A Novel Application of Deep Learning (Convolutional Neural Network) for Traumatic Spinal Cord Injury Classification Using Automatically Learned Features of EMG Signal.

In this study, a traumatic spinal cord injury (TSCI) classification system is proposed using a convolutional neural network (CNN) technique with automatically learned features from electromyography (EMG) signals for a non-human primate (NHP) model. A comparison between the proposed classification system and a classical classification method (k-nearest neighbors, kNN) is also presented. Developing such an NHP model with a suitable assessment tool (i.e., classifier) is a crucial step in detecting the effect of TSCI using EMG, which is expected to be essential in the evaluation of the efficacy of new TSCI treatments. Intramuscular EMG data were collected from an agonist/antagonist tail muscle pair for the pre- and post-spinal cord lesion from five Macaca fasicularis monkeys. The proposed classifier is based on a CNN using filtered segmented EMG signals from the pre- and post-lesion periods as inputs, while the kNN is designed using four hand-crafted EMG features. The results suggest that the CNN provides a promising classification technique for TSCI, compared to conventional machine learning classification. The kNN with hand-crafted EMG features classified the pre- and post-lesion EMG data with an F-measure of 89.7% and 92.7% for the left- and right-side muscles, respectively, while the CNN with the EMG segments classified the data with an F-measure of 89.8% and 96.9% for the left- and right-side muscles, respectively. Finally, the proposed deep learning classification model (CNN), with its learning ability of high-level features using EMG segments as inputs, shows high potential and promising results for use as a TSCI classification system. Future studies can confirm this finding by considering more subjects.

Neurophysiological Characterization of a Non-Human Primate Model of Traumatic Spinal Cord Injury Utilizing Fine-Wire EMG Electrodes.

This study aims to characterize traumatic spinal cord injury (TSCI) neurophysiologically using an intramuscular fine-wire electromyography (EMG) electrode pair. EMG data were collected from an agonist-antagonist pair of tail muscles of Macaca fasicularis, pre- and post-lesion, and for a treatment and control group. The EMG signals were decomposed into multi-resolution subsets using wavelet transforms (WT), then the relative power (RP) was calculated for each individual reconstructed EMG sub-band. Linear mixed models were developed to test three hypotheses: (i) asymmetrical volitional activity of left and right side tail muscles (ii) the effect of the experimental TSCI on the frequency content of the EMG signal, (iii) and the effect of an experimental treatment. The results from the electrode pair data suggested that there is asymmetry in the EMG response of the left and right side muscles (p-value < 0.001). This is consistent with the construct of limb dominance. The results also suggest that the lesion resulted in clear changes in the EMG frequency distribution in the post-lesion period with a significant increment in the low-frequency sub-bands (D4, D6, and A6) of the left and right side, also a significant reduction in the high-frequency sub-bands (D1 and D2) of the right side (p-value < 0.001). The preliminary results suggest that using the RP of the EMG data, the fine-wire intramuscular EMG electrode pair are a suitable method of monitoring and measuring treatment effects of experimental treatments for spinal cord injury (SCI).

Case report of an oral fibroma occurring in a patient with familial multiple lipomas.

A wide variety of lesions may manifest in the oral soft tissues that could be confusing and challenging for the clinicians. These lesions could be as simple as trauma-induced ulcers that need about 2 weeks to heal, to a more complicated situation such as oral cancer. The key points in developing diagnosis and a possible treatment plan may include a comprehensive oral examination, simple understanding of normal oral tissue features, and knowledge of common oral lesions. This will help in the development of a differential diagnosis of the oral lesions/masses based on the risk factors in that particular patient. In this case report, we present a simple oral mass in a patient who had an oral fibroma and lipomas in other areas.

Study of the inferior alveolar canal and mental foramen on digital panoramic images.

OBJECTIVES: To study the radiographic location of the mental foramen and appearance of the inferior alveolar canal and the relationship between image gray values and the clarity of inferior alveolar canal on the digital panoramic images and to evaluate if the histogram equalization of the digital image would improve the visualization of the inferior alveolar canal outline on the digital panoramic images in the mandible. METHODS: Five hundred digital panoramic images were evaluated by two examiners using a specific inclusion criteria. Only the right side of the mandible was studied. Chi-square analyses were used for comparisons of distributions. Mean and median pixel values were analyzed separately with a one-way analysis of variance. Also, percentages were calculated to report the usefulness of the histogram equalization for visualization of canal. RESULTS: RESULTS show variation in location of mental foramen. Most frequent location of the mental foramen was reported as first and second premolar region. Chi-square analysis showed that the frequency of occurrence of the mental foramen was equally probable for any of the three locations. The study did not find significant usefulness of the gray values obtained from the histogram equalization in predicting the clarity of inferior alveolar canal outlines. CLINICAL SIGNIFICANCE: Knowing the normal relationship and the anatomical variation of the maxillofacial structures for each patient is important for surgical implant treatment planning to avoid future complications. It is also important to be familiar with the advantages and limitations of diagnostic aids available before making treatment planning decisions based on such findings. KEYWORDS: Digital imaging, Panoramic, Inferior alveolar canal, Mental foramen. How to cite this article: Pria CM, Masood F, Beckerley JM, Carson RE. Study of the Inferior Alveolar Canal and Mental Foramen on Digital Panoramic Images. J Contemp Dent Pract 2011;12(4):265-271. Source of support: Nil Conflict of interest: None declared.

A comparison of panoramic image quality between a digital radiography storage phosphor system and a film-based system.

AIM: To compare digital panoramic images acquired for the presurgical assessment of third molars captured with a storage phosphor-based system with conventional film panoramic radiographs. METHODS AND MATERIALS: A total of 51 pairs of digital and conventional panoramic images, made simultaneously, were included in this study. The images were evaluated for diagnostic quality prior to third molar surgery by two experienced oral surgeons and rated with a four-point grading scale. RESULTS: Despite the fact that conventional panoramic images were rated higher than the digital images, the difference was not statistically significant. CONCLUSIONS: Conventional and digital panoramic images were found to be of comparable image quality with regard to their diagnostic contribution to third molar surgery. CLINICAL SIGNIFICANCE: This study is contributory to understanding differences in image quality between digital and conventional panoramic radiography for certain diagnostic tasks. The lack of significant differences in image quality may be an endorsement for digital panoramic radiography.

Comparison study of classification methods of intramuscular electromyography data for non-human primate model of traumatic spinal cord injury.

Traumatic spinal cord injury is a serious neurological disorder. Patients experience a plethora of symptoms that can be attributed to the nerve fiber tracts that are compromised. This includes limb weakness, sensory impairment, and truncal instability, as well as a variety of autonomic abnormalities. This article will discuss how machine learning classification can be used to characterize the initial impairment and subsequent recovery of electromyography signals in an non-human primate model of traumatic spinal cord injury. The ultimate objective is to identify potential treatments for traumatic spinal cord injury. This work focuses specifically on finding a suitable classifier that differentiates between two distinct experimental stages (pre-and post-lesion) using electromyography signals. Eight time-domain features were extracted from the collected electromyography data. To overcome the imbalanced dataset issue, synthetic minority oversampling technique was applied. Different ML classification techniques were applied including multilayer perceptron, support vector machine, K-nearest neighbors, and radial basis function network; then their performances were compared. A confusion matrix and five other statistical metrics (sensitivity, specificity, precision, accuracy, and F-measure) were used to evaluate the performance of the generated classifiers. The results showed that the best classifier for the left- and right-side data is the multilayer perceptron with a total F-measure of 79.5% and 86.0% for the left and right sides, respectively. This work will help to build a reliable classifier that can differentiate between these two phases by utilizing some extracted time-domain electromyography features.

Incidence of nasopalatine canal perforation in relation to virtual implant placement: A cone beam computed tomography study.

BACKGROUND: The nasopalatine canal (NPC) is of special importance when considering implant therapy in the maxillary central incisors' region. PURPOSE: To investigate the incidence of NPC perforation in relation to virtual immediate implant placement. MATERIALS AND METHODS: A search through the cone beam computed tomography (CBCT) database of The University of Oklahoma-College of Dentistry was conducted. First, canal related measurements were conducted. Second, digital prosthetic planning was performed. Then, immediate implants were virtually placed and additional measurements were performed. Perforation rate was assessed. Last, data obtained was statistically analyzed. RESULTS: A total of 217 scans fulfilled the inclusion criteria. Only 8% of cases showed NPC perforation. The perforation occurred at mid-third of the implant or at the mid and apical third in 33% and 22% of the cases, respectively. A statistically significant association was found between perforation of NPC and bone width palatal to the root of the central incisor (P < .0001) as well as canal angulation (P = .0196). NPC angulation (°) and palatal bone width (mm) predisposed to a higher risk of perforation. Only 27.78% of the perforations could be overcome by the installation of shorter implants. CONCLUSIONS: Low incidence of NPC perforation could be expected when immediately placing implants in the maxillary incisor region.

Presence of carotid artery calcification on panoramic radiographs of patients with chronic diseases.

This study sought to investigate carotid artery calcification (CAC) on panoramic radiographs from both healthy patients and those patients suffering from different chronic diseases. A total of 247 patients met the inclusion criteria and were reviewed. Ninety-two patients had one or more chronic diseases as indicated by their records; the remaining 155 patients had no mention of a chronic disease and were considered to be healthy controls. Among all patients, 13% had evidence of CAC, 21% of the patients with one or more chronic diseases had CAC, and only 8% of the patients in the control group had CAC. Those with liver disease only had the highest proportion (33%) of CAC.

Bisphosphonates, osteonecrosis of the jaw, and dental treatment recommendations.

Millions of patients in the United States take bisphosphonates for management of malignant bone metastases, osteoporosis, osteitis deformans (Paget's disease), and osteogenesis imperfecta. Since 2003, over 200 cases of osteonecrosis of the jaws have been described, mostly in patients with multiple myeloma or breast cancer patients, and to a lesser extent in patients on oral medications.

Alterations in Tooth Structure and Associated Systemic Conditions.

A variety of factors can affect the normal development of tissues and may lead to variation in the normal compliment of teeth and development of alterations in the shape and size of teeth. These anomalies can be congenital, developmental, or acquired. Dental anomalies can present as isolated traits or be associated with systemic conditions and syndromes for which early diagnosis and genetic testing may result in better treatment outcomes and quality of life. Dentists play an essential role in the multidisciplinary management of these abnormalities. This article discusses some of these tooth alterations and associated systemic and genetic conditions.

Model of Traumatic Spinal Cord Injury for Evaluating Pharmacologic Treatments in Cynomolgus Macaques (Macaca fasicularis).

Here we present the results of experiments involving cynomolgus macaques, in which a model of traumatic spinal cord injury (TSCI) was created by using a balloon catheter inserted into the epidural space. Prior to the creation of the lesion, we inserted an EMG recording device to facilitate measurement of tail movement and muscle activity before and after TSCI. This model is unique in that the impairment is limited to the tail: the subjects do not experience limb weakness, bladder impairment, or bowel dysfunction. In addition, 4 of the 6 subjects received a combination treatment comprising thyrotropin releasing hormone, selenium, and vitamin E after induction of experimental TSCI. The subjects tolerated the implantation of the recording device and did not experience adverse effects due the medications administered. The EMG data were transformed into a metric of volitional tail moment, which appeared to be valid measure of initial impairment and subsequent natural or treatment-related recovery. The histopathologic assessment demonstrated widespread axon loss at the site of injury and areas cephalad and caudad. Histopathology revealed evidence of continuing inflammation, with macrophage activation. The EMG data did not demonstrate evidence of a statistically significant treatment effect.

Comparison of Healing Following Tooth Extraction With Ridge Preservation Using Anorganic Bovine Bone Mineral Particulate and Self-Expanding Composite Graft.

OBJECTIVES: To study the radiographic mean grey values after bone grafting and to clinically evaluate the intraoral alveolar ridge dimensional stability with anorganic bovine bone mineral (ABBM) particulate and a patented self-expanding composite graft (SECG) after 6 months of healing. METHODS: A total of 20 single-rooted tooth-extraction sites grafted with either ABBM or SECG were evaluated radiographically and clinically after 6 months of healing, prior to dental implant placement. A multivariable mixed regression model was used. RESULTS: Mean grey values at the coronal, midroot, and apex levels within the socket were compared. A significant difference was shown in the midroot and apex maxillary regions. For both of these regions, the estimated mean grey value of ABBM was significantly lower than that of SECG. No significant difference was noted in the ridge-width change patterns between the two materials. CONCLUSION: This study supports that suggestion that newer SECG is as efficacious in terms of mean grey value and alveolar ridge stability as the previously available ABBM.

The effects of BID length and shape on the surface area and volume of tissue exposed during dental radiography.

Using projection geometry, algebraic formulas, and different beam indicating devices (BIDs), the surface area and volume of tissue exposed for a hypothetical patient was determined. Combinations of 4 BID lengths and shapes were used: 4-inch (10.2 cm.) pointed plastic, 8-inch (20.3 cm.) round plastic, 14-inch (35.6 cm.) round aluminum, and 14-inch (35.6 cm.) rectangular aluminum. As each subject BID was progressively lengthened and collimated, the area and volume of tissue exposed was reduced. The calculated area and volume of exposed tissue for the 14-inch rectangular aluminum open-ended lead-lined BID was 16.6 cm.2 and 327.7 cm.3, respectively. This represented 9% of the area and 8% of the volume of tissue exposed using the 4-inch round pointed plastic BID or a 91% (area) and 92% (volume) reduction in patient exposure.

Biological therapy and dentistry: a review paper.

In recent years, a new class of drugs has revolutionized the treatment of autoimmune, allergic, infectious, and many more diseases. This new class of drugs is made of 3 groups-cytokines, monoclonal antibodies, and fusion proteins-that may target special damaged cells but not all the cells. These drugs may have side effects such as infection, hypersensitivity, hematologic disorders, cancer, hepatotoxicity, and neurologic disorders. However, there is not enough evidence or long-term studies of the mechanism of action and side effects of these drugs. Patients receiving biological therapies may need special consideration in dentistry. This paper is a review of the classification, mechanism of action, and side effects of these drugs and dental consideration for patients receiving biological therapies.

Comparison of panoramic radiography and panoramic digital subtraction radiography in the detection of simulated osteophytic lesions of the mandibular condyle.

OBJECTIVE: The aim of this study was to compare panoramic temporomandibular joint radiography, unenhanced and color-enhanced digital-subtraction radiography with respect to detectability of simulated osteophytic lesions of the mandibular condyle. METHODS: Three dry human skulls with no obvious temporomandibular joint pathology were selected. Four sizes of bone chips were placed on the anterior aspect of the condyle at medial, central, and lateral locations. Panoramic radiographs were made with and without the chips in place. These paired radiographs were digitized, and unenhanced and color-enhanced digital-subtraction images of the original panoramic images were obtained. Eight observers evaluated 72 randomized images of each modality for the presence or absence of simulated osteophytic lesions of the mandibular condyle, grading the images on a 100-point scale. RESULTS: A(z) values for overall diagnostic accuracy of the three imaging modalities were 0.5376 for panoramic radiography, 0.7861 for unenhanced digital subtraction radiography, and 0.7923 for color-enhanced digital-subtraction radiography. Digital-subtraction radiography improved the detection accuracy of the original panoramic films. CONCLUSION: Panoramic radiographs were significantly less accurate in the detection of simulated osteophytic lesions of the mandibular condyle than the two digital-subtraction techniques.

Antibiotic prophylaxis: a literature review.

Antibiotic prophylaxis has been a matter of great interest and has been discussed by researchers and clinicians over the years. Changes and recommendations have been made in order to clarify protocol and make it safer for patients. Various organizations such as the American Heart Association, American Academy of Oral Surgeons, American Dental Association, and American Academy of Oral Medicine have played vital roles in formulating guidelines for antibiotic prophylaxis. These recommendations for prevention of infective endocarditis have been based on clinical experiences and research as well as expert opinion. This paper summarizes the most recent guidelines for general readers so that informed decisions may be made that are in the interest of patients and practitioners.

Findings from panoramic radiographs of the edentulous population and review of the literature.

OBJECTIVE: The purpose of this study was to evaluate the frequency of positive radiographic findings in panoramic radiographs of edentulous arches. METHOD: A sample of 327 panoramic radiographs was selected from the patient pool at the University of Oklahoma College of Dentistry. Radiographs were evaluated for presence of retained root tips, impacted teeth, radiolucent and radiopaque areas, soft tissue calcifications, and foreign bodies. RESULTS: Approximately 57.5% of panoramic radiographs revealed no positive radio-graphic findings, while the remaining 42.5% contained 1 or more positive radiographic findings. Thirty-nine root fragments were identified, and the majority were located in the maxilla. However, only 5 pathological findings (3.8%) required treatment modification before denture fabrication. CONCLUSIONS: Results of the study do not support routine pretreatment panoramic radiography on patients seeking denture fabrication. Panoramic radiography is a valuable diagnostic tool in the pretreatment assessment of partially and completely edentulous patients, but their routine use in such patients should be discouraged.