Prevalence and severity of orbital blowout fractures.

We aimed to study the prevalence of orbital blowout fractures and evaluate the causes and the location of orbital cavity fractures. In this cross-sectional study, the medical records of all patients admitted with facial trauma were assessed, sociodemographic information as well as the aetiology of trauma extracted, and the computed tomographic images of the patients were reassessed. Location of orbital blowout fractures and the severity of orbital fractures were evaluated. A total of 203 cases had blowout fractures (175 male and 28 female patients with a mean (SD) age of 36 (16) years. Road traffic accidents (n=139, 69%) were the most common cause of orbital blowout fractures. Falls (n=29, 14%) and assault (n=20, 10%) were the other causes of trauma to the orbital structure, which resulted in blowout fractures. The medial wall was the most commonly involved location (n=81, 40%) followed by orbital floor (n=64, 32%), the combination of medial wall and floor (n=36, 18%), medial wall and maxilloethmoidal strut combination (n=13, 6%), and all the three locations altogether (n=9, 4%). Most of the blow-out fractures had mild severity (n=107, 53%). There was a significant relation between the severity and location of the blowout fractures (p<0.001).

Mandibular Trabecular Bone Analysis Using Local Binary Pattern for Osteoporosis Diagnosis.

BACKGROUND: Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and micro-architectural deterioration of bone tissue, leading to bone fragility and increased fracture risk. Since Panoramic image is a feasible and relatively routine imaging technique in dentistry; it could provide an opportunistic chance for screening osteoporosis. In this regard, numerous panoramic derived indices have been developed and suggested for osteoporosis screening. Jaw trabecular pattern is one of the main bone strength factors and trabecular bone pattern assessment is important factor in bone quality analysis. Texture analysis applied to trabecular bone images offers an ability to exploit the information present on conventional radiographs. OBJECTIVE: The purpose of this study was to evaluate the relationship between Jaw trabecular pattern in panoramic image and osteoporosis based on image texture analyzing using local binary pattern. MATERIAL AND METHODS: An experiment is evaluated in this paper based on a real hand-captured database of panoramic radiograph images from osteoporosis and non-osteoporosis person in Namazi Hospital, Shiraz, Iran .An approach is proposed for osteoporosis diagnosis consisting of two steps. First, modified version of local binary patterns is used to extract discriminative features from jaw panoramic radiograph images. Then, classification is done using different classifiers. RESULTS: Comparative results show that the proposed approach provides classification accuracy about 99.6%, which is higher than many state-of-the-art methods. CONCLUSION: High classification accuracy, low computational complexity, multi-resolution and rotation invariant are among advantages of our proposed approach.

Diagnosis of Tempromandibular Disorders Using Local Binary Patterns.

BACKGROUND: Temporomandibular joint disorder (TMD) might be manifested as structural changes in bone through modification, adaptation or direct destruction. We propose to use Local Binary Pattern (LBP) characteristics and histogram-oriented gradients on the recorded images as a diagnostic tool in TMD assessment. MATERIAL AND METHODS: CBCT images of 66 patients (132 joints) with TMD and 66 normal cases (132 joints) were collected and 2 coronal cut prepared from each condyle, although images were limited to head of mandibular condyle. In order to extract features of images, first we use LBP and then histogram of oriented gradients. To reduce dimensionality, the linear algebra Singular Value Decomposition (SVD) is applied to the feature vectors matrix of all images. For evaluation, we used K nearest neighbor (K-NN), Support Vector Machine, Naïve Bayesian and Random Forest classifiers. We used Receiver Operating Characteristic (ROC) to evaluate the hypothesis. RESULTS: K nearest neighbor classifier achieves a very good accuracy (0.9242), moreover, it has desirable sensitivity (0.9470) and specificity (0.9015) results, when other classifiers have lower accuracy, sensitivity and specificity. CONCLUSION: We proposed a fully automatic approach to detect TMD using image processing techniques based on local binary patterns and feature extraction. K-NN has been the best classifier for our experiments in detecting patients from healthy individuals, by 92.42% accuracy, 94.70% sensitivity and 90.15% specificity. The proposed method can help automatically diagnose TMD at its initial stages.

In vitro Evaluation of the Relationship between Gray Scales in Digital Intraoral Radiographs and Hounsfield Units in CT Scans.

BACKGROUND: Jaw bone quality plays an essential role in treatment planning and prognosis of dental implants. Regarding several available methods for bone density measurements, they are not routinely used before implant surgery due to hard accessibility. OBJECTIVE: An in vitro investigation of correlation between average gray scale in direct digital radiographs and Hounsfield units in CT-Scan provides a feasible method for evaluating alveolar bone quality prior to implant surgery. METHODS: 26 sheep's mandibles in which a square shape ROI marked by gutta percha, were prepared. Three direct digital radiographs (CCD sensor) from every specimen were taken using 80, 100 and 200 milli-seconds. Then, the average gray levels for ROIs were calculated using a costume-made software. Next, the specimens were scanned using a 16-slice spiral CT and the Hounsfield Unit of each ROI was calculated. Pearson analysis measured the correlation between Hounsfield units and average gray levels. RESULTS: There was a positive correlation between Hounsfield unit and average gray level in the radiographs and the correlation was better in higher exposure times. CONCLUSION: It is possible to estimate Hounsfield unit and bone density in the jaw bones using average gray scale in a digital radiograph. This approach is easy, simple and available and also results in lower patient exposure comparing other bone densitometric analysis methods.

Dental anomalies and dental age assessment in treated children with acute lymphoblastic leukemia.

BACKGROUND: This cross sectional study was performed to evaluate dental ages and incidence of dental anomalies in children treated for acute lymphoblastic leukemia (ALL). METHODS AND MATERIALS: A total of 25 ALL patient who passed at least 2 years of chemotherapy and 25 healthy sex and age matched children were evaluated. Dental age as well as dental anomalies in shape, size, number, and structure was recorded based on their panoramic radiographies which were taken for dental purposes. RESULTS: The number of dental anomalies significantly increased in ALL treated children. Seven ALL cases (28%) in compression to only one (4%) in control group had at least one dental anomaly. However, there was neither statistically significant differences between the mean of dental (p=0.32) and chronologic age (p=0.12) in both groups, nor between dental age of cases and control group (p=0.62).The age at the onset of treatment as well as treatment durations has not affected dental age and the incidence of dental anomalies significantly (p<0.05). CONCLUSION: Chemotherapy in children results in emergence of dental anomaly. Dental age, maturity, and development process however seems to be independent from chemotherapy.

Multiple idiopathic apical root resorption: a case report.

The aim of this case report was to present a case of multiple idiopathic apical root resorption which is a rare condition in a 17-year-old adult male. External root resorption of the permanent teeth is a multifactorial process. Well-recognized causes of apical root resorption in permanent teeth include orthodontic therapy, trauma, periapical or periodontal inflammation, tumors, cysts, occlusal stress, impacted teeth, systemic conditions, endocrine imbalances and dietary habits. When none of these causes are present, it is termed idiopathic root resorption which may be either cervical or apical. Multiple idiopathic apical root resorption is a rare condition which is usually detected as an incidental radiographic finding. However, it may cause pain and mobility in severe cases.