Basic principles for use of dental cone beam computed tomography: consensus guidelines of the European Academy of Dental and Maxillofacial Radiology

Retrospective analysis of the upper airway anatomy and Sella turcica morphology across different skeletal malocclusions: a computerized technique

OBJECTIVE

This study aimed to investigate the normal volumetric space and variations in the measurements of different landmarks in adults with different skeletal relations of the maxilla and the mandible based on CBCT data. The study also analyses these landmarks to locate any correlations.

BACKGROUND

Numerous studies in orthodontics have found a relationship between orthodontic treatment and changes in the anatomy and function of the airway. Severe changes in airway morphology can cause breathing difficulties, lower quality of life, and even result in life-threatening conditions such as obstructive sleep apnoea. Consequently, orthodontic diagnosis and treatment planning require a thorough understanding of the airway space and its function.

METHODS

The present retrospective study was conducted using CBCT records of 120 adult patients, containing 40 samples of each skeletal class (20 males and 20 females). The boundaries were defined for the 3 major regions: the nasopharynx, the oropharynx, and the hypopharynx. Various measurements were recorded across these regions, as well as selective cephalometric landmarks. The obtained data was used to calculate average and standard deviation, while regression analysis was used to evaluate correlations and t-test was used to test statistical significance of gender differences.

RESULTS

The results demonstrate that skeletal Class III individuals exhibit a reduced airway volume in the nasopharynx compared to other groups, whereas skeletal Class II individuals displayed a diminished airway volume in the hypopharynx. A strong correlation was observed for Sella turcica parameters. There were no significant differences in skeletal parameters across genders. Nasopharynx cavity volume demonstrated significant differences between skeletal Class I-Class III as well as between skeletal Class II-Class III. Hypopharynx cavity volume also demonstrated significant differences between skeletal Class I-Class II and between skeletal Class II-Class III.

CONCLUSION

The major findings are the presence of a reduced nasopharyngeal volume in skeletal Class III malocclusions while skeletal Class II individuals displayed a diminished hypopharyngeal volume, making these critical areas to consider during the diagnostic and orthodontic treatment planning stages. This study also revealed a consistent correlation between Sella turcica parameters across various facial skeletal profiles, with skeletal Class II patients exhibiting a distinct pattern and skeletal Class I and Class III demonstrating an average relationship.

When Maxillofacial CBCT Permits Fortuitously to Diagnose Primary Non-Hodgkin's Lymphoma: A Case Report

A 47-year-old male with an unremarkable medical history was referred for atypical endodontic pain and treatment of his left upper molars. Clinical and radiographic examinations revealed an extensive, undefined osteolytic area around these teeth. A subsequent bone biopsy diagnosed diffuse large B-cell lymphoma, a high-grade non-Hodgkin's lymphoma. The hematology team prescribed six cycles of chemotherapy, supplemented by two cycles of methotrexate. Practitioners should be alerted by atypical tooth pain to consider 3D imaging to exclude malignant pathology as early as possible. Teaching point: An atypical tooth pain should alert the practitioner and guide them towards 3D imaging to eliminate diagnostic of malignant pathology as early as possible.

Examination of coronoid foramen and coronoid canal with CBCT

Objective

This study aimed to examine the coronoid foramen using CBCT not only according to its localization, distribution to gender and age but also to determine whether there are canals associated with the coronoid foramen and to identify them and their clinical significance.

Methods

488 images obtained between 2022 and 2023 were retrospectively evaluated in sagittal, horizontal, and coronal sections. During the evaluation of the images, the number and localization of the coronoid foramen and the coronoid canals originating from this foramen were recorded and examined. In addition, the patient images were divided into different age groups and the presence of coronoid foramen was analyzed.

Results

Coronoid foramen was detected in 5.1 % and coronoid canal in 1.6 % of the images. Unilateral coronoid foramen was found in 1.4 % and bilateral coronoid foramen was found in 3.7 % of the patients. Unilateral coronoid canal was found in 1.0 % and bilateral coronoid canal in 0.6 % of the patients. When the presence of coronoid foramen was analyzed according to age groups, no significant difference was found between age groups.

Conclusion

Recognition of the coronoid foramen and coronoid canal will not only reduce the likelihood of complications in surgical procedures but also influence the treatment plan. Further research is needed to recognize the content of this variations.

AAPM Task Group Report 261: Comprehensive quality control methodology and management of dental and maxillofacial cone beam computed tomography (CBCT) systems

Cone-beam computed tomography (CBCT) systems specifically designed and manufactured for dental, maxillofacial imaging (MFI) and otolaryngology (OLR) applications have been commercially available in the United States since 2001 and have been in widespread clinical use since. Until recently, there has been a lack of professional guidance available for medical physicists about how to assess and evaluate the performance of these systems and about the establishment and management of quality control (QC) programs. The owners and users of dental CBCT systems may have only a rudimentary understanding of this technology, including how it differs from conventional multidetector CT (MDCT) in terms of acceptable radiation safety practices. Dental CBCT systems differ from MDCT in several ways and these differences are described. This report provides guidance to medical physicists and serves as a basis for stakeholders to make informed decisions regarding how to manage and develop a QC program for dental CBCT systems. It is important that a medical physicist with experience in dental CBCT serves as a resource on this technology and the associated radiation protection best practices. The medical physicist should be involved at the pre-installation stage to ensure that a CBCT room configuration allows for a safe and efficient workflow and that structural shielding, if needed, is designed into the architectural plans. Acceptance testing of new installations should include assessment of mechanical alignment of patient positioning lasers and x-ray beam collimation and benchmarking of essential image quality performance parameters such as image uniformity, noise, contrast-to-noise ratio (CNR), spatial resolution, and artifacts. Several approaches for quantifying radiation output from these systems are described, including simply measuring the incident air-kerma (Kair) at the entrance surface of the image receptor. These measurements are to be repeated at least annually as part of routine QC by the medical physicist. QC programs for dental CBCT, at least in the United States, are often driven by state regulations, accreditation program requirements, or manufacturer recommendations.

Incidental findings in cone beam computed tomography (CBCT) scans for implant treatment planning: a retrospective study of 404 CBCT scans

OBJECTIVES

To investigate the prevalence of incidental findings and need for further dental treatment and analyse the influence of size of field-of-view (FOV) and age in cone beam computed tomography (CBCT) for pre-implant planning.

METHODS

404 CBCT scans were examined retrospectively for incidental findings and need for further dental treatment. Incidental finding-frequencies and need for further treatment were assessed for different age (< 40 years, 40-60 years, > 60 years) and FOV groups (small, medium, large). Intraexaminer and interexaminer agreements were evaluated.

RESULTS

In 82% of the scans at least one incidental finding was found, with a total of 766 overall. More incidental findings were found in scans with large FOV (98% vs. 72%, OR = 22.39 large vs. small FOV, p < 0.0001) and in scans of patients > 60 years (OR = 5.37 patient's age > 60 years vs. < 40 years, p = 0.0003). Further dental treatment due to incidental findings was needed in 31%. Scans with large FOV were more likely to entail further treatment (OR = 3.55 large vs. small FOV, p < 0.0001). Partial edentulism and large FOV were identified as risk factors for further treatment (p = 0.0003 and p < 0.0001). Further referral of the patient based on incidental findings was judged as indicated in 5%. Intra- and inter-examiner agreements were excellent (kappa = 0.944/0.805).

CONCLUSIONS

A considerable number of incidental findings with need for further dental treatment was found in partially edentulous patients and in patients > 60 years. In pre-implant planning of elderly patients, the selection of large FOV CBCT scans, including dentoalveolar regions not X-rayed recently, help to detect therapeutically relevant incidental findings.

The use of CBCT in orthodontics with special focus on upper airway analysis in patients with sleep-disordered breathing

Applications of cone-beam CT (CBCT) in orthodontics have been increasingly discussed and evaluated in science and practice over the last two decades. The present work provides a comprehensive summary of current consolidated practice guidelines, cutting-edge innovative applications, and future outlooks about potential use of CBCT in orthodontics with a special focus on upper airway analysis in patients with sleep-disordered breathing. The present scoping review reveals that clinical applications of CBCT in orthodontics are broadly supported by evidence for the diagnosis of dental anomalies, temporomandibular joint disorders, and craniofacial malformations. On the other hand, CBCT imaging for upper airway analysis-including soft tissue diagnosis and airway morphology-needs further validation in order to provide better understanding regarding which diagnostic questions it can be expected to answer. Internationally recognized guidelines for CBCT use in orthodontics are existent, and similar ones should be developed to provide clear indications about the appropriate use of CBCT for upper airway assessment, including a list of specific clinical questions justifying its prescription.

Facial Asymmetry-Demystifying the Entity

Introduction/Background

Perfect facial symmetry has always been considered a hallmark of beauty, but, is almost elusive in nature. However, clinically evident skeletal facial asymmetry on the other hand is quite common, which can result from congenital deformities, developmental abnormalities, secondary to maxillofacial trauma and it is an entity maxillofacial surgeons deal with on a regular basis. Surgical correction of facial asymmetry is challenging, as it not only involves the correction of the skeletal asymmetry for an aesthetic outcome, but, also the improvement of the soft tissue drape and dental occlusal harmony. This results in rehabilitation of functional components of orofacial complex like speech, deglutition and phonation.

Objective

With this paper, we intend to throw a light on this challenging aspect of maxillofacial surgery, along with giving the next generation of maxillofacial surgeons a direction to explore the topic further.

Conclusion

Meticulous evaluation and diagnosis of the patient's problems with latest diagnostic methods like 3-dimensional imaging and surgical treatment with orthognathic surgery, gap arthroplasty or distraction osteogenesis, utilizing cutting edge 3-D virtual planning will result in better outcomes.This review will collate the information available in the literature, along with the authors' recommendations for better planning and execution of this challenging puzzle of facial asymmetry.

A New Classification of the Morphology of Complete Ponticulus Posticus on Cone Beam Computed Tomography

The objectives of this retrospective study were to measure the prevalence of complete ponticulus posticus (CPP), to propose a new classification based on two different shapes of CPP, to compare these shapes with age and gender, and to test two different methods of measurements of the diameters of CPP on cone beam computed tomography (CBCT).

MATERIAL AND METHODS

We used 2012 CBCT scans from Planmeca Promax 3D Mid and Romexis 5.1 software tools to measure the height and width of the CPP, and we measured the surface of the CPP using an ellipse tool. We classified the CPP into "thin" and "thick" shape.

RESULTS

the prevalence of CPP was 9.49% with 97 male and 94 female patients. The unilateral type was found in 131 patients, while the bilateral type was found in 60 patients. Intra-observer reliability was evaluated using the intraclass correlation coefficient (ICC). The ICC was 0.875 for height, 0.872 for width, and 0.885 for the ellipse area. Both methods present very good intra-observer reproducibility. The "thin" group tended to be older and significantly more related to female patients. The "thick" group was associated with younger male patients.

CONCLUSIONS

the proposed classification of CPP may be used when reporting the CBCT large field of view. There is still a need to increase the knowledge on the atlas and on its main variant, such as complete PP.

Patient shielding during dentomaxillofacial radiography: Recommendations from the American Academy of Oral and Maxillofacial Radiology

BACKGROUND

The American Academy of Oral and Maxillofacial Radiology established an ad hoc committee to draft evidence-based recommendations and clinical guidance for the application of patient contact shielding during dentomaxillofacial imaging.

TYPES OF STUDIES REVIEWED

The committee reviewed monographs and reports from radiation protection organizations and studies that reported radiation dose to gonads, breasts, and thyroid gland from dentomaxillofacial imaging.

RESULTS

Considering the absence of radiation-induced heritable effects in humans and the negligible dose to the gonads and fetus from dentomaxillofacial imaging, the committee recommends discontinuing shielding of the gonads, pelvic structures, and fetuses during all dentomaxillofacial radiographic imaging procedures. On the basis of radiation doses from contemporaneous maxillofacial imaging, the committee considered that the risks from thyroid cancer are negligible and recommends that thyroid shielding not be used during intraoral, panoramic, cephalometric, and cone-beam computed tomographic imaging.

PRACTICAL IMPLICATIONS

This position statement informs and educates the reader on evolving radiation protection practices and provides simple, unequivocal guidance to dental personnel to implement these guidelines. State and local authorities should be contacted to update regulations to reflect these recommendations.

Radiologic findings of osteonecrosis, osteoradionecrosis, osteomyelitis and jaw metastatic disease with cone beam CT

PURPOSE

The purpose of this study was to assess CBCT scans of patients with medication related osteonecrosis of the jaws (MRONJ), osteoradionecrosis (ORN), osteomyelitis (OM) and jaw metastatic disease (JM), evaluate the presence and extent of radiologic findings, identify radiologic parameters that may distinguish the four entities and last, introduce a new modified radiographic index (CRIm), in order to contribute to the diagnosis of these conditions.

METHODS

Τwo major databases were retrospectively searched for fully documented and diagnosed CBCT scans of MRONJ, ORN, OM and JM from 2006 to 2019. 335 CBCT scans met the inclusion criteria and were assessed under standardized viewing conditions blindly by 2 observers. The CRIm index proposed in this study evaluates: lytic changes, sclerosis, periosteal bone formation, sequestration, non-healing extraction sockets and other findings which included: sinus implication, inferior alveolar canal implication and jaw fracture. Lytic changes, sclerosis, periosteal bone formation, sequestration and non-healing extraction sockets were scored as: absent (0), localized/single (1) and extensive/multiple (2). Each one of other findings were scored individually as: absent (0) and present (1). For statistical analysis t-test, Pearson's r correlation coefficient, one-way ANOVA and Bonferonni were performed.

RESULTS

Extensive lytic changes were the most common finding, especially for ORN, where it occurred in all CBCT scans (100%). The mean value of the CRIm index differs significantly between CBCT scans with MRONJ and JM, as well as between those with OM and JM (Bonferroni p < 0.001).

CONCLUSIONS

The new modified Composite Radiographic Index introduced in this study, appears to have improved an objective approach to the previously used Composite Radiographic Index by means of cumulative radiologic features. Τhe predominance of certain radiologic features in one or more of these entities may lead the diagnostician towards the correct diagnosis.

Ultra-low-dose CBCT scan: rational map for ear surgery

PURPOSE

This study will evaluate the clinical quality and usability of peripheral image data from the temporal bone area obtained using a sinonasal ultra-low-dose (ULD) cone-beam computed tomography (CBCT) scan and compare them to those obtained using a high-resolution (HR) CBCT.

METHODS

The population consisted of 66 anatomical sites (ears of 33 subjects) imaged using two modalities: an HR CBCT (Scanora 3Dx scanner; Soredex, Tuusula, Finland) and a ULD CBCT (Promax 3D Mid scanner; Plandent, Helsinki, Finland). The image quality (IQ) for every anatomical site in each image was rated using a Likert scale from 0 to 5.

RESULTS

The quality of ULD CBCT scans was clinically sufficient in over 95% of the assessed images of the sigmoid sinus, jugular bulb, epitympanum and mastoid antrum as well as external acoustic meatus (all p > 0.05 compared to HR CBCT). The IQ was clinically sufficient in 75-94% of the assessed images of the scutum, mastoid segment of the facial nerve, cochlea and semicircular canals (all p < 0.05 compared to HR CBCT). The overall IQ of the HR CBCT scans was good or excellent.

CONCLUSION

CBCT imaging and the data at image margins are underutilized. CBCT can produce excellent structural resolution with conventional imaging parameters, even with off-focus images. Using ultra-low doses of radiation, the produced IQ is clinically sufficient. We encourage ear surgeons to check the patients' imaging history and to consider the use of imaging modalities that involve lower radiation doses especially when conducting repetitive investigations and with children.

A Comparative Assessment of the Upper Pharyngeal Airway Dimensions among Different Anteroposterior Skeletal Patterns in 7–14-Year-Old Children: A Cephalometric Study

Background: The pharyngeal airway is a crucial part of the respiratory system’s function. Assessing the pharyngeal airway dimensions in different skeletal types is important in the orthodontic treatment of growing patients. The aim of this study was to compare the upper pharyngeal airway dimensions of 7–14-year-old children with different skeletal types. Methods: Three-hundred-sixty-one lateral cephalometric radiographs were grouped based on their skeletal patterns determined by the ANB angle as skeletal type I (n = 123), type II (n = 121), and type III (n = 117). The radiographs were divided into 4 groups: 7/8 YO (7–8 years old), 9/10 YO, 11/12 YO, and 13/14 YO. The cephalometric measurements comprised SNA, SNB, ANB, Ad1-PNS, Ad2-PNS, McUP, and McLP. An ANOVA was used to compare the group results. Results: Significant differences in Ad1-PNS, Ad2-PNS, McUP, and McLP in skeletal types II and III were found between age groups. Most upper pharyngeal airway dimensions in skeletal types II and III children were significantly wider in the 13/14 YO group than in the other age groups. Conclusion: The upper pharyngeal airway dimensions increased age-dependently in 7–14-year-old children, especially in skeletal types II and III. The upper pharyngeal airway dimensions could serve as a guide in differentiating the different skeletal classes in clinical settings.

Dehiscence and buccal bone thickness after rapid maxillary expansion in young patients with unilateral cleft lip and palate

INTRODUCTION

The present study aimed to evaluate the consequences of rapid maxillary expansion in the buccal bone thickness and dehiscence of subjects with unilateral cleft lip and palate.

METHODS

This prospective cohort study consisted of 30 participants, 20 males and 10 females, between 8 and 15 years old. Participants were allocated into 3 groups, according to the type of maxillary constriction, and were treated with different types of expanders: G1, hyrax; G2, fan-type; G3, inverted mini-hyrax. Cone-beam computed tomography scans were performed immediately before treatment and after 90 days of retention. Linear measurements were obtained by the same calibrated and blinded examiner.

RESULTS

An average of 0.8 mm decrease in buccal bone thickness (P <0.001) and a 0.5 mm increase in dehiscence (P <0.001) were observed. There was no significant difference between the cleft and noncleft side for all variables (P >0.05), as there was no significant difference between groups (P >0.05).

CONCLUSION

The findings in this study allow the conclusion that the orthopedic forces of rapid maxillary expansion lead to a decrease in the posterior buccal bone volume in unilateral cleft lip and palate patients.

A perspective on the diagnosis of cracked tooth: imaging modalities evolve to AI-based analysis

Despite numerous clinical trials and pre-clinical developments, the diagnosis of cracked tooth, especially in the early stages, remains a challenge. Cracked tooth syndrome is often accompanied by dramatic painful responses from occlusion and temperature stimulation, which has become one of the leading causes for tooth loss in adults. Current clinical diagnostical approaches for cracked tooth have been widely investigated based on X-rays, optical light, ultrasound wave, etc. Advances in artificial intelligence (AI) development have unlocked the possibility of detecting the crack in a more intellectual and automotive way. This may lead to the possibility of further enhancement of the diagnostic accuracy for cracked tooth disease. In this review, various medical imaging technologies for diagnosing cracked tooth are overviewed. In particular, the imaging modality, effect and the advantages of each diagnostic technique are discussed. What's more, AI-based crack detection and classification methods, especially the convolutional neural network (CNN)-based algorithms, including image classification (AlexNet), object detection (YOLO, Faster-RCNN), semantic segmentation (U-Net, Segnet) are comprehensively reviewed. Finally, the future perspectives and challenges in the diagnosis of the cracked tooth are lighted.

A 3D Digital Analysis of the Hard Palate Wound Healing after Free Gingival Graft Harvest: A Pilot Study in the Short Term

Purpose: Within this context, this pilot study aimed to evaluate the healing dynamics process of the hard palate after free gingival graft harvesting in the short term (3 months), utilizing digital imaging technology and tridimensional analysis software. Furthermore, assessing the results found to verify the existence of a relationship between gender or age with tissue loss. Materials and Methods: For connective-tissue harvesting, fifteen patients with gingival recessions type (RT) 1 and RT2 were selected. On the surgery day (before the procedure) and after three months, palatal impressions were taken in all patients, and cast models were done for posterior model scanning. The following variables were analyzed: mean thickness alterations (x¯ TA), maximum thickness loss (MTL), mean maximum thickness loss (x¯ MTL), and volume alterations (VA). A descriptive and bivariate analysis of the data was done. The data were submitted for statistical evaluation and were significant if p < 0.05. Results: Fifteen patients were analyzed, 11 females (73.3%) and four males (26.7%). The patients’ average age was 28 ± 8.52 years (ranging between 16 and 48 years old). The palatal wound region’s mean thickness and volume changes were −0.26 mm (±0.31) and 46.99 mm3 (±47.47 mm3) at three months. There was no statistically significant result correlating age/gender with any variable evaluated. Conclusions: Connective tissue graft harvesting promoted changes with a standard volume and thickness loss of palatal soft tissue. A 3D digital evaluation was a non-invasive method with a reproducible technique for measuring thickness or volume after connective tissue is collected. There was no relationship between age/gender and any variables analyzed.

Inter-observer reliability in cone-beam computed tomography assessment of the retromolar canal: A practical plan to improve diagnostic imaging

Purpose

This study aimed to investigate inter-observer reliability among observers with different levels of proficiency and the diagnostic imaging reliability of cone-beam computed tomography (CBCT) images of the retromolar canal.

Materials and Methods

CBCT images of 307 patients were assessed for the presence of retromolar canals (RMCs) by 3 observers independently. Diagnoses were made twice by each observer at intervals of more than 3 weeks. Inter-observer reliability was assessed using the kappa coefficient. One observer had no experience in diagnosis using CBCT images. Therefore, a specialist in diagnostic imaging explained the CBCT images for interpretation and practiced diagnostic imaging together with this observer, while the other observer interpreted the images independently. Thereafter, the observers re-evaluated the images.

Results

The interobserver kappa coefficients (including bilateral RMCs) calculated at the first reading were low, ranging from 0.21 to 0.61. Their values ranged from 0.95 (right side) to 1.00 (left side) after one-on-one practice with a diagnostic imaging specialist, while the values ranged from 0.65 (right side) to 0.66 (left side) without one-on-one practice.

Conclusion

Diagnostic accuracy was improved through diagnostic imaging practice. To improve the anatomical interpretation of images, it is important to practice diagnostic imaging with a specialist in diagnostic imaging. One-on-one instruction about diagnostic imaging was an effective method of training.

[Applications of cone beam computed tomography of the craneofacial structure in medical specialties. A review]

Cone-beam computed tomography (CBCT) of the craniofacial structure has demonstrated its usefulness in the dental area during the last decades, thus it has become a fundamental tool in the diagnosis, planning, and evaluation of treatment, and although it was not developed for the exclusive use in dentistry, as it is commonly considered, it is used in other areas such as medicine. It is specifically used in the head and neck area where different medical specialties interact, and at the same time these interact with dental specialties, so knowing the advantages of CBCT over different imaging technologies in the medical area is necessary. The purpose of this review was to describe the applications of observation, diagnosis, planning, and evolution of treatments using maxillofacial HSCT in different medical specialties. This work highlights the use of TCHC in different medical applications and highlights where it is most useful compared to other technologies.

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

OBJECTIVES

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Orthodontists' criteria for prescribing cone-beam computed tomography-a multi-country survey

OBJECTIVES

This study aimed to describe and compare CBCT imaging prescription in clinical practice among orthodontists from five countries in Europe and America. Additionally, it investigated factors associated with the prescribing and the use of guidelines for CBCT imaging.

MATERIALS AND METHODS

A cross-sectional survey was carried out using an online questionnaire sent to all registered orthodontists in Belgium, Brazil, Canada, Romania, and the United States of America (USA). The data were analyzed by descriptive statistics, bivariate tests, and Poisson regression.

RESULTS

The final sample consisted of 1284 participants. CBCT was prescribed by 84.4% of the participants for selected cases (84.9%), mainly for impacted teeth (92.4%), presurgical planning (54.1%), and root resorption (51.9%). High cost was most frequently the limiting factor for CBCT prescription (55.4%). Only 45.2% of those who were using CBCT imaging reported adhering to guidelines. CBCT imaging prescription was associated with the orthodontists' countries (p < .009, except for Belgium, p = .068), while the use of guidelines was associated with the respondents' country and additional training on CBCT imaging (p < .001).

CONCLUSIONS

Orthodontists refer patients for CBCT for selected indications (impacted teeth, root resorption, presurgical planning, dentofacial deformities, as suggested by the international guidelines, and also for upper airway and temporomandibular joint evaluation). Many do not adhere to specific guidelines. There are substantial variations between the countries about the orthodontists' referral for CBCT and guideline usage, irrespective of gender. CBCT prescription may be limited by financial barriers, adhering to specific guidelines and prior CBCT training.

CLINICAL RELEVANCE

CBCT prescription among orthodontists must be based on prescription criteria and current guidelines. It is advised to improve CBCT education and training to enhance CBCT selection, referral, analysis, and interpretation in orthodontic practice.

Three-dimensional accuracy of partially guided implant surgery based on dental magnetic resonance imaging

OBJECTIVES

To measure in vivo 3D accuracy of backward-planned partially guided implant surgery (PGIS) based on dental magnetic resonance imaging (dMRI).

MATERIAL AND METHODS

Thirty-four patients underwent dMRI examinations. Tooth-supported templates were backward planned using standard dental software, 3D-printed, and placed intraorally during a cone beam computed tomography (CBCT) scan. Treatment plans were verified for surgical viability in CBCT, and implants were placed with guiding of the pilot drill. High-precision impressions were taken after healing. The 3D accuracy of 41 implants was evaluated by comparing the virtually planned and definitive implant positions with respect to implant entry point, apex, and axis. Deviations from the dMRI-based implant plans were compared with the maximum deviations calculated for a typical single implant.

RESULTS

Twenty-eight implants were placed as planned in dMRI. Evaluation of 3D accuracy revealed mean deviations (99% confidence intervals) of 1.7 ± 0.9mm (1.2-2.1mm) / 2.3 ± 1.1mm (1.8-2.9 mm) / 7.1 ± 4.8° (4.6-9.6°) for entry point / apex / axis. The maximum deviations calculated for the typical single implant surpassed the upper bounds of the 99% CIs for the apex and axis, but not for the entry point. In the 13 other implants, dMRI-based implant plans were optimized after CBCT. Here, deviations between the initial dMRI plan and definitive implant position were only in part higher than in the unaltered group (1.9 ± 1.7 mm [0.5-3.4 mm] / 2.5 ± 1.5 mm [1.2-3.8 mm] / 6.8 ± 3.8° [3.6-10.1°] for entry point / apex / axis).

CONCLUSIONS

The 3D accuracy of dMRI-based PGIS was lower than that previously reported for CBCT-based PGIS. Nonetheless, the values seem promising to facilitate backward planning without ionizing radiation.

Dental cone beam CT: An updated review

Cone beam computed tomography (CBCT) is a diverse 3D x-ray imaging technique that has gained significant popularity in dental radiology in the last two decades. CBCT overcomes the limitations of traditional two-dimensional dental imaging and enables accurate depiction of multiplanar details of maxillofacial bony structures and surrounding soft tissues. In this review article, we provide an updated status on dental CBCT imaging and summarise the technical features of currently used CBCT scanner models, extending to recent developments in scanner technology, clinical aspects, and regulatory perspectives on dose optimisation, dosimetry, and diagnostic reference levels. We also consider the outlook of potential techniques along with issues that should be resolved in providing clinically more effective CBCT examinations that are optimised for the benefit of the patient.

Recent Advances in Cone-beam CT in Oral Medicine

BACKGROUND

The cone-beam computed tomography (CBCT) technology has continuously evolved since its appearance in oral medicine in the early 2000s.

OBJECTIVES

To present recent advances in CBCT in oral medicine: i) selection of recent and consensual evidence-based sources, ii) structured summary of the information based on an iterative framework and iii) compliance with ethical, public health and patient-centered concerns.

MAIN FINDINGS

We will focus on technological advances, such as sensors and reconstruction algorithms used to improve the constant quality of the image and dosimetry. CBCT examination is now performed in almost all disciplines of oral medicine: currently, the main clinical disciplines that use CBCT acquisitions are endodontics and oral surgery, with clearly defined indications. Periodontology and ear, nose and throat medicine are more recent fields of application. For a given application and indication, the smallest possible field of view must be used. One of the major challenges in contemporary healthcare is ensuring that technological developments do not take precedence over admitted standards of care. The entire volume should be reviewed in full, with a systematic approach. All findings are noted in the patient's record and explained to the patient, including incidental findings. This presupposes the person reviewing the images is sufficiently trained to interpret such images, inform the patient and organize the clinical pathway, with referrals to other medical or oral medicine specialties as needed.

CONCLUSION

A close collaboration between dentists, medical physicists, radiologists, radiographers and engineers is critical for all aspects of CBCT technology.

Visual or visual-tactile examination to detect and inform the diagnosis of enamel caries

BACKGROUND

The detection and diagnosis of caries at the initial (non-cavitated) and moderate (enamel) levels of severity is fundamental to achieving and maintaining good oral health and prevention of oral diseases. An increasing array of methods of early caries detection have been proposed that could potentially support traditional methods of detection and diagnosis. Earlier identification of disease could afford patients the opportunity of less invasive treatment with less destruction of tooth tissue, reduce the need for treatment with aerosol-generating procedures, and potentially result in a reduced cost of care to the patient and to healthcare services.

OBJECTIVES

To determine the diagnostic accuracy of different visual classification systems for the detection and diagnosis of non-cavitated coronal dental caries for different purposes (detection and diagnosis) and in different populations (children or adults).

SEARCH METHODS

Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 30 April 2020); Embase Ovid (1980 to 30 April 2020); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 30 April 2020); and the World Health Organization International Clinical Trials Registry Platform (to 30 April 2020). We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included diagnostic accuracy study designs that compared a visual classification system (index test) with a reference standard (histology, excavation, radiographs). This included cross-sectional studies that evaluated the diagnostic accuracy of single index tests and studies that directly compared two or more index tests. Studies reporting at both the patient or tooth surface level were included. In vitro and in vivo studies were considered. Studies that explicitly recruited participants with caries into dentine or frank cavitation were excluded. We also excluded studies that artificially created carious lesions and those that used an index test during the excavation of dental caries to ascertain the optimum depth of excavation.

DATA COLLECTION AND ANALYSIS

We extracted data independently and in duplicate using a standardised data extraction and quality assessment form based on QUADAS-2 specific to the review context. Estimates of diagnostic accuracy were determined using the bivariate hierarchical method to produce summary points of sensitivity and specificity with 95% confidence intervals (CIs) and regions, and 95% prediction regions. The comparative accuracy of different classification systems was conducted based on indirect comparisons. Potential sources of heterogeneity were pre-specified and explored visually and more formally through meta-regression.

MAIN RESULTS

We included 71 datasets from 67 studies (48 completed in vitro) reporting a total of 19,590 tooth sites/surfaces. The most frequently reported classification systems were the International Caries Detection and Assessment System (ICDAS) (36 studies) and Ekstrand-Ricketts-Kidd (ERK) (15 studies). In reporting the results, no distinction was made between detection and diagnosis. Only two studies were at low risk of bias across all four domains, and 15 studies were at low concern for applicability across all three domains. The patient selection domain had the highest proportion of high risk of bias studies (49 studies). Four studies were assessed at high risk of bias for the index test domain, nine for the reference standard domain, and seven for the flow and timing domain. Due to the high number of studies on extracted teeth concerns regarding applicability were high for the patient selection and index test domains (49 and 46 studies respectively). Studies were synthesised using a hierarchical bivariate method for meta-analysis. There was substantial variability in the results of the individual studies: sensitivities ranged from 0.16 to 1.00 and specificities from 0 to 1.00. For all visual classification systems the estimated summary sensitivity and specificity point was 0.86 (95% CI 0.80 to 0.90) and 0.77 (95% CI 0.72 to 0.82) respectively, diagnostic odds ratio (DOR) 20.38 (95% CI 14.33 to 28.98). In a cohort of 1000 tooth surfaces with 28% prevalence of enamel caries, this would result in 40 being classified as disease free when enamel caries was truly present (false negatives), and 163 being classified as diseased in the absence of enamel caries (false positives). The addition of test type to the model did not result in any meaningful difference to the sensitivity or specificity estimates (Chi2(4) = 3.78, P = 0.44), nor did the addition of primary or permanent dentition (Chi2(2) = 0.90, P = 0.64). The variability of results could not be explained by tooth surface (occlusal or approximal), prevalence of dentinal caries in the sample, nor reference standard. Only one study intentionally included restored teeth in its sample and no studies reported the inclusion of sealants. We rated the certainty of the evidence as low, and downgraded two levels in total for risk of bias due to limitations in the design and conduct of the included studies, indirectness arising from the in vitro studies, and inconsistency of results.

AUTHORS' CONCLUSIONS

Whilst the confidence intervals for the summary points of the different visual classification systems indicated reasonable performance, they do not reflect the confidence that one can have in the accuracy of assessment using these systems due to the considerable unexplained heterogeneity evident across the studies. The prediction regions in which the sensitivity and specificity of a future study should lie are very broad, an important consideration when interpreting the results of this review. Should treatment be provided as a consequence of a false-positive result then this would be non-invasive, typically the application of fluoride varnish where it was not required, with low potential for an adverse event but healthcare resource and finance costs. Despite the robust methodology applied in this comprehensive review, the results should be interpreted with some caution due to shortcomings in the design and execution of many of the included studies. Studies to determine the diagnostic accuracy of methods to detect and diagnose caries in situ are particularly challenging. Wherever possible future studies should be carried out in a clinical setting, to provide a realistic assessment of performance within the oral cavity with the challenges of plaque, tooth staining, and restorations, and consider methods to minimise bias arising from the use of imperfect reference standards in clinical studies.

Radiological changes in maxillary sinus morphology after lateral sinus floor augmentation

&lt;b&gt;Background:&lt;/b&gt; Restoration of the masticatory function in patients with edentulous posterior maxilla is often challenging due to the severe atrophy of the alveolar ridges and proximity of the maxillary sinus, resulting in insufficient bone quantity for implant-supported dentures. &lt;br&gt;&lt;b&gt;Aim:&lt;/b&gt; The purpose of this study was to analyze the changes in Schneiderian membrane thickness after lateral sinus floor augmentation (LSFA) using cone beam computed tomography (CBCT). &lt;br&gt;&lt;b&gt;Material and methods:&lt;/b&gt; WLSFA procedures using different bone grafting materials were performed in 87 patients, operated on in two clinical institutions from 2016 to 2018. CBCT examination was performed in all patients before the LSFA procedure, at 1 month after surgery, and after 6 months, before implant placement or loading. &lt;br&gt;&lt;b&gt;Results: &lt;/b&gt;Minor r adiological changes in mucous membrane morphology were observed preoperatively in 17.1% of patients. Postoperative CBCT in the early postsurgical period demonstrated that the number of intact non-specific sinuses decreased significantly, i.e. from 86.7% to 26.7%. The number of cases with local hypertrophia of the mucous membrane increased from 20.3% to 26.7%. Mucosal thickening was observed in 41.7% vs 7.5%. The number of intact sinuses increased to 57.8%. The number of cases with local membrane hypertrophia also increased - to 37.4%. The number of cases with mucosal thickening or fluid accumulation decreased significantly to 11.8 and 5.3% respectively. In 2 cases the development of chronic sinusitis required secondary surgeries. &lt;br&gt;&lt;b&gt;Conclusion:&lt;/b&gt; The present retrospective study revealed that minor radiological changes in the morphology of the maxillary sinus mucosa were observed preoperatively in 17.1% of patients who underwent LSFA procedures. In the early and late postoperative period their frequency increased to 68.5% and 47.1%, respectively. However, the clinical signs of sinusitis developed only in 19.26% of patients. No significant correlations were found between the frequency and severity of postoperative radiological changes and residual bone height, sinus anatomy, initial state of the mucous membrane and type of the grafting material.

Management of early hepatocellular carcinoma: results of the Delphi consensus process of the Americas Hepato-Pancreato-Biliary Association

BACKGROUND

There are many potential treatment options for patients with early stage hepatocellular carcinoma (HCC) and practice patterns vary widely. This project aimed to use a Delphi conference to generate consensus regarding the management of small resectable HCC.

METHODS

A base case was established with review by members of AHPBA Research Committee. The Delphi panel of experts reviewed the literature and scored clinical case statements to identify areas of agreement and disagreement. Following initial scoring, discussion was undertaken, questions were amended, and scoring was repeated. This cycle was repeated until no further likelihood of reaching consensus existed.

RESULTS

The panel achieved agreement or disagreement consensus regarding 27 statements. The overarching themes included that resection, ablation, transplantation, or any locoregional therapy as a bridge to transplant were all appropriate modalities for early or recurrent HCC. For larger lesions, consensus was reached that radiofrequency ablation and microwave ablation were not appropriate treatments.

CONCLUSION

Using a validated system for identifying consensus, an expert panel agreed that multiple treatment modalities are appropriate for early stage HCC. These consensus guidelines are intended to help guide physicians through treatment modalities for early HCC; however, clinical decisions should continue to be made on a patient-specific basis.

Cone-Beam Computed Tomography: A User-Friendly, Practical Roadmap to the Planning and Execution of Every Rhinoplasty-A 5-Year Review

BACKGROUND

Cone-beam computed tomography has recently rapidly developed worldwide as a versatile and convenient alternative to traditional computed tomography for imaging of the maxillofacial region. However, most surgeons performing rhinoplasty are surprisingly unfamiliar with it, in both the plastic surgery and ear, nose, and throat communities.

METHODS

The broad clinical experience of a single center over the past 5 years is reviewed. The many applications of cone-beam computed tomography to primary and secondary rhinoplasty are analyzed regarding septum, turbinates, nasal bones, skin thickness, and other issues. The importance of a paradigm shift from a two-dimensional to a three-dimensional approach in image reconstruction is demonstrated, together with the value of surface contour enhancement.

RESULTS

Cone-beam computed tomography has a multitude of practical applications highly relevant to rhinoplasty. The surface image will strengthen aesthetic analysis, and the detailed preview of bony and functional anatomy will facilitate surgical planning. Cone-beam computed tomography serves as a roadmap to plan and execute rhinoplasties more predictably and efficiently. The availability of spatial views and accurate detail, together with the possibility of easy, accurate measuring, offers a plenitude of potential applications.

CONCLUSIONS

Cone-beam computed tomography is a user-friendly, quick technique with abundant advantages in planning any rhinoplasty. It causes the patient no inconvenience and has very few, if any, drawbacks, with these being limited to radiation exposure and limited cost.

Electrical conductance for the detection of dental caries

BACKGROUND

Caries is one of the most prevalent, preventable conditions worldwide. A wide variety of management options are available at different thresholds of disease, ranging from non-operative preventive strategies such as improved oral hygiene, reduced sugar diet, and application of topical fluoride, to minimally invasive treatments for early lesions which are limited to enamel, through to selective removal and restoration for extensive lesions. The cornerstone of caries detection is a visual and tactile dental examination, however, an increasing array of methods of caries lesion detection have been proposed that could potentially support traditional methods of detection and diagnosis. Earlier identification of disease could afford patients the opportunity of less invasive treatment with less destruction of tooth tissue, reduce the need for treatment with aerosol-generating procedures, and potentially result in a reduced cost of care to the patient and to healthcare services.

OBJECTIVES

Our primary objective was to determine the diagnostic accuracy of different electrical conductance devices for the detection and diagnosis of non-cavitated coronal dental caries in different populations (children, adolescents, and adults) and when tested against different reference standards.

SEARCH METHODS

Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 26 April 2019); Embase Ovid (1980 to 26 April 2019); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 26 April 2019); and the World Health Organization International Clinical Trials Registry Platform (to 26 April 2019). We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included diagnostic accuracy studies that compared electrical conductance devices with a reference standard of histology or an enhanced visual examination. This included prospective studies that evaluated the diagnostic accuracy of single index tests and studies that directly compared two or more index tests. We included studies using previously extracted teeth or those that recruited participants with teeth believed to be sound or with early lesions limited to enamel. Studies that explicitly recruited participants with more advanced lesions that were obviously into dentine or frankly cavitated were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently using a piloted study data extraction form based on the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Sensitivity and specificity with 95% confidence intervals (CIs) were reported for each study. This information was displayed as coupled forest plots, and plotted as summary receiver operating characteristic (SROC) plots, displaying the sensitivity-specificity points for each study. Due to variability in thresholds we estimated diagnostic accuracy using hierarchical summary receiver operating characteristic (HSROC) methods.

MAIN RESULTS

We included seven studies reporting a total of 719 tooth sites or surfaces, with an overall prevalence of the target condition of 73% (528 tooth sites or surfaces). The included studies evaluated two index tests: the electronic caries monitor (ECM) (four studies, 475 tooth surfaces) and CarieScan Pro (three studies, 244 tooth surfaces). Six studies used histology as the reference standard, one used an enhanced visual examination. No study was considered to be at low risk of bias across all four domains or low concern for applicability or both. All studies were at high (five studies) or unclear (two studies) risk of bias for the patient selection domain. We judged two studies to be at unclear risk of bias for the index test domain, and one study to be at high risk of bias for the reference standard and flow and timing domains. We judged three studies to be at low concern for applicability for patient selection, and all seven studies to be of low concern for reference standard and flow and timing domains. Studies were synthesised using a hierarchical method for meta-analysis. There was variability in the results of the individual studies, with sensitivities which ranged from 0.55 to 0.98 and specificities from 0 to 1.00. These extreme values of specificity may be explained by a low number of healthy tooth surfaces in the included samples. The diagnostic odds ratio (DOR) was 15.65 (95% CI 1.43 to 171.15), and indicative of the variability in the included studies. Through meta-regression we observed no meaningful difference in accuracy according to device type or dentition. Due to the small number of studies we were unable to formally investigate other potential sources of heterogeneity. We judged the certainty of the evidence as very low, and downgraded for risk of bias due to limitations in the design and conduct of the included studies, imprecision arising from the relatively small number of surfaces studied, and inconsistency due to the variability of results.

AUTHORS' CONCLUSIONS

The design and conduct of studies to determine the diagnostic accuracy of methods to detect and diagnose caries in situ is particularly challenging. The evidence base to support the detection and diagnosis of caries with electrical conductance devices is sparse. Newer electrical conductance devices show promise and further research at the enamel caries threshold using a robust study design to minimise bias is warranted. In terms of applicability, any future studies should be carried out in a clinical setting to provide a realistic assessment within the oral cavity where plaque, staining, and restorations can be problematic.

Transillumination and optical coherence tomography for the detection and diagnosis of enamel caries

BACKGROUND

Caries is one of the most prevalent and preventable conditions worldwide. If identified early enough then non-invasive techniques can be applied, and therefore this review focusses on early caries involving the enamel surface of the tooth. The cornerstone of caries detection and diagnosis is a visual and tactile dental examination, although alternative approaches are available. These include illumination-based devices that could potentially support the dental examination. There are three categories of illumination devices that exploit various methods of application and interpretation, each primarily defined by different wavelengths, optical coherence tomography (OCT), near-infrared (NIR), and fibre-optic technology, which incorporates more recently developed digital fibre optics (FOTI/DIFOTI).

OBJECTIVES

To estimate the diagnostic test accuracy of different illumination tests for the detection and diagnosis of enamel caries in children or adults. We also planned to explore the following potential sources of heterogeneity: in vitro or in vivo studies with different reference standards; tooth surface (occlusal, proximal, smooth surface, or adjacent to a restoration); single or multiple sites of assessment on a tooth surface; and the prevalence of caries into dentine.

SEARCH METHODS

Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 15 February 2019); Embase Ovid (1980 to 15 February 2019); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 15 February 2019); and the World Health Organization International Clinical Trials Registry Platform (to 15 February 2019). We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included diagnostic accuracy study designs that compared the use of illumination-based devices with a reference standard (histology, enhanced visual examination with or without radiographs, or operative excavation). These included prospective studies that evaluated the diagnostic accuracy of a single index test and studies that directly compared two or more index tests. Both in vitro and in vivo studies of primary and permanent teeth were eligible for inclusion. We excluded studies that explicitly recruited participants with caries into dentine or frank cavitation. We also excluded studies that artificially created carious lesions and those that used an index test during the excavation of dental caries to ascertain the optimum depth of excavation.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently and in duplicate using a standardised data extraction form and quality assessment based on QUADAS-2 specific to the clinical context. Estimates of diagnostic accuracy were determined using the bivariate hierarchical method to produce summary points of sensitivity and specificity with 95% confidence regions. The comparative accuracy of different illumination devices was conducted based on indirect and direct comparisons between methods. Potential sources of heterogeneity were pre-specified and explored visually and more formally through meta-regression.

MAIN RESULTS

We included 24 datasets from 23 studies that evaluated 16,702 tooth surfaces. NIR was evaluated in 6 datasets (673 tooth surfaces), OCT in 10 datasets (1171 tooth surfaces), and FOTI/DIFOTI in 8 datasets (14,858 tooth surfaces). The participant selection domain had the largest number of studies judged at high risk of bias (16 studies). Conversely, for the index test, reference standard, and flow and timing domains the majority of studies were judged to be at low risk of bias (16, 12, and 16 studies respectively). Concerns regarding the applicability of the evidence were judged as high or unclear for all domains. Notably, 14 studies were judged to be of high concern for participant selection, due to selective participant recruitment, a lack of independent examiners, and the use of an in vitro study design. The summary estimate across all the included illumination devices was sensitivity 0.75 (95% confidence interval (CI) 0.62 to 0.85) and specificity 0.87 (95% CI 0.82 to 0.92), with a diagnostic odds ratio of 21.52 (95% CI 10.89 to 42.48). In a cohort of 1000 tooth surfaces with a prevalence of enamel caries of 57%, this would result in 142 tooth surfaces being classified as disease free when enamel caries was truly present (false negatives), and 56 tooth surfaces being classified as diseased in the absence of enamel caries (false positives). A formal comparison of the accuracy according to device type indicated a difference in sensitivity and/or specificity (Chi2(4) = 34.17, P < 0.01). Further analysis indicated a difference in the sensitivity of the different devices (Chi2(2) = 31.24, P < 0.01) with a higher sensitivity of 0.94 (95% CI 0.88 to 0.97) for OCT compared to NIR 0.58 (95% CI 0.46 to 0.68) and FOTI/DIFOTI 0.47 (95% CI 0.35 to 0.59), but no meaningful difference in specificity (Chi2(2) = 3.47, P = 0.18). In light of these results, we planned to formally assess potential sources of heterogeneity according to device type, but due to the limited number of studies for each device type we were unable to do so. For interpretation, we presented the coupled forest plots for each device type according to the potential source of heterogeneity. We rated the certainty of the evidence as low and downgraded two levels in total due to avoidable and unavoidable study limitations in the design and conduct of studies, indirectness arising from the in vitro studies, and imprecision of the estimates.

AUTHORS' CONCLUSIONS

Of the devices evaluated, OCT appears to show the most potential, with superior sensitivity to NIR and fibre-optic devices. Its benefit lies as an add-on tool to support the conventional oral examination to confirm borderline cases in cases of clinical uncertainty. OCT is not currently available to the general dental practitioner, and so further research and development are necessary. FOTI and NIR are more readily available and easy to use; however, they show limitations in their ability to detect enamel caries but may be considered successful in the identification of sound teeth. Future studies should strive to avoid research waste by ensuring that recruitment is conducted in such a way as to minimise selection bias and that studies are clearly and comprehensively reported. In terms of applicability, any future studies should be undertaken in a clinical setting that is reflective of the complexities encountered in caries assessment within the oral cavity.

Nature and clinical significance of incidental findings in maxillofacial cone-beam computed tomography: a systematic review

OBJECTIVE

This systematic review was conducted to assess the types, potential clinical significance, and treatment implications of incidental findings (IFs) in CBCT diagnostic imaging of the maxillofacial region.

MATERIAL AND METHODS

The authors searched several electronic databases and grey literature without time restriction for studies on the IFs in maxillofacial CBCT. Studies that classified the IFs based on their potential clinical significance were included. The methodological quality of the included studies was evaluated by the STROBE criteria.

RESULTS

The online searches of the electronic databases yielded 1323 records. Five articles were included in the final qualitative analysis. The methodological quality ranged from low to moderate risk of bias. Percentages of IFs with high (requiring intervention/referral), moderate (requiring monitoring), and low clinical significance ranged from 0.3 to 31.4%, 15.6 to 28.9%, and 43.46 to 71.1%, respectively. There was an inconsistency between the studies in the clinical significance of 58.8% of the IFs identified.

CONCLUSION

Most IFs in maxillofacial CBCT are either normal variants or findings that do not require referral or treatment. There was no clear consensus on the recommended management of most common IFs. The lack of consensus on clinical significance emphasizes the importance of collaboration between medical and dental specialties to establish professional guidelines for the management of commonly encountered IFs in CBCT.

Evaluation of cone-beam computed tomography over a small field of view in a water bath based on the modulation transfer function with repeating-edge oversampling

PURPOSE

The spatial resolution of cone-beam computed tomography (CBCT) in small fields of view (FOVs) is important for clinical applications. However, it is difficult to measure spatial resolution reliably due to error factors such as noise. The aim of this study was to obtain a modulation transfer function (MTF) more accurately.

METHODS

A CBCT apparatus was used with small FOV. An aluminum pipe slightly tilted at an inclination ratio of 77/3 (25.7) was used as the measurement phantom. The MTF was calculated from the edge image of the phantom. The actual oversampling ratio was determined by regression analysis. The experiment was repeated 16 times and the edge-spread function (ESF) was approximated by the least-square method. Furthermore, a low-pass filter (LPF) was applied to eliminate the component at frequencies above the Nyquist frequency. Finally, the MTF was calculated from the pre-processed ESF.

RESULTS

Results showed that pre-processing reduced the noise of the ESF. The MTFs at frequencies of 1.0 and 2.0 LP/mm were 0.59 and 0.18, respectively, in air and 0.52 and 0.16, respectively, in water.

CONCLUSION

The repeating-edge oversampling method combined with ESF pre-processing improved the accuracy of the MTF under clinically relevant conditions with a phantom.

Fluorescence devices for the detection of dental caries

BACKGROUND

Caries is one of the most prevalent and preventable conditions worldwide. If identified early enough then non-invasive techniques can be applied, and therefore this review focusses on early caries involving the enamel surface of the tooth. The cornerstone of caries detection is a visual and tactile dental examination, however alternative methods of detection are available, and these include fluorescence-based devices. There are three categories of fluorescence-based device each primarily defined by the different wavelengths they exploit; we have labelled these groups as red, blue, and green fluorescence. These devices could support the visual examination for the detection and diagnosis of caries at an early stage of decay.

OBJECTIVES

Our primary objectives were to estimate the diagnostic test accuracy of fluorescence-based devices for the detection and diagnosis of enamel caries in children or adults. We planned to investigate the following potential sources of heterogeneity: tooth surface (occlusal, proximal, smooth surface or adjacent to a restoration); single point measurement devices versus imaging or surface assessment devices; and the prevalence of more severe disease in each study sample, at the level of caries into dentine.

SEARCH METHODS

Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 30 May 2019); Embase Ovid (1980 to 30 May 2019); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 30 May 2019); and the World Health Organization International Clinical Trials Registry Platform (to 30 May 2019). We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included diagnostic accuracy study designs that compared a fluorescence-based device with a reference standard. This included prospective studies that evaluated the diagnostic accuracy of single index tests and studies that directly compared two or more index tests. Studies that explicitly recruited participants with caries into dentine or frank cavitation were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently using a piloted study data extraction form based on the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Sensitivity and specificity with 95% confidence intervals (CIs) were reported for each study. This information has been displayed as coupled forest plots and summary receiver operating characteristic (SROC) plots, displaying the sensitivity-specificity points for each study. We estimated diagnostic accuracy using hierarchical summary receiver operating characteristic (HSROC) methods. We reported sensitivities at fixed values of specificity (median 0.78, upper quartile 0.90).

MAIN RESULTS

We included a total of 133 studies, 55 did not report data in the 2 x 2 format and could not be included in the meta-analysis. 79 studies which provided 114 datasets and evaluated 21,283 tooth surfaces were included in the meta-analysis. There was a high risk of bias for the participant selection domain. The index test, reference standard, and flow and timing domains all showed a high proportion of studies to be at low risk of bias. Concerns regarding the applicability of the evidence were high or unclear for all domains, the highest proportion being seen in participant selection. Selective participant recruitment, poorly defined diagnostic thresholds, and in vitro studies being non-generalisable to the clinical scenario of a routine dental examination were the main reasons for these findings. The dominance of in vitro studies also means that the information on how the results of these devices are used to support diagnosis, as opposed to pure detection, was extremely limited. There was substantial variability in the results which could not be explained by the different devices or dentition or other sources of heterogeneity that we investigated. The diagnostic odds ratio (DOR) was 14.12 (95% CI 11.17 to 17.84). The estimated sensitivity, at a fixed median specificity of 0.78, was 0.70 (95% CI 0.64 to 0.75). In a hypothetical cohort of 1000 tooth sites or surfaces, with a prevalence of enamel caries of 57%, obtained from the included studies, the estimated sensitivity of 0.70 and specificity of 0.78 would result in 171 missed tooth sites or surfaces with enamel caries (false negatives) and 95 incorrectly classed as having early caries (false positives). We used meta-regression to compare the accuracy of the different devices for red fluorescence (84 datasets, 14,514 tooth sites), blue fluorescence (21 datasets, 3429 tooth sites), and green fluorescence (9 datasets, 3340 tooth sites) devices. Initially, we allowed threshold, shape, and accuracy to vary according to device type by including covariates in the model. Allowing consistency of shape, removal of the covariates for accuracy had only a negligible effect (Chi2 = 3.91, degrees of freedom (df) = 2, P = 0.14). Despite the relatively large volume of evidence we rated the certainty of the evidence as low, downgraded two levels in total, for risk of bias due to limitations in the design and conduct of the included studies, indirectness arising from the high number of in vitro studies, and inconsistency due to the substantial variability of results.

AUTHORS' CONCLUSIONS

There is considerable variation in the performance of these fluorescence-based devices that could not be explained by the different wavelengths of the devices assessed, participant, or study characteristics. Blue and green fluorescence-based devices appeared to outperform red fluorescence-based devices but this difference was not supported by the results of a formal statistical comparison. The evidence base was considerable, but we were only able to include 79 studies out of 133 in the meta-analysis as estimates of sensitivity or specificity values or both could not be extracted or derived. In terms of applicability, any future studies should be carried out in a clinical setting, where difficulties of caries assessment within the oral cavity include plaque, staining, and restorations. Other considerations include the potential of fluorescence devices to be used in combination with other technologies and comparative diagnostic accuracy studies.

Tests to detect and inform the diagnosis of root caries

BACKGROUND

Root caries is a well-recognised disease, with increasing prevalence as populations age and retain more of their natural teeth into later life. Like coronal caries, root caries can be associated with pain, discomfort, tooth loss, and contribute significantly to poorer oral health-related quality of life in the elderly. Supplementing the visual-tactile examination could prove beneficial in improving the accuracy of early detection and diagnosis. The detection of root caries lesions at an early stage in the disease continuum can inform diagnosis and lead to targeted preventive therapies and lesion arrest.

OBJECTIVES

To assess the diagnostic test accuracy of index tests for the detection and diagnosis of root caries in adults, used alone or in combination with other tests.

SEARCH METHODS

Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 31 December 2018); Embase Ovid (1980 to 31 December 2018); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 31 December 2018); and the World Health Organization International Clinical Trials Registry Platform (to 31 December 2018). We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included diagnostic accuracy study designs that compared one or more index tests (laser fluorescence, radiographs, visual examination, electronic caries monitor (ECM), transillumination), either independently or in combination, with a reference standard. This included prospective studies that evaluated the diagnostic accuracy of single index tests and studies that directly compared two or more index tests. In vitro and in vivo studies were eligible for inclusion but studies that artificially created carious lesions were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently and in duplicate using a standardised data extraction and quality assessment form based on the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) specific to the review context. Estimates of diagnostic test accuracy were expressed as sensitivity and specificity with 95% confidence intervals (CI) for each dataset. We planned to use hierarchical models for data synthesis and explore potential sources of heterogeneity through meta-regression.

MAIN RESULTS

Four cross-sectional diagnostic test accuracy studies providing eight datasets with data from 4997 root surfaces were analysed. Two in vitro studies evaluated secondary root caries lesions on extracted teeth and two in vivo studies evaluated primary root caries lesions within the oral cavity. Four studies evaluated laser fluorescence and reported estimates of sensitivity ranging from 0.50 to 0.81 and specificity ranging from 0.40 to 0.80. Two studies evaluated radiographs and reported estimates of sensitivity ranging from 0.40 to 0.63 and specificity ranging from 0.31 to 0.80. One study evaluated visual examination and reported sensitivity of 0.75 (95% CI 0.48 to 0.93) and specificity of 0.38 (95% CI 0.14 to 0.68). One study evaluated the accuracy of radiograph and visual examination in combination and reported sensitivity of 0.81 (95% CI 0.54 to 0.96) and specificity of 0.54 (95% CI 0.25 to 0.81). Given the small number of studies and important differences in the clinical and methodological characteristics of the studies we were unable to pool the results. Consequently, we were unable to formally evaluate the comparative accuracy of the different tests considered in this review. Using QUADAS-2 we judged all four studies to be at overall high risk of bias, but only two to have applicability concerns (patient selection domain). Reasons included bias in the selection process, use of post hoc (data driven) positivity thresholds, use of an imperfect reference standard, and use of extracted teeth. We downgraded the certainty of the evidence due to study limitations and serious imprecision of the results (downgraded two levels), and judged the certainty of the evidence to be very low.

AUTHORS' CONCLUSIONS

Visual-tactile examination is the mainstay of root caries detection and diagnosis; however, due to the paucity of the evidence base and the very low certainty of the evidence we were unable to determine the additional benefit of adjunctive diagnostic tests for the detection and diagnosis of root caries.

Timing of Spheno-Occipital Synchondrosis Ossification in Children and Adolescents with Cleft Lip and Palate: A Retrospective Case-Control Study

Background: Cleft lip and palate (CLP) can affect the development of the maxilla; which may create a midfacial deficiency as well as an interference of the facial growth pattern and dentofacial esthetics. Objective: This study aimed to estimate the chronological age of complete fusion of the spheno-occipital synchondrosis (SOS) in cleft lip and palate patients and a control group; using cone beam computed tomography (CBCT) images. Methods: In this retrospective study; 125 patients were enrolled (cleft lip and palate group (n = 91); control group (n = 34)). Age comparison was made with a chi-square test; and a Kaplan–Meier analysis determined the median time to reach complete fusion of the spheno-occipital synchondrosis (p < 0.05). Results: The experimental group showed statistically significant differences in the median time for complete ossification between males and females (p = 0.019). The median time for complete ossification of the spheno-occipital synchondrosis was; for males; 15.0 years in both groups; for females; it was 14.0 years and 13.0 years in the experimental group and in the control group; respectively. Both for males and females; there were no statistically significant differences between experimental and control groups (p = 0.104). Conclusions: The present study showed no differences in the ossification of the spheno-occipital synchondrosis between individuals with and without cleft lip and/or palate.

Professional consensus on orthodontic risks: What orthodontists should tell their patients

INTRODUCTION

Effective communication of risk is a requisite for valid consent, shared decision-making, and the provision of person-centered care. No agreed standard for the content of discussions with patients about the risks of orthodontic treatment exists. This study aimed to produce a professional consensus recommendation about the risks that should be discussed with patients as part of consent for orthodontic treatment.

METHODS

A serial cross-sectional survey design using a modified electronic Delphi technique was used. Two survey rounds were conducted nationally in the United Kingdom using a custom-made online system. The risks used as the prespecified items scored in the Delphi exercise were identified through a structured literature review. Orthodontists scored treatment risks on a 1-9 scale (1 = not important, 9 = critical to discuss with patients). The consensus that a risk should be discussed as part of consent was predefined as ≥70% orthodontists scoring risk as 7-9 and <15% scoring 1-3.

RESULTS

The electronic Delphi was completed by 237 orthodontists who reached a professional consensus that 10 risks should be discussed as part of consent for orthodontic treatment; demineralization, relapse, resorption, pain, gingivitis, ulceration, appliances breaking, failed tooth movements, treatment duration, and consequences of no treatment.

CONCLUSIONS

A professional orthodontic consensus has been reached that 10 key risks should be discussed with patients as part of consent for orthodontic treatment. The information in this evidence base should be tailored to patients' individual needs and delivered as part of a continuing risk communication process.

Imaging Anatomy of the Jaw and Dentition with Cone Beam Computed Tomography

Knowledge of dental, maxillary, and mandibular anatomy and the use of correct nomenclature is critical in the evaluation of a mandibulofacial and/or maxillofacial imaging data set. The use of the correct diagnostic imaging tool tailored to the patient's needs is of equal importance. This article highlights imaging anatomy and cross-sectional imaging modalities mainly focusing on cone beam computed tomography of the mandibulofacial and maxillofacial region.

The crucial role of imaging in digital dentistry

One of the recent trends in dentistry - and this in every field from the restorative to the orthodontic one- is the introduction of simplified completely digital workflows. Digital dentistry is supposed to allow dentists to work more efficiently, and this at higher precision, and with the possibility of all-in-one sessions using in-house computerized techniques. In this workflow, one of the major tools for simulating and transferring dental treatments is imaging. Both 3D low dose radiographic as well as optical imaging are playing crucial roles and have been overwhelming the market. Novel design platforms, compact and extremely fast milling and printing units are now also plentiful and rapidly being adopted in practice. Nevertheless, many of the steps in this digital dentistry process, no matter how simplified, present risks that can contribute to reduced precision and clinical difficulties. It is therefore the purpose of the article to briefly describe the role of imaging in this digital workflow, and where the pitfalls can be found that may lead to errors and imprecision.

Cone-Beam Computed Tomography Incidental Findings in Individuals With Cleft Lip and Palate

OBJECTIVES

The use of cone-beam computed tomography (CBCT) is well-established in clinical practice. This study seeks to categorize and quantify the incidental finding (IF) rate on CBCT in patients with cleft lip and palate (CLP) prior to orthodontic or surgical treatment.

METHODS

This is systematic retrospective review of head and neck CBCTs in patients with nonsyndromic CLP taken between 2012 and 2019 at a single tertiary referral center. All assessments were performed independently by 4 observers (a head and neck radiologist and 3 orthodontists, including 2 fellowship-trained cleft-craniofacial orthodontists ). The images were divided into 9 anatomical areas and screened using serial axial slices and 3D reconstructions. The absolute number of IFs was reported for each area and statistical analysis was performed.

RESULTS

Incidental findings were found in 106 (95.5%) of the 111 patients. The most common sites were the maxilla (87.4%, principally dental anomalies), paranasal sinuses (46.8%, principally inflammatory opacification), and inner ear cavities (18.9%, principally inflammatory opacification). Eleven patients had skull malformations. Thirty-three patients had IFs in 1 anatomical area, 49 patients in 2 anatomical areas, 19 patients in 3 areas, and 5 patients presented with IFs in 4 of the 9 anatomical areas.

DISCUSSION

In patients with CLP, IFs on CBCT exam were present in the majority of cases. Most patients with IFs had them in multiple anatomical areas of the head and neck. The maxillary dental-alveolar complex was the most common area. Inflammatory changes in the inner ear cavities and paranasal sinuses were also common; however, cervical spine and skull abnormalities were also identified. Clinicians caring for patients with CLP should be aware of IFs, which may warrant further investigation and treatment.

Orthosurgical Management of Class III Malocclusion Emphasizing the Pivotal Role of CBCT

Management of skeletal class III malocclusions in a nongrowing individual remains a challenging and arduous task for the orthodontist. The skeletal class III malocclusion is often not amenable to camouflage procedures and requires a surgical correction of the underlying skeletal bases to achieve esthetic and functional treatment results. These patients often require one or more extractions to remove the preexisting dentoalveolar compensations prior to the surgical procedure which is undertaken as part of presurgical orthodontics. Postsurgical orthodontics is often of limited duration and is concerned with the settling of occlusion and obtaining tight cuspal interdigitation. Cone-beam computed tomography is a recent innovation which has revolutionized imaging in dentistry. Within orthodontics, it has proven to be of great value in orthosurgical planning and evaluation of posttreatment results including root parallelism and root resorption. This case report describes orthosurgical management of class III malocclusion utilizing cone-beam computed tomography in treatment planning.

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.

Best clinical practice guidance for prescribing dental radiographs in children and adolescents: an EAPD policy document

BACKGROUND

The European Academy of Paediatric Dentistry (EAPD) proposes this best clinical practice guidance to help practitioners decide when and how to prescribe dental radiographs in children and adolescents.

METHODS

Four expert working groups conducted each a systematic review of the literature. The main subjects were radiation protection, intraoral dental radiography (bitewing and periapical radiographs), panoramic radiography (PR) and cone-beam computed tomography (CBCT). In addition, three workshops were held during the corresponding EAPD Interim Seminar in Chania (Crete, Greece) in 2019. On the basis of the identified evidence, all invited experts presented their findings and during the workshops aspects of clinical relevance were discussed.

RESULTS

Several clinical-based recommendations and statements were agreed upon.

CONCLUSION

There is no or low-grade evidence about the efficacy of dental radiographic examinations in young populations. The given recommendations and rationales should be understood as best clinical practice guidance. It is essential to respect the radiological principles of an individualized and patient-specific justification. When a dental radiograph is required, its application needs to be optimized, aiming at limiting the patient's exposure to ionising radiation according to the ALADAIP principle (As Low As Diagnostically Achievable being Indication-oriented and Patient-specific).

Ameloblastoma incidentally detected in cone-beam computed tomography sialography: A case report and review of the literature

BACKGROUND AND OVERVIEW

Cone-beam computerized tomographic (CBCT) imaging is increasingly used in the maxillofacial region for various purposes. The volumetric dataset created by means of CBCT increases the possibility of detecting incidental findings.

CASE DESCRIPTION

In this case report, the authors describe an otherwise healthy 45-year-old man who was referred from the Sjogren's Syndrome Center in Jerusalem, Israel, for bilateral parotid CBCT sialographic imaging owing to xerostomia lasting for 4 months. CBCT sialographic imaging using iodine contrast material showed normal glandular structure and activity according to the postcannulation panoramic imaging. CBCT sialographic imaging routine volume interpretation revealed a lesion in the mandibular area causing destruction and perforation of the cortical plates, partial disappearance of adjacent lamina dura, and resorption of adjacent teeth, suggesting an aggressive benign tumor. Histopathologic examination confirmed mural cystic ameloblastoma, which was resected with preservation of the mental nerve and the lower mandibular border. The patient received bone graft and implants, with regular follow-ups and no recurrence after 4 years.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

This case strengthens the need for thorough examination of the whole CBCT imaging volume within and outside the region of interest to detect incidental findings with clinical importance.

A three-dimensional finite element analysis of mechanical function for 4 removable partial denture designs with 3 framework materials: CoCr, Ti-6Al-4V alloy and PEEK

Polyetheretherketone (PEEK) is a new material used for the frameworks of removable partial dentures (RPD). The questions whether the PEEK framework has similar stress distribution on oral tissue and displacement under masticatory forces as titanium alloy (Ti-6Al-4V) or cobalt-chromium alloy (CoCr) remain unclear and worth exploring. A patient's intraoral data were obtained via CBCT and master model scan. Four RPDs were designed by 3Shape dental system, and the models were processed by three-dimensional finite element analysis. Among three materials tested, PEEK has the lowest maximum von Mises stress (VMS) on periodontal ligament (PDL), the greatest maximum VMS on mucosa, the maximum displacement on free-end of framework, and the lowest maximum VMS on framework. Results suggested that PEEK framework has a good protective effect on PDL, suggesting applications for patients with poor periodontal conditions. However, the maximum displacement of the free-end under masticatory force is not conducive for denture stability, along with large stress on the mucosa indicate that PEEK is unsuitable for patients with more loss of posterior teeth with free-end edentulism.

IAEA survey of dental cone beam computed tomography practice and related patient exposure in nine Central and Eastern European countries

OBJECTIVES

Cone beam CT (CBCT) in dentistry and maxillofacial surgery is a widely used imaging method for the assessment of various maxillofacial and dental pathological conditions. The objective of this study was to summarize the results of a multinational retrospective-prospective study that focused on patient exposure in this modality.

METHODS

The study included 27 CBCT units and 325 adult and paediatric patients, in total. Data on patients, clinical indications, technical parameters of exposure, patient dose indicator, or, alternatively, dose to phantom were collected. The dose indicator used was air kerma-area product, P_KA.

RESULTS

In most scanners operators are offered with a variety of options regarding technical parameters, especially the field of view size. The median and the third quartile value of P_KA for adult patients in 14 different facilities were 820 mGy cm² and 1000 mGy cm² (interquartile range = 1058 mGy cm²), and 653 mGy cm² and 740 mGy cm² (interquartile range = 1179 mGy cm²) for children, as reported by four different institutions. Phantom dose data were reported from 15 institutions, and median P_KA ranged from 125 mGy cm² to 1951 mGy cm². Median P_KA values varied by more than a 10-fold between institutions, mainly due to differences in imaging protocol used, in particular field of view and tube current-exposure time product.

CONCLUSIONS

The results emphasize the need for a cautious approach to using dental CBCT. Imaging only when the clinical indications are clear, accompanied with the appropriate radiographic techniques and the optimum imaging protocol, will help reduce radiation dose to patients.

Cone-Beam Computed Tomography in Orthodontics

Unlike patients receiving implants or endodontic treatment, most orthodontic patients are children who are particularly sensitive to ionizing radiation. Cone-beam computed tomography (CBCT) carries risks and benefits in orthodontics. The principal risks and limitations include ionizing radiation, the presence of artifacts, higher cost, limited accessibility, and the need for additional training. However, this imaging modality has several recognized indications in orthodontics, such as the assessment of impacted and ectopic teeth, assessment of pharyngeal airway, assessment of mini-implant sites, evaluation of craniofacial abnormalities, evaluation of sinus anatomy or pathology, evaluation of root resorption, evaluation of the cortical bone plate, and orthognathic surgery planning and evaluation. CBCT is particularly justified when it brings a benefit to the patient or changes the outcome of the treatment when compared with conventional imaging techniques. Therefore, CBCT should be considered for clinical orthodontics for selected patients. Prescription of CBCT requires judicious and sound clinical judgment. The central question of this narrative review article is: when does CBCT add value to the practice of orthodontics? To answer this question, this article presents discussion on radiation dosage of CBCT and other imaging techniques used in orthodontics, limitations of CBCT in orthodontics, justifying the use of CBCT in orthodontics, and the benefits and evidence-based indications of CBCT in orthodontics. This review summarizes the central themes and topics in the literature regarding CBCT in orthodontics and presents ten orthodontic cases in which CBCT proved to be valuable.

The ins and outs of root resorption

Root resorption is a poorly understood phenomenon and is often misdiagnosed and, as a result, inappropriately treated. The aim of this paper is to provide a practical guide for diagnosis of root resorption lesions using a simple classification, and to describe the principles of management of these resorptive defects in everyday practice.

Evaluation of the survival of implant placement simultaneously with sinus augmentation: relationship in maxillary sinus pathologies

OBJECTIVES

This retrospective study aimed to evaluate the effects of existing maxillary sinus pathologies on the survival rates of dental implants placed simultaneously with sinus augmentation.

METHODS

Cone-beam computed tomography images of 88 patients (34 females, 54 males), who underwent sinus augmentation, were retrospectively analyzed and the patients were divided into two groups: with (pathology group) and without pathology (control group). All maxillary sinus pathologies were recorded and categorized into mucosal thickening ( ≥ 3 mm), antral pseudocyst (polypoid mucosal thickening), and complete opacification. Implant survival rates were evaluated after a mean follow-up period of 28.2 ± 9.8 months based on the patient's records and control radiographs.

RESULTS

A total of 115 maxillary sinuses of 88 patients with 168 dental implants were included in the study. Maxillary sinus pathology was detected in 45 patients in the pathology group and 43 patients in the control group. In the pathology group, one implant was lost out of 82 implants during the 27.8 ± 9.5 months follow-up period, while in the control group, 5 implants were lost out of 86 implants during the 25.1 ± 10 months follow-up period. There was no statistically significant difference in the survival rates between the two groups.

CONCLUSIONS

The study concluded that the presence of pathology in the maxillary sinus before surgery does not affect the survival rates of dental implants placed simultaneously with sinus augmentation. The most common pathology noted included mucosal thickening (61.4%), which was detected in 35 patients.

Ex vivo comparison of CBCT and digital periapical radiographs for the quantitative assessment of periodontal defects

OBJECTIVES

Accurate imaging is essential for effective treatment planning in periodontology. The aim of this ex vivo study was to investigate the accuracy of cone beam computed tomography (CBCT) and digital periapical radiographs (PA) in imaging periodontal defects. Hypotheses are: 1. That CBCT is a more accurate method than PA concerning vertical measurements of periodontal bone defects2. That CBCT itself is an accurate method to describe vertical periodontal bone loss MATERIAL AND METHODS: In this study, 117 periodontal defects from 10 human cadavers were investigated radiographically by CBCT and PA by one calibrated observer. Afterwards the vertical bone loss was measured with a periodontal probe by the same calibrated observer. Differences between radiographic and clinical measurements were calculated and analyzed. Bland-Altmann plots including 95% limits of agreement were calculated.

RESULTS

The 95% limits of agreement ranged from 3.29 to -3.27 mm between clinical measurements and measurements in PAs, and from 2.13 to -1.97 mm in CBCTs. The mean difference between clinical and radiographic measurements was 0.0009 mm for PA and 0.0835 mm for CBCT.

CONCLUSIONS

When comparing the clinical measurements, CBCT had a higher agreement and less deviations than PAs, and CBCT seems to be an accurate method to describe vertical periodontal bone loss.

CLINICAL RELEVANCE

Accurate description of defects is helpful for accurate treatment planning.

Potential neurovascular damage as a result of dental implant placement in the anterior maxilla

Introduction A patient requested dental implant therapy to replace his missing upper left central incisor. Pre-operative cone beam computed tomography (CBCT) imaging revealed a complex neurovascular supply to the anterior maxilla.Discussion Imaging demonstrated accessory neurovascular canals around the nasopalatine foramen which directly communicate with canalis sinuosus. They are, therefore, most likely to carry branches of the anterior superior alveolar nerve and vessels. One of these canals was directly in the path of proposed dental implant placement. A review of the dental literature suggests that such anatomical variation is relatively common. Some authors have proposed that injury to these structures is a cause of intractable pain following dental implant placement. Following discussion with the patient, it was agreed that the provision of an adhesive bridge was a realistic alternative in this case.Conclusion The availability of CBCT imaging in recent years has shown that complex neurovascular anatomy in the anterior maxilla is not uncommon. Evidence is lacking regarding the relevance of this to dental implant placement but it is possible that injury to these structures explains some cases of postoperative intractable pain.