Genome-wide Association Study Identifies Novel Risk Loci for Apical Periodontitis

INTRODUCTION

Apical periodontitis (AP) is a common consequence of root canal infection leading to periapical bone resorption. Microbial and host genetic factors and their interactions have been shown to play a role in AP development and progression. Variations in a few genes have been reported in association with AP; however, the lack of genome-wide studies has hindered progress in understanding the molecular mechanisms involved. Here, we report the first genome-wide association study of AP in a large and well-characterized population.

METHODS

Male and female adults (n = 932) presenting with deep caries and AP (cases), or deep caries without AP (controls) were included. Genotyping was performed using the Illumina Expanded Multi-Ethnic Genotyping Array (MEGA). Single-variant association testing was performed adjusting for sex and 5 principal components. Subphenotype association testing, analyses of genetically regulated gene expression, polygenic risk score, and phenome-wide association (PheWAS) analyses were also conducted.

RESULTS

Eight loci reached near genome-wide significant association with AP (P < 5 × 10-6); gene-focused analyses replicated 3 previously reported associations (P < 8.9 × 10-5). Sex-specific and subphenotype-specific analyses revealed additional significant associations with variants genome-wide. Functionally oriented gene-based analyses revealed 8 genes significantly associated with AP (P < 5 × 10-5), and PheWAS analysis revealed 33 phecodes associated with AP risk score (P < 3.08 × 10-5).

CONCLUSIONS

This study identified novel genes/loci contributing to AP and specific contributions to AP risk in men and women. Importantly, we identified additional systemic conditions significantly associated with AP risk. Our findings provide strong evidence for host-mediated effects on AP susceptibility.

Differential Diagnosis of Cysts and Granulomas Supported by Texture Analysis of Intraoral Radiographs

The aim of this study was to evaluate whether textural analysis could differentiate between the two common types of lytic lesions imaged with use of radiography. Sixty-two patients were enrolled in the study with intraoral radiograph images and a histological reference study. Full textural analysis was performed using MaZda software. For over 10,000 features, logistic regression models were applied. Fragments containing lesion edges were characterized by significant correlation of structural information. Although the input images were stored using lossy compression and their scale was not preserved, the obtained results confirmed the possibility of distinguishing between cysts and granulomas with use of textural analysis of intraoral radiographs. It was shown that the important information distinguishing the aforementioned types of lesions is located at the edges and not within the lesion.

[Comparative characteristics of root formation and mineralization features in the permanent teeth according to cone beam computed tomography data]

AIM

Studying features of root formation and mineralization in permanent teeth of children and adults.

MATERIAL AND METHODS

The root formation features were studied in 2800 children's permanent teeth aged 6-15 in Moscow and Moscow region; cone beam computed tomography was performed according to the orthodontic indications. CBCT method was also used to study the apical foramen diameter, width of the permanent teeth periodontal fissure, perform clinical examination and treatment of youngsters and young people (aged 12-25, n=180) with pulpitis (K04.03), apical periodontitis (K04.5) and uncompleted processes of hard tissues mineralization and hard tissues with different degrees of maturation; as well as groups of adults (aged 30-50, n=170) with pulpitis (K04.03) and apical periodontitis (K04.5) in permanent teeth with completed processes of hard tissues mineralization.

RESULTS

CBCT is objective for visualizing teeth of both jaws which allows determining root formation stages in children's permanent teeth and high precision during one examination visit. Teeth Youngster's and young peopl's teeth have expressed anatomical and structural features during 5-6 years after root formation completion: apical foramen diameter of 0.71±0.004 mm, periodontal fissure width of 1.01±0.004 mm, hard tissues density in apical part of root is 12282.71 units HU, which is different from analogous readings in people over 25 where they make 0.61±0.004 mm (p<0.05); 0.71±0.003 mm (p<0.05); 1428.6±0.89 units HU (p<0.05) respectively.

CONCLUSION

CBCT is a useful tool for visualization of dental roots allowing precise definition of root developmental stage in permanent teeth in children by one diagnostic imaging procedure.

Comparison of the diagnostic efficacy of 2D radiography and cone beam computed tomography in persistent apical periodontal disease: A PRISMA-DTA systematic review and meta-analysis

OBJECTIVE

The objective of this study was to answer the question: Do conventional radiographs (periapical/panoramic) afford better diagnostic outcomes than cone beam computed tomography (CBCT) as a complement for clinical diagnosis of apical lesions with persistent apical periodontitis or disease after root canal treatment?

STUDY DESIGN

Five electronic databases were searched and provided information to enable construction of a table to determine primary diagnostic measures and secondary parameters. The evidence was appraised with the Quality Assessment of Diagnostic Accuracy Studies tool and GRADEpro software.

RESULTS

Twenty-seven articles (9903 diagnostic images) were included. The pooled sensitivity, specificity, area under the receiver operating characteristic curve (AUC_ROC), positive predictive value, negative predictive value, negative likelihood ratio, and accuracy were 0.58, 1, 0.77, 1, 0.68, 0.45, and 0.79, respectively.

CONCLUSIONS

Moderate certainty evidence suggested that conventional radiographs showed poor sensitivity and excellent specificity but good diagnostic performance in terms of AUC_ROC and accuracy. Sensitivity, AUC_ROC, and negative likelihood ratio values could be reduced if the time elapsed to diagnosis after root canal treatment exceeded 5 years. The use of CBCT with a reduced field of view or a 2D radiographic technique should be weighed considering patient-specific and indication-oriented criteria as taking precedence over the therapeutic goal.

Radiology in Endodontics

Endodontics requires radiographic imaging for diagnosis, treatment planning, therapy, and follow-up. Dental radiography allows for the identification of pathologic changes in the periradicular tissues that cannot be visualized by clinical inspection. For the precise execution of endodontic therapy, regular radiographic verification of individual treatment steps is necessary. As a review for clinicians, normal and pathologic findings relevant to Endodontics are presented. Key radiographic imaging techniques, such as the paralleling and bisecting techniques, as well as horizontal and vertical eccentric radiographs, are discussed. The increasing utilization and impact of cone-beam computed tomography providing 3-dimensional volume imaging are reviewed.

A Novel Volume-based Cone-beam Computed Tomographic Periapical Index

INTRODUCTION

The purpose of this study was to evaluate the variations in the volume of periapical lesions scored using a cone-beam computed tomographic periapical index (CBCTPAI) and to develop a new volume-based periapical index.

METHODS

Cone-beam computed tomographic images were obtained from InteleViewer (Intelerad Medical Systems Incorporated, Montreal, Canada). Teeth with a periapical radiolucency or with a history of endodontic treatment were included in this study. Using 3-dimensional medical imaging processing software (Mimics Research; Materialise NV, Leuven, Belgium), the maximum diameter of 273 periapical lesions and their corresponding CBCTPAI score was determined. The software was then used to determine the volume of the lesions using a semiautomatic segmentation technique.

RESULTS

There was a substantial variation in the volume for CBCTPAI scores 3, 4, and 5, which was demonstrated by the variance and range, thus making it difficult to use the current CBCTPAI as a method to predict volume and treatment outcomes. A new index, the cone-beam computed tomographic periapical volume index (CBCTPAVI), was developed using partition classification analysis. The results for the new index demonstrated high levels of sensitivity, specificity, precision, and area under the curve, all at 0.90 or more, except 1 sensitivity for CBCTPAVI 1 at 0.875. Overall, the accurate classification rate was 98.169%, and the root mean square error rate was low at 0.07.

CONCLUSIONS

The proposed CBCTPAVI will allow clinicians to classify lesions based on their true 3-dimensional size, accurately assess healing of lesions, and predict treatment outcomes.

The Association between Choice of Diagnostic Imaging Modality and Long-term Treatment Outcomes for Patients Undergoing Nonsurgical Root Canal Treatment on Maxillary First Molars

INTRODUCTION

Radiography has played a fundamental role in the advancement of nonsurgical root canal therapy (NSRCT), allowing for more accurate diagnosis and treatment. Typically, providers choose to perform NSRCT using periapical (PA) radiographs alone or, often in more difficult cases, in conjunction with cone-beam computed tomographic (CBCT) imaging. This study aimed to evaluate the outcomes of NSRCT based on imaging modality selection for the initial treatment of maxillary first molars.

METHODS

A retrospective chart review was conducted using 1385 cases of NSRCT on maxillary first molars. Charts were reviewed for patient demographics and treatment outcomes. Based on the imaging modality used, patients were stratified into 2 groups (PA radiographs alone or PA radiographs + CBCT imaging). Those who required additional treatment(s) after the completion of NSRCT were classified as having "posttreatment disease." Statistical analysis was performed to assess the differences between groups.

RESULTS

After the completion of primary endodontic therapy, 5.8% (n = 81) of the entire sample had posttreatment disease. CBCT imaging was used in 13.4% (n = 185) of NSRCTs. Although not significant, cases that were difficult enough to require the use of CBCT imaging had a higher rate of posttreatment disease compared to those that could be completed with PA radiographs alone (8.6% vs 5.4%, P > .05). Results from a multivariable logistic regression model showed that the need for CBCT imaging had a nonsignificant positive association with posttreatment disease (P > .05).

CONCLUSIONS

The decision to use CBCT imaging appears to serve as a proxy for case complexity and the associated increase in risk of posttreatment disease. This is important to keep in mind when assessing treatment prognosis.

Endodontic management of mandibular second molar fused to odontome with 12-month follow-up using cone beam computed tomography: A case report

Fusion is a developmental anomaly characterised by the union of two adjacent teeth or tooth-like substance. Odontomes are malformation of the dental tissue which arise during normal tooth development. They are usually asymptomatic but often associated with tooth eruption disturbance. In this paper, we report a rare case of fusion involving permanent mandibular second molar with an odontome, which led to a partial eruption of the molar as well as its devitalisation. Successful endodontic management was carried out in this case with a supplementary disinfection procedure using XP Endo finisher (FKG Dentaire, La Chaux-de-Fonds, Switzerland). The use of high-end diagnostic imaging modalities such as cone beam computed tomography (CBCT) helped in making a confirmatory diagnosis; determining the treatment plan before undertaking the actual treatment; for better understanding of the fused tooth's complicated root morphology; and for its effective management and to follow up this unusual case for 12 months.

Applications of cone beam computed tomography in endodontics

Background

Endodontic disease can adversely affect the quality of life and therefore early diagnosis and consequent timely treatment is of paramount importance for the Endodontist. Radiology is an essential component in treatment planning, disease monitoring and assessment of treatment outcome. Periapical radiographs and panoramic radiography are frequently utilised but they provide only two-dimensional representation of three-dimensional structures. The advent of cone beam computed tomography (CBCT) offers three-dimensional accuracy of the hard tissue images with a reasonable cost and this has revolutionised imaging of the dentomaxillofacial structures. This imaging system has been seen to overcome some limitations of conventional radiography, as brought out in this review. The improvement in the accuracy is, however, accompanied at the cost of increased radiation exposure to the patient. Nevertheless, smaller areas of exposure are normally appropriate for endodontic imaging, and adjustment in the exposure parameters can further moderate the effective dose (Loubele et al. 37(6):309-18, 2008).

Aims and objectives

The aim of this review is to present the pertinent literature on the various applications of cone beam computed tomography in the field of endodontics.

Methods

Literature was electronically searched on the following sources; Medline and Keats Library. Further, a manual search was performed on the following journals: International Endodontic Journal, Journal of Endodontics, Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, Endodontology, Journal of Dental Research, European Journal of Oral Sciences & Odontology and Dentomaxillofacial Radiology. A preliminary search was performed to gain an idea of the available literature using keywords ‘Cone Beam Computed Tomography’ to view the volume of the literature evident and identify questions to be addressed in this review. The initial search showed 243 potential articles. After scrutinising the titles and abstracts of the retrieved articles, 70 relevant studies were reviewed in full text. Furthermore, ‘published guidelines on the use of CBCT’ were also searched so as to include the results as an additional source material. All the articles eligible to be included in the review were in the English language and ranged from the year 1960 to the present. Also all the studies reviewed were based on the various uses of cone beam computed tomography in the field of endodontics. The keywords used to search were ‘Cone Beam Computed Tomography (CBCT)’, ‘Conventional radiography’, ‘Applications of CBCT in endodontics’, ‘CBCT and tooth morphology’, ‘CBCT and apical periodontitis’, ‘CBCT and vertical root fractures’, ‘CBCT and resorption’, ‘CBCT and pre-surgical assessment’, ‘CBCT and dento-alveolar trauma’ and ‘CBCT and endodontic outcome’.

Results

Every case is unique and CBCT should be considered only after studying each case individually. CBCT imaging needs to be adopted or used where information from conventional imaging systems is either inadequate for the management of endodontic problems or inconclusive. Having said that, it is safe to state that CBCT imaging has the potential to become the first choice for endodontic treatment planning and outcome assessment, especially when new scanners with lower radiation doses and enhanced resolution would be available.

Use of Texture Feature Maps for the Refinement of Information Derived from Digital Intraoral Radiographs of Lytic and Sclerotic Lesions

The aim of this study was to examine whether additional digital intraoral radiography (DIR) image preprocessing based on textural description methods improves the recognition and differentiation of periapical lesions. (1) DIR image analysis protocols incorporating clustering with the k-means approach (CLU), texture features derived from co-occurrence matrices, first-order features (FOF), gray-tone difference matrices, run-length matrices (RLM), and local binary patterns, were used to transform DIR images derived from 161 input images into textural feature maps. These maps were used to determine the capacity of the DIR representation technique to yield information about the shape of a structure, its pattern, and adequate tissue contrast. The effectiveness of the textural feature maps with regard to detection of lesions was revealed by two radiologists independently with consecutive interrater agreement. (2) High sensitivity and specificity in the recognition of radiological features of lytic lesions, i.e., radiodensity, border definition, and tissue contrast, was accomplished by CLU, FOF energy, and RLM. Detection of sclerotic lesions was refined with the use of RLM. FOF texture contributed substantially to the high sensitivity of diagnosis of sclerotic lesions. (3) Specific DIR texture-based methods markedly increased the sensitivity of the DIR technique. Therefore, application of textural feature mapping constitutes a promising diagnostic tool for improving recognition of dimension and possibly internal structure of the periapical lesions.

Diagnostic accuracy of cone-beam computed tomography scans with high- and low-resolution modes for the detection of root perforations

Purpose

This study compared the diagnostic accuracy of cone-beam computed tomography (CBCT) scans obtained with 2 CBCT systems with high- and low-resolution modes for the detection of root perforations in endodontically treated mandibular molars.

Materials and Methods

The root canals of 72 mandibular molars were cleaned and shaped. Perforations measuring 0.2, 0.3, and 0.4 mm in diameter were created at the furcation area of 48 roots, simulating strip perforations, or on the external surfaces of 48 roots, simulating root perforations. Forty-eight roots remained intact (control group). The roots were filled using gutta-percha (Gapadent, Tianjin, China) and AH26 sealer (Dentsply Maillefer, Ballaigues, Switzerland). The CBCT scans were obtained using the NewTom 3G (QR srl, Verona, Italy) and Cranex 3D (Soredex, Helsinki, Finland) CBCT systems in high- and low-resolution modes, and were evaluated by 2 observers. The chi-square test was used to assess the nominal variables.

Results

In strip perforations, the accuracies of low- and high-resolution modes were 75% and 83% for NewTom 3G and 67% and 69% for Cranex 3D. In root perforations, the accuracies of low- and high-resolution modes were 79% and 83% for NewTom 3G and was 56% and 73% for Cranex 3D.

Conclusion

The accuracy of the 2 CBCT systems was different for the detection of strip and root perforations. The Cranex 3D had non-significantly higher accuracy than the NewTom 3G. In both scanners, the high-resolution mode yielded significantly higher accuracy than the low-resolution mode. The diagnostic accuracy of CBCT scans was not affected by the perforation diameter.

Optimizing the reconstruction filter in cone-beam CT to improve periodontal ligament space visualization: An in vitro study

Purpose

Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space.

Materials and Methods

Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms.

Results

Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter.

Conclusion

Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.

A comparative study of cone-beam computed tomography and periapical radiographs in decision-making after endodontic instrument fractures

PURPOSE

This study aimed to compare the diagnostic efficacies of periapical radiographs (PRs) and cone-beam computed tomography (CBCT) scans on clinicians' decision-making in diagnosing and providing treatment of fractured instruments in root canals during glide path preparation.

METHODS

40 maxillary molar teeth were selected and randomly divided into 4 groups. In each experimental group (n = 10), Hedstroem stainless steel instruments were fractured in mesiobuccal (MB) or distobuccal (DB) root canals. In group 1 (#0.06), group 2 (#0.08), group 3 (#0.10), and group 4 (#0.15), instruments were forced to fracture. PRs and CBCT scans were evaluated and compared. Observers were asked to use the following scoring system to decide whether to: 1. remove the fragment; 2. leave the fragment in situ; 3. bypass the fragment; or 4. use a surgical approach for removing the fragment.

RESULTS

CBCT observers mostly decided on removing and bypassing the fractured fragment, while radiograph observers mostly decided to leave fragments in situ. However, there was no significant difference between these parameters when CBCT scans were compared to PRs for decision-making of the fractured instruments (p≥0.05) regarding different sizes of root canal instruments.

CONCLUSIONS

In decision-making regarding fractured instruments during glide path preparation, clinicians should strategize treatment options based on variables using high-resolution images that reflect accurate scenarios through PRs or CBCT scans that also take into account low radiation dosage in situ PRs have precedence for a diagnostic approach.

Apical Periodontitis and Endodontic Treatment in Patients with Type II Diabetes Mellitus: Comparative Cross-sectional Survey

AIMS

The aims of this study were to investigate the prevalence of apical periodontitis (AP) in diabetes mellitus (DM) patients compared with nondiabetic patients and to examine the effect of glycemic control on the prevalence of AP.

MATERIALS AND METHODS

Radiographs of a group of DM patients were compared with those of a matched nondiabetic group to identify AP. The diabetic group was subdivided according to the level of glycemic control into two subgroups: A well-controlled DM and a poorly controlled DM. The periapical index score was used to assess the periapical status. All groups were compared in regard to the presence of AP lesions, the number of end-odontically treated teeth (ET), and the percentage of failure of endodontically treated teeth (AP/ET ratio). Statistical Package for the Social Sciences (SPSS version 20.0, Chicago, Illinois, USA) was used for all the analyses; p ≤ 0.05 was considered as statistically significant.

RESULTS

The prevalence of AP was higher in diabetic group than in the nondiabetic group (13.5 vs 11.9% respectively). Diabetic group had more teeth with endodontic treatment ET compared with nondiabetic group (4.18 vs 1.82% respectively); this difference was statistically significant (p = 0.001) along with higher AP/ET ratio (27.7 vs 19.3 respectively). The poorly controlled DM group had a higher prevalence of AP lesions compared with the well-controlled DM group (18.29 vs 9.21 respectively). This difference was statistically significant (p = 0.001); they also had a higher percentage of ET (5.55 vs 3.13% respectively) and AP/ ET ratio (32.0 vs 21.8% respectively).

CONCLUSION

This survey demonstrates a higher prevalence of AP in DM patients compared with nondiabetic group, with an increased prevalence of persistent chronic AP. Compared with a well-controlled diabetic group, a poor glycemic control may be associated with a higher prevalence of AP and increased rate of endodontic failures.

CLINICAL SIGNIFICANCE

Counseling diabetic patients, particularly those with poor glycemic control, about the risk of failure of endodontic treatment can be part of planning management, which could include refereeing diabetic patients who need endodontic treatment for consultant care.

Contrast-to-noise ratio with different settings in a CBCT machine in presence of different root-end filling materials: an in vitro study

OBJECTIVES

To compare the contrast-to-noise ratio (CNR) of multiple acquisition settings for four types of retrograde filling materials in CBCT images taken for endodontic surgery follow-up.

METHODS

20 maxillary central incisors were endodontically treated and obturated with 4 different root-end filling materials: amalgam, mineral trioxide aggregate, SuperEBA(™) (Harry J Bosworth Company, Skokie, IL) and Biodentine™ (Septodont, Saint-Maur-des-Faussés, France). Teeth were placed in a skull and scanned, one by one, with the Planmeca ProMax(®) 3D Max (Planmeca, Helsinki, Finland); at different voltages: 66, 76, 84 and 96 kVp; with low, normal and high resolution and high definition (HD); with and without metal artefact reduction (MAR). Images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the CNR. The dose-area product was registered, and the effective dose calculated.

RESULTS

No statistically significant difference was noted between the four materials. 84 and 96 kVp with low resolution and the use of MAR-generated images that have statistically better CNR than 66 and 76 kVp with HD, normal and high resolutions and without MAR. The use of low resolution also generated the smallest value of effective dose.

CONCLUSIONS

The best setting for radiographic follow-up in an endodontic surgery with retrograde filling on the Planmeca ProMax is 96 kVp with low resolution and high MAR; this setting produced one of the lowest effective doses.

Management of a Two-rooted Maxillary Central Incisor Using Cone-beam Computed Tomography: Importance of Three-dimensional Imaging

We report a rare case of a two-rooted maxillary central incisor, stressing the importance of three-dimensional imaging in treatment planning and conservative approach of management. Endodontic treatment of this central incisor was carried out with a successful outcome.

AAE and AAOMR Joint Position Statement: Use of Cone Beam Computed Tomography in Endodontics 2015 Update

The following statement was prepared by the Special Committee to Revise the Joint American Association of Endodontists/American Academy of Oral and Maxillofacial Radiology Position on Cone Beam Computed Tomography, and approved by the AAE Board of Directors and AAOMR Executive Council in May 2015. AAE members may reprint this position statement for distribution to patients or referring dentists.

Diagnosis of acute dental trauma: the importance of standardized documentation: a review

In 1985 Andreasen and Andreasen published a paper on the diagnosis of luxation injuries and outlined the importance of standardized clinical, radiographic, and photographic techniques. Now 30 years later, these recommendations remain current in the International Association of Dental Traumatology (IADT) guidelines for the management of dental trauma and describe circumstances surrounding the time of injury, the extent of trauma (e.g., type of luxation injury), healing potential (e.g., stage of root development) as well as information concerning subsequent treatment. The purpose of this review was to include findings for other types of trauma and to discuss more recent studies that augment and/or improve on the original findings from 30 years ago. The present review discusses the use of a standardized clinical registration (pulpal sensibility testing, laser Doppler flowmetry, mobility testing), radiographic survey, and photographic registration of the traumatized patient. Moreover, the value of digital radiographs and recent developments in computer tomography with respect to possible enhancement of the trauma diagnosis are discussed.

The importance of cone-beam computed tomography in the management of endodontic problems: a review of the literature

INTRODUCTION

To obtain essential information in clinical endodontics, cone-beam computed tomographic (CBCT) imaging can be used in all phases of treatment including diagnosis, treatment planning, during the treatment phase, and through post-treatment assessment and follow-up. The purpose of this article was to review the use of CBCT imaging in the diagnosis, treatment planning, and assessing the outcome of endodontic complications.

METHODS

Literature was selected through a search of PubMed electronic databases for the following keywords: tooth root injuries, tooth root radiography, tooth root perforation, tomography, cone-beam computed tomography, endodontic complications, tooth root internal/external resorption, root fractures, and broken instruments. The research was restricted to articles published in English. One hundred twelve articles met the inclusion criteria and were included in this review.

RESULTS

Currently, intraoral radiography is the imaging technique of choice for the management of endodontic disease, but CBCT imaging appears to have a superior validity and reliability in the management of endodontic diagnosis and complications.

CONCLUSIONS

Endodontic cases should be judged individually, and CBCT imaging should be considered in situations in which information from conventional imaging systems may not yield an adequate amount of information to allow the appropriate management of endodontic problems. CBCT imaging has the potential to become the first choice for endodontic treatment planning and outcome assessment, especially when new scanners with lower radiation doses will be available.

Differential diagnosis of vertical root fractures using reconstructed three-dimensional models of bone defects

OBJECTIVES

The purpose of this study was to evaluate the accuracy of diagnosing vertical root fractures (VRFs) by comparing the volume of bone defects in VRFs with those in non-VRFs on reconstructed three-dimensional (3D) models (TDMs) using CBCT.

METHODS

32 maxillary pre-molars and anterior teeth with radiolucent areas were evaluated on pre-operative CBCT images. Of the 32 teeth, 16 had a fractured root (VRF group) and 16 had a non-fractured root (non-VRF group). The radiolucent area of each tooth was traced in each dimension [mesiodistal, buccolingual and horizontal (the apicoincisal aspect)] by two observers, and 3D images were reconstructed with the Amira(®) software (Visage Imaging Inc., Richmond, Australia). The volume, V, of the TDM was divided into the coronal side and the periapical side at the horizontal slice through the apical foramen, and v was defined as the volume of the coronal side. The values of v/V were calculated for all cases. The Mann-Whitney U test was used to compare values between the VRF group and the non-VRF group (p < 0.05). A receiver operating characteristic (ROC) curve was constructed to select the optimal cut-point.

RESULTS

There was a statistically significant difference in the value of v/V between the two groups (p < 0.05). With a cut-point derived from the ROC curve, and the sensitivity, specificity and accuracy of predicting the VRFs were 1.00, 0.75 and 0.88, respectively.

CONCLUSIONS

Lesions resulting from VRFs can be distinguished from those of non-VRFs on 3D CBCT images with a high degree of accuracy, based on their different 3D shapes.

Endodontic and esthetic management of a dilacerated maxillary central incisor having two root canals using cone beam computed tomography as a diagnostic aid

Traumatic injuries to the primary dentition are quite common. When primary teeth are subjected to trauma, force transmission and/or invasion of the underlying tooth germs lying in close proximity can result in a variety of disturbances in the permanent successors. Few of these disturbances include hypoplasia, dilaceration, or alteration in the eruption sequence and pattern. Dilaceration is defined as an angulation or sharp bend or curve in the linear relationship of the crown of a tooth to its root. A rare case of maxillary left central incisor having crown dilaceration and Vertucci's type II canal configuration with symptomatic periapical periodontitis is reported. Cone beam computed tomography was used for better understanding of the anomaly and complicated root canal morphology. The tooth was successfully managed by nonsurgical root canal therapy and restoration with resin composite to restore esthetics.

A novel method to estimate the volume of bone defects using cone-beam computed tomography: an in vitro study

INTRODUCTION

The routine use of high-resolution images derived from 3-dimensional cone-beam computed tomography (CBCT) datasets enables the linear measurement of lesions in the maxillary and mandibular bones on 3 planes of space. Measurements on different planes would make it possible to obtain real volumetric assessments. In this study, we tested, in vitro, the accuracy and reliability of new dedicated software developed for volumetric lesion assessment in clinical endodontics.

METHODS

Twenty-seven bone defects were created around the apices of 8 teeth in 1 young bovine mandible to simulate periapical lesions of different sizes and shapes. The volume of each defect was determined by taking an impression of the defect using a silicone material. The samples were scanned using an Accuitomo 170 CBCT (J. Morita Mfg Co, Kyoto, Japan), and the data were uploaded into a newly developed dedicated software tool. Two endodontists acted as independent and calibrated observers. They analyzed each bone defect for volume. The difference between the direct volumetric measurements and the measurements obtained with the CBCT images was statistically assessed using a lack-of-fit test. A correlation study was undertaken using the Pearson product-moment correlation coefficient. Intra- and interobserver agreement was also evaluated.

RESULTS

The results showed a good fit and strong correlation between both volume measurements (ρ > 0.9) with excellent inter- and intraobserver agreement.

CONCLUSIONS

Using this software, CBCT proved to be a reliable method in vitro for the estimation of endodontic lesion volumes in bovine jaws. Therefore, it may constitute a new, validated technique for the accurate evaluation and follow-up of apical periodontitis.

The detection of periapical pathosis using digital periapical radiography and cone beam computed tomography - part 2: a 1-year post-treatment follow-up

AIM

Part 2 of this clinical study aims to compare the radiographic change in periapical status of individual roots determined using digital periapical radiographs versus cone beam computed tomography (CBCT) 1year after primary root canal treatment and to determine the radiological outcome of treatment for each tooth.

METHODOLOGY

Periapical radiographs and CBCT scans of 123 teeth in 99 patients assessed 1year after completion of primary root canal treatment by a single operator were compared with their respective pre-treatment (diagnostic) periapical radiographs and CBCT scans. The presence or absence as well as the increase or decrease in size of existing periapical radiolucency was assessed by a consensus panel consisting of two calibrated examiners. The panel viewed the images under standardized conditions. Paired comparison of the outcome diagnosis of individual roots and teeth was performed using generalized McNemar's or Stuart-Maxwell test of symmetry analysis.

RESULTS

The 'healed' rate (absence of periapical radiolucency) for all roots combined was 92.7% using periapical radiographs and 73.9% for CBCT (P<0.001). This rate increased to 97.2% and 89.4%, respectively, when the 'healing' group (reduced size of periapical radiolucency) was included (P<0.001). A statistically significant difference in outcome diagnosis of single roots was observed between DPA and CBCT in single-rooted teeth and the buccal or mesio-buccal roots of multi-rooted teeth (P<0.05). Analysis by tooth revealed that the 'healed' rate (absence of periapical radiolucency) was 87% using periapical radiographs and 62.5% using CBCT (P<0.001). This increased to 95.1% and 84.7%, respectively, when the 'healing' group (reduced size of periapical radiolucency) was included (P<0.002). Outcome diagnosis of teeth showed a statistically significant difference between systems (P<0.001). Reconstructed CBCT images revealed more failures (17.6%) in teeth with no pre-operative periapical radiolucencies compared with periapical radiographs (1.3%) (P=0.031). In teeth with existing pre-operative periapical radiolucencies, reconstructed CBCT images also showed more failures (13.9%) compared with periapical radiographs (10.4%).

CONCLUSION

Diagnosis using CBCT revealed a lower healed and healing rate for primary root canal treatment than periapical radiographs, particularly in roots of molars. There was a 14 times increase in failure rate when teeth with no pre-operative periapical radiolucencies were assessed with CBCT compared with periapical radiographs at 1year.

The diagnosis and conservative treatment of a complex type 3 dens invaginatus using cone beam computed tomography (CBCT) and 3D plastic models

AIM

To investigate the use of 3D plastic models, printed from cone beam computed tomography (CBCT) data, for accurate diagnosis and conservative treatment of a complex case of dens invaginatus.

SUMMARY

A chronic apical abscess with a draining sinus tract was diagnosed during the treatment planning stage of orthodontic therapy. Radiographic examination revealed a large radiolucent area associated with an invaginated right maxillary central incisor, which was found to contain a vital pulp. The affected tooth was strategic in the dental arch. Conventional periapical radiographs provided only partial information about the invagination and its relationship with the main root canal and with the periapical tissues. A limited-volume CBCT scan of the maxilla did not show evidence of communication between the infected invagination and the pulp in the main root canal, which could explain the pulp vitality. A novel method was adopted to allow for instrumentation, disinfection and filling of the invagination, without compromising the vitality of the pulp in the complex root canal system. The CBCT data were used to produce precise 3D plastic models of the tooth. These models facilitated the treatment planning process and the trial of treatment approaches. This approach allowed the vitality of the pulp to be maintained in the complex root canal space of the main root canal whilst enabling the healing of the periapical tissues.

KEY LEARNING POINTS

Even when extensive periapical pathosis is associated with a tooth with type III dens invaginatus, pulp sensibility tests should be performed. CBCT is a diagnostic tool that may allow for the management of such teeth with complex anatomy. 3D printed plastic models may be a valuable aid in the process of assessing and planning effective treatment modalities and practicing them ex vivo before actually performing the clinical procedure. Unconventional technological approaches may be required for detailed treatment planning of complex cases of dens invaginatus.

Endodontic management of mandibular second molar fused to a supernumerary tooth, using spiral computed tomography as a diagnostic aid: a case report

Fusion is a developmental anomaly characterized by the union of two adjacent teeth. In this paper we report a rare case of fusion involving permanent mandibular second molar with supernumerary tooth. The rarity with which this entity appears, along with its complex characteristics, often makes it difficult to treat. The use of high-end diagnostic imaging modalities such as spiral computed tomography can help the clinician in making a confirmatory diagnosis and determining the treatment plan before undertaking the actual treatment. In the present case, we have used spiral computed tomography (SCT) for better understanding the complicated root canal morphology of the fused tooth and successful management of this rare case.

Imaging techniques in endodontics: an overview

This review provides an overview of the relevance of imaging techniques such as, computed tomography, cone beam computed tomography, and ultrasound, to endodontic practice. Many limitations of the conventional radiographic techniques have been overcome by the newer methods. Advantages and disadvantages of various imaging techniques in endodontic practice are also discussed.

Cone beam computed tomography in endodontics

Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillo-facial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontics. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice.

The use of cone beam computed tomography in the management of dens invaginatus affecting a strategic tooth in a patient affected by hypodontia: a case report

AIM

To report on the use of cone beam computed tomography (CBCT) in the diagnosis and management of dens invaginatus.

SUMMARY

Chronic apical periodontitis of an invaginated maxillary lateral incisor was diagnosed in a patient suffering from hypodontia and awaiting active orthodontic therapy. Loss of the tooth would have complicated orthodontic treatment. Conventional periapical radiographs provided insufficient information about the nature of the invagination and its relation to the root canal to formulate an appropriate plan for treating the tooth. A small volume CBCT scan of the tooth revealed that the invagination and the root canal were completely separate, non-communicating spaces and that the wall of the invagination acted as an obstruction to the effective chemomechanical debridement of the infected root canal. An innovative method of accessing the infected root canal, based on information from the CBCT images, was adapted to permit its instrumentation, disinfection and filling.

KEY LEARNING POINTS

• Teeth with dens invaginatus requiring endodontic treatment present diagnostic and technical challenges. • CBCT can provide essential information in the management of dens invaginatus.

Use of cone beam computed tomography in endodontics

Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imaging adjunct for endodontics.

Case report: Cone-beam ct imaging in the management of a double tooth

BACKGROUND

The diagnosis and management strategies of double teeth have largely relied on clinical examination and conventional radiographic findings. Cone-Beam Computed Tomography (Cone-beam CT) was developed in the late 1990's and, therefore, is a relatively recent addition to the imaging armamentarium for use in Maxillofacial Radiology. There have been no publications in the dental literature demonstrating the use of Cone-beam CT or 3D stereolithography in the diagnosis and surgical planning of the management of double teeth.

CASE REPORT

An 11 year old girl presented with a double left lateral maxillary incisor. Conventional plain film radiography failed to provide the requisite information for pre-operative planning. Cone-beam Computed Tomography (Cone-beam CT) allowed determination of location of fusion, three-dimensional (3D) visualisation of pulpal anatomy and the construction of a 3D stereolithographic model for surgical planning. The double tooth was surgically divided in situ under local analgesia. The redundant distal unit was extracted and the residual mesial unit built up in composite resin following physiological mesial drift of displaced maxillary left canine. No endodontic therapy was required.

FOLLOW-UP

At a 10-month follow-up visit, clinical and radiographic vitality and success was noted.

CONCLUSION

The great amount of radiological information which Cone-beam CT can offer not only improves pre-operative and surgical planning, but the 3D models provided can be used to further educate and inform patients and guardians in the management of double teeth.

Optical approach to the periodontal ligament under orthodontic tooth movement: a preliminary study with optical coherence tomography

INTRODUCTION

Optical coherence tomography (OCT) is a diagnostic tool that can make near-histologic tomographic images without a biohazard. Due to its high resolution (average, 4 microm) and safety (using light as the source), it has been applied widely in medical fields to replace invasive biopsies. But the trials in dentistry have been restricted to mainly detecting dental caries and oral cancer. In this preliminary study for successive human studies, we tried to evaluate whether OCT can be helpful in determining tooth movement under light orthodontic forces.

METHODS

Orthodontic distraction forces (0, 5, and 10 g) were applied to the mandibular incisors of 6 white rats (10 weeks old) for 5 days by using individualized loop springs (round Elgiloy, 0.018-in diameter, Rocky Mountain Orthodontics, Denver, Colo). The changed periodontal ligaments were imaged with OCT and digital intraoral radiography 2 dimensionally. Both tensile and compressive ligaments were measured and compared.

RESULTS

With OCT images, we could measure changed ligaments from all directions; radiography could not show the portions overlapped by teeth. The averages of measured ligament width in OCT were larger than those from radiography in all groups.

CONCLUSIONS

This preliminary study shows the possible evaluation and prediction of precise tooth responses under orthodontic forces by using real-time OCT.