Cone Beam Computed Tomography.

In the last several decades, the need for 3D images in dentistry have developed. Computerized tomography was first introduced mainly with the advent of implantology, but its use remained limited to a small number of specialists, due to its indications, access and dose radiation. In the late 90's, a new technology using a cone-shaped beam and a reciprocating detector, which rotates around the patient 360 degrees and acquires projected data in a single rotation, namely the cone beam computerized tomography (CBCT), invaded dentistry, making the perception of 3D easily acceptable to dentists and their patients.

Cone beam computed tomography in implant dentistry: recommendations for clinical use.

BACKGROUND: In implant dentistry, three-dimensional (3D) imaging can be realised by dental cone beam computed tomography (CBCT), offering volumetric data on jaw bones and teeth with relatively low radiation doses and costs. The latter may explain why the market has been steadily growing since the first dental CBCT system appeared two decades ago. More than 85 different CBCT devices are currently available and this exponential growth has created a gap between scientific evidence and existing CBCT machines. Indeed, research for one CBCT machine cannot be automatically applied to other systems. METHODS: Supported by a narrative review, recommendations for justified and optimized CBCT imaging in oral implant dentistry are provided. RESULTS: The huge range in dose and diagnostic image quality requires further optimization and justification prior to clinical use. Yet, indications in implant dentistry may go beyond diagnostics. In fact, the inherent 3D datasets may further allow surgical planning and transfer to surgery via 3D printing or navigation. Nonetheless, effective radiation doses of distinct dental CBCT machines and protocols may largely vary with equivalent doses ranging between 2 to 200 panoramic radiographs, even for similar indications. Likewise, such variation is also noticed for diagnostic image quality, which reveals a massive variability amongst CBCT technologies and exposure protocols. For anatomical model making, the so-called segmentation accuracy may reach up to 200 µm, but considering wide variations in machine performance, larger inaccuracies may apply. This also holds true for linear measures, with accuracies of 200 µm being feasible, while sometimes fivefold inaccuracy levels may be reached. Diagnostic image quality may also be dramatically hampered by patient factors, such as motion and metal artefacts. Apart from radiodiagnostic possibilities, CBCT may offer a huge therapeutic potential, related to surgical guides and further prosthetic rehabilitation. Those additional opportunities may surely clarify part of the success of using CBCT for presurgical implant planning and its transfer to surgery and prosthetic solutions. CONCLUSIONS: Hence, dental CBCT could be justified for presurgical diagnosis, preoperative planning and peroperative transfer for oral implant rehabilitation, whilst striving for optimisation of CBCT based machine-dependent, patient-specific and indication-oriented variables.

Cone-beam computed tomography with automated bone subtraction in preoperative embolization for pelvic bone tumors.

PURPOSE: To evaluate the usefulness of cone-beam computed tomography with automated bone subtraction (CBCT-ABS) in the preoperative embolization of hypervascular tumors located in the pelvic bone. MATERIALS AND METHODS: This retrospective study included 26 patients with pelvic bone tumors who underwent preoperative embolization between January 2014 and October 2016. A CBCT-ABS scan was taken in a total of 17 patients (CBCT-ABS group), and only a series of digital subtraction angiographies (DSAs) was taken in the remaining 9 patients (DSA group). The percent devascularization, number of angiographic runs, total dose-area product (DAP), fluoroscopy time, interventional procedure time, operative time, and estimated blood loss were compared between the two groups using Mann-Whitney test. RESULTS: The percent devascularization, interventional procedure time, fluoroscopy time, operative time, and estimated blood loss were not statistically different between the two groups (p > 0.05). On the other hand, the number of angiographic runs in the CBCT-ABS group was significantly lower than that in the DSA group (p = 0.029). The total DAP of the CBCT-ABS group (mean, 17700.7 µGym2) was higher than that of the DSA group (mean, 8939.4 µGym2) (p = 0.002). CONCLUSIONS: The use of CBCT-ABS during the preoperative embolization of pelvic bone tumors significantly reduces the number of angiographic runs at the cost of an increased radiation dose.

Effects from changes to the Medicare Benefits Schedule in 2014 on cone beam computed tomography and panoramic radiography scans across Australia.

INTRODUCTION: This study examines the effects of the new Medicare Benefits Schedule (MBS) operating from 1st November 2014 on the number of Medicare rebated panoramic radiography (PR) and cone beam computed tomography (CBCT) scans. METHODS: Data for rebated PR and CBCT scans were extracted from Medicare Australia Statistics online for four 12-month periods: November 2011-October 2012, November 2012-October 2013, November 2013-October 2014 and December 2014-November 2015. RESULTS: There was a reduction in the number of CBCT scans rebated across Australia under the new MBS. Nationally, December 2014-November 2015 showed a 65.3% reduction in the number of CBCT scans when compared to the peak in the previous 12 months under the old MBS. The number of rebated PR scans remained constant. CONCLUSION: The new MBS implemented on 1st November 2014 resulted in a reduction in the number of rebated CBCT scans, but had no effect on rebated PR scans. Overall, there has been considerable cost savings for Medicare due to the change in MBS. Additionally, the reduction in the number of rebated CBCT scans has resulted in a substantial reduction in the ionising radiation load to the Australian community as a whole, but especially the younger age groups.

Economic evaluation comparing intraoperative cone beam CT-based navigation and conventional fluoroscopy for the placement of spinal pedicle screws: a patient-level data cost-effectiveness analysis.

BACKGROUND CONTEXT: Pedicle screws are routinely used in contemporary spinal surgery. Screw misplacement may be asymptomatic but is also correlated with potential adverse events. Computer-assisted surgery (CAS) has been associated with improved screw placement accuracy rates. However, this technology has substantial acquisition and maintenance costs. Despite its increasing usage, no rigorous full economic evaluation comparing this technology to current standard of care has been reported. PURPOSE: Medical costs are exploding in an unsustainable way. Health economic theory requires that medical equipment costs be compared with expected benefits. To answer this question for computer-assisted spinal surgery, we present an economic evaluation looking specifically at symptomatic misplaced screws leading to reoperation secondary to neurologic deficits or biomechanical concerns. STUDY DESIGN/SETTING: The study design was an observational case-control study from prospectively collected data of consecutive patients treated with the aid of CAS (treatment group) compared with a matched historical cohort of patients treated with conventional fluoroscopy (control group). PATIENT SAMPLE: The patient sample consisted of consecutive patients treated surgically at a quaternary academic center. OUTCOME MEASURES: The primary effectiveness measure studied was the number of reoperations for misplaced screws within 1 year of the index surgery. Secondary outcome measures included were total adverse event rate and postoperative computed tomography usage for pedicle screw examination. METHODS: A patient-level data cost-effectiveness analysis from the hospital perspective was conducted to determine the value of a navigation system coupled with intraoperative 3-D imaging (O-arm Imaging and the StealthStation S7 Navigation Systems, Medtronic, Louisville, CO, USA) in adult spinal surgery. The capital costs for both alternatives were reported as equivalent annual costs based on the annuitization of capital expenditures method using a 3% discount rate and a 7-year amortization period. Annual maintenance costs were also added. Finally, reoperation costs using a micro-costing approach were calculated for both groups. An incremental cost-effectiveness ratio was calculated and reported as cost per reoperation avoided. Based on reoperation costs in Canada and in the United States, a minimal caseload was calculated for the more expensive alternative to be cost saving. Sensitivity analyses were also conducted. RESULTS: A total of 5,132 pedicle screws were inserted in 502 patients during the study period: 2,682 screws in 253 patients in the treatment group and 2,450 screws in 249 patients in the control group. Overall accuracy rates were 95.2% for the treatment group and 86.9% for the control group. Within 1 year post treatment, two patients (0.8%) required a revision surgery in the treatment group compared with 15 patients (6%) in the control group. An incremental cost-effectiveness ratio of $15,961 per reoperation avoided was calculated for the CAS group. Based on a reoperation cost of $12,618, this new technology becomes cost saving for centers performing more than 254 instrumented spinal procedures per year. CONCLUSIONS: Computer-assisted spinal surgery has the potential to reduce reoperation rates and thus to have serious cost-effectiveness and policy implications. High acquisition and maintenance costs of this technology can be offset by equally high reoperation costs. Our cost-effectiveness analysis showed that for high-volume centers with a similar case complexity to the studied population, this technology is economically justified.

Applications of Cone-Beam Computed Tomography in Oral and Maxillofacial Surgery: An Overview of Published Indications and Clinical Usage in United States Academic Centers and Oral and Maxillofacial Surgery Practices.

PURPOSE: The American Association of Oral and Maxillofacial Surgeons appointed a task force to study the indications, safety, and clinical practice patterns of cone-beam computed tomography (CBCT) in oral and maxillofacial surgery (OMS). The charge was to review the published applications of CBCT in OMS, identify the current position of academic thought leaders in the field, and research the adoption and usage of the technology at the clinical practitioner level. MATERIALS AND METHODS: This study reviewed the CBCT world literature and summarized published indications for the modality. A nationwide survey of academic thought leaders and practicing oral and maxillofacial surgeons was compiled to determine how the modality is currently being used and adopted by institutions and practices. RESULTS: This report summarizes published applications of CBCT that have been vetted by the academic and practicing OMS community to define current indications. The parameters of patient safety, radiation exposure, accreditation, and legal issues are reviewed. An overview of third-party adoption of CBCT is presented. CONCLUSION: CBCT is displacing 2-dimensional imaging in the published literature, academia, and private practice. Best practices support reading the entire scan volume with a written report defining results, patient exposure, and field of view. Issues of patient safety, ALARA ("as low as reasonably achievable"), accreditation, and the legal and regulatory environment are reviewed. Third-party patterns for reimbursements vary widely and seem to lack consistency. There is much confusion within the provider community about indications, authorizations, and payment policies. The current medical and dental indications for CBCT in the clinical practice of OMS are reviewed and an industry guideline is proposed. These guidelines offer a clear way of differentiating consensus medical indications and common dental uses for clinicians. This matrix should bring a predictable logic to third-party authorizations, billing, and predictable payments for this emerging technology in OMS.

Economic and health implications of routine CBCT examination before surgical removal of the mandibular third molar in the Danish population.

OBJECTIVES: This epidemiological study aimed to analyse economical and societal consequences in Denmark if CBCT is used routinely as a diagnostic method before removal of the mandibular third molar. Furthermore, the aim was to calculate the excess cancer incidence from this practice. METHODS: 17 representative dental clinics in the regions of Denmark were visited by two observers, who registered the total number of patients in each clinic, the number of removed mandibular third molars from patients' files together with the age and gender of these patients. The data were collected from 2008 to 2014. The total number of removed mandibular third molars in Denmark each year was derived from the collected data and information on patients' contacts with dentists from Statistics Denmark as a sum of contributions from each region. The contribution of a region was obtained as the number of removed mandibular third molars in the selected clinics in the region times the ratio of the number of patients in the selected clinics in the region to the total number of patients with contact to a general practitioner in the region in 2011. Existing knowledge on the costs for panoramic and CBCT imaging was used to calculate total costs. The cancer incidence was calculated from lifetime attributable risk curves based on linear risk assumptions. RESULTS: The selected clinics included 109,686 patients, and 1369 mandibular third molars had been surgically removed. Using data from Statistics Denmark gave an estimated annual number of removed mandibular third molars of 36,882 at a total cost of €6,633,400. The additional cancer incidence was estimated to be approximately 0.46 per year. CONCLUSIONS: The data should be used in a cost-effectiveness analysis of the clinical efficacy of CBCT imaging before removal of mandibular third molars.

[Application possibilities and initial experience with digital volume tomography in hand and wrist imaging]. / Digitale Volumentomografie (DVT) des knöchernen Handskeletts: Erste Erfahrungen und Anwendungsmöglichkeiten.

During the last decade, DVT (digital volume tomography) imaging has become a widely used standard technique in head and neck imaging. Lower radiation exposure compared to conventional computed tomography (MDCT) has been described. Recently, DVT has been developed as an extremity scanner and as such represents a new imaging technique for hand surgery. We here describe the first 24 months experience with this new imaging modality in hand and wrist imaging by presenting representative cases and by describing the technical background. Furthermore, the method's advantages and disadvantages are discussed with reference to the given literature.

Image and surgery-related costs comparing cone beam CT and panoramic imaging before removal of impacted mandibular third molars.

OBJECTIVES: The aim of this prospective clinical study was to derive the absolute and relative costs of cone beam CT (CBCT) and panoramic imaging before removal of an impacted mandibular third molar. Furthermore, the study aimed to analyse the influence of different cost-setting scenarios on the outcome of the absolute and relative costs and the incremental costs related to surgery. METHODS: A randomized clinical trial compared complications following surgical removal of a mandibular third molar, where the pre-operative diagnostic method had been panoramic imaging or CBCT. The resources implied in the two methods were measured with health economic tools. The primary outcome was total costs defined as the sum of absolute imaging costs and incremental surgery-related costs. The basic variables were capital costs, operational costs, radiological costs, radiographic costs, overheads and patient resource utilization. Differences in resources used for surgical and post-surgical management were calculated for each patient. RESULTS: Converted to monetary units, the total costs for panoramic imaging equalized €49.29 and for CBCT examination €184.44. Modifying effects on this outcome such as differences in surgery time, treatment time for complications, pre- and post-surgical medication, sickness absence, specialist treatment and hospitalization were not statistically significant between the two diagnostic method groups. CONCLUSIONS: Costs for a CBCT examination were approximately four times the costs for panoramic imaging when used prior to removal of a mandibular third molar. The use of CBCT did not change the resources used for surgery, post-surgical treatment and patient complication management.

The use of cone beam computed tomography in the postoperative assessment of orbital wall fracture reconstruction.

PURPOSE: Computed tomography (CT) is currently the standard in postoperative evaluation of orbital wall fracture reconstruction, but cone beam computed tomography (CBCT) offers potential advantages including reduced radiation dose and cost. The purpose of this study is to examine objectively the image quality of CBCT in the postoperative evaluation of orbital fracture reconstruction, its radiation dose, and cost compared with CT. MATERIALS AND METHODS: Four consecutive patients with orbital wall fractures in whom surgery was indicated underwent orbital reconstruction with radio-opaque grafts (bone, titanium-reinforced polyethylene, and titanium plate) and were assessed postoperatively with orbital CBCT. CBCT was evaluated for its ability to provide objective information regarding the adequacy of orbital reconstruction, radiation dose, and cost. RESULTS: In all patients, CBCT was feasible and provided hard tissue image quality comparable to CT with significantly reduced radiation dose and cost. However, it has poorer soft tissue resolution, which limits its ability to identify the extraocular muscles, their relationship to the reconstructive graft, and potential muscle entrapment. CONCLUSIONS: CBCT is a viable alternative to CT in the routine postoperative evaluation of orbital fracture reconstruction. However, in the patient who develops gaze restriction postoperatively, conventional CT is preferred over CBCT for its superior soft tissue resolution to exclude extraocular muscle entrapment.

Development and implementation of a low-cost phantom for quality control in cone beam computed tomography.

A phantom for quality control in cone beam computed tomography (CBCT) scanners was designed and constructed, and a methodology for testing was developed. The phantom had a polymethyl methacrylate structure filled with water and plastic objects that allowed the assessment of parameters related to quality control. The phantom allowed the evaluation of essential parameters in CBCT as well as the evaluation of linear and angular dimensions. The plastics used in the phantom were chosen so that their density and linear attenuation coefficient were similar to those of human facial structures. Three types of CBCT equipment, with two different technological concepts, were evaluated. The results of the assessment of the accuracy of linear and angular dimensions agreed with the existing standards. However, other parameters such as computed tomography number accuracy, uniformity and high-contrast detail did not meet the tolerances established in current regulations or the manufacturer's specifications. The results demonstrate the importance of establishing specific protocols and phantoms, which meet the specificities of CBCT. The practicality of implementation, the quality control test results for the proposed phantom and the consistency of the results using different equipment demonstrate its adequacy.

An evidence-based concept of implant dentistry. Utilization of short and narrow platform implants.

As a profession, we must remember that tooth replacement is not a luxury; it is often a necessity for health reasons. Although bone augmentation and CBCT and expensive surgical guides are often indicated for complex cases, they are being overused. Simple or straightforward implant cases, when there is sufficient natural bone for narrow or shorter implant, can be predictable performed by well-trained GPs and other trained specialists. Complex cases requiring bone augmentation and other complexities as described herein, should be referred to a surgical specialist. Implant courses and curricula have to be based on the level of complexity of implant surgery that each clinician wishes to provide to his or her patients. Using a "logical approach" to implant dentistry keeps cases simple or straightforward, and more accessible to patients by the correct use of narrow and shorter implants.

Does three-dimensional imaging offer a financial benefit for treating maxillary molars with furcation involvement? A pilot clinical case series.

AIM: To assess the financial benefit of cone beam computed tomography (CBCT) for the treatment options of maxillary molars including periodontal surgery and extraction followed by implant placement. MATERIAL AND METHODS: Twelve patients with generalized chronic periodontitis were recruited, and CBCT was performed in maxillary molars (n = 22) with clinical furcation involvement and increased probing pocket depths. Treatment recommendations were either based on conventional periodontal diagnostics (clinical examinations and periapical radiographs), or based on the additional CBCT data. Clinical recommendations comprised a minimal (e.g. supportive periodontal treatment) and a maximal invasive therapy (e.g. extraction and implant placement), and these were compared with CBCT-based recommendations. According to the Swiss dental tariff structure, the probabilities of saving costs or time, and the numbers needed to treat were analysed with an empirical cumulative distribution function. RESULTS: Average cost reduction from CBCT amounted to CHF 915 ± 1470 and saved 136 ± 217 min. Greatest reductions were found with maximal invasive clinically based treatment decisions (CHF 1566 ± 1840), particularly for second molars (CHF 2485 ± 2226). To compensate CBCT costs, 1.7 subjects were needed to treat to at least break even. CONCLUSIONS: Data from CBCT facilitated a reduction in treatment costs and time for periodontally involved maxillary molars in Switzerland. Based on these cost analyses, however, CBCT as additional diagnostic measure is justified only when more invasive therapies are planned.