Spectral Analysis Methods for Improved Resolution and Sensitivity: Enhancing SPR and LSPR Optical Fiber Sensing.

Biochemical-chemical sensing with plasmonic sensors is widely performed by tracking the responses of surface plasmonic resonance peaks to changes in the medium. Interestingly, consistent sensitivity and resolution improvements have been demonstrated for gold nanoparticles by analyzing other spectral features, such as spectral inflection points or peak curvatures. Nevertheless, such studies were only conducted on planar platforms and were restricted to gold nanoparticles. In this work, such methodologies are explored and expanded to plasmonic optical fibers. Thus, we study-experimentally and theoretically-the optical responses of optical fiber-doped gold or silver nanospheres and optical fibers coated with continuous gold or silver thin films. Both experimental and numerical results are analyzed with differentiation methods, using total variation regularization to effectively minimize noise amplification propagation. Consistent resolution improvements of up to 2.2× for both types of plasmonic fibers are found, demonstrating that deploying such analysis with any plasmonic optical fiber sensors can lead to sensing resolution improvements.

Artificial intelligence for oral cancer diagnosis: What are the possibilities?

Oral cancer could be prevented. The primary strategy is based on prevention. Most patients with oral cancer present to the hospital network with advanced staging and a low chance of cure. This condition may be related to physicians' difficulty of making an early diagnosis. With the advancement of information technology, artificial intelligence (AI) holds great promise in terms of assisting in diagnosis. Few machine learning algorithms have been developed for this purpose to date. In this paper, we will discuss the possibilities for diagnosing oral cancer using AI as a tool, as well as the implications for the population. A set of photographic images of oral lesions has been segmented, indicating not only the area of the lesion but also the class of lesion associated with it. Different neural network architectures were trained with the goal of fine segmentation (pixel by pixel), classification of image crops, and classification of whole images based on the presence or absence of a lesion. The accuracy results are acceptable, opening up possibilities not only for identifying lesions but also for classifying the pathology associated with them.

Tomographic study of Jaw bone changes in patients with bisphosphonate-related osteonecrosis.

BACKGROUND: Bisphosphonates (BP) are synthetic pyrophosphate-like substances with antiresorptive properties and specifically affect osteoclastic activity. In 2007, the American Association of Oral and Maxillofacial Surgeons (AAOMS) defined diagnostic criteria for Osteonecrosis of the Jaws Associated with Bisphosponates (BRONJ). BRONJ is mainly diagnosed by clinical features, but the detection of early bone changes by imaging may help prevent and better understand the disease. The objective of this study was to evaluate maxillary changes in CBCT in patients using BP. MATERIAL AND METHODS: All included patients were diagnosed with osteonecrosis and received bisphosphonate drugs in the last ten years. All imaging examinations were obtained by I-CAT and 3D Accuitomo. The multiplanar reconstructions were analyzed by an examiner without knowledge of the clinical aspects and location of the lesions. RESULTS: The study sample consisted of 21 patients, the majority of the sample represented patients with cancer (76.2%), the other patients had osteoporosis (23.8%). Only four patients (19.04%) received alendronate, while intravenous bisphosphonates, such as zoledronate and pamidronate, represented the treatment of most of our sample. Most of our patients presented stage 1 and 2 MRONJ (85.7%), whose lesions were mainly observed in the mandible (52.4%). Fifty-seven percent of the patients had at least one bone change. CONCLUSIONS: In BRONJ, bone changes vary between exposed and non-exposed areas and one aspect of the study was: persistent extraction cavities in the BRONJ lesion region and high frequency of periodontal ligament space widening in areas that are not involved in BRONJ lesions. This reflects the very important role of dental and periodontal diseases in the pathophysiology of BRONJ. Thus, preventive measures should be prioritized for patients exposed to anti-resorptive drugs. Key words:Cone-Beam computed tomography, osteonecrosis, bisphosphonate-associated osteonecrosis of the jaw.

Green Teeth Related to Bilirubin Levels.

OBJECTIVE: To describe a form of tooth pigmentation caused by serum bilirubin deposition during dental calcification in a premature child. The bilirubin levels during the three months after birth are presented. In this period the crowns of the primary teeth are still forming. Such anomaly does not have symptoms, but has a displeasing effect and great anxiety within the family. CASE REPORT: The case reported here highlights the relevance of past medical history, especially the diagnoses of prolonged conjugated hyperbilirubinemia, in this case, to confirm them and to comfort the family. In this case, no esthetic treatment had been undertaken because the child was still too young and not yet concerned. The dental treatment plan included regular checkups every 3 months for maintaining oral health to prevent caries. CONCLUSION: As this is a rare condition that affects the teeth, parents will most likely look for a dentist for treatment. Therefore, dentists must be aware or such abnormalities and take a multidisciplinary approach, thus making it possible to establish a final diagnosis.

Salivary biomarkers as tools for oral squamous cell carcinoma diagnosis: A systematic review.

BACKGROUND: The oral squamous cell carcinoma (OSCC) survival rate is influenced by the fact that diagnoses occur mostly in late stages of the disease. Thus, there is a clear contribution in the early findings, making the use of minimally invasive techniques for diagnosis, such as analysis of salivary markers, interesting tools. METHODS: A systematic review was performed with all studies that establish a comparison between the levels of saliva-based markers found in patients with OSCC compared with cancer-free individuals. RESULTS: Twenty-eight studies were included. Of them, only 12 showed some caution with oral conditions before sample collection. A wide range of potential markers was evaluated; however, the comparison between studies was impaired because each marker was hardly explored by more than 1 article. CONCLUSION: The lack of methodological criteria within studies and the absence of consensus on marker choice are obstacles for future researches. © 2016 Wiley Periodicals, Inc. Head Neck 39: 797-811, 2017.

Osteonecrose maxilar em pacientes portadores de doenças neoplásicas sob uso de bisfosfonatos / Jaw osteonecrosis in patients with neoplastic diseases taking bisphosphonates

A osteonecrose induzida por bisfosfonatos é uma complicação que pode ocorrer em pacientes acometidos por doença osteolítica tais como mieloma múltiplo, portadores de metástases tumorais em tecido ósseo, osteoporose e que fizeram uso de droga do grupo dos bisfosfonatos. A despeito dos benefícios do uso destes fármacos, a osteonecrose maxilar é uma importante complicação. Seu mecanismo de ação reduz a reabsorção óssea, o estímulo à atividade osteoblástica, a inibição do recrutamento e promoção da apoptose de osteoclastos. Até o presente momento, não há na literatura um protocolo de tratamento para a osteonecrose por bisfosfonatos. No presente trabalho, os autores fazem uma revisão da literatura e descrevem dois casos clínicos em pacientes do sexo feminino, com diferentes doenças, mieloma múltiplo e metástases ósseas por carcinoma de mama, acometidas por osteonecrose em mandíbula induzida por bisfosfonatos.

The use of bisphosphonates among patients affected by osteolytic diseases, such as multiple myeloma, metastatic bone lesions and osteoporosis has been associated with the risk of osteonecrosis of the jaws. Bisphosphonates are found in areas of the bone that are undergoing inflammation or resorption. They are phagocytosed and internalized by osteoclasts. Once in the bone, these bisphosphonates cause apoptosis or cell death of the osteoclasts and as a result they may inhibit osteoclast-mediated bone resorption. Bisphosphonates seem to affect osteoclasts when it comes to both numbers and function. Although bisphosphonates are potent and valuable inhibitors of osteoclastic bone lesions, several unanswered questions exist regarding the risk of developing osteonecrosis and the management of this complication. This study reports two clinical cases of osteonecrosis of the jaws associated with the use of bisphosphonates. According to the findings, the two patients (women) with different neoplasms: multiple myeloma and breast cancer with metastatic bone lesions presented some signs and symptoms of osteonecrosis.