A framework for costing diagnostic methods in oral health care: An application comparing a new imaging technology with the conventional approach for maxillary canines with eruption disturbances

Objectives: The aims were (i) to propose a framework for costing diagnostic methods in oral health care and (ii) to illustrate the application of the framework to the radiographic examination of maxillary canines with eruption disturbances. Methods: The framework for costing, following Drummond et al.(2005), includes three elements: (i) identification of different resources used in producing and delivering the service, (ii) measurement of the amount of each resource required and (iii) valuation of the resources in monetary terms. Four data collection instruments were designed – a protocol for apportioning the cost of capital equipment to each diagnostic procedure, separate forms for recording consumable items, for the time of different health care providers used for a diagnostic examination and a patient survey for calculation of the total cost to the patient associated with the examination. The framework was applied to the radiographic examination of maxillary canines with eruption disturbances comparing two imaging methods: (i) a new method with cone beam computed tomography and panoramic radiography and (ii) a conventional method using intraoral and panoramic radiography. The primary analysis was performed from the perspective of the health care system. A separate analysis included patient costs with health care system costs to provide a societal perspective. Comparison of the two perspectives allows consideration of whether any costs savings to the health care system are generated at the expense of greater costs for patients and their families. Data for the cost-analysis were retrieved from 47 patients (mean age 14 years) referred to a department of radiology for examination of maxillary canines. Results:Application of the framework for costing allowed us to compare the resources used to perform examinations of the two methods. The mean total cost per examination for the new method was 128.38€ and 81.80€ for the conventional method, resulting in an incremental cost per examination of the new method of 46.58€. Conclusions: The application of the framework demonstrates the feasibility of measuring and comparing the total costs as well as the distribution of total costs between providers and patients for different approaches to this common examination

Segmentation of Trabecular Jaw Bone on Cone Beam CT Datasets

The term bone quality is often used in a dentomaxillofacial context, for example in implant planning, as bone density and bone structure have been linked to primary implant success.Nackaerts O., Depypere M., Zhang G., Vandenberghe B. , Maes F., Jacobs R., SEDENTEXCT Consortium , ''Segmentation of trabecular jaw bone on cone beam CT datasets'', Clinical implant dentistry and related research, vol. 17, no. 6, pp. 1082-1091, December 2015.status: publishe

Comparison of 6 cone-beam computed tomography systems for image quality and detection of simulated canine impaction-induced external root resorption in maxillary lateral incisors

INTRODUCTION: The most frequent adverse effect of canine impaction is resorption of the adjacent incisors. The subjective image quality and the radiographic diagnostic accuracy for detection of simulated canine-induced external root resorption lesions in maxillary lateral incisors were compared among 6 cone-beam computed tomography (CBCT) systems in vitro. METHODS: A child cadaver skull in the early mixed dentition was obtained. This skull had an impacted maxillary left canine and allowed a reliable simulation. Simulated root resorption cavities were created in 8 extracted maxillary left lateral incisors by the sequential use of 0.16-mm diameter round burs in the distopalatal root surface. Cavities of varying depths were drilled in the middle or apical thirds of each tooth root according to 3 setups: slight (0.15, 0.20, and 0.30 mm), moderate (0.60 and 1.00 mm), and severe (1.50, 2.00, and 3.00 mm) resorption. The lateral incisors, including 2 intact teeth, were repositioned individually in the alveolus with approximal contacts to the impacted maxillary left canine. Six sets of radiographic images were obtained with 3D Accuitomo-XYZ Slice View Tomograph (J. Morita, Kyoto, Japan), Scanora 3D CBCT (Soredex, Tuusula, Finland), Galileos 3D Comfort (Sirona Dental Systems, Bensheim, Germany), Picasso Trio (E-WOO Technology, Giheung-gu, Republic of Korea), ProMax 3D (Planmeca OY, Helsinki, Finland), and Kodak 9000 3D (Trophy, Croissy-Beaubourg, France) for each tooth setup. The CBCT images were acquired and subsequently analyzed by 12 observers. Linear models for repeated measures were used to compare the CBCT systems for the image quality and the degree of agreement between the diagnosed severity of root resorption and the true severity. RESULTS: The differences in the image quality between CBCT systems were statistically significant (P 0.05) among the different CBCT systems. CONCLUSIONS: High image quality is important when detecting root resorption. The CBCT systems used in this study had high accuracy with no significant differences between them in the detection of the severity of root resorption.status: publishe

Dose distribution for dental cone beam CT and its implication for defining a dose index

OBJECTIVES: To characterize the dose distribution for a range of cone beam CT (CBCT) units, investigating different field of view sizes, central and off-axis geometries, full or partial rotations of the X-ray tube and different clinically applied beam qualities. The implications of the dose distributions on the definition and practicality of a CBCT dose index were assessed. METHODS: Dose measurements on CBCT devices were performed by scanning cylindrical head-size water and polymethyl methacrylate phantoms, using thermoluminescent dosemeters, a small-volume ion chamber and radiochromic films. RESULTS: It was found that the dose distribution can be asymmetrical for dental CBCT exposures throughout a homogeneous phantom, owing to an asymmetrical positioning of the isocentre and/or partial rotation of the X-ray source. Furthermore, the scatter tail along the z-axis was found to have a distinct shape, generally resulting in a strong drop (90%) in absorbed dose outside the primary beam. CONCLUSIONS: There is no optimal dose index available owing to the complicated exposure geometry of CBCT and the practical aspects of quality control measurements. Practical validation of different possible dose indices is needed, as well as the definition of conversion factors to patient dose.status: publishe

Pre-surgical treatment planning of maxillary canine impactions using panoramic vs cone beam CT imaging

Objectives: The aim of this prospective study was to compare the impact of using two-dimensional (2D) panoramic radiographs and three-dimensional (3D) cone beam CT for the surgical treatment planning of impacted maxillary canines. Methods: This study consisted of 32 subjects (19 females, 13 males) with a mean age of 25 years, referred for surgical intervention of 39 maxillary impacted canines. Initial 2D panoramic radiography was available, and 3D cone beam CT imaging was obtained upon clinical indication. Both 2D and 3D pre-operative radiographic diagnostic sets were subsequently analysed by six observers. Perioperative evaluations were conducted by the treating surgeon. McNemar tests, hierarchical logistic regression and linear mixed models were used to explore the differences in evaluations between imaging modalities. Results: Significantly higher confidence levels were observed for 3D image-based treatment plans than for 2D image-based plans (p < 0.001). The evaluations of canine crown position, contact relationship and lateral incisor root resorption were significantly different between the 2D and 3D images. By contrast, pre- and perioperative evaluations were not significantly different between the two image modalities. Conclusions: Surgical treatment planning of impacted maxillary canines was not significantly different between panoramic and cone beam CT images.status: publishe

Variation in costs of cone beam CT examinations among healthcare systems

Objectives: To analyse the costs of cone beam CT (CBCT) in different healthcare systems for patients with different clinical conditions. Methods: Costs were calculated for CBCT performed in Cluj (Romania), Leuven (Belgium), Malmö (Sweden) and Vilnius (Lithuania) on patients with (i) a maxillary canine with eruption disturbance, (ii) an area with tooth loss prior to implant treatment or (iii) a lower wisdom tooth planned for removal. The costs were calculated using an approach based on the identification, measurement and valuation of all resources used in the delivery of the service that combined direct costs (capital equipment, accommodation, labour) with indirect costs (patients’ and accompanying persons’ time, ‘‘out of pocket’’ costs for examination fee and visits). Results: The estimates for direct and indirect costs varied among the healthcare systems, being highest in Malmö and lowest in Leuven. Variation in direct costs was mainly owing to different capital costs for the CBCT equipment arising from differences in purchase prices (range J148 000–227 000). Variation in indirect costs were mainly owing to examination fees (range J0–102.02). Conclusions: Cost analysis provides an important input for economic evaluations of diagnostic methods in different healthcare systems and for planning of service delivery. Additionally, it enables decision-makers to separate variations in costs between systems into those due to external influences and those due to policy decisions. A cost evaluation of a dental radiographic method cannot be generalized from one healthcare system to another, but must take into account these specific circumstances

Effective radiation dose and eye lens dose in dental cone beam CT: effect of field of view and angle of rotation

To quantify the effect of field of view (FOV) and angle of rotation on radiation dose in dental cone beam CT (CBCT) and to define a preliminary volume-dose model.status: publishe