective:

The aim of this study was to determine the root and canal morphology of the maxillary and mandibular anterior teeth in a Turkish population by analyzing cone-beam computed tomography (CBCT) images.

Materials and Methods:

CBCT images of 417 females and 410 males with a mean age of ranging from 14 to 70 years were examined in this study. A total of 1453 maxillary central incisors, 1504 maxillary lateral incisors, 1523 maxillary canines, 1582 mandibular central incisors, 1603 mandibular lateral incisors, and 1604 mandibular canines were analyzed. The number of root canals and the canal configurations were investigated and then were classified according to Vertucci's classification. The data were analyzed with the Pearson Chi-square test.

Results:

The Type 1 canal configuration was most prevalent in the maxillary anterior teeth (96.8-99.7%). The Types 2, 3, 4, and 5 canal configurations were observed within the range of 0-1.3%, 0-0.8%, 0-0.7%, and 0-1.8%, respectively. In the mandibular anterior teeth, the Type 1 canal configuration was most prevalent (77-95%). The Types 2, 3, 4, and 5 canal configurations were observed within a range of 0.2-2.7%, 0.2-1.6%, 0.9-5.9%, and 1.8-14.4%, respectively. The prevalence of two canals was higher in males than in females both in the maxillary and mandibular anterior teeth (P < 0.05).

Conclusions:

Type 1 was the most prevalent canal configuration of maxillary and mandibular anterior teeth in the Turkish population. Type 5 was the most frequently observed canal configuration of the two canalled teeth. The incidence of root canal numbers and configurations differed with sex.

A Diagnosis of Maxillary Sinus Fracture with Cone-Beam CT: Case Report and Literature Review

The purpose of this article is to present the case of maxillofacial trauma patient with maxillary sinus fracture diagnosed with cone-beam computed tomography (CBCT) and to explore the applications of this technique in evaluating the maxillofacial region. A 23-year-old male patient attempted to our clinic who had an injury at midface with complaints of swelling, numbness. The patient was examined before in emergency center but any diagnosis was made about the maxillofacial trauma. The patient re-examined clinically and radiographically. A fracture on the frontal wall of maxillary sinus is determined with the aid of CBCT. The patient consulted with the department of maxillofacial surgery and it is decided that any surgical treatment was not necessary. The emerging technique CBCT would not be the primary choice of imaging maxillofacial trauma. Nevertheless, when advantages considered this imaging procedure could be the modality of choice according to the case.

Diagnostic efficacy of cone-beam computed tomography for mandibular fractures

OBJECTIVE

The aim of the study was to determine the clinical efficacy of maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of suspected mandibular fractures and to evaluate whether findings would lead to a change in treatment.

STUDY DESIGN

CBCT imaging was performed for 164 patients with suspected mandibular fractures (231 sites) but equivocal clinical and radiological findings (conventional radiography). Images were interpreted by oral and maxillofacial surgeons and treatment decisions based on pre and postimaging were compared. Linear regression analyses were performed.

RESULTS

For 63.2% of sites (n = 146) the suspected diagnosis was confirmed by CBCT (P < .0001; R(2) = 0.93). For 4.33% of sites (n = 10) no fracture was identified. Additional fractures were identified in 17.75% (n = 41) and additional infractures in 14.72% (n = 34). The treatment plan was altered for 9.52% of sites (n = 22).

CONCLUSIONS

CBCT imaging of suspected mandibular fractures resulted in a change in the treatment plan in 9.52%.

Frontobasilar fractures: proposal for image reviewing algorithm

OBJECTIVE

The aim of this study was to develop and test the utility of a novel systematic protocol to analyze CT images of patients with trauma in the anterior cranial base and upper midface.

MATERIAL AND METHODS

The radiological data and primary reports of 27 consecutive patients with a frontal skull base fracture treated in two tertiary care hospitals from 2007 to 2011 were scrutinized. A novel algorithm for systematic image reviewing was used to assess the CT images and the findings were compared with the primary radiological reports.

RESULTS

The systematic review detected a substantial number of fractures and defects in anatomical structures that had not been systematically reported in the primary, on-call reports. Anterior skull base fracture was not initially reported in 32% of the patients; however, the algorithm detected this in 93% of them. The corresponding rates for fracture through cribriform plate were 28% and 72% and for fracture through the sella or hypophyseal area 22% and 78%. There were two fractures of the clivus and these were initially missed.

CONCLUSIONS

Despite the failure to identify these fractures radiologically in the primary setting, all patients were still considered to have received appropriate treatment, but, the use of an image-reviewing algorithm will enhance the specificity of CT in the diagnosis of frontobasilar fractures.

Mandibular fracture patterns consistent with posterior maxillary fractures involving the posterior maxillary sinus, pterygoid plate or both: CT characteristics

OBJECTIVES

The aim of this study was to determine the incidence of posterior maxillary fractures involving the posterior maxillary sinus wall, pterygoid plate or both, unrelated to major midface fractures in patients with mandibular fractures, and to characterize associated fractures.

METHODS

A CT study was performed in patients with mandibular fractures to identify posterior maxillary fractures. Patients aged under 16 years, those with mandibular fractures involving only dentoalveolar components and those with concurrent major midfacial fractures were excluded.

RESULTS

13 (6.7%) of 194 patients with mandibular fractures also had posterior maxillary fractures (case group). The injury pattern correlated with the external force directed to the lateral side of the mandible (p < 0.001), alcohol consumption (p = 0.049), the presence of multifocal fractures (p = 0.002) and the fracture regions in the symphysis/parasymphysis (p = 0.001) and the angle/ramus (p = 0.001). No significant difference between the case and non-case groups was seen for age, sex or cause of trauma. Non-displaced fractures in the ipsilateral posterior mandible occurred with significant frequency (p = 0.001) when the posterior maxillary fractures involved only the sinus.

CONCLUSIONS

Mandibular fractures accompanied by posterior maxillary fractures are not rare. The finding of a unilateral posterior maxillary fracture on CT may aid the efficient radiological examination of the mandible based on possible patterns of associated fractures, as follows: in the ipsilateral posterior region as a direct fracture when the impact is a medially directed force, and in the symphysis/parasymphysis or contralateral condylar neck as an indirect fracture.

Radiographic detection of artificially created horizontal root fracture using different cone beam CT units with small fields of view

OBJECTIVES

To compare limited cone beam computerized tomography (CBCT) units with different field of views (FOVs) and voxel sizes in detecting artificially created horizontal root fracture (HRF) in extracted human teeth.

METHODS

Artificial HRF was created in the horizontal plane in 40 teeth. Another 40 intact teeth served as a control group. 80 teeth were placed in the respective maxillary anterior sockets of a human dry skull in groups. Six image sets were obtained: (1) Accuitomo 170, 40 × 40 mm FOV (0.080 mm(3)); (2) Accuitomo 170, 60 × 60 mm FOV (0.125 mm(3)); (3) Kodak 9000, 50 × 37 mm FOV (0.076 mm(3)); (4) Kodak 9000, 50 × 37 mm FOV (0.100 mm(3)); (5) Vatech Pax-Duo3D 50 × 50 mm FOV (0.080 mm(3)) and (6) Vatech Pax-Duo3D 85 × 85 mm FOV (0.120 mm(3)). Images were evaluated twice by five observers. Kappa values were calculated for observer agreement. Areas under the receiver operating characteristic (ROC) curves (Az values) were calculated, and the Az values for each image type were compared using t-tests (α = 0.05).

RESULTS

Intraobserver kappa coefficients ranged from 0.81 to 0.95 for the Accuitomo 170 images, from 0.80 to 0.92 for the Kodak 9000 images and from 0.76 to 0.95 for Vatech PanX-Duo3D. The Az values for different image types and observers ranged from 0.93 to 0.97 for Accuitomo 170 images, from 0.93 to 0.98 for Kodak 9000 images and from 0.93 to 0.97 for the Vatech PanX-Duo3D images. No statistically significant differences (p > 0.05) were found between the Az values.

CONCLUSIONS

Limited CBCT units performed similarly in detecting simulated HRF.

Cone beam computed tomography and intraoral radiography for diagnosis of dental abnormalities in dogs and cats

The development of veterinary dentistry has substantially improved the ability to diagnose canine and feline dental abnormalities. Consequently, examinations previously performed only on humans are now available for small animals, thus improving the diagnostic quality. This has increased the need for technical qualification of veterinary professionals and increased technological investments. This study evaluated the use of cone beam computed tomography and intraoral radiography as complementary exams for diagnosing dental abnormalities in dogs and cats. Cone beam computed tomography was provided faster image acquisition with high image quality, was associated with low ionizing radiation levels, enabled image editing, and reduced the exam duration. Our results showed that radiography was an effective method for dental radiographic examination with low cost and fast execution times, and can be performed during surgical procedures.

[Interventional multidimodal hybrid unit: from pre-operative planning to immediate post-operative control]

INTRODUCTION

Computer assisted surgery has rapidly developed over the last decade, essentially due to the development of navigation and 3D virtual surgical planning and image fusion technologies. The recent introduction of intra-operative cone-beam CT scan (CBCT), which integrates flat panel technology, allows for high resolution bone imaging, the quality and accuracy of which is similar to the one obtained by conventional spiral CT scan. The combination of these two technologies in a "hybrid" operating unit enables the convergence of the pre-, intra- and post-operative steps in a linear computer-assisted processing chain, which optimises surgery accuracy, predictability and patient outcomes while potentially reducing costs, operating times and need for further surgical revision.

TECHNICAL NOTE

The "hybrid" unit includes: 1) the operating room (65 m(2)) equipped with horizontal laminar-flow, a mobile monoplane ceiling suspended C-arm CBCT scan system with a flat panel detector, a wireless navigation system, and an interactive wall-mount touch screen 2) the control room (18 m(2)) separated from the operating room by an X-ray lead protective glass window, including two separate computer workstations for 3D image integration and processing 3) the scrub room (17 m(2)) with two separate stainless steel surgical wash-basins. The intra-operative protocol includes the following steps: 1) elaboration of the patient specific pre-operative computed planning and simulation based on pre-operatively and/or intra-operatively acquired patient images 2) intra-operative navigational guidance setting 3) surgical procedure 4) intra-operative 3D CT imaging 5) suture.