Journal of Oral and Maxillofacial Radiology

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 8  |  Issue : 1  |  Page : 5--9

New device for dental radiographic standardization


Jorge Abrao1, Jefferson Xavier de Oliveira2, André Felipe Abrão1, Giselle Guimarães do Carmo1, Kátia Rie Yabiku Utsunomiya1, Rachelle Elisa Arantes Gobo1, Rafael Golghetto Domingos1,  
1 Department of Orthodontics, School of Dentistry, University of São Paulo, São Paulo, Brazil
2 Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil

Correspondence Address:
Giselle Guimarães do Carmo
Av. Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo
Brazil

Abstract

Context: The device for dental radiographic standardization (DDRS) was developed to minimize the distortions in conventional periapical radiographs or digital subtraction, improving the effectiveness of the technique. Objectives: The objective of this study is to present the DDRS and prove its effectiveness through comparative test, performed with the techniques of Bissetrix and Parallelism. Configurations and Design: The DDRS adapts to the universal radiographic positioner, is economical, and easy to operate. It is recommended for the use in research, where standardization is a requirement. Subjects and Methods: DDRS is produced using the additive manufacturing method for prototyping, after creating a three-dimensional (3D) model using a specific program (Autodesk Inventor 2016, Autodesk, Inc, California, USA). The final prototype was converted to the STL format, which was later read by a 3D printer (3D Machine ONE, São Paulo, Brazil). To perform the tests, three radiographic techniques were compared, Bisecting angle technique, parallelism and DDRS fitted to the universal positioner, and two examiners performed the evaluation independently. Statistical Analysis Used: Differences between the techniques were compared by the analysis of variance, followed by Dunnett’s multiple comparisons. The variability of the measured values among the techniques was compared by the Levene’s test. The intraclass correlation coefficients were calculated to evaluate the reproducibility and interexaminer agreement for each technique and parameter. Results: DDRS eliminates the effect of distortion factors that normally affect conventional methods, allowing greater reliability in the interpretation of the image before, during, and after treatment. Conclusions: The DDRS should be used for clinical and routine research purposes, facilitating comparisons of the same image at different time intervals, with minimized errors of vertical and horizontal angulation. This allows greater reliability in the interpretation of the image in relation to the structures of interest.



How to cite this article:
Abrao J, de Oliveira JX, Abrão AF, do Carmo GG, Yabiku Utsunomiya KR, Arantes Gobo RE, Domingos RG. New device for dental radiographic standardization.J Oral Maxillofac Radiol 2020;8:5-9


How to cite this URL:
Abrao J, de Oliveira JX, Abrão AF, do Carmo GG, Yabiku Utsunomiya KR, Arantes Gobo RE, Domingos RG. New device for dental radiographic standardization. J Oral Maxillofac Radiol [serial online] 2020 [cited 2020 Aug 3 ];8:5-9
Available from: http://www.joomr.org/text.asp?2020/8/1/5/288832


Full Text



 Introduction



Periapical radiography is routinely used in different areas of dentistry, diagnosis of periapical and periodontal bone lesions,[1],[2],[3] evaluation of external root resorption,[4] interproximal diagnosis of caries,[5] and evaluation of bone changes around implants.[6]

Problems such as the lack of standardization of the operator with regard to the Bisecting Angle Technique and the difficulty of obtaining stable records using the parallelism technique impede the standardization and affect the reproducibility of images. Difficulties have been encountered in obtaining these images, mainly with regard to errors in the application of the technique.[7],[8]

The device for dental radiographic standardization (DDRS) was developed specifically to improve the effectiveness of the technique and to minimize angular distortions in conventional periapical radiographs or digital subtraction; DDRS is cost-effective and easy to operate [Figure 1] and [Figure 2]. It is recommended for the use in research, in which standardization is a requirement. The DDRS facilitates radiographic image standardization and projection of the anatomical structures in the same position, allowing comparisons and radiographic measurements with greater fidelity.{Figure 1}{Figure 2}

 Subjects and Methods



The DDRS is produced using the additive manufacturing method for prototyping, after the creation of a three-dimensional (3D) model using a specific program (Autodesk Inventor 2016, Autodesk, Inc, California, USA). This 3D model was created after several prototypes were developed by the authors. The final prototype was converted to STL format, which was later read by a 3D printer (3D Machine ONE, 3D Machine, São Paulo, Brazil). Protected patent under number BR 10 2017 001,412–6.

The material used for its 3D printing is polylactic acid – a biodegradable and biocompatible thermoplastic derived from the starch present in grains (like corn) or sugar cane that has been successfully used in medical implants for humans.[9],[10]

Technical description of dental radiographic standardization

The DDRS has four subdivisions, each with a specific function: fitting, angulation, support, and guidance, as shown in [Figure 3].{Figure 3}

The fitting [[Figure 3], Itens 3a, b and f] enables the device to fit perfectly to the universal radiographic positioner. The angulation [[Figure 3], Itens 3g and h] presents a sphere path, which allows the antero-posterior movement of the individualized plate, and a sphere, which allows the inclination of the segmented plate and can be adjusted according to the palate depth. The support [[Figure 3], Item 3c] presents a support base for the fixation of the individualized plate. The guidance [[Figure 3], Itens 3d and e] is designed to guide the alignment of the cylinder of the X-ray cone to the film/radiographic sensor, horizontally and vertically, to minimize radiographic distortions.

Tests were performed to verify the reproducibility of DDRS

Approval by the Ethics Committee or informed consent was not required as it was a laboratory manikin-based study that has not used any material of animal or human origin.

Step 1: Dental model assembly

Artificial teeth (Manequins Odontológicos Marília Ltd, Marília, Brazil) with anatomical characteristics and root canals similar to human teeth, which allow the insertion of a 19.76 mm long endodontic file in the mesiovestibular root of upper and lower first molars, were selected. These teeth were adapted according to their respective positions and the structure of a dental manikin following the manufacturer’s recommendations, and subsequently, they were fixed with chemically activated acrylic resin (Classic Jet, São Paulo, Brazil). This assembly was performed according to individualized characteristics for each hemiarch.

Step 2: Dental radiographic standardization preparation

Dental plaster models were obtained by molding the dental manikin. Using these models, individualized plates were prepared for each hemiarch. Using chemically activated acrylic resin, these individualized plates were fixed to the support base of the DDRS. Each plate covered 6–8 teeth, conferring stability and retention.

The radiographic digital sensor was adapted according to the universal positioner (Indusbello, Londrina, Brazil). Subsequently, this set was inserted into the fitting base of DDRS. To obtain correct angulation, the horizontal and vertical rods were oriented according to the occlusal plane and long axis of the teeth. Once the desired angulation was obtained, the sphere of the support base was fixed to the sphere path using chemically activated acrylic resin.

Finally, the set, which includes individualized plates, DDRS, and universal positioner, was fitted to the manikin’s teeth and radiography was performed.

Step 3: Radiographic imaging and image measurements

For this study, a Krystal-X Easy owandy digital radiographic sensor (Micro Image, São Paulo, Brazil) and Spectro 70 X-radiographic appliance (Dabi Atlante, São Paulo, Brazil) were used with an exposure time of 0.1 s (8 mA, 70 kVp). The images were generated using the software dental master dicom 2014 (Micro Image, version 1.0.5).

Fifteen repetitions were performed for each hemiarch upper right hemiarch (URH); upper left hemiarch (ULH); lower right hemiarch (LRHH) and lower left hemiarch (LLH) with intervals of >15 min using the three techniques in the following order: Bisecting angle technique, parallelism technique with the universal positioner, and DDRS fitted to the universal positioner.

For calibration, an 18.03-mm long endodontic file (Kerr, Orange, USA), which was adapted according to the digital radiographic sensor, was used as reference. To obtain the measurements of the root file, extreme points were selected in the software. All the measurements were performed by two independent examiners [Figure 4].{Figure 4}

 Results



The values of the repetitions were expressed, according to the radiographic technique, as mean and standard deviation by each examiner. Differences between the techniques and their difference with regard to the reference value (19.76 mm) were compared by the analysis of variance, followed by Dunnett’s multiple comparisons for unequal variances, when there was a difference among the techniques. The variability of the measured values among the techniques was compared by Levene’s test.

The intraclass correlation coefficients with respective 95% confidence intervals (Fleiss, 1986) were calculated to evaluate the reproducibility and inter-examiner agreement for each technique and parameter [Table 3].{Table 1}{Table 2}{Table 3}

The analysis was performed using the IBM-SPSS (International Business Machines Corporation (IBM), Armonk, Nova York, EUA) for Windows software version 20.0, and the values were tabulated using Microsoft-Excel 2003 software. The tests were performed at a significance level of 5%.

 Discussion



The proposed DDRS differs from the existing devices,[11],[12] because it is a feasible individualized confection device for any intraoral region of interest.

Comparative studies report that the use of different software applications associated with digital radiography minimizes the possibility of handling angular errors.[13] The software generally presents an automatic mode to eliminate the errors;[3],[14],[15] however, horizontal and vertical angular differences (>5°–15°) evade the software’s ability to eliminate these lapses. [Table 1] shows that as evaluated by both the examiners, there were significant differences in the URH, ULH, and LLH, with a lower variability among the DDRS measurements than the measurements obtained using bisecting angle and parallelism techniques, indicating fidelity in the repetition of the radiographs at different time intervals [Figure 5].{Figure 5}

Regarding the comparison among the techniques [Table 2], the bisecting angle technique presented a lower mean value for the ULH as measured by both the examiners (P < 0.05), which can be explained by the lack of standardization of the technique. Operator handling inaccuracies are minimized with the DDRS using the horizontal and vertical guide rods, simplifying the angular positioning of the radiographic beam.

 Conclusions



The device for dental radiographic standardization is an efficient method to standardize the periapical radiographic technique when compared to universal positioners, allowing radiographic imaging comparisons at different time intervals with greater fidelity.

Acknowledgment

Special acknowledgement to Gustavo Takara, responsible for 3D printing services and collaboration in the material selection and design of DDRS.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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