|Year : 2016 | Volume
| Issue : 4 | Page : 370-374
Assessment of fracture line in maxillofacial region using panoramic digital radiographs and panoramic inverted digital radiographs: A comparative study
Avinash M L Tejasvi1, Geetha Paramkusam1, Venkateswarlu Meduri1, Balaji Babu Bangi1, Harsha Bhayya1, Pavani Donempudi2
1 Department of Oral Medicine and Radiology, Kamineni Institute of Dental Sciences, Narketpally, Telangana, India
2 Department of Oral Medicine and Radiology, Late Shri Yashwantrao Chavan Memorial Medical and Rural Development Foundation's Dental College and Hospital, Ahmednagar, Maharashtra, India
|Date of Submission||01-Oct-2015|
|Date of Acceptance||21-Jan-2017|
|Date of Web Publication||21-Feb-2017|
Dr. Avinash M L Tejasvi
Department of Oral Medicine and Radiology, Kamineni Institute of Dental Sciences, Narketpally - 508 254, Telangana
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction: Many times fractures go undetected, if not examined properly. For initial diagnosis and proper treatment plan of facial injuries, diagnostic images play a crucial role in providing necessary information. Aims and Objectives: To compare the diagnostic accuracy of conventional digital radiography and inverted digital panoramic imaging in detecting maxillofacial fractures. Materials and Methods: A total of 50 orthopantomographs were collected from the archives of dental and maxillofacial radiology. High quality radiographs with maximum sharpness, ideal contrast, and density were only included which were made using a digital OPG machine. The digital data were saved as jpeg files. Both conventional radiographs as well as inverted digitized images were evaluated by 3 expert radiologists twice with an interval of 10 days. The presence of a radiolucent line in conventional digital radiographs and radiopaque line in inverted digital image which depicted the fracture line was classified according to a 3 point confidence scale. Statistical Analysis Used: Intra observer variation was calculated using Student t test. Inter examiner agreement was calculated by kappa statistics by point (κ). Results: All the examiners showed poor to fair agreement for mandibular fractures and displacement of fracture line in both direct digital and inverted panoramic radiograph. Conclusions: Both the imaging modalities were reliable and there was no significant difference in the diagnostic accuracy.
Keywords: Dental radiography, digital radiography, mandibular fractures, panoramic radiography
|How to cite this article:|
Tejasvi AM, Paramkusam G, Meduri V, Bangi BB, Bhayya H, Donempudi P. Assessment of fracture line in maxillofacial region using panoramic digital radiographs and panoramic inverted digital radiographs: A comparative study. J Indian Acad Oral Med Radiol 2016;28:370-4
|How to cite this URL:|
Tejasvi AM, Paramkusam G, Meduri V, Bangi BB, Bhayya H, Donempudi P. Assessment of fracture line in maxillofacial region using panoramic digital radiographs and panoramic inverted digital radiographs: A comparative study. J Indian Acad Oral Med Radiol [serial online] 2016 [cited 2021 Jan 28];28:370-4. Available from: https://www.jiaomr.in/text.asp?2016/28/4/370/200628
| Introduction|| |
Significant percentage of maxillofacial trauma patients are encountered nowadays worldwide, and hence necessary investigations are of paramount importance. Of all the maxillofacial bones, mandible is more prone and commonly encounters fracture. Knowledge of the fracture pattern and the etiology of the injury is important for the management of maxillofacial fractures. According to the cause of trauma, mandible has unique characteristic features in terms of age and gender distribution, as well as the site and severity of fractures. Many times, these fractures go undetected, if not examined properly. For initial diagnosis and proper treatment plan of facial injuries, diagnostic images play a crucial role in providing necessary information. It has been well documented that panoramic radiographs provide diagnostic accuracy in detecting mandibular fractures. However, in diagnosing fractures of middle facial region, it proves to be an inadequate modality. Despite various specialized imaging modalities being available, most researchers still prefer panoramic radiographs over other extraoral radiograph for mandibular fractures.
Advanced digital imaging modalities are an alternative to conventional film-based radiography. Diagnostic imaging in dentistry is mainly based on computer-based methods because of rapidly emerging direct and indirect digital imaging systems. With the help of this technology, image manipulation, such as conversion of film-based radiographs to digitized images, can be done. Radiographic interpretation in digitized image can be enhanced by altering the brightness, contrast, colorization, or application of inversion effects to radiographs, which are advantageous in compensating visual limitation of human observers and for task-dependent routines for specific diagnostic questions.
Previous studies have shown an ambiguous result pertaining to the application of inversion effect to images. Black background permits optimal image contrast for dark objects, and the examiners can adjust the images according to their preferences using computed programs. According to Paul et al., reversal of the original image allows enhancement of contours and makes the image more easily recognized by human visual system. Thus, undisplaced mandibular fracture is clearly visible after inversion effects are applied to radiographs.
Studies concerning digitized panoramic radiographs with a view to improve the imaging of maxillofacial trauma radiographs are deficient in the literature. Hence, we conducted a study to explore this simple and inexpensive procedure for analysis of the mandibular fractures and to evaluate the diagnostic agreement of direct digital panoramic radiographs and inverted panoramic radiographs in the detection of the mandibular fractures. To study the diagnostic agreement of the radiographic interpretation, three calibrated examiners read the radiographs twice on two different occasions, independently and under blind conditions, to verify intraexaminer agreement. Only if the intraexaminer agreement was good, we estimated interexaminer agreement. If the examiners did not agree with themselves, they could not agree with someone else.
| Materials and Methods|| |
Fifty orthopantomographs were collected from the archives of maxillofacial radiology. These radiographs included maxillofacial fractures of varying degrees. High quality radiographs with maximum sharpness, ideal contrast and density were only included, which were made using a digital OPG machine. Inversion of the digital images was done using Dental Studio software. Both the conventional and inverted images were saved as.jpeg files. The presence of a radiolucent line in conventional digital radiographs [Figure 1] and radiopaque line in inverted digital image [Figure 2], which depicted the fracture line, were classified according to a three-point confidence scale.
|Figure 1: Fracture line seen as a radiolucent line in conventional digital radiograph|
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|Figure 2: Fracture line seen as a radiopaque line in inverted digital image|
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The three-point confidence scale included
- Fracture line not seen
- Fracture line clearly seen
- Fracture line very clearly seen.
The extent of fracture line was also given a three-point scale which included
- Displacement not seen
- Displacement clearly seen
- Displacement very clearly seen.
Both conventional radiographs as well as inverted images were evaluated by three expert oral radiologists twice with an interval of 10 days to check for interexaminer and intraexaminer variations. All the images were given a code, which was not known to the all the three examiners to eliminate observer bias. Images were displayed on a 15 inch and 24-bit video monitor (Dell Inspiron 15R) at a zoom of 100% using Microsoft picture manager. For all the examiners, the screen was placed at an optimum distance of 60 cm or 2 feet in a silent, isolated room to prevent distraction, and the room light was maintained dim to prevent extraneous light to reach retina. Monitor resolution was kept constant for all the images at 1024 × 786 pixels. Once the evaluation was done, all the scores were tabulated and sent for statistical analysis. Interexaminer as well as intraexaminer agreement was calculated by kappa statistics by point (κ).
| Results|| |
[Table 1] showed κ values for intraobserver assessment of the mandibular fracture and displacement of fracture lines in both direct digital panoramic radiograph (DDPR) and inverted panoramic radiograph (IPR). Observer C showed substantial agreement for the mandibular fracture in both DDPR and IPR. Observer A showed a moderate agreement for mandibular fractures in DDPR, whereas in IPR a poor intraobserver agreement was seen. Further, observer B showed a fair agreement for mandibular fractures in DDPR, whereas in IPR a poor intra observer agreement was seen. Similarly, for the displacement of fracture line, observers B and C showed a substantial intraobserver agreement in both DDPR and IPR, whereas observer A showed a moderate intra observer agreement in both DDPR and IPR.
|Table 1: Intraexaminer agreement by kappa statistics for detection of fracture line and displacement of fracture fragment in the direct digital panoramic radiograph (DDPR) and inverted panoramic radiograph (IPR)|
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[Table 2] shows κ values for interobserver assessment of the mandibular fracture and displacement of fracture lines in both direct DDPR and IPR. There was a fair agreement between observers A and B for the mandibular fracture in both DDPR and IPR. When B and C were assessed, there was fair agreement in DDPR and moderate agreement in IPR for the assessment of fracture line. Similarly, when C and A were assessed there was a fair agreement in both DDPR and IPR for the assessment of fracture line. Interobserver agreement for the displacement of fractured lines between observers A and B showed a moderate agreement in DDPR and fair agreement in IPR. When B vs. C, and C vs. A were assessed, there was poor agreement in DDPR and IPR, respectively, for the displacement of fracture lines.
|Table 2: Interexaminer agreement by kappa statistics for detection of fracture line and displacement of fracture fragment in the direct digital panoramic radiograph (DDPR) and inverted panoramic radiograph (IPR)|
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| Discussion|| |
Fractures localized to dental and paradental structures of maxillofacial region present difficulties to the dentist. Most of the maxillofacial traumatic injuries involve the dentition alone up to 50% or both the dentitions, as well as the adjacent soft tissue up to 36%. Traumatic injury to the maxillofacial region requires early evaluations and proper treatment plan as they are emergency situations in dentistry. Prognosis of any case depends upon correct diagnosis and treatment done to the patient. Yet, practitioners in dentistry mainly depend on two-dimensional imaging modalities. Advances in digital imaging technology has substituted film-based radiographs in dentistry and have given new alternatives to detect maxillofacial fractures, with reduced radiation doses, as the sensors are more sensitive to radiation than film.
Inversion gray scale mode has been used in general medicine and radiology for the detection of pulmonary lesions. It has the potential to increase the diagnostic accuracy as a slight change in the intensity of an image is best appreciated by the eye in dark regions as compared to light regions. There are few studies reported in literature on the evaluation of gray scale reversal for identification of pulmonary nodules. Studies conducted by Sheline et al., Diederick et al. and Lungren et al. proved that the use of the gray-scale inversion method has greater specificity than the traditional chest radiographs for lung nodule detection. However, MacMahon et al. found that, for a variety of radiographic findings including pneumothorax, interstitial disease, bone lesions, and pulmonary nodules, diagnostic accuracy was greater with standard digitized images than inverse-intensity images. Despite controversy among authors, many of the examiners prefer the use of inverse gray mode, however, diagnostic efficacy was inferior.
In the present study, the intraobserver agreement for assessing mandibular fracture and fracture fragment displacement showed that observer C presented higher intraobserver agreement than the other two observers (A and B) in both DDPR and IPR. Observer A showed a moderate agreement for mandibular fractures in DDPR (P = 0.0001), whereas in IPR (P = 0.296) poor intraobserver agreement was seen; moreover, observer B showed fair agreement for mandibular fractures in DDPR (P = 0.008) whereas in IPR (P = 0.277) a poor intraobserver agreement was seen. Similarly, for the displacement of fracture line, observers B and C showed a substantial intraobserver agreement in both DDPR and IPR (P = 0.0001) whereas observer A showed a moderate intraobserver agreement in both DDPR and IPR (P = 0.0001). The interobserver agreement showed that there was a moderate agreement between observers B and C for the mandibular fracture in both IPR (P = 0.0001); for the displacement of fractured lines, moderate agreement was seen in DDPR between Observers A and B (P = 0.0001). Variations in the results observed by examiner C may be due to the individual characters such as emotional and visual features at the time of examination.
Punhani et al. conducted a similar study for the assessment of fracture line using conventional and inverted imaging, and concluded that conventional panoramic radiography was more reliable than inverted digitized radiography for mandibular fracture detection; however, for fracture detection in mid face region, the inverted method was more reliable than conventional PNS radiographs. Sakakura et al. in their study stated that diagnostic agreement was low for the detection of mandibular canal and mental foramen in conventional and inverted scanned panoramic radiographs. Gulnara et al. measured periodontal bone loss using inverted and unprocessed digitized radiographs and concluded that both the imaging modalities were reliable and there was no significant difference in the diagnostic accuracy. In a similar study, Rafael et al. concluded that periodontal bone defect measurements on an inverted digital image were inferior to film based radiography and underestimated the amount of bone loss.
| Conclusion|| |
In the present study, it was felt by observers that both the imaging modalities were reliable and there was no significant difference in the diagnostic accuracy for the identification of fracture. However, displacement of fractured fragment was clear on digital inverted panoramic images, and inversion helped to visualize fracture of the superimposed bones easily in bones black images. As the present study was based on intraobserver and interobserver agreement in the interpretation of two different radiographic methods, and because the agreement levels of an observer might change during radiographic interpretation at two different times, it was difficult to assess which observer was correct or which is the best method for interpretation. Further studies with computed tomography as the gold standard method of facture assessment should be used to compare different radiographs.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2]