Evaluation of the thickness and internal structure of the masseter muscle with ultrasonography in female bruxism patients.

OBJECTIVES: The aim of this study was to evaluate the differences in the thickness and internal structure of the masseter muscle in individuals with and without bruxism by ultrasonography. MATERIALS AND METHODS: A total of 60 female patients with and without bruxism whose ages were ranging between 20 and 35 were included in the study. The masseter muscle thickness was measured during rest and maximum bite position. Ultrasonographic internal structure of the masseter muscle is classified according to the visibility of echogenic bands. In addition, the echogenic internal structure of the masseter muscle was evaluated with quantitative muscle ultrasound. RESULTS: The masseter muscle thickness was significantly higher in both positions in patients with bruxism (p < 0.05). There was no significant difference between two groups in the evaluation of echogenicity (p > 0.05). CONCLUSIONS: Ultrasonography is a useful and important diagnostic method for evaluating masseter muscle without using radiation.

Diagnostic accuracy of panoramic radiography and ultrasonography in detecting periapical lesions using periapical radiography as a gold standard.

OBJECTIVES: The purpose of this study was to compare the accuracy of imaging techniques in diagnosing periapical lesions. METHODS: Imaging records of 80 patients (51 females, 29 males, aged between 14 and 75 years) including periapical and panoramic radiographs and ultrasonographic images were selected from databases of Selcuk University Dentistry Faculty. Periapical radiographs were accepted as gold-standard and 160 anterior maxillary and mandibular teeth with or without periapical lesion were included to the study. Three specialist observers (dental radiologists) evaluated the presence and appearance of periapical lesions on panoramic radiograph and ultrasonographic images.Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic value of panoramic radiographs and ultrasonography were determined. RESULTS: Sensitivity was 0.80 and 0.77 for ultrasonographic images and panoramic radiographs, respectively which shows that periapical lesion was correctly detected in 80% of the cases with ultrasound and in 77% of the cases with panoramic radiography. Specificity values were determined as 0.97 for ultrasound and 0.95 for panoramic radiography. Overall diagnostic accuracy was 0.86 and 0.84 for ultrasound and panoramic radiography, respectively. CONCLUSIONS: Periapical and panoramic radiographs are commonly used to visualize periapical lesions. Besides, ultrasonography is an alternative method to digital radiographic techniques in the diagnosis of anterior teeth with periapical lesions.

The effects of image compression on quantitative measurements of digital panoramic radiographs

Objectives: The aims of this study were to explore how image compression affects density, fractal dimension, linear and angular measurements on digital panoramic images and assess inter and intra-observer repeatability of these measurements. Study Design: Sixty-one digital panoramic images in TIFF format (Tagged Image File Format) were compressed to JPEG (Joint Photographic Experts Group) images. Two observers measured gonial angle, antegonial angle, mandibular cortical width, coronal pulp width of maxillary and mandibular first molar, tooth length of maxillary and mandibular first molar on the left side of these images twice. Fractal dimension of the selected regions of interests were calculated and the density of each panoramic radiograph as a whole were also measured on TIFF and JPEG compressed images. Intra-observer and inter-observer consistency was evaluated with Cronbach’s alpha. Paired samples t-test and Kolmogorov-Smirnov test was used to evaluate the difference between the measurements of TIFF and JPEG compressed images.Results: The repeatability of angular measurements had the highest Cronbach’s alpha value (0.997). There was statistically significant difference for both of the observers in mandibular cortical width (MCW) measurements (1st ob. p: 0.002; 2nd ob. p: 0.003), density (p<0.001) and fractal dimension (p<0.001) between TIFF and JPEG images. There was statistically significant difference for the first observer in antegonial angle (1st ob p< 0.001) and maxillary molar coronal pulp width (1st ob. p< 0.001) between JPEG and TIFF files. Conclusions: The repeatability of angular measurements is better than linear measurements. Mandibular cortical width, fractal dimension and density are affected from compression. Observer dependent factors might also cause statistically significant differences between the measurements in TIFF and JPEG images (AU)

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The effects of image compression on quantitative measurements of digital panoramic radiographs.

OBJECTIVES: The aims of this study were to explore how image compression affects density, fractal dimension, linear and angular measurements on digital panoramic images and assess inter and intra-observer repeatability of these measurements. STUDY DESIGN: Sixty-one digital panoramic images in TIFF format (Tagged Image File Format) were compressed to JPEG (Joint Photographic Experts Group) images. Two observers measured gonial angle, antegonial angle, mandibular cortical width, coronal pulp width of maxillary and mandibular first molar, tooth length of maxillary and mandibular first molar on the left side of these images twice. Fractal dimension of the selected regions of interests were calculated and the density of each panoramic radiograph as a whole were also measured on TIFF and JPEG compressed images. Intra-observer and inter-observer consistency was evaluated with Cronbach's alpha. Paired samples t-test and Kolmogorov-Smirnov test was used to evaluate the difference between the measurements of TIFF and JPEG compressed images. RESULTS: The repeatability of angular measurements had the highest Cronbach's alpha value (0.997). There was statistically significant difference for both of the observers in mandibular cortical width (MCW) measurements (1st ob. p: 0.002; 2nd ob. p: 0.003), density (p<0.001) and fractal dimension (p<0.001) between TIFF and JPEG images. There was statistically significant difference for the first observer in antegonial angle (1st ob p< 0.001) and maxillary molar coronal pulp width (1st ob. p< 0.001) between JPEG and TIFF files. CONCLUSIONS: The repeatability of angular measurements is better than linear measurements. Mandibular cortical width, fractal dimension and density are affected from compression. Observer dependent factors might also cause statistically significant differences between the measurements in TIFF and JPEG images.

The effects of compression on the image quality of digital panoramic radiographs.

Size reduction through compression is an important issue that needs to be investigated for possible effects on image quality. The aim of the present study was to evaluate the subjective image quality of digital panoramic radiographs which were lossless and lossy compressed for the visualization of various anatomical structures. Fifty-five digital panoramic radiographs in Tagged Image File Format (Tiff) were used in the study. Two types of lossy (Joint Photographic Experts Group (Jpeg)) and one type of lossless (Lempel-Ziv-Welch) compression were applied to the original radiographs. These radiographs were evaluated by two observers separately for the visibility of some anatomical structures with visual grading. Mean quality number for each radiograph was obtained. The differences between the mean quality numbers in each compression and original image mode were evaluated with Friedman test. Pair-wise comparisons revealed that there were statistically significant differences between all groups (p = 0.000) for all comparisons except for Jpeg_1 and Jpeg_2 groups. Kappa statistics was used to evaluate inter- and intra-observer agreements. Intra-observer agreements were ranging from 0.229 to 1.000 and inter-observer agreements were ranging from 0.154 to 1.000. The observers had better inter- and intra-observer agreements in highly compressed Jpeg_1 images. The anatomical structures evaluated in this study had better visibility in Tiff images than Jpeg images except for mandibular canal and mental foramen. While Jpeg compressed images offer high inter- and intra-observer agreements, the visibility of anatomical structures are better in Tiff images except for mandibular canal and mental foramen.

Alveolar bone changes under overhanging restorations.

The aim of this study was to investigate changes in the trabecular architecture of the alveolar bone beneath overhanging restorations with bitewing radiographs in patients having no radiographically visible vertical bone loss. Twenty-eight digital bitewing radiographs with overhanging restorations and 28 digital bitewing radiographs without any restorations belonging to the contralateral side of the same patient were included in the study. Regions of interests (ROI) were created in the alveolar bone along the interproximal regions. These ROIs were segmented to binary images with ImageJ, and, within these binary images, the number of radiographically visible trabecular bone islands per unit area was counted; in addition, the Feret diameter and fractal dimension (FD) were measured. It was found that the mean number of objects per unit area was statistically different in alveolar bone with overhanging restorations from control sites (p < 0.0001). However, the FeD (p = 0.179) and FD (p = 0.963) did not show statistically significant differences between alveolar bone with and without overhanging restorations.

Evaluating mandibular cortical index quantitatively.

OBJECTIVES: The aim was to assess whether Fractal Dimension and Lacunarity analysis can discriminate patients having different mandibular cortical shape. METHODS: Panoramic radiographs of 52 patients were evaluated for mandibular cortical index. Weighted Kappa between the observations were varying between 0.718-0.805. These radiographs were scanned and converted to binary images. Fractal Dimension and Lacunarity were calculated from the regions where best represents the cortical morphology. RESULTS: It was found that there were statistically significant difference between the Fractal Dimension and Lacunarity of radiographs which were classified as having Cl 1 and Cl 2 (Fractal Dimension P:0.000; Lacunarity P:0.003); and Cl 1 and Cl 3 cortical morphology (Fractal Dimension P:0.008; Lacunarity P:0.001); but there was no statistically significant difference between Fractal Dimension and Lacunarity of radiographs which were classified as having Cl 2 and Cl 3 cortical morphology (Fractal Dimension P:1.000; Lacunarity P:0.758). CONCLUSIONS: FD and L can differentiate Cl 1 mandibular cortical shape from both Cl 2 and Cl 3 mandibular cortical shape but cannot differentiate Cl 2 from Cl 3 mandibular cortical shape on panoramic radiographs.

Osteosarcoma: a case report.

Although osteosarcoma of the head and neck is a relatively rare disease, it is a highly malignant bone tumor. Diagnosis of the tumor is important especially in early stages for improving prognosis. The patients with orofacial pain firstly prefer to go to dentists. Such kind of pain may be associated with an oral or maxillofacial cancer. The dentists must be careful for evaluating the clinical and radiologic clues. These clues determine the biopsy necessity, type and management plan. The aim of this case presentation is to emphasize the importance of dentists on diagnosis and prognosis of oral malignancies.