Effects of Digital Image Processing Filters on Detection of Lateral Cephalometric Landmarks

Document Type : Original Article

Authors

1 Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

2 Department of Orthodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

3 Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. 3-Department of Orthodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical

4 Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

5 Department of Periodontology, Faculty of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Abstract

Background and Objectives:  Accurate identification of landmarks of lateral cephalometric radiographic is important for analysis. The objective of this study was to investigate the effects of digital image processing filters on detection of lateral cephalometric landmarks.
Subjects and Methods: Lateral cephalometric radiographs were acquired from 30 patients. The unprocessed images and those processed using Shadow, Sharpen, Negative and 3D Emboss filters were assessed by two observers and scored for clarity of points A, B, N, Orbitale, Pronasal, Subnasal, Pogonion’ and Menton’. The results were statistically analyzed using Friedman and Wilcoxon tests.
Results: For detection of points N، Orbitale and Pronasal، 3d emboss filter had the lowest rating and the other methods were not significantly different. For detection of points A، Subnasal، Pogonion’ and Menton’, 3d emboss and negative filters had the lowest rating and these two filters were not significantly different and the other methods were not significantly different. For point B all methods were not significantly different.
Conclusions: The results of this study clearly showed that processing of lateral cephalometric radiographs with different filters does not necessarily lead to improvement of the image but a wrong selection algorithms and filters may reduce the diagnostic quality of the images.
 

1-Eppley BL, Sadove AM. Computerized digital enhancement in craniofacial cephalometric radiography. J Oral Maxillofac Surg 1991 Oct; 49(10): 1038-43.
2-Giordano D, Leonardi R, Maiorana F, Spampinato C. Cellular Neural Networks and Dynamic Enhancement for Cephalometric Landmarks Detection. Artificial Intelligence and Soft Computing 2006; 4029: 768-77.
3-Leonardi RM, Giordano D, Maiorana F, Greco M. Accuracy of cephalometric landmarks on monitor-displayed radiographs with and without image emboss enhancement. Eur J Orthod 2010 Jun; 32(3):242–7.
4-Molander B, Grondahl HG, Ekestubbe A. Quality of film-based and digital panoramic radiography. Dentomaxillofac Radiol 2004 Jan; 33(1): 32-36.
5-Oshagh M, Shahidi SH, Danaei SHM. Effects of image enhancement on reliability of landmark identification in digital cephalometry. Indian J Dent Res  2010 Jan- Feb; 24(1): 98–103.
6-Weismann RB, Scheetz JP, Silveira A, Farman TT, Farman AG. Cephalometric landmark clarity in photostimulable phosphor images using pseudo-color and emboss enhancements. Int J Comput Assist Radiol Surg 2006 Jul; 1(2): 105–12.
7-Farman TT, Farman AG. Optimal processing and enhancement of 16-bit photostimulable phosphor images.  Radiology 2000; 217(P): 657- 43.
8-Weisemann R, Scheetz J, Silveira A, Farman T, Farman A. Effect of Pixel Histogram Distribution on Perceived Anatomical Landmark Clarity of Photostimulable Phosphor Cephalograms. Int J CARS 2006;1(2): 97.
9-Analoui M. Radiographic image enhancement. Part I: spatial domain techniques. Dentomaxillofac Radiol 2001; 30: 1–9.
10-Lehmann TM, Troeltschl E, Spitzerl K. Image processing and enhancement provided by commercial dental software programs. Dentomaxillofacial Radiology 2002 July; 31(4): 264 – 272.
11-Baksi BG, Alpoz E, Sogur E, Mert A. Perception of anatomical structures in digitally filtered and conventional panoramic radiographs: a clinical evaluation. Dentomaxillofac Radiol 2010 Oct; 39(7): 424-30.
12-Eickholz P, Riess T, Lenhard M, Hassfeld S, Staehle HJ. Digital radiography of interproximal bone loss; validity of different filters. J Clin Periodontol 1999 May; 26(5): 294-300.
13-Yalcinkaya S, Kunzel A, Willers R, Thoms M, Becker J. Overall image quality of digitally filtered radiographs acquired by the Durr Vistascan system compared with conventional radiographs. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006 May; 101(5): 643-51.