Application of cone beam computed tomography in oral and maxillofacial surgery

Using cone-beam CT for appropriate nostril selection in nasotracheal intubation

OBJECTIVES

Nasotracheal intubation is a standard blind procedure associated with various complications. The selection of the appropriate nostril is crucial to preventing most of these complications. The present study aimed to evaluate the predictive ability of cone-beam CT (CBCT) images to select the correct nostril for nasotracheal intubation.

METHODS

The study encompassed 60 patients who underwent maxillofacial surgery with nasotracheal intubation under general anaesthesia. While the anaesthetist made the appropriate nostril selection clinically according to a simple occlusion test and spatula test, the radiologist made the selection after analysing various CBCT findings such as the angle and direction of nasal septum deviation (NSD), minimum bone distance along the intubation path, and the presence of inferior turbinate hypertrophy. The appropriateness of these choices made blindly at different times was evaluated using descriptive statistics, chi-squared test, and independent samples t-test.

RESULTS

The study found that 83.3% of the suggested nostril intubations were successful. We also observed that intubation duration was longer when inferior turbinate hypertrophy was present (P = .031). However, there was no statistical relationship between the presence of epistaxis and septal deviation (P = .395). Nonetheless, in 64.3% of cases with epistaxis, the intubated nostril and the septum deviation direction were the same.

CONCLUSIONS

Pre-operative evaluations using CBCT can aid anaesthetists for septum deviation and turbinate hypertrophy, as both can impact intubation success rates and duration.

Epidemiology and Management Paradigm of Head and Neck Infections, Including COVID-19 Pandemic Period: A 10-Year Retrospective Study in a Maxillofacial Center of Cluj-Napoca

Background. The management of odontogenic infections varies across the globe. To shed light on the subject, this study delves into the practices of the Oral and Maxillofacial Department at Cluj-Napoca County Hospital. Material and Methods. This comprehensive retrospective analysis of 10 years of clinical experience covered a range of factors, including demographics, clinical and investigations factors, medical and surgical treatment approaches, and follow-up. Additionally, the study examined the change in trends over the course of the COVID-19 pandemic. Results. While head and neck infection occurrence had a decreasing trend before the COVID-19 pandemic, during the pandemic era the number of patients almost doubled. The infections were prevalent in the submandibular space, teeth being the prevalent cause. Young adults are prone to suffer from odontogenic infections. High levels of C reactive protein, ASA II-IV risk, and hepatic dysfunction indicated a longer time of hospitalization. The majority of antibiograms were negative, and the positive ones indicated Streptococcus and Staphylococcus species as prevalent pathogens. Extra- or intraoral surgical drainage and wide-spectrum antibiotics proved to be the workhorse for odontogenic infections. Conclusion. This study advances our understanding of oral and maxillofacial surgery and offers actionable strategies for improving patient outcomes in similar healthcare institutions worldwide.

A cone-beam computed tomography study of canalis sinuosus and its accessory canals in a South African population

OBJECTIVES

Canalis sinuosus (CS) is a clinically relevant structure in the anterior maxilla. The present study aimed to determine the prevalence and distribution of CS and its accessory canals (ACs) in the South African population and describe its anatomical variations.

METHODS

In total, 500 cone-beam computed tomography (CBCT) scans of the anterior maxilla were assessed for prevalence, sidedness, diameter, and distribution of CS. The frequency, number, diameter, configuration, and point of termination of ACs were also recorded. Statistical analysis was performed using analysis of variance, Kruskal-Wallis, chi-squared, and Fisher Exact tests with P < 0.05.

RESULTS

CS was present in most cases (99.6%), and commonly occurred bilaterally (98.8%). The mean diameter of CS was 1.08 mm (range: 0.50 mm-2.39 mm). Sex, population group, and age had no significant effect on the prevalence or sidedness of CS. Additionally, 535 ACs were observed in 58.8% of the sample, with 42.9% of ACs found bilaterally and 57.1% unilaterally. The mean diameter of the ACs was 0.86 mm on the left and 0.87 mm on the right (range; 0.50 mm-1.52 mm). The majority of ACs maintained a straight vertical configuration (72.3%). ACs most commonly terminated in the anterior palatal region of the maxilla (57.2%). No significant differences were found in any groups mentioned (P > 0.05).

CONCLUSIONS

A high prevalence of CS as well as ACs were observed in the sample population. Due to their clinical significance, surgical planning with the aid of high quality CBCT scans of the anterior maxilla is advisable.

The relation between persistent foramen tympanicum and degenerative bone alterations in temporomandibular joint region

OBJECTIVES

The aim of this study was to evaluate, using cone-beam computed tomography (CBCT), the relationship of persistent foramen tympanicum (PFT) with degenerative changes in the temporomandibular joint (TMJ) and the presence of pneumatized glenoid fossae and articular eminences.

METHOD

Two experienced oral and maxillofacial radiologists evaluated 510 CBCT scans, from which 94 patients were divided into two groups: G1-patients with PFT and G2-control group. The location of the PFT, presence, or absence of degenerative TMJ changes and morphology were evaluated. Similarly, all images were evaluated for the presence of pneumatized articular eminence and glenoid fossa. The Chi-square test and Fisher's Exact test were used for the categorical variables. A multinomial logistic regression model was performed for subgroup analysis. To assess the estimation-chance occurrence of TMJ alterations the Odds Ratio analysis was used.

RESULTS

Statistically significant results were found for erosion, planning, and subchondral cyst. Regarding TMJ morphology, significant results were found for: round, flat, and others. Moreover, it was possible to observe that patients who had the PFT were approximately 48 times more likely to manifest TMJ alterations and approximately 3 times more likely to manifest articular eminence pneumatization.

CONCLUSION

Since individuals who have FTP have a greater chance of having TMJ and PEA changes, it is important for the dental radiologist to be aware of these signs in CBCT scans for a correct diagnosis.

TRIAL REGISTRATION NUMBER

CAAE: 34328214.3.0000.0104 (11/30/2014).

A Combined Ventral Extraoral and Intraoral Approach for Mandibulectomy in 9 Cats: A Case Series

This retrospective case series describes a combined ventral extraoral and intraoral approach for mandibulectomy in cats and highlights the importance of prompt management of the postoperative iatrogenic malocclusion through dental extraction, crown height reduction with vital pulp therapy or root canal therapy of the contralateral mandibular canine tooth. Nine cats were reviewed for signalment, history and physical examination, diagnostic workup, tumor type, mandibulectomy extension, lymph node removal as well as both intraoperative and postoperative complications. The performed surgical procedure was a combination of an extraoral approach ventrally to the mandible and an intraoral approach to remove the whole or a part of the mandible. Lymphadenectomy was achieved using the same surgical access. None of the cats had intraoperative complications. Postoperative complications were limited to regional swelling and drooling lasting a week. Seven cats were able to eat immediately after the surgery. Of the other 2 cats, 1 regained the ability to eat within a month and 1 only ate from the owner's hands. The surgical approach for mandibulectomy described allowed better access and visualization of the caudal part of the mandible and direct access to regional lymph nodes. Moreover, if the expected postoperative malocclusion is managed during the same surgical procedure, there is a higher rate of postoperative eating ability compared to what is reported in the literature.

Applications of Cone Beam Computed Tomography Scans in Dental Medicine and Potential Medicolegal Issues

A cone beam central tomography (CBCT) scan produces images in orthogonal and non-orthogonal with great spatial resolution. When a dental health care practitioner (DHP) orders a CBCT scan, they should consider if it is truly indicated, as CBCT scans carry up to four times the dosage of radiation compared to panoramic radiographs. Any diagnostic imaging obtained of a patient should include a formal interpretive report commenting on the findings within the imaging. Ordering of limited field of view (FOV) CBCT scans and failing to report on abnormal findings present outside of the region of interest (ROI) is a potential medicolegal issue.

Diagnostic performance of stitched and non-stitched cross-sectional cone-beam computed tomography images of a non-displaced fracture of ovine mandibular bone

Purpose

This study assessed the diagnostic performance of stitched and non-stitched cross-sectional cone-beam computed tomography (CBCT) images of non-displaced ovine mandibular fractures.

Materials and Methods

In this ex vivo study, non-displaced fractures were artificially created in 10 ovine mandibles (20 hemi-mandibles) using a hammer. The control group comprised 8 hemi-mandibles. The non-displaced fracture lines were oblique or vertical, <0.5 mm wide, 10-20 mm long, and only in the buccal or lingual cortex. Fracture lines in the ramus and posterior mandible were created to be at the interface or borders of the 2 stitched images. CBCT images were obtained from the specimens with an 80 mm × 80 mm field of view before and after fracture induction. OnDemand software (Cybermed, Seoul, Korea) was used for stitching the CBCT images. Four observers evaluated 56 (28 stitched and 28 non-stitched) images to detect fracture lines. The diagnostic performance of stitched and non-stitched images was assessed by calculating the area under the receiver operating characteristic curve (AUC). Sensitivity and specificity values were also calculated (alpha=0.05).

Results

The AUC was calculated to be 0.862 and 0.825 for the stitched and non-stitched images, respectively (P=0.747). The sensitivity and specificity were 90% and 75% for the non-stitched images and 85% and 87% for the stitched images, respectively. The inter-observer reliability was shown by a Fleiss kappa coefficient of 0.79, indicating good agreement.

Conclusion

No significant difference was found in the diagnostic performance of stitched and non-stitched cross-sectional CBCT images of non-displaced fractures of the ovine mandible.

Evaluation of the contour of edentulous jaw sections in the transversal plane and the buccolingual vertical-level disparity in CBCT and panoramic radiography images: a retrospective comparative study

PURPOSE

This study investigates whether edentulous jaw sections in the planned implant position exhibit jaw contours funnel-shaped or exhibit pronounced retraction of the jaw (unusual jaw contours) in the transversal plane of the three-dimensional (3D) images, not visible in two-dimensional (2D) images.

METHODS

A total of 335 patients with an edentulous section of the jaw that required dental implants were selected. Anonymised radiologic patients' data were collected, comprising cone-beam computed tomography (CBCT) images of the edentulous jaw sections. In the first stage, unusual jaw contours were examined, including funnel-shaped or pronounced retraction of the jaw and hypodense regions with an undercut and/or bone deficit. In the second stage, the variation in the height of the alveolar ridge between the lingual and buccal contour in the edentulous jaw sections was assessed.

RESULTS

The CBCT images of an unusual jaw contour were observed in 8 cases (2.4%) in the maxilla on the left and 10 cases (3%) in the maxilla on the right. In the mandible, a jaw contour deviates in 39 cases (12.1%) on the left side and 39 cases (12.1%) on the right side. A height difference was detected in the upper jaw in 307 cases and the lower jaw in 265 cases. The discrepancy was 2.09 mm (± 2.25 mm) in the maxilla and 3.97 mm (± 3.45 mm) in the mandible.

CONCLUSIONS

The CBCT scan provides useful information to avoid complications in the preoperative planning phase and surgical planning in implant dentistry.

Soft and Hard Tissue Changes Subsequent to Spontaneous Healing of the Extraction Sockets Using Cone-Beam Computed Tomography: A Cross-Sectional Study

Objective

This study sought to compare the thickness of hard and soft tissues between edentulous and contralateral tooth sites.

Materials and Methods

This split-mouth study evaluated 153 partially edentulous patients. The measurements were made on cone-beam computed tomography (CBCT) scans. The soft tissue thickness was measured at the cementoenamel junctional (CEJ) level, and at 2, 4, and 6 mm apical to the CEJ in the facial and palatal aspects. The bone thickness of the opposite quadrant was also recorded at 2, 4, and 6 mm apical to the CEJ. The Mann-Whitney U test and the Spearman's rank correlation coefficient were applied for further statistical analyses.

Results

At the edentulous sites, significant soft tissue loss was noted at the CEJ level (p < 0.0001) and a considerable gain was noted at 2, 4, and 6 mm apical to the CEJ (p = 0.004, p < 0.0001, p ≤ 0.0001, respectively). A significant hard tissue loss was noted at 2 mm apical to the CEJ but a significant hard tissue gain was observed at the edentulous sites (p < 0.0001). The soft tissue gain at 6 mm apical to the CEJ was significantly associated with an increase in buccolingual diameter (p = 0.004) while the hard tissue loss at 2 mm apical to the CEJ was significantly correlated with a reduction in buccolingual diameter (p = 0.020).

Conclusion

Different amounts of tissue thickness alterations occurred in different levels of socket.

Does clinical experience with dental traumatology impact 2D and 3D radiodiagnostic performance in paediatric dentists? An exploratory study

Background

The aim of this study is to evaluate the impact of experience with traumatic dental injuries (TDI) on paediatric dentists’ performance and self-assessed confidence when radiodiagnosing traumatic dental injuries (TDI) and to explore whether this is influenced by the imaging technique used (2D versus 3D).

Materials and methods

Both 2D and 3D radiological images of young anterior permanent teeth having experienced dental trauma were assessed randomly by a panel of paediatric dentists using structured scoring sheets. The impact of level of experience with dental traumatology on radiological detection, identification and interpretation of lesions and on observer’s self-assessed confidence was evaluated. Findings were compared to benchmark data deriving from expert consensus of an experienced paediatric endodontologist and dentomaxillofacial radiologist. Results were analysed using generalized linear mixed modelling.

Results

Overall, observers performed moderately to poor, irrespective of their level of TDI experience and imaging modality used. No proof could be yielded that paediatric dentists with high TDI experience performed better than those with low experience, for any of the outcomes and irrespective of the imaging modality used. When comparing the use of 3D images with 2D images, significantly higher sensitivities for the detection and correct identification of anomalies were observed in the low experienced group (P < 0.05). This was not the case regarding interpretation of the findings. Self-assessed confidence was significantly higher in more experienced dentists, both when using 2D and 3D images (P < 0.05).

Conclusion

There was no proof that paediatric dentist’s higher experience with TDI is associated with better radiodiagnostic performance. Neither could it be proven that the use of Cone Beam Computed Tomography (CBCT) contributes to an improved interpretation of findings, for any experience level. More experienced dentists feel more confident, irrespective of the imaging modality used, but this does not correlate with improved performance. The overall poor performance in image interpretation highlights the importance of teaching and training in both dental radiology and dental traumatology.

A Comparative Study on the Voxel Values in Alveolar Bones Acquired by MDCT and Newly Developed Dental Dual-Energy CBCT

The purpose of this study was to analyze the effectiveness of newly developed dental dual-energy (DE) cone-beam computed tomography (CBCT) to compare both the voxel values in hard bone tissue of DE-CBCT and multidetector computed tomography (MDCT) images, collected in a clinical trial conducted at Seoul National University Dental Hospital. A software implemented as a scripted module of a three-dimensional (3D) slicer was developed to register the volume data from the MDCT space to DE-CBCT, locate the same 3D regions of interest (ROIs) in each image space, and extract the statistics of the ROIs. The mean values were paired and used as representative values of the ROIs. A scatter plot with the line of equality and Bland–Altman (BA) plot of difference for a pair of measured means were used for statistical analysis. Of the ROI pairs, 96% were within ±15% from the identity line, and more than 95% of the measured ROI pairs were within the limits of agreement of the 95% confidence intervals (CIs), with the CI of the limits in BA plots. The newly developed dental DE-CBCT showed a level of voxel value accuracy similar to that of MDCT.

Flat-panel conebeam CT in the clinic: history and current state

Research into conebeam CT concepts began as soon as the first clinical single-slice CT scanner was conceived. Early implementations of conebeam CT in the 1980s focused on high-contrast applications where concurrent high resolution ( < 200    μ m ), for visualization of small contrast-filled vessels, bones, or teeth, was an imaging requirement that could not be met by the contemporaneous CT scanners. However, the use of nonlinear imagers, e.g., x-ray image intensifiers, limited the clinical utility of the earliest diagnostic conebeam CT systems. The development of consumer-electronics large-area displays provided a technical foundation that was leveraged in the 1990s to first produce large-area digital x-ray detectors for use in radiography and then compact flat panels suitable for high-resolution and high-frame-rate conebeam CT. In this review, we show the concurrent evolution of digital flat panel (DFP) technology and clinical conebeam CT. We give a brief summary of conebeam CT reconstruction, followed by a brief review of the correction approaches for DFP-specific artifacts. The historical development and current status of flat-panel conebeam CT in four clinical areas-breast, fixed C-arm, image-guided radiation therapy, and extremity/head-is presented. Advances in DFP technology over the past two decades have led to improved visualization of high-contrast, high-resolution clinical tasks, and image quality now approaches the soft-tissue contrast resolution that is the standard in clinical CT. Future technical developments in DFPs will enable an even broader range of clinical applications; research in the arena of flat-panel CT shows no signs of slowing down.

Three-Dimensional Leeds Orthodontic Root Resorption Target Scale (3D-LORTS): A new structured pictographic tool for reporting root resorption caused by impacted maxillary canines detected on CBCT images and its impact on orthodontic treatment planning

OBJECTIVES

The objective of this study was to determine whether use of a root resorption pictogram, the Three-Dimensional Leeds Orthodontic Root Resorption Target Scale (3D-LORTS), in addition to cone beam computed tomography reports was associated with a change in orthodontic extraction decisions in cases with impacted maxillary canines and associated root resorption of adjacent teeth and to assess orthodontists' experiences using the pictogram.

STUDY DESIGN

Orthodontists completed a web-based survey in which they selected their preferred treatment plan for 6 cases. Each case was randomly presented twice, initially without and then subsequently with the pictogram. Statistical analysis was conducted to assess differences in extraction decisions with and without the pictogram and the participants' experiences using the 3D-LORTS.

RESULTS

A total of 194 orthodontists completed the survey. Significant differences in treatment decisions were found for 3 individual cases (P < .05) and for the 6 cases overall (P < .05). The majority of participants had positive perceptions of the pictogram, particularly with respect to ease of use, effect on understanding of root resorption location and severity, and usefulness as a communication aid.

CONCLUSIONS

Inclusion of the pictogram in cone beam computed tomography reports was associated with an overall change in orthodontists' extraction decisions. The majority of orthodontists reported positive experiences using the 3D-LORTS.

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

Statement of the Problem:

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

Purpose:

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

Materials and Method:

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

Results:

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

Conclusion:

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

Radiologic evaluation of the fossa navicularis: incidence, morphometric features, and clinical implications

INTRODUCTION

The aim of this study was to determine the incidence and morphometric and morphological characteristics of fossa navicularis (FN) on cone beam computed tomography (CBCT) images of healthy adults MATERIALS AND METHODS: CBCT images of 900 individuals (450 males, 450 females, over the age of 18) admitted to Gaziantep University, Dentistry Faculty were retrospectively examined. The incidence and shape of FN were determined. Transverse diameter (TDFN), sagittal diameter (SDFN), depth in transverse section (DFNT), depth in sagittal section (DFNS), and the shortest distance between the deepest point of FN and intracranial cavity (FNI) were measured.

RESULTS

FN was detected in 122 (59 males and 63 females) of 900 (13.56%) CBCT images. No statistically significant difference was observed between gender and the incidence of FN. SDFN, TDFN, DFNS, DFNT and FNI were measured as 4.04 ± 1.71, 4.28 ± 1.34, 1.79 ± 0.68, 2.34 ± 0.85, and 6.76 ± 2.23 mm, respectively. Besides, FN was described as oval in 95 of 122 (77.87%) cases, while as round in 27 (22.23%) cases.

CONCLUSIONS

The incidence of FN is rare; however, it may be responsible for serious consequences by causing infections from the nasopharynx to the intracranial cavity. As far as we know, the distance between the deepest point of FN and the intracranial cavity was measured for the first time in the literature with this study.

Reliability of panoramic radiography in predicting proximity of third molars to the mandibular canal: A comparison using cone-beam computed tomography

Purpose

The purpose of this study was to analyze the reliability of 7 panoramic radiographic signs for predicting proximity of the root apices of mandibular third molars to the mandibular canal using cone-beam computed tomography and to correlate these findings with the Pell and Gregory and the Winter classification systems.

Materials and Methods

An observational, cross-sectional, descriptive study was conducted on 74 patients with bilateral impacted mandibular third molars. Four panoramic radiographic signs were observed in the tooth root (darkening, deflection, and narrowing of the root apices, and bifid apices), and another 3 in the mandibular canal (diversion, narrowing, and interruption of the mandibular canal). Cone-beam computed tomography images were analyzed to identify disruption and diversion of the mandibular canal and root deflection.

Results

Binary logistic regression showed that only 4 of the 7 panoramic radiographic signs were able to predict proximity of the root apices of the mandibular third molars to the mandibular canal: darkening of the root, deflection of the root, narrowing of the root, and interruption of the mandibular canal (P<0.05).

Conclusion

Darkening, deflection, and narrowing of the root, in tandem with the interruption of the mandibular canal on panoramic radiographs, indicate that cone-beam computed tomography should be performed when planning the extraction of impacted mandibular third molars. Proximity between mandibular third molars and the mandibular canal is correlated with the Winter classification.

Breaking new ground in mineralized tissue: Assessing tissue quality in clinical and laboratory studies

Mineralized tissues, such as bone and teeth, have extraordinary mechanical properties of both strength and toughness. This mechanical behavior originates from deformation and fracture resistance mechanisms in their multi-scale structure. The term quality describes the matrix composition, multi-scale structure, remodeling dynamics, water content, and micro-damage accumulation in the tissue. Aging and disease result in changes in the tissue quality that may reduce strength and toughness and lead to elevated fracture risk. Therefore, the capability to measure the quality of mineralized tissues provides critical information on disease progression and mechanical integrity. Here, we provide an overview of clinical and laboratory-based techniques to assess the quality of mineralized tissues in health and disease. Current techniques used in clinical settings include radiography-based (radiographs, dual energy x-ray absorptiometry, EOS) and x-ray tomography-based methods (high resolution peripheral quantitative computed tomography, cone beam computed tomography). In the laboratory, tissue quality can be investigated in ex vivo samples with x-ray imaging (micro and nano-computed tomography, x-ray microscopy), electron microscopy (scanning/transmission electron imaging (SEM/STEM), backscattered scanning electron microscopy, Focused Ion Beam-SEM), light microscopy, spectroscopy (Raman spectroscopy and Fourier transform infrared spectroscopy) and assessment of mechanical behavior (mechanical testing, fracture mechanics and reference point indentation). It is important for clinicians and basic science researchers to be aware of the techniques available in different types of research. While x-ray imaging techniques translated to the clinic have provided exceptional advancements in patient care, the future challenge will be to incorporate high-resolution laboratory-based bone quality measurements into clinical settings to broaden the depth of information available to clinicians during diagnostics, treatment and management of mineralized tissue pathologies.

Imaging of Radiolucent Jaw Lesions

Radiolucent lesions in the jaw bones comprise a whole spectrum of odontogenic and nonodontogenic lesions. Although the imaging appearance is not always specific, careful radiologic analysis may contribute to characterization of these lesions. A useful approach is to first analyze the absence or presence of a relationship of the lesion to the teeth. The relation may be either near the tooth apex or crown of the tooth. Other lesions may or may not show any specific anatomical location. After analysis of the primary location of the lesion, additional criteria that may help in further imaging characterization are lesion demarcation and morphology, involvement of the cortex and periosteum, and soft tissue changes. This article describes the most characteristic and prevalent radiolucent lesions of the jaws at each location. In routine clinical practice, cone beam computed tomography is sufficient for appropriate lesion characterization, although magnetic resonance imaging may be useful in selected cases.

Evaluation of the Metal Artifact Caused by Dental Implants in Cone Beam Computed Tomography Images

Statement of the problem: The presence of a metal object such as dental implants in the scan field may cause artifacts on the cone-beam computed tomography (CBCT) images, which can reduce the diagnostic quality and accuracy of images. Purpose: The aim of this in vitro study was to compare the severity of implant-induced metal artifacts on CBCT images. Materials and method: To this end, a dry human mandible and a maxilla were selected, then two Roxolid and two Zirconium fixtures with different diameters were placed in the central incisor and first molar sockets and fixed with dental wax. The mandible and maxilla were placed in the simulated phantom for soft tissue, and the occlusal plane was adjusted parallel to the horizon. Images were taken at standard and high resolutions using two CBCT units. The CBCT gray values were measured in three longitudinal sections of the fixture (cervical, middle and apical) and the contrast noise ratio (CNR) was calculated. The CNR values of images were analyzed based on the fixture material, resolution, jaw, unit parameters and fixture size by using the paired t-test and different fixture sections by one-way ANOVA. Results: Depending on the CBCT unit, the CNR values in Roxolid and Zirconium fixtures are completely different. Under higher exposure parameters, the CNR values of the Roxolid and Zirconium fixtures were significantly higher in the maxilla than mandible. However, the fixture size and longitudinal section type did not have a significant effect on the CNR values. Conclusion: In contrast to the fixture material, scanning parameters and jaw type, differences in the size and longitudinal section of the fixtures had no impact on artifact severity.

Head motion during cone-beam computed tomography: Analysis of frequency and influence on image quality

Purpose

Image artifacts caused by patient motion cause problems in cone-beam computed tomography (CBCT) because they lead to distortion of the 3-dimensional reconstruction. This prospective study was performed to quantify patient movement during CBCT acquisition and its influence on image quality.

Materials and Methods

In total, 412 patients receiving CBCT imaging were equipped with a wireless head sensor system that detected inertial, gyroscopic, and magnetometric movements with 6 dimensions of freedom. The type and amplitude of movements during CBCT acquisition were evaluated and image quality was rated in 7 different anatomical regions of interest. For continuous variables, significance was calculated using the Student t-test. A linear regression model was applied to identify associations of the type and extent of motion with image quality scores. Kappa statistics were used to assess intra- and inter-rater agreement. Chi-square testing was used to analyze the impact of age and sex on head movement.

Results

All CBCT images were acquired in a 10-month period. In 24% of the investigations, movement was recorded (acceleration: >0.10 [m/s²]; angular velocity: >0.018 [°/s]). In all examined regions of interest, head motion during CBCT acquisition resulted in significant impairment of image quality (P<0.001). Movement in the horizontal and vertical axes was most relevant for image quality (R²>0.7).

Conclusion

Relevant head motions during CBCT imaging were frequently detected, leading to image quality loss and potentially impairing diagnosis and therapy planning. The presented data illustrate the need for digital correction algorithms and hardware to minimize motion artefacts in CBCT imaging.

Applying synthetic radiography to intraoral tomosynthesis: a step towards achieving 3D imaging in the dental clinic

OBJECTIVES

A practical approach to three-dimensional (3D) intraoral imaging would have many potential applications in clinical dentistry. Stationary intraoral tomosynthesis (sIOT) is an experimental 3D imaging technology that holds promise. The purpose of this study was to explore synthetic radiography as a tool to improve the clinical utility of the images generated by an sIOT scan.

METHODS

Extracted tooth specimens containing either caries adjacent to restorations (CAR) or vertical root fractures (VRF) were imaged by sIOT and standard dental radiography devices. Qualitative assessments were used to compare the conspicuity of these pathologies in the standard radiographs and in a set of multi-view synthetic radiographs generated from the information collected by sIOT.

RESULTS

The sIOT-based synthetic 2D radiographs contained less artefact than the image slices in the reconstructed 3D stack, which is the conventional approach to displaying information from a tomosynthesis scan. As a single sIOT scan can be used to generate synthetic radiographs from multiple viewing angles, the interproximal space was less likely to be obscured in the synthetic images compared to the standard radiograph. Additionally, the multi-view synthetic radiographs can potentially improve the display of CAR and VRFs as compared to a single standard radiograph.

CONCLUSIONS

This preliminary experience combining synthetic radiography and sIOT in extracted tooth models is encouraging and supports the ongoing study of this promising approach to 3D intraoral imaging with many potential applications.

Evaluation of motion artifacts in cone-beam computed tomography with three different patient positioning

OBJECTIVES

Cone-beam computed tomography (CBCT), despite its advantages, has some drawbacks, such as artifacts and movement of the patient during scanning may lead to motion artifacts (MAs). This retrospective study aimed to evaluate the MAs in three different CBCT devices and to analyze their relationship with age, the gender of the patients, and scanning times.

METHODS

This study included 360 CBCT images from three institutions scanned in standing, sitting and supine positions. MAs presence, age, gender, and scanning times were recorded. Of the patients, 129 were scanned in standing position, 131 in sitting position, and 100 in supine position.

RESULTS

MAs were found in 6.7% of patients in total; 8%, 7.6%, and 4% in standing, sitting, and supine positions, respectively. No statistically significant relationship was observed between MAs presence and patient position. The mean age of the patients with MAs was higher than patients without, in total and in standing positions. Scanning time showed no correlation with artifact presence.

CONCLUSIONS

Patient position is not related to MAs presence. The age of the patient is a factor in movement, and has a high impact in standing position. Although insignificant, MAs were less common in supine position than sitting and standing positions. Sitting and supine positioning might reduce motion artifacts in older patients.

Nasopalatine canal and periapical radiolucency fusion following dentoalveolar trauma: A CBCT-based case-control study

BACKGROUND/AIM

There is a lack of evidence regarding the radiological characteristics of a periapical radiolucency (PRL) fusion with the nasopalatine canal (NPC) following dentoalveolar trauma. The aim of this study was to assess the NPC enlargement resulting from fusion with a PRL and its relationship with the surrounding anatomical structures.

MATERIAL AND METHODS

A total of 100 patients was retrospectively recruited and divided into two groups: case group and control group. The case group consisted of 50 cone-beam computed tomography scans of the maxilla of patients (32 males, 18 females; age range: 11-83 years) with a known history of dentoalveolar trauma in the maxillary anterior region and the presence of an undiagnosed and/or asymptomatic NPC and PRL fusion. An age- and gender-matched control group of 50 patients (32 males, 18 females; age range: 11-82 years) without trauma history to the upper anterior teeth, demonstrating normal maxillary scans, was recruited. A subjective scoring criterion was established for assessing the characteristics of the fused lesion and its relationship with the buccal/palatal alveolar cortex, nasal cavity cortex, NPC cortical border, and maxillary sinus floor.

RESULTS

The fused NPC and PRL was mainly lobular in appearance (88%) with non-corticated well-defined margins (80%). Male patients showed larger (68%) dimensions compared with female patients (32%). The NPC cortical bone was the most commonly perforated structure in relation to fusion (72%), whereas maxillary sinus cortical bone was the least effected (2%). A statistically significant difference was observed between the NPC dimensions in the control and test groups, with fused lesions having larger mesiolateral, craniocaudal, and buccopalatal dimensions (P < .001).

CONCLUSIONS

Periapical radiolucencies should be treated as soon as possible before they fuse with NPC. In case of fusion, surgical enucleation should be considered as the treatment of choice.

Accuracy of the Cone Beam Computed Tomography in the Detection of Bone Invasion in Patients with Oral Cancer: A Systematic Review

This review article aims to analyze the diagnostic accuracy of the cone beam computed tomography (CBCT) with respect to other imaging methods in detection of bone tissue invasion by oral squamous cell carcinoma (OSCC). The review was carried out of English language studies in PubMed Search, National Library of Medicine, between 1990 and 2017. For each study, sensitivity, specificity, and positive (LR+) and negative (LR-) likelihood ratio, as well as the diagnostic accuracy, and positive and negative predictive values were calculated. Of the 62 collected articles, 7 fulfilled the inclusion criteria. Tests and respective articles included were computed tomography (CT, four studies), magnetic resonance imaging (MRI, five studies), C (two studies), single-photon emission tomography (SPECT, two studies), multi-slice computed tomography (MSCT, two studies), and panoramic radiography (PR, two studies). The analytic data show values of LR+ were 14.4 (CT), 37.9 (MRI), 27.8 (CBCT), 25.5 (SPECT), 37.0 (MSCT), 4.8 (PR), respectively. The values of LR- were 0.35 (CT), 0.24 (MRI), 0.10 (CBCT), 0.06 (SPECT), 0.31 (MSCT), and 0.36 (PR), respectively. The positive and negative predictive values for bone tissue invasion by OSCC were 90.31%-74.91% (CT), 90.63%-78.69% (MRI), 80.05%-89.83% (CBCT), 72.97%-95.53% (SPECT), 87.44%-73.74% (MSCT), and 84.245%-69.18% (PR), respectively. The level of scientific evidence available today is weak. To better define the impact of CBCT on clinical decision-making, further studies with uniform methodological approach are needed.

Evaluation of morphometric features of fossa navicularis using cone-beam computed tomography in a Turkish subpopulation

Purpose

Fossa navicularis is a bone defect in the clivus. Familiarity with this anatomical variant is important because it is close to vital anatomical structures in the base of the skull. The aim of this study was to determine the prevalence and morphometric properties of fossa navicularis within the clivus in a Turkish subpopulation using cone-beam computed tomography (CBCT).

Materials and Methods

A total of 168 CBCT scans (female: 96, male: 71) were evaluated. High-quality CBCT images of patients without a syndromic condition or a history of neurological disease or surgery were included in the study. The prevalence, depth, length, and width of the fossa navicularis were performed.

Results

The prevalence of fossa navicularis was 27.5% (n=46 patients). Sex was not associated with the depth, length, or width of the fossa navicularis (P>0.05). A significant positive correlation was found between age and length of the fossa navicularis (P>0.05).

Conclusion

Fossa navicularis was found to be rare (27.5%). Anatomical variants of the skull base can also be clearly identified on CBCT images. The results of this study may be useful to radiologists, anatomists, and surgeons interested in the skull base.

The presentation of odontogenic keratocysts in the jaws with an emphasis on the tooth-bearing area: a systematic review and meta-analysis

PURPOSE

This study was conducted in order to gain insight in the actual ratio of odontogenic keratocysts occurring in the tooth-bearing area as compared to the posterior region of the jaws in order to come up with reliable data to base upon a rational treatment policy.

METHODS

We searched MEDLINE, Web of Science, Scopus, and Cochrane databases for studies reporting on the location of mandibular and maxillary odontogenic keratocysts. All records were independently assessed and a meta-analysis was performed. Risk difference with a confidence interval of 95% of having the lesion in the posterior region versus the tooth-bearing area was the effect measure. P value for the summary effect of < 0.05 was considered statistically significant.

RESULTS

The 2615 records retrieved were reduced to 34 studies to be qualitatively/quantitatively assessed. The pooled values showed that the difference in the clinical risk of having keratocysts in the posterior region of the mandible and in the tooth-bearing area of the maxilla is 21 and 43%, respectively (P < 0.02 and P < 0.00001).

CONCLUSIONS

A substantial amount of keratocysts occur in the tooth-bearing area of the jaws, requiring attention.

Cone Beam Computed Tomography in Oral and Maxillofacial Surgery: An Evidence-Based Review

Cone Beam Computed Tomography (CBCT) is a valuable imaging technique in oral and maxillofacial surgery (OMS) that can help direct a surgeon’s approach to a variety of conditions. A 3-dimensional analysis of head and neck anatomy allows practitioners to plan appropriately, operate with confidence, and assess results post-operatively. CBCT imaging has clear indications and limitations. CBCT offers the clinician 3-dimensional and multi-planar views for a more accurate diagnosis and treatment without the financial burden and radiation exposure of conventional computed tomography (CT) scans. Furthermore, CBCT overcomes certain limitations of 2-dimensional imaging, such as distortion, magnification, and superimposition. However, CBCT lacks the detailed depiction of soft tissue conditions for evaluation of pathologic conditions, head and neck infections, and temporomandibular joint (TMJ) disc evaluation. This review evaluates the evidence-based research supporting the application of CBCT in the various fields of oral and maxillofacial surgery, including dentoalveolar surgery, dental implants, TMJ, orthognathic surgery, trauma, and pathology, and will assess the value of CBCT in pre-operative assessment, surgical planning, and post-operative analysis when applicable. Additionally, the significant limitations of CBCT and potential areas for future research will be discussed.

Breaking Symmetry: A Quantitative Analysis of Facial Skeleton Disharmony in Children Born with Bilateral Cleft Lip and Palate

Bilateral cleft lip and palate (BCLP) occurs when craniofacial precursors fail to form or fuse properly during development. The aim of this retrospective, cross-sectional investigation was to quantify directional asymmetry (DA) of the facial skeleton of children born with Veau Class IV nonsyndromic BCLP. To accomplish this goal, coordinate values of anatomical landmarks were acquired from three-dimensional cone beam computed tomographic images of the craniofacial skeleton of middle- to late-aged children born with BCLP and age- and sex-matched controls and used to compare patterns of asymmetry variation. Multivariate analyses revealed different patterns of DA variation across samples and identified approximately 30% of DA measures as significantly different. Magnitudes of statistically significant linear distances differ in the craniofacial region, with most smaller DA differences located near the orbits and frontal bone, while larger differences were localized mostly to the midface, alveolar ridge, and nasal borders. Generally, areas of the craniofacial skeleton derived from the maxillary and nasal prominences demonstrated the highest magnitudes of DA. The methods and results presented will be useful to biomedical researchers when identifying the extent to which patients with BCLP diverge from typical developmental expectations. Quantifying DA and assessing local differences across the craniofacial complex can aid medical practitioners when developing treatments to improve BCLP surgical algorithms and outcomes. Anat Rec, 302:1726-1732, 2019. © 2019 American Association for Anatomy.

Diagnostic Yield of Dental Radiography and Cone-Beam Computed Tomography for the Identification of Anatomic Structures in Cats

The objective of this study was to evaluate the diagnostic yield of dental radiography (DR) and 3 cone-beam computed tomography (CBCT) methods for the identification of predefined anatomic structures in cats. For 5 feline cadaver heads and 22 client-owned cats admitted for evaluation and treatment of dental disease, a total of 22 predefined anatomic structures were evaluated separately by use of the DR method and 3 CBCT software modules [multiplanar reconstructions (MPR), tridimensional (3-D) rendering, and reconstructed panoramic views (Pano)]. A semi quantitative scoring system was used, and mean scores were calculated for each anatomic structure and imaging method. The Friedman test was used to evaluate values for significant differences in diagnostic yield. For values that were significant the Wilcoxon signed rank test was used with the Bonferroni-Holm multiple comparison adjustment to determine significant differences among each of the possible pairs of diagnostic methods. Differences of diagnostic yield among the DR and 3 CBCT methods were significant for 17 of 22 anatomic structures. For these structures, DR scores were significantly higher than scores for Pano views for 2 of 17 structures, but DR scores were significantly lower than scores for Pano views for 6 anatomic structures, tridimensional rendering for 10 anatomic structures, and MPR for 17 anatomic structures. In conclusion, it was found that CBCT methods were better suited than DR for the identification of anatomic structures in cats. Results of this study can serve as a basis for CBCT evaluation of dentoalveolar and other maxillofacial bony lesions in cats.

Prevalence of anatomical variants in the clivus: fossa navicularis magna, canalis basilaris medianus, and craniopharyngeal canal

PURPOSE

This study determined the prevalence of fossa navicularis magna (FNM), canalis basilaris medianus (CBM), and craniopharyngeal canal (CPC), the size of FNMs, and types of CBM using 3D computed tomography (CT) images.

METHODS

A total of 1059 3D images [649 cone beam computed tomography (CBCT) and 410 CT] were evaluated in this study. The prevalence of FNM, CBM, and CPC, length, width, and depth of FNM, and type of CBM were assessed.

RESULTS

Overall, FNM was identified in 7.6%, CPC in 0.3%, and CBM in 2.5% of the study group. Type 2 (0.1%) and Type 6 (0.1%) are the least common CBM types. There was no significant difference between genders for depth and width measurements (p > 0.05), however, the length of FNM was significantly higher in males than females in CBCT images (p = 0.02).

CONCLUSION

FNM, CBM, and CPC are rare anatomical variants of clivus. However, they can facilitate spread of infection to the skull base or vice-versa. These types of anatomical variations should be known by radiologists to avoid unnecessary diagnosis and treatment procedures and to distinguish anatomic variations from pathological conditions.

Dose reduction in CT imaging for facial bone trauma in adults: A narrative literature review

Trauma to the facial area accounts for a significant number of admissions to the emergency department. Diagnostic imaging is almost always required, and is critical in determining patient management. Multi‐detector computed tomography (MDCT) appears consistently in the literature as the gold‐standard imaging modality for facial bones, but results in a high radiation dose to the patient. This makes the application and advancement of dose reduction and dose optimisation methods vital. This narrative review presents a critical analysis of the literature concerning diagnostic imaging of facial bone trauma, with an emphasis on dose reduction methods for MDCT. Databases including Pubmed, Medline, Web of Science and Scopus were used to investigate this topic, with the key words: facial bone trauma, computed tomography (CT) imaging and dose reduction. Exclusion criteria included studies on nasal bone fracturing, dental imaging, elective surgeries and paediatric imaging. The literature shows overwhelming support for MDCT, given its accuracy, efficiency and ease of operation. Noise reducing reconstruction algorithms show promise as a successful method of dose reduction in facial bone imaging. Investigations of more innovative techniques also appear within the literature, including diagnostic cone‐beam CT (CBCT), intraoperative CBCT and dual‐source CT (DSCT), but further research is required to confirm their clinical value.

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

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

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

OBJECTIVES:

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

METHODS:

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

RESULTS:

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

CONCLUSIONS:

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

Use of cone beam computed tomography in implant dentistry: current concepts, indications and limitations for clinical practice and research

Diagnostic radiology is an essential component of treatment planning in the field of implant dentistry. This narrative review will present current concepts for the use of cone beam computed tomography imaging, before and after implant placement, in daily clinical practice and research. Guidelines for the selection of three-dimensional imaging will be discussed, and limitations will be highlighted. Current concepts of radiation dose optimization, including novel imaging modalities using low-dose protocols, will be presented. For preoperative cross-sectional imaging, data are still not available which demonstrate that cone beam computed tomography results in fewer intraoperative complications such as nerve damage or bleeding incidents, or that implants inserted using preoperative cone beam computed tomography data sets for planning purposes will exhibit higher survival or success rates. The use of cone beam computed tomography following the insertion of dental implants should be restricted to specific postoperative complications, such as damage of neurovascular structures or postoperative infections in relation to the maxillary sinus. Regarding peri-implantitis, the diagnosis and severity of the disease should be evaluated primarily based on clinical parameters and on radiological findings based on periapical radiographs (two dimensional). The use of cone beam computed tomography scans in clinical research might not yield any evident beneficial effect for the patient included. As many of the cone beam computed tomography scans performed for research have no direct therapeutic consequence, dose optimization measures should be implemented by using appropriate exposure parameters and by reducing the field of view to the actual region of interest.

Comparison of hand and semiautomatic tracing methods for creating maxillofacial artificial organs using sequences of computed tomography (CT) and cone beam computed tomography (CBCT) images

INTRODUCTION

The aim of this study was to compare the paranasal sinus volumes obtained by manual and semiautomatic imaging software programs using both CT and CBCT imaging.

METHODS

121 computed tomography (CT) and 119 cone beam computed tomography (CBCT) examinations were selected from the databases of the authors' institutes. The Digital Imaging and Communications in Medicine (DICOM) images were imported into 3-dimensonal imaging software, in which hand mode and semiautomatic tracing methods were used to measure the volumes of both maxillary sinuses and the sphenoid sinus. The determined volumetric means were compared to previously published averages.

RESULTS

Isometric CBCT-based volume determination results were closer to the real volume conditions, whereas the non-isometric CT-based volume measurements defined coherently lower volumes. By comparing the 2 volume measurement modes, the values gained from hand mode were closer to the literature data. Furthermore, CBCT-based image measurement results corresponded to the known averages.

CONCLUSIONS

Our results suggest that CBCT images provide reliable volumetric information that can be depended on for artificial organ construction, and which may aid the guidance of the operator prior to or during the intervention.

Cone Beam CT in Diagnosis and Surgical Planning of Dentigerous Cyst

Diagnosis and preoperative planning are critical in the execution of any surgical procedure. Panoramic radiography is a routine method used in dentistry to assist clinical diagnosis; however, with this technique 3D anatomical structures are compressed into 2D images, resulting in overlapping of structures which are of interest in the diagnosis. In this study we report the case of a patient who presented with a dentigerous cyst of expressive dimensions in the body of the mandible region. The surgery was planned and executed after observing the margins of the lesion by Cone Beam Computed Tomography (CBCT). We conclude that CBCT is a precise method to help diagnosis; it provides greater accuracy in surgical treatment planning through 3D image display, allowing more effective results.

Cone Beam Computed Tomography Heralding New Vistas in Appropriate Diagnosis and Efficient Management of Incidentally Found Impacted Mesiodens

As dentistry continues to go "digital," the field has seen a phenomenal increase in the use of digital imaging in dental practice. Complex impacted mesiodens present potential treatment complications and sometimes possible patient morbidity. Objectives of diagnostic imaging are to aid in diagnosis, decision making, and enhance treatment outcomes. As cases become more complex, sophisticated multiplane imaging methods allowing for a three-dimensional view are more likely to meet these objectives as opposed to traditional two-dimensional radiography. The clinical report elucidates with the help of an illustrative patient how cone beam computed tomography imaging can assist the surgeon during surgical treatment planning, risk assessment, and treatment outcomes of impacted mesiodens.

Cone beam computed tomography scanning and diagnosis for dental implants

Cone beam computed tomography (CBCT) has become an important new technology for oral and maxillofacial surgery practitioners. CBCT provides improved office-based diagnostic capability and applications for surgical procedures, such as CT guidance through the use of computer-generated drill guides. A thorough knowledge of the basic science of CBCT as well as the ability to interpret the images correctly and thoroughly is essential to current practice.

CT Scan as an Essential Tool in Diagnosis of Non-radiopaque Sialoliths

Sialolithiasis is the second most common disease of the salivary glands and the main cause of salivary gland obstruction. Diagnosis of calculi/sialoliths can be made by means of an elaborate history, precise clinical examination and radiographic support. But all sialoliths do not present with predictable signs and symptoms and radiographic appearance. Sialoliths have a variety of manifestations and they may or may not be radiopaque. Non-radiopaque sialoliths are difficult to diagnose radiographically. Although newer techniques like CBCT, CT virtual sialandoscopy and established techniques like sialography, xeroradiography can be useful in selected cases. A regular CT scan is an excellent tool in the diagnosis of a non-radiopaque sialolith and associated salivary gland changes. CT scan should be considered as an important tool of imaging for diagnosis, treatment planning and follow-up of all cases of sialoliths and associated pathologies of the salivary gland.

Calculating nasoseptal flap dimensions: a cadaveric study using cone beam computed tomography

We hypothesize that three-dimensional imaging using cone beam computed tomography (CBCT) is suitable for calculating nasoseptal flap (NSF) dimensions. To evaluate our hypothesis, we compared CBCT NSF dimensions with anatomical dissections. The NSF reach and vascularity were studied. In an anatomical study (n = 10), CBCT NSF length and surface were calculated and compared with anatomical dissections. The NSF position was evaluated by placing the NSF from the anterior sphenoid sinus wall and from the sella along the skull base towards the frontal sinus. To visualize the NSF vascularity in CBCT, the external carotic arteries were perfused with colored Iomeron. Correlations between CBCT NSFs and anatomical dissections were strongly positive (r > 0.70). The CBCT NSF surface was 19.8 cm(2) [16.6-22.3] and the left and right CBCT NSF lengths were 78.3 mm [73.2-89.5] and 77.7 mm [72.2-88.4] respectively. Covering of the anterior skull base was possible by positioning the NSF anterior to the sphenoid sinus. If the NSF was positioned from the sella along the skull base towards the frontal sinus, the NSF reached partially into the anterior ethmoidal sinuses. CBCT is a valuable technique for calculating NSF dimensions. CBCT to demonstrate septum vascularity in cadavers proved to be less suitable. The NSF reach for covering the anterior skull base depends on positioning. This study encourages preoperative planning of a customized NSF, in an attempt to spare septal mucosa. In the concept of minimal invasive surgery, accompanied by providing customized care, this can benefit the patients' postoperative complaints.

Characteristic features of the adenomatoid odontogenic tumour on cone beam CT

OBJECTIVES

To illustrate characteristic features of adenomatoid odontogenic tumour (AOT) on CBCT.

METHODS

The archived CBCT and panoramic radiographs of eight patients histopathologically diagnosed as AOT were analysed. The radiographic features displayed on both radiographic images were carefully described and compared.

RESULTS

All eight AOT cases presented as unilocular and well-demarcated lesions on both CBCT and panoramic images. CBCT images displayed three-dimensional interpretation of AOT lesions, especially the detailed intralesional radiopacities. Numerous discrete radiopaque foci scattered in the lesion with evident contrast to the radiolucent background could be considered as one of the characteristic features of AOT on CBCT.

CONCLUSIONS

Compared with panoramic radiography, CBCT seems to possess better potential in diagnosing AOT.