Radiographic diagnosis of root fractures: a systematic review, meta-analyses and sources of heterogeneity

Developing evidence-based clinical imaging guidelines for the diagnosis of vertically fractured teeth

OBJECTIVES

This study aimed to develop an evidence-based clinical imaging guideline for teeth suspected with vertical root fractures.

METHODS

An adaptation methodology based on the Korean Clinical Imaging Guidelines (K-CIG) was used in the guideline development process. After searching for guidelines using major databases such as Ovid-Medline, Elsevier-Embase, National Guideline Clearinghouse, and Guideline International Network, as well as domestic databases such as KoreaMed, KMbase, and KoMGI, two reviewers analyzed the retrieved articles. The retrieved articles were included in this review using well-established inclusion criteria.

RESULTS

Twenty articles were identified through an online search, of which three were selected for guideline development. Based on these three guidelines, this study developed specific recommendations concerning the optimal imaging modality for diagnosing teeth suspected of vertical root fractures.

CONCLUSIONS

Periapical radiography is the preferred method for assessing teeth with mastication-related pain and suspected vertical root fractures. However, if intraoral radiographs do not provide sufficient information about root fractures, a small FOV CBCT may be considered. However, the use of CBCT in endodontically treated teeth is significantly constrained by the presence of artificial shading.

Influence of the metal post material, tooth location in the dental arch, and metal artifact reduction tool on vertical root fracture diagnosis in cone beam CT

This study aimed to evaluate the influence of the metal post composition, tooth location in the dental arch, and metal artifact reduction (MAR) on vertical root fracture (VRF) diagnosis in cone beam computed tomography (CBCT). Twenty-two unirradicular premolars (12 sound and 10 fractured) and two alveolar sockets of a mandible (anterior and posterior regions) composed the sample. CBCT scans of each tooth with a metal post placed into the root canal-silver-palladium (Ag-Pd), cobalt-chromium (Co-Cr), or nickel-chromium (Ni-Cr)-were individually acquired for each mandibular region, and two conditions of MAR, using a OP300 device (Instrumentarium, Finland). Images were assessed by five evaluators independently for VRF detection. Diagnostic values were calculated and compared among all groups using multi-way ANOVA with Tukey post hoc test to investigate the effect of post material, anatomical region, and MAR on VRF diagnosis (α = 0.05). Values of area under the receiver operating curve and specificity were not influenced by the studied factors (p > 0.05). Sensitivity was influenced by the MAR in both mandibular regions (p < 0.05). In the anterior region, sensitivity values increased when the MAR was enabled, regardless of the metal post material (p < 0.05). Similar behavior was noticed in the posterior region for Ni-Cr (p < 0.05) but not for Ag-Pd and Co-Cr posts (p > 0.05). The MAR improved the sensitivity in VRF diagnosis for all tested metal posts in the mandibular anterior region and for the Ni-Cr post in the mandibular posterior region. Therefore, for images obtained in the OP300 CBCT device, activation of the MAR is suggested in these cases.

Cone-Beam Computed Tomography (CBCT)-Based Diagnosis of Dental Bone Defects

Cone Beam Computed Tomography (CBCT) has completely changed the way that bone disorders are diagnosed and treated, especially in the dental and maxillofacial domains. This article examines the diverse applications of computed tomography (CBCT) in the diagnosis and treatment of facial trauma, including mandibular, dentoalveolar, and other facial fractures, as well as bone abnormalities like dislocations and fractures. CBCT is useful for a wide range of dental conditions and greatly improves diagnostic accuracy in periodontics, orthodontics, endodontics, and dental implantology. Additionally, a comparison between CBCT and conventional imaging methods was conducted, emphasizing the latter's inferior 3D imaging capabilities, allowing for more precise treatment planning and better patient outcomes with CBCT. Although CBCT has many benefits, it also has some drawbacks, such as requiring specific training for accurate interpretation, cost considerations, and a higher radiation exposure than with traditional dental X-rays. In order to optimize benefits and reduce risks, the conclusion highlights CBCT's revolutionary influence on clinical practice while arguing for its prudent and responsible application.

Methodological assessment and overall confidence in the results of systematic reviews with meta-analyses focusing on traumatic dental injuries: A cross-sectional study

BACKGROUND/AIMS

High methodological quality is required to interpret results of systematic reviews (SRs) in a reliable and accurate manner. The primary aim of this study was to appraise the methodologic quality of SRs with meta-analysis within the field of traumatic dental injuries using the A MeaSurement Tool to Assess systematic Reviews (AMSTAR) 2 tool and assess overall confidence in their results. A secondary aim was to identify potential predictive factors associated with methodological quality.

MATERIALS AND METHODS

SRs with meta-analyses published in English in the field of traumatic dental injuries from inception to March 2023 were identified. The methodological quality of the included reviews was assessed using the AMSTAR 2 checklist. Two independent evaluators scored each AMSTAR 2 item as "yes" if it was adequately addressed, "partial yes" if it was partially addressed, and "no" if it was not addressed. The overall confidence in the results of each review was classified as "High," "Moderate," "Low," or "Critically low." Using multiple regression, the relationship between five predictor variables (journal impact factor, year of publication, number of authors, journal adherence to Preferred Reporting Items for Systematic reviews and Meta-analyses [PRISMA] guidelines and a priori protocol registration) and the total AMSTAR 2 scores was analyzed. The p-value was 5%.

RESULTS

Forty-one SRs were included. The overall confidence in the results of 13 reviews was categorized as "Critically low," 18 as "Low," 3 as "Moderate" and 7 as "High." Among the five predictor variables analyzed statistically, impact factor of the journal and year of publication significantly influenced the total AMSTAR 2 scores. The number of authors, adherence to PRISMA guidelines, and a priori protocol registration had no significant impact on AMSTAR 2 scores.

CONCLUSION

The overall confidence in the results of SRs with meta-analysis within the field of traumatic dental injuries was "Low" or "Critically Low" in the vast majority of studies (31 of 41). SRs with meta-analyses published in journals with higher impact factors and more recent publications had significantly higher methodological quality.

Influence of a Metal Artifact Reduction Filter on the Diagnostic Accuracy of Complete and Incomplete Vertical Root Fractures

INTRODUCTION

This study aimed to assess the influence of the e-vol DX BAR filter on the diagnostic accuracy of complete and incomplete vertical root fractures (VRFs).

METHODS

Twenty single-rooted teeth were selected. The tooth crowns were removed, and the root canals were prepared up to a 40/.06 instrument (ProTaper Next). Each specimen was scanned in a Prexion 3D cone-beam computed tomography (CBCT) device, in a dry human skull, in 4 different situations: no root canal filling, gutta-percha, fiberglass post, and metal post. The specimens were fractured in a universal testing machine by using a customized wedge. Each specimen was reinspected to confirm the presence of incomplete VRFs. Another set of CBCT scans was performed. Then, the fractures were completed in the universal testing machine, the teeth were reinspected, and the CBCT images were acquired again. Images were assessed by using the e-Vol DX software system, with the BAR filter and with the original images, for the diagnosis of VRFs. Statistical analysis was performed by using the DeLong and McNemar tests for the comparison of the area under the receiver operating characteristic curves (AUC), accuracy, sensitivity, and specificity values.

RESULTS

The use of the BAR filter did not improve the diagnostic values of AUC, accuracy, sensitivity, and specificity in both fracture patterns (P > .05). Incomplete VRFs presented significantly lower AUC, accuracy, and sensitivity compared with complete VRFs (P < .0001).

CONCLUSIONS

The BAR filter did not improve the diagnostic accuracy of VRFs. The intracanal materials also did not influence the diagnosis. Incomplete VRFs were highly associated with a decrease in sensitivity.

Development of a predictive model for identifying previously undetected vertical root fractures

This study aimed to develop a predictive model to screen for undetected vertical root fractures (VRFs) in root canal treated teeth. We included 95 root canal treated teeth with suspected VRFs; 77 for training and 18 for validation. Following clinical and cone-beam CT parameters were recorded: sex, tooth type, coronal restoration, time interval from completion of endodontic treatment to definitive diagnosis (TI), type of bone loss (BL), apical extent of root filling (AR) and the ratio of root filling diameter to the actual diameter in the coronal (1/3TA) and middle (2/3TA) root thirds. A predictive model p = 1/(1 - e-x ) was generated, where x = -7.433 + 1.977BL + 1.479 (2/3TA) + 1.102 AR; the sensitivity and specificity were 0.852 and 0.875 for training and 0.917 and 0.833 for validation. VRF teeth were more likely to have vertical bone loss and overfilled root canals. This model had a high diagnostic efficacy for VRFs.

A novel two-staged single-visit treatment of a maxillary central incisor with complicated crown-root fracture with additional horizontal mid-root fracture - A case report with a 5-year follow-up

A concomitant complicated crown-root fracture (CCRF) and horizontal root fracture (HRF) is rarely reported in literature. This report proposes a two-staged single-visit treatment to salvage maxillary central incisor with coexisting CCRF and HRF. A female patient with CCRF with additional HRF (AHRF) of maxillary left central incisor was successfully managed with a novel two-staged treatment strategy. Stage 1 included stabilization of AHRF followed by fragment reattachment in Stage 2 of the treatment. At 5 years of followup, clinical examinations revealed no mobility or discoloration of the reattached fragment with satisfactory periodontal condition. Conebeam computed tomography revealed accurate approximation of reattached fragment to the remaining tooth and the HRF showed type II (connective tissue) healing pattern. This case report concludes that two-staged treatment can be performed as an alternative treatment to invasive therapy like extraction.

A diagnostic accuracy study on an innovative auto-edge detection technique for identifying simulated implant fractures on radiographic images

Implant fracture is a rare but devastating complication of treatment in partially or fully edentulous patients which requires prompt diagnosis. Nevertheless, studies on defining the most accurate technique for the detection of implant fractures are lacking. In the present study, the Canny edge detection algorithm was applied on multiple radiographic modalities including parallel periapical (PPA), oblique periapical (OPA), and cone beam CT (CBCT) with and without metal artifact reduction (MAR) to examine its accuracy for diagnosis of simulated implant fractures. Radiographs were taken from 24 intact implants and 24 implants with artificially created fractures. Images were evaluated in their original and Canny formats. The accuracy of each radiograph was assessed by comparison with a reference standard of direct observation of the implant. The greatest area under the receiver operating characteristic curve belonged to Canny CBCT with MAR (0.958), followed by original CBCT with MAR (0.917), original CBCT without MAR = Canny CBCT without MAR = Canny OPA (0.875), Canny PPA (0.833), original PPA = original OPA (0.792), respectively. The Canny edge detection algorithm is suggested as an innovative method for accurate diagnosis of clinically suspected implant fractures on CBCT and periapical radiographies.

Recent Advances in the Diagnosis of Enamel Cracks: A Narrative Review

Cracked teeth can pose a diagnostic dilemma for a clinician as they can mimic several other conditions. The constant physiological stress along with any pathological strain like trauma or iatrogenic causes can lead to the development of microcracks in the teeth. Constant exposure to immense stress can cause the progression of these often-undiagnosed tooth cracks to cause tooth fractures. This review aims to outline the etiology of tooth cracks, their classification, and recent advances in the diagnosis of enamel cracks. Diagnosing a cracked tooth can be an arduous task as symptoms differ according to the location and extension of the incomplete fracture. Early detection is critical because restorative treatment can prevent fracture propagation, microleakage, pulpal or periodontal tissue involvement, and catastrophic cusp failure. Older methods of crack detection are not sensitive or specific. They include clinical examination, visual inspection, exploratory excavation, and percussion test. The dye test used blue or gentian violet stains to highlight fracture lines. Modern methods include transillumination, optical coherence tomography Swept-Source Optical Coherence Tomography (SSOCT), near-infrared imaging, ultrasonic system, infrared thermography, and near-infrared laser. These methods appear to be more efficacious than traditional clinical dental imaging techniques in detecting longitudinal tooth cracks. Clinically distinguishing between the various types of cracks can be difficult with patient-reported signs and symptoms varying according to the location and extension of the incomplete fracture. Cracks are more common in restored teeth. Technological advances such as transillumination allow for early detection and enhanced prognosis.

Establishment of Narrow Root Fracture Models Using Modified Temperature Cycling Method and Diagnosis Using Different Cone-Beam CT Units

AIM

Using a modified thermal cycling method to establish narrow root fracture models and evaluate the diagnosis efficiency of them using four different cone-beam CT (CBCT) units. Methodology. Fifty-six intact teeth were selected, and the crowns of the teeth were embedded using general purpose acrylic resin. 50 root fracture models were established by soaking these teeth in liquid nitrogen and hot water cyclically; 6 teeth were used as the negative control. All the 56 teeth were scanned with the smallest voxel size of four different CBCT units (NewTom VGi, Planmeca Promax 3D Max, Kavo 3D eXam, and Soredex Scanora3D). 10 teeth were randomly selected, and the roots were sliced using slow-speed saw to obtain horizontal root sections. Scanning electron microscope (SEM) was used to measure the width of the fracture lines (FLs). The CBCT images were evaluated for the presence or absence of fracture lines. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the diagnosis of FLs using the four CBCT units.

RESULTS

Fifty narrow root fracture models were successfully established, and 25 root sections with 45 FLs were acquired. The width of FLs was from 3.43 μm to 143 μm; 32.2% of the points had width under 25 μm, while only 9.6% of them had width over 75 μm. The accuracy was 0.41, 0.54, 0.41, and 0.30 for NewTom VGi, Planmeca Promax 3D Max, Kavo 3D eXam, and Soredex Scanora3D, respectively.

CONCLUSIONS

The modified temperature cycling method is a simple and effective method to establish narrow root fracture models, and the diagnosis efficiency for these narrow fracture lines was quite poor using all the four different CBCT units.

Vertical root fractures in root treated teeth-current status and future trends

Vertical root fracture (VRF) is a common reason for the extraction of root filled teeth. The accurate diagnosis of VRF may be challenging due to the absence of clinical signs, whilst conventional radiographic assessment is often inconclusive. However, an understanding of the aetiology of VRFs, and more importantly, the key predisposing factors, is crucial in identifying teeth that may be susceptible. Thorough clinical examination with magnification and co-axial lighting is essential in identifying VRFs, and although CBCT is unable to reliably detect VRFs per se, the pattern of bone loss typically associated with VRF can be fully appreciated, and therefore, increases the probability of correct diagnosis and management. The prevalence of VRFs in root filled teeth is significantly greater than in teeth with vital pulps, demonstrating that the combination of loss of structural integrity, presence of pre-existing fractures and biochemical effects of loss of vitality, are highly relevant. Careful assessment of the occlusal scheme, presence of deflective contacts and identification of parafunctional habits is imperative in both preventing and managing VRFs. Furthermore, anatomical factors such as root canal morphology, may predispose certain teeth to VRF. The influence of access cavity design and root canal instrumentation protocols should be considered although the impact of these on the fracture resistance of root filled teeth is not clearly validated. The post-endodontic restoration of root filled teeth should be expedient and considerate to the residual tooth structure. Posts should be placed 'passively' and excessive 'post-space' preparation should be avoided. This narrative review aims to present the aetiology, potential predisposing factors, histopathology, diagnosis and management of VRF and present perspectives for future research. Currently, there are limited options other than extraction for the management of VRF, although root resection may be considered in multi-rooted teeth. Innovative techniques to 'repair' VRFs using both orthograde and surgical approaches require further research and validation. The prevention of VRFs is critical; identifying susceptible teeth, utilizing conservative endodontic procedures, together with expedient and appropriate post-endodontic restorative procedures is paramount to reducing the incidence of terminal VRFs.

Determination of a cone-beam CT low-dose protocol for root fracture diagnosis in non-endodontically treated anterior maxillary teeth

OBJECTIVES

The aim of this study was to determine a "low-dose protocol" which provides acceptable diagnostic accuracy for detection of root fractures in unrestored anterior maxillary teeth, using an ex vivo model.

METHODS

48 maxillary anterior teeth, half with horizontal or oblique root fractures, were imaged using CBCT in an anthropomorphic model. Nine X-ray exposure combinations were used, including the manufacturer's standard ("reference") exposure and high-resolution settings ("HiRes"), by varying kV, exposure time, and rotation angle. Measurements of Dose Area Product (DAP) were recorded. Five dental radiologists assessed the scans for root fractures and judged image quality. Parameters of diagnostic accuracy were calculated, including area under the Receiver Operating Characteristic curve (A_z). Objective measures of image quality were made at the same exposure combinations using an image quality phantom.

RESULTS

Although there was a significant linear relationship between DAP and mean A_z, only the lowest DAP exposure combination had a mean A_z significantly different to the reference exposure. There was no significant effect on other diagnostic accuracy parameters when using HiRes compared with the reference exposure. There was a significant positive relationship between DAP and contrast resolution. HiRes did not significantly improve contrast resolution and made a small improvement to spatial resolution.

CONCLUSIONS

Scope existed for radiation dose reduction compared with the manufacturer's guidance. There was no improvement in diagnostic accuracy using HiRes settings. A cautious recommendation for this CBCT machine is that it is possible to achieve a dose reduction of about 20% compared with the reference exposure parameters.

A Critical Review of the Differential Diagnosis of Root Fracture Line in CBCT scans

The objective of this critical review of literature is to discuss relevant clinical factors associated with root fractures (RF) visualized by using a new CBCT software. RF constitutes a common occurrence and a challenge in clinical practice, in which the diagnosis becomes essential for the definition of rapid and precise decision-making. The characterization of RF may involve different aspects, such as orientation of the fracture line (horizontal, vertical, oblique), root position of the fracture (cervical, middle, apical third), fracture's coronal-radicular position (coronary, coronal-radicular, radicular), continuity of the fracture (crack, incomplete fracture, complete), bone extension of the fracture (supraosseous, bone level, infraosseous fracture). Imaging examinations have been routinely used to aid in the RF diagnosis. Even with high-resolution cone-beam computed tomography (CBCT) scans, many doubts often remain about the diagnostic outcome. Many interferences in the analysis of image quality to determine the diagnosis are identified, such as the sharpness, the noise, light and dark artifacts, among others. The professional's knowledge is essential for identifying the different patterns of fracture lines and their repercussions on adjacent bone tissues, as well as for the analysis of artifacts that may hide or show similarities to fracture lines. Fractures lines and root fractures that may be associated with phantom conditions that mimic fractures should be carefully analyzed. CBCT is the exam indicated to identify a root fracture. It is also added to the success of the diagnosis that the professional has scientific knowledge, training and mastery of advanced CBCT software.

Dental undergraduate students' ability in the diagnosis of root fractures: Comparative analysis of different imaging methods

OBJECTIVE

The aim of this study was to evaluate the diagnostic ability of dental undergraduate students to detect horizontal and oblique root fractures (ORFs) using different imaging techniques.

MATERIALS AND METHODS

Nine teeth were selected and randomly divided in three groups in order to create a fracture line without fragments separation: control (without fracture), horizontal root fracture (HRF), and ORF. The root fracture was created using perpendicular force and was confirmed by transillumination. A model with two adjacent teeth was created, and different imaging techniques were performed: conventional periapical radiograph; mesially and distally shifted periapical radiographs; cone-beam computer tomography (CBCT). Twenty students that had participation on dental trauma clinic at the year of 2019 were invited to identify root fractures by a five-point scale: (i) fracture definitely not present, (ii) fracture probably not present, (iii) uncertain whether fracture is present or not, (iv) fracture probably present, and (v) fracture definitely present. Data were analyzed by Kappa test for agreement evaluation.

RESULTS

Comparing each student to the gold standard, there was a variation in reproducibility and performance from poor to substantial (0.042-0.667). Reproducibility values ranged from poor to good for all periapical radiographs both in the diagnosis of ORF (-0.33-0.667) and in HRF (0-1).

CONCLUSIONS

In CBCT images, the students' ability was lower in HRF detection in comparison with the oblique ones. The students showed limited capacity to diagnose root fractures; however when CBCT was used, the performance was more satisfactory than when periapical radiographs were used.

Cone beam CT optimisation for detection of vertical root fracture with metal in the field of view or the exomass

Dose optimisation has been revisited in the literature due to the frequent use of cone beam computed tomography (CBCT). Although the reduction of the field-of-view (FOV) size has shown to be an effective strategy, this indirectly increases the negative effect from the exomass. The aim of this study was to evaluate the diagnostic accuracy of an optimised CBCT protocol in the detection of simulated vertical root fracture (VRF) in the presence of metal in the exomass and/or inside the FOV. Twenty teeth were endodontically instrumented and VRF was induced in half of them. All teeth were individually placed in a human mandible covered with a soft tissue equivalent material, metallic materials were placed at different dispositions in the exomass and/or endomass, and CBCT scans were obtained at two dose protocols: standard and optimised. Five radiologists evaluated the images and indicated the presence of VRF using a 5-point scale. Area under the ROC curve (AUC), sensitivity, and specificity were calculated and compared using ANOVA (α = 0.05). Overall, AUC, sensitivity, and specificity did not differ significantly (p > 0.05) between the dose protocols. In conclusion, optimised dose protocols should be considered in the detection of simulated VRF irrespective of the occurrence of artefacts from metallic materials in the exomass and/or inside the FOV.

Diagnosis of cracked teeth using cone-beam computed tomography: literature review and clinical experience

Cone-beam computed tomography (CBCT) has been widely used in diagnosis of vertical root fractures (VRFs) in recent years. According to the American Association of Endodontists (AAE) classification, there are five types of cracked teeth and VRF is one of them. Due to the variability and overlapping of the cracks and fractures, some narrow fractures on the roots of VRFs could not be detected by CBCT, and some wide cracks on the crown of cracked teeth could be detected by CBCT. In this review, we firstly discussed the value of CBCT in the diagnosis of the AAE five types of cracked teeth and presented CBCT manifestations of some typical cases. Secondly, we summarized the factors influencing the diagnosis of cracks/fractures using CBCT, namely, CBCT device-related factors, patient-related factors, and evaluator-related factors. The possible strategies to improve the diagnostic accuracy in the clinic practice are also discussed in this part. Finally, we compared the differences of root fractures with lateral canals and external root resorption on CBCT images.

Influence of CBCT metal artifact reduction on vertical radicular fracture detection

Purpose

This study evaluated the influence of a metal artifact reduction (MAR) tool in a cone-beam computed tomography (CBCT) device on the diagnosis of vertical root fractures (VRFs) in teeth with different root filling materials.

Materials and Methods

Forty-five extracted human premolars were classified into three subgroups; 1) no filling; 2) gutta-percha; and 3) metallic post. CBCT images were acquired using an Orthopantomograph 300 unit with and without a MAR tool. Subsequently, the same teeth were fractured, and new CBCT scans were obtained with and without MAR. Two oral radiologists evaluated the images regarding the presence or absence of VRF. Receiver operating characteristic (ROC) curves and diagnostic tests were performed.

Results

The overall area under the curve values were 0.695 for CBCT with MAR and 0.789 for CBCT without MAR. The MAR tool negatively influenced the overall diagnosis of VRFs in all tested subgroups, with lower accuracy (0.45–0.72), sensitivity (0.6–0.67), and specificity (0.23–0.8) than were found for the images without MAR. In the latter group, the accuracy, sensitivity, and specificity values were 0.68–0.77, 0.67–083, and 0.53–087, respectively. However, no significant difference was found between images with and without MAR for the no filling and gutta-percha subgroups (P>0.05). In the metallic post subgroup, CBCT showed a significant difference according to MAR use (P<0.05).

Conclusion

The OP 300 MAR tool negatively influenced the detection of VRFs in teeth with no root canal filling, gutta-percha, or metallic posts. Teeth with metallic posts suffered the most from the negative impact of MAR.

Diagnosis and Management of Traumatic Dental Injuries Using Intraoral Radiography and Cone-beam Computed Tomography: An In Vivo Investigation

INTRODUCTION

The aim of this study was to compare periapical radiographs (PRs) and upper standard occlusal (USO) radiographs with cone-beam computed tomographic (CBCT) imaging on clinicians' confidence in the diagnosis and management of traumatic dental injuries (TDIs).

METHODS

This study included 35 maxillary anterior teeth from 25 patients with at least 1 PR (parallax view) and a CBCT scan. Fourteen patients also had a USO radiograph. Ten examiners selected a diagnosis and treatment plan, which were compared with a reference standard. Sensitivity, specificity, positive and negative predictor values, and receiver operating characteristic analysis were used to determine the diagnostic accuracy.

RESULTS

CBCT imaging exhibited significantly higher sensitivity than both conventional radiographic techniques combined (PRs and PRs + USO radiographs) for all diagnoses (TDI: 99% vs 84%, lateral luxation: 80% vs 34%, extrusions: 92% vs 42%, and cortical plate fracture: 58% vs 1%) other than horizontal root fractures in which the results were close to statistical significance (88% vs 69%). CBCT imaging was significantly more accurate for all diagnoses (TDI: 91% vs 70%, lateral luxations: 83% vs 61%, extrusive luxations: 92% vs 68%, alveolar cortical plate fractures: 78% vs 48%, and horizontal root fractures: 93% vs 82%). Examiners had the most confidence with CBCT imaging and the least confidence in diagnosing using PRs + USO radiographs than with PRs alone. Agreement with management plans was significantly better using CBCT imaging compared with PRs and PRs + USO radiographs.

CONCLUSIONS

CBCT imaging improved the clinical diagnosis of TDIs. The addition of USO radiographs to PRs did not improve the diagnosis of TDIs in this investigation. CBCT imaging improved confidence in the diagnosis of TDI cases and treatment planning compared with conventional radiography.

Two decades of research on CBCT imaging in DMFR - an appraisal of scientific evidence

OBJECTIVE

This article aims to appraise how scientific evidence related to CBCT has changed over the years, based on levels of evidence and diagnostic efficacy.

METHODS

A general search strategy was used in different databases (Pubmed, Embase, and Web of Science) to identify systematic reviews (SRs) on CBCT until November of 2020. The SRs included were divided according to different specialties of dentistry. A critical review of the articles was made, describing the level of evidence and efficacy.

RESULTS

In total, 75 articles were selected. There was an increase in the number of SRs on CBCT from 2014 onwards, as 83% of the SRs on this topic were published after 2013, and 72% between 2016 and to date. Twenty SRs (27%) performed meta-analysis. Only 28% of the SRs provided a detailed description of CBCT protocols. According to SR evidence, almost all specialties of dentistry have advanced concomitantly with the introduction of CBCT. The majority of SRs were related to clinical applications (level 2 of efficacy), followed by technical parameters (level 1 of efficacy). Only some CBCT models were mentioned in the SRs selected.

CONCLUSION

Over the course of 20 years, SRs related to CBCT applications for a broad range of dental specialties have been published, with the vast majority of studies at levels 1 and 2 of diagnostic efficacy. Not all CBCT models available on the market have been scientifically validated. At all times, one should remain cautious as such not to simply extrapolate in vitro results to the clinical setting. Also, considering the wide variety of CBCT devices and protocols, reported results should not be overstated or generalized, as outcomes often refer to specific CBCT devices and protocols.

[Imaginology in the diagnosis and planning of root duct systems: an updated review]

Root canal systems present a varied morphological conformation for each group of teeth. Several authors have described the anatomical conformation and its variants in different classifications, including the main, collateral, lateral, secondary, accessory, interduct, recurrent, apical delta and interradicular cavus canals. Currently, radiology still does not allow visualization of all these structures. However, proper use of imaging techniques together with the use of new 3D equipment for adjustments of acquisition parameters with adequate software and algorithms allows greater image precision, facilitating diagnosis and the planning of the most adequate approach for endodontic treatments. The objective of this article was to conduct a review of the literature to identify new concepts and useful imaging tools for better diagnoses.

Assessment of true vertical root fracture line in endodontically treated teeth using a new subtraction software - A Micro-CT and CBCT study

This study aimed to find true facture lines in endodontically treated teeth on CBCT images using digital subtraction and to evaluate the influence of width of facture lines in the diagnosis. Thirty-two endodontically treated teeth with vertical root fractures (VRFs) from 30 patients were included in this study. The CBCT images of the patients and the micro-CT images of extracted teeth were imported into our digital subtraction software to distinguish the true facture lines from the streak artefacts. Of them, 23(71.87%) teeth did not present true fracture lines on the CBCT images (CBCT negative), and 9 (28.13%) teeth presented true fracture lines on the CBCT images (CBCT positive). The width of the facture lines was significantly different between these two groups (P < 0.05). To summarise, for in vivo endodontically treated teeth with subtle VRFs, many true fractures lines could not be demonstrated on CBCT images and wider fractures could be better distinguished.

Influence of the exomass on the detection of simulated root fracture in cone-beam CT - an ex-vivo study

OBJECTIVES

To evaluate the influence of exomass-related metal artefacts on the detection of simulated vertical root fracture (VRF) in cone-beam computed tomography (CBCT).

METHODS

20 teeth were endodontically instrumented and VRF was induced in half of them. All teeth were individually placed in an empty socket of a human mandible. Metallic materials were differently arranged in the exomass [zone outside of the field of view (FOV) but between the X-ray source and the receptor] and/or endomass (zone inside of the FOV), and CBCT scans were obtained. Four radiologists evaluated the presence of VRF using a 5-point scale. Sensitivity, specificity, and area under the receiver operating curve (AUC) were compared using ANOVA. Also, the tooth of interest was replaced with a tube filled with a radiopaque solution and all CBCT scans were repeated to analyse the data objectively. Mean grey and noise values were obtained from the tube and compared using ANOVA followed by Tukey's test (α = 0.05).

RESULTS

Mean grey values were significantly lower and noise was significantly higher when metallic materials were present in the endomass or both the exomass and endomass. Sensitivity, specificity, and AUC were not influenced by the artefacts from the metallic materials irrespective of the arrangement condition.

CONCLUSIONS

Exomass-related metal artefacts did not influence the diagnosis of simulated VRF in CBCT.

Does anthropomorphic model design in ex vivo studies affect diagnostic accuracy for dental root fracture using CBCT?

OBJECTIVES

The evidence for diagnostic accuracy using cone beam computed tomography (CBCT) for dental applications depends heavily on ex vivo research, but there is little knowledge of whether the model used affects the diagnostic accuracy results. The objective of this study was to determine the impact of different designs of anthropomorphic models on diagnostic accuracy for the specific task of dental root fracture detection.

METHODS

Horizontal or oblique root fracture was induced in 24 of 48 permanent maxillary incisors. The 48 teeth were scanned by CBCT using standard clinical exposure factors on five occasions, each with a different model design. Scans were viewed by five dental and maxillofacial radiologists, who each made a forced diagnosis of fracture or no fracture in each root and a judgment on root fracture using a five-point confidence scale. Sensitivity (Se), specificity (Sp) and areas under receiver operating characteristic (ROC) curve (Az) were calculated for each observer for each model.

RESULTS

There were no significant differences between the diagnostic accuracy measurements recorded using different models. There were, however, numerous significant differences between observers using the same anthropomorphic model.

CONCLUSIONS

Despite the differences in X-ray attenuation between the five model designs, the results suggest that the anthropomorphic model does not affect the results of diagnostic accuracy studies on root fracture using this CBCT machine at standard clinical exposures. This provides some confidence in the previously published evidence. The interobserver diagnosis differences indicate that research using only two observers could provide misleading results.

Evidence mapping and quality assessment of systematic reviews in dental traumatology

BACKGROUND/AIMS

Evidence mapping of systematic reviews (SRs) systematically and comprehensively identifies, organizes, and summarizes the distribution of scientific evidence in a field. The aims of this study were to delineate domains in dental traumatology (DT), evaluate the existing SRs within the domains, and identify the paucity of evidence for future research.

METHODS

Domains and sub-domains of DT were established according to the methods of qualitative research. The protocol for evidence mapping was prepared as per the guidelines of GEM and PRISMA. The search strategy was formulated using words and MeSH terms in eight databases without restriction of languages and year of publication. Gray literature, protocol registries, and references of selected articles were also searched. Duplicates were removed, and the final selection of SRs was completed. Data extraction and quality analysis using the ROBIS tool and the PRISMA checklist were performed.

RESULTS

The overall search resulted in 64 SRs from 1999 to 2020 with 44 published in last six years. The highest number of SRs had been performed in the Prognostic domain (n = 19) followed by the domains of Epidemiology (n = 15), Therapeutics (n = 10), Oral Biology (n = 7), Diagnostics (n = 6), Preventive (n = 5), and Research Methods (n = 2). Within each domain, there were variabilities in the number of reviewers, a priori protocols, search limitations, risk of bias methods, and meta-analysis. Of the SRs, including 4 Cochrane reviews, 28.4% were inconclusive. A low risk of bias was found in 48.4% of the SRs. Among the registered and ongoing SRs, six were from the domain of epidemiology, two in the domain of therapeutics, five from prognostics, and one each in the domains of prevention and research methods.

CONCLUSION

The SRs in DT could be mapped in seven domains with variabilities in the methods. The majority had an a priori registered protocol and a low risk of reporting errors. Within the Epidemiology and Preventive domains, SRs were present in all the sub-domains with the majority demonstrating low-risk of bias (ROB). The domain of prognosis had SRs in most sub-domains but with a high ROB. Insufficient numbers of SRs were present in most sub-domains of the Diagnostics, Therapeutics, Research Methods and Oral Biology domains.

Assessment of fractures in endodontically treated teeth restored with and without root canal posts using high-resolution cone beam computed tomography

Background

Root fractures are a diagnostic challenge for dentists in endodontic treatment. This study aimed to determine the relationship between the characteristics of tooth fractures and the presence of root canal posts in endodontically treated teeth using high-resolution cone beam computed tomography (CBCT).

Material and Methods

Fifty high-resolution CBCT scans of endodontically treated teeth with a diagnosis of fracture were obtained, of which 30 were from women and 20 were from men. These scans were acquired with three Veraviewepocs 3D units and one 3D Accuitomo 170 unit, with a 40 × 40-mm field of view and 125 μm voxel size. The variables assessed included the type of fracture, extent of fracture, type of retention, post length, cause of endodontic failure, location of the lesion, and time required to detect the fracture (difficulty score). For data analysis, the chi-squared test, Student’s t-test, and multiple linear regression (α <0.05) were used.

Results

No association was found between the type of fracture and type of retention or between the type of fracture and its extent (P>0.05). On the other hand, the type of fracture significantly influenced the time required for its detection. Additionally, the most difficult plane for detecting the fracture and the difficulty score were associated, with statistically significant results.

Conclusions

The type of fracture in endodontically treated teeth was not associated with the type of post used for restoration. All of the CBCT systems used to detect tooth fracture showed the same efficiency.

Key words:Cone-Beam CT, Tooth Fracture, Root Canal Post.

Cone-beam computed tomography and its applications in dental and maxillofacial radiology

Cone-beam computed tomography (CBCT) was first used in dental and maxillofacial radiology (DMFR) at the end of the 1990s. Since then, it has been successfully established as the standard three-dimensional radiographic imaging technique in DMFR, with a wide variety of applications in this field. This manuscript briefly reviews the background information on the technology and summarises available data on effective dose and dose optimisation. In addition, typical clinical applications and indications of the technique in DMFR are presented.

Diagnostic efficacy of cone beam computed tomography in paediatric dentistry: a systematic review

Purpose

To determine in which clinical situations it is indicated or contra-indicated to prescribe cone beam computed tomography (CBCT) for paediatric patients.

Methods

Systematic review of in vivo paediatric research studies of diagnostic efficacy using CBCT, with supplementary searches for guideline documents on CBCT and for systematic reviews permitting inclusion of ex vivo and adult studies.

Results

After screening, 190 publications were included, mostly case studies. No systematic reviews were found of in vivo paediatric research. Fourteen studies of diagnostic efficacy were identified. The supplementary searches found 18 guideline documents relevant to the review and 26 systematic reviews. The diagnostic efficacy evidence on CBCT was diverse and often of limited quality. There was ex vivo evidence for diagnostic accuracy being greater using CBCT than radiographs for root fractures. The multiplanar capabilities of CBCT are advantageous when localising dental structures for surgical planning. Patient movement during scanning is more common in children which could reduce diagnostic efficacy.

Conclusions

No strong recommendations on CBCT are possible, except that it should not be used as a primary diagnostic tool for caries. Guidelines on use of CBCT in the paediatric age group should be developed cautiously, taking into account the greater radiation risk and the higher economic costs compared with radiography. CBCT should only be used when adequate conventional radiographic examination has not answered the question for which imaging was required. Clinical research in paediatric patients is required at the higher levels of diagnostic efficacy of CBCT.

Electronic supplementary material

The online version of this article (10.1007/s40368-019-00504-x) contains supplementary material, which is available to authorized users.

Evaluation of an artificial intelligence system for detecting vertical root fracture on panoramic radiography

OBJECTIVES

The aim of this study was to evaluate the use of a convolutional neural network (CNN) system for detecting vertical root fracture (VRF) on panoramic radiography.

METHODS

Three hundred panoramic images containing a total of 330 VRF teeth with clearly visible fracture lines were selected from our hospital imaging database. Confirmation of VRF lines was performed by two radiologists and one endodontist. Eighty percent (240 images) of the 300 images were assigned to a training set and 20% (60 images) to a test set. A CNN-based deep learning model for the detection of VRFs was built using DetectNet with DIGITS version 5.0. To defend test data selection bias and increase reliability, fivefold cross-validation was performed. Diagnostic performance was evaluated using recall, precision, and F measure.

RESULTS

Of the 330 VRFs, 267 were detected. Twenty teeth without fractures were falsely detected. Recall was 0.75, precision 0.93, and F measure 0.83.

CONCLUSIONS

The CNN learning model has shown promise as a tool to detect VRFs on panoramic images and to function as a CAD tool.

The detection of vertical root fractures in post-core restored teeth with cone-beam CT: in vivo and ex vivo

OBJECTIVES

To compare the accuracy of cone-beam CT ex vivo and in vivo for the detection of artificially created large and small vertical root fractures in extracted teeth restored with post-core.

METHODS

Individual metal cast post-cores were fixed in the root canals of 50 extracted single-rooted human teeth. In 30 teeth fractures were created by tapping posts with a hammer. The teeth were sterilised in autoclave and embedded into bite-plates made of silicon impression material. Cone-beam CT scanning was performed ex vivo and in vivo . For the in vivo scanning, teeth in sterile plastic bags were inserted into the mouths of volunteers. Then the teeth were sectioned with low-speed saw and the widths of the VRFs were measured microscopically. The teeth were distributed into 2 groups in accordance with the measured fractures' widths: large (wider than 180-250 µm) and small (80-150 µm). Five observers assessed the presence of vertical root fractures on axial CBCT slices. Sensitivity, specificity, accuracy and inter examiner agreement were calculated.

RESULTS

The accuracy of cone-beam CT in vitro for large and small vertical root fractures detection was 0.56 and 0.40 respectively (p = 0.043). The sensitivity values were 0.53 and 0.27 for large and small vertical root fractures, respectively (p = 0.043). The visualisation of fracture lines in vivo was impossible in 90 % of cases, because of low image quality. Inter examiner reliability analysis showed κ values ranging from 0.02 to 0.54.

CONCLUSIONS

Fracture width affected the in vitro detectability of vertical root fractures by cone-beam CT in teeth with metal cast post-cores. The detectability of root fractures in vivo was decreased because of low image quality, making the assessment of sound tooth tissue impossible.

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.

Effect of object position in the field of view and application of a metal artifact reduction algorithm on the detection of vertical root fractures on cone-beam computed tomography scans: An in vitro study

Purpose

To assess the effects of object position in the field of view (FOV) and application of a metal artifact reduction (MAR) algorithm on the diagnostic accuracy of cone-beam computed tomography (CBCT) for the detection of vertical root fractures (VRFs).

Materials and Methods

Sixty human single-canal premolars received root canal treatment. VRFs were induced in 30 endodontically treated teeth. The teeth were then divided into 4 groups, with 2 groups receiving metal posts and the remaining 2 only having an empty post space. The roots from different groups were mounted in a phantom made of cow rib bone, and CBCT scans were obtained for the 4 different groups. Three observers evaluated the images independently.

Results

The highest frequency of correct diagnoses of VRFs was obtained with the object positioned centrally in the FOV, using the MAR algorithm. Peripheral positioning of the object without the MAR algorithm yielded the highest sensitivity for the first observer (66.7%). For the second and third observers, a central position improved sensitivity, with or without the MAR algorithm. In the presence of metal posts, central positioning of the object in the FOV significantly increased the diagnostic sensitivity and accuracy compared to peripheral positioning.

Conclusion

Diagnostic accuracy was higher with central positioning than with peripheral positioning, irrespective of whether the MAR algorithm was applied. However, the effect of the MAR algorithm was more significant with central positioning than with peripheral positioning of the object in the FOV. The clinical experience and expertise of the observers may serve as a confounder in this respect.