1. Articles from petra wilder-smith

    1-19 of 19
    1. Intra-operative point-of-procedure delineation of oral cancer margins using optical coherence tomography

      Intra-operative point-of-procedure delineation of oral cancer margins using optical coherence tomography

      Objectives Surgical margin status is a significant determinant of treatment outcome in oral cancer. Negative surgical margins can decrease the loco-regional recurrence by five-fold. The current standard of care of intraoperative clinical examination supplemented by histological frozen section, can result in a risk of positive margins from 5 to 17 percent. In this study, we attempted to assess the utility of intraoperative optical coherence tomography (OCT) imaging with automated diagnostic algorithm to improve on the current method of clinical evaluation of surgical margin in oral cancer. Materials and methods We have used a modified handheld OCT device with automated algorithm ...

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    2. Optical Coherence Tomography as an Oral Cancer Screening Adjunct in a Low Resource Settings

      Optical Coherence Tomography as an Oral Cancer Screening Adjunct in a Low Resource Settings

      Oral cancer is the sixth most common cancer worldwide, predominantly seen in low and middle-income countries (LMIC). Two thirds of all cases are detected at a late stage when prognosis and treatment outcomes are poor. Oral lesions are commonly detected by visual inspection, followed by invasive surgical biopsy and time consuming histopathological analysis. Optical Coherence Tomography (OCT), a minimally invasive tomographic imaging technology, can be used to non-invasively identify premalignant or malignant change in the oral mucosa. In this study, a mobile OCT imaging system was designed, constructed and tested for its performance as a point-of-care oral diagnostic device. Twenty ...

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    3. Stimuli-disassembling gold nanoclusters for diagnosis of early stage oral cancer by optical coherence tomography

      Stimuli-disassembling gold nanoclusters for diagnosis of early stage oral cancer by optical coherence tomography

      A key design consideration in developing contrast agents is obtaining distinct, multiple signal changes in diseased tissue. Plasmonic gold nanoparticles (Au NPs) have been developed as contrast agents due to their strong surface plasmon resonance (SPR). This study aims to demonstrate that stimuli-responsive plasmonic Au nanoclusters (Au NCs) can be used as a contrast agent for optical coherence tomography (OCT) in detecting early-stage cancer. Au NPs were clustered via acid-cleavable linkers to synthesize Au NCs that disassemble under mildly acidic conditions into individual Au NPs, simultaneously diminishing SPR effect (quantified by scattering intensity) and increasing Brownian motion (quantified by Doppler ...

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    4. Comparison of caries diagnostic modalities: A clinical study in 40 subjects

      Comparison of caries diagnostic modalities: A clinical study in 40 subjects

      Background and Objectives Few studies have been published that evaluate the usefulness of different caries- diagnostic modalities in general dental practice. The goal of this study was to compare the results of screening for coronal dental caries in a general dental practice using clinical observations, radiographs, laser fluorescence (DIAGNOdent™) (LF), and optical coherence tomography (OCT). Diagnostic agreement between OCT and LF versus standard clinical techniques for detecting caries was determined in 40 subjects. Study Designs/Materials and Methods Forty patients with >1 coronal carious lesion as determined by prescreening using clinical examination and radiographs were enrolled in this study. Subjects ...

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    5. Multimodality imaging of the effects of a novel dentifrice on oral biofilm

      Multimodality imaging of the effects of a novel dentifrice on oral biofilm

      Objective Oral biofilm formation and progression on the surface of the tooth can lead to advanced oral disease such as gingivitis. The purpose of this randomized, controlled, double-blinded study was to evaluate the effects of a novel dental gel on oral plaque biofilm using multimodal imaging techniques. Materials and Methods Twenty-five subjects with moderate gingival inflammation (Löe and Silness Gingival Index ≥2) and pocket depths <4 were randomly assigned to brush twice daily for 21 days with the test or the control dental gel. In vivo multimodality in situ imaging was performed over a 3-week period using in vivo ...

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    6. Assessment of early occlusal caries pre- and post- sealant application—An imaging approach

      Assessment of early occlusal caries pre- and post- sealant application—An imaging approach

      Background and Objective Clinicians have difficulty assessing and monitoring early occlusal caries. Traditional clinical exam and radiographs are unable to detect the subtle alterations in enamel indicative of de- or re-mineralization, particularly under dental sealants. Although clinicians have used laser fluorescence (LF) to address this gap, this modality has demonstrated weak correlation with histology. The International Caries Detection and Assessment System (ICDAS-II) has demonstrated high sensitivity and specificity for caries detection, but since it is based on visual assessment, it is of no use in areas beneath the most commonly used dental sealants which are opaque. Optical coherence tomography (OCT ...

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    7. A prospective study to assess in vivo optical coherence tomography imaging for early detection of chemotherapy-induced oral mucositis

      A prospective study to assess in vivo optical coherence tomography imaging for early detection of chemotherapy-induced oral mucositis

      Background and Objective Oral mucositis (OM) is a common and severe complication of many cancer therapies. Currently, prediction and early detection are not possible and objective monitoring remains problematic. Goal of this prospective study is to assess non-invasive imaging using optical coherence tomography (OCT) for early detection and evaluation of chemotherapy-induced OM in 48 patients, 12 of whom developed clinical mucositis. Study Design/Materials and Methods In 48 patients receiving neoadjuvant chemotherapy for primary breast cancer, oral mucosal health was assessed clinically, and imaged using non-invasive OCT. Images were evaluated for mucositis using an imaging-based scoring system ranging from 0 ...

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    8. An imaging-based approach to the evaluation of xerostomia

      An imaging-based approach to the evaluation of xerostomia

      Background and Objective Goal was to evaluate the potential of in vivo optical coherence tomography (OCT) imaging to determine the response of patients with xerostomia to a dry mouth toothpaste versus fluoride toothpaste placebo. Study Design/Materials and Methods Ten subjects with xerostomia participated in this double-blind, crossover, placebo-controlled study. After examination and OCT imaging, subjects used the first product for 15 days, followed by a 7-day washout period, and then they used the second product for 15 days. Data were acquired at 5-day intervals, also before and after the washout. Results Visual examination and tongue blade adhesion test did ...

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    9. Multimodality approach to optical early detection and  mapping of oral neoplasia

      Multimodality approach to optical early detection and  mapping of oral neoplasia
      Early detection of cancer remains the best way to ensure patient survival and quality of life. Squamous cell carcinoma is usually preceded by dysplasia presenting as white, red, or mixed red and white epithelial lesions on the oral mucosa (leukoplakia, erythroplakia). Dysplastic lesions in the form of erythroplakia can carry a risk for malignant conversion of 90%. A noninvasive diagnostic modality would enable monitoring of these lesions at regular intervals and detection of treatment needs at a very early, relatively harmless stage. The specific aim of this work was to test a multimodality approach [three-dimensional optical coherence tomography (OCT) and ...
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    10. Ability of optical coherence tomography to detect caries beneath commonly used dental sealants

      Ability of optical coherence tomography to detect caries beneath commonly used dental sealants
      Background and Objective The onset and progression of early tooth decay is often preventable with dental sealants. However, occasionally decay progresses underneath the sealant. Current technology does not permit monitoring of potential lesion progression or arrest. Dental sealants themselves mask the visual cues that identify early tooth decay, and radiographs are not sufficiently sensitive. Therefore, clinicians can be reluctant to use dental sealant. The objective of this ex vivo study was to evaluate the ability of dentists to detect decay beneath commonly used dental sealants using optical coherence tomography (OCT) imaging. Study Designs/Materials/Methods Forty extracted teeth were divided ...
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    11. Efficient and facile delivery of gold nanoparticles in vivo using dissolvable microneedles for contrast-enhanced optical coherence tomography

      Efficient and facile delivery of gold nanoparticles in vivo using dissolvable microneedles for contrast-enhanced optical coherence tomography
      Obtaining sufficient contrast is an indispensable requirement for detecting early stage cancer using optical coherence tomography (OCT), an emerging diagnostic tool that detects abnormal lesions with micrometer resolutions in real time. PEGylated gold nanoparticles (Au NPs; 87 nm in diameter) were formulated in aqueous dissolvable microneedles (dMNs; 200 μm height) for efficient, precisely controlled, and convenient delivery of Au NPs into hamster oral tissue in vivo. The Au NPs were then further briefly dissipated by ultrasound (US). The results showed 33% and 20% increase in average optical scattering intensity (contrast level) in dysplastic and normal tissues, respectively, and pinpointed pathological ...
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    12. Potential of optical coherence tomography for early diagnosis of oral malignancies

      Potential of optical coherence tomography for early diagnosis of oral malignancies
      With nearly 1,500,000 new patients diagnosed every year in the USA, cancer poses a considerable challenge to healthcare today. Oral cancer is responsible for a sizeable portion of deaths due to cancer, primarily because it is diagnosed at a late stage when the prognosis is poor. Current methods for diagnosing oral cancer need to be augmented by better early detection, monitoring and screening modalities. A new approach is needed that provides real-time, accurate, noninvasive diagnosis. The results of early clinical trials using in vivo optical coherence tomography for the diagnosis of oral dysplasia and malignancy are encouraging.
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    13. Overcoming barriers in topical administration of gold nanoparticles for optical coherence tomography using multimodal delivery

      Overcoming barriers in topical administration of gold nanoparticles for optical coherence tomography using multimodal delivery
      Optical coherence tomography (OCT) is a non-invasive and promising imaging modality with high resolution that is an order of magnitude higher than current diagnostic techniques. However, its use in detecting early-stage cancer is limited due to insufficient contrast level in biological tissue, which can be enhanced by harnessing contrast agents [e.g., gold nanoparticles (Au NPs)]. Enhanced penetration by creating micropassages and distribution by ultrasonic force (multimodal topical delivery) was proven to overcome two major barriers (stratum corneum and epithelial barriers) in topically administering Au NPs using an in vivo oral dysplasia hamster model (overall 150% enhanced OCT contrast). Expanded ...
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    14. Detection of vesicant-induced upper airway mucosa damage in the hamster cheek pouch model using optical coherence tomography

      Detection of vesicant-induced upper airway mucosa damage in the hamster cheek pouch model using optical coherence tomography
      Hamster cheek pouches were exposed to 2-chloroethyl ethyl sulfide [CEES, half-mustard gas (HMG)] at a concentration of 0.4, 2.0, or 5.0 mg/ml for 1 or 5 min. Twenty-four hours post–HMG exposure, tissue damage was assessed by both stereomicrography and optical coherence tomography (OCT). Damage that was not visible on gross visual examination was apparent in the OCT images. Tissue changes were found to be dependent on both HMG concentration and exposure time. The submucosal and muscle layers of the cheek pouch tissue showed the greatest amount of structural alteration. Routine light microscope histology was performed ...
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    15. Quantification of Dental Erosions in Patients With GERD Using Optical Coherence Tomography Before and After Double-Blind, Randomized Treatment With Esomeprazole or Placebo

      OBJECTIVES: Dental erosion, the chemical dissolution of enamel without bacterial involvement, is a rarely reported manifestation of gastroesophageal reflux disease (GERD), as well as of recurrent vomiting and dietary habits. It leads to loss of tooth substance, hypersensitivity, functional impairment, and even tooth fracture. To date, dental erosions have been assessed using only very basic visual methods, and no evidence-based guidelines or studies exist regarding the prevention or treatment of GERD-related dental erosions. METHODS: In this randomized, double-blind study, we used optical coherence tomography (OCT) to quantify dental tissue demineralization and enamel loss before and after 3 weeks of acid-suppressive ...
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    16. Optical approach to the salivary pellicle

      The salivary pellicle plays an important role in oral physiology, yet noninvasive in situ characterization and mapping of this layer remains elusive. The goal of this study is to develop an optical approach for the real-time, noninvasive mapping and characterization of salivary pellicles using optical coherence tomography (OCT) and optical coherence microscopy (OCM). The long-term goals are to improve diagnostic capabilities in the oral cavity, gain a better understanding of physiological and pathological processes related to the oral hard tissues, and monitor treatment responses. A salivary pellicle is incubated on small enamel cubes using human whole saliva. OCT and OCM ...
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    17. In vivo diagnosis of oral dysplasia and malignancy using optical coherence tomography: Preliminary studies in 50 patients

      In vivo, non-invasive optical coherence tomography (OCT) permits high-resolution imaging of tissue surfaces and subsurfaces, with the potential capability for detection and mapping of epithelial pathologies.To evaluate the clinical capability of non-invasive in vivo OCT for diagnosing oral dysplasia and malignancy.In 50 patients with oral lesions, conventional clinical examination was followed by OCT imaging, then standard biopsy and histopathology. Two blinded, pre-standardized investigators separately diagnosed each lesion based on (1) OCT and (2) histopathology.Intra- and inter-observer agreement between diagnoses based on histopathology and imaging data was excellent, with [kappa] values between 0.844 and 0.896. Sensitivity ...
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    18. Enhanced detection of early-stage oral cancer in vivo by optical coherence tomography using multimodal delivery of gold nanoparticles

      Contrast in optical coherence tomography (OCT) images can be enhanced by utilizing surface plasmon resonant gold nanoparticles. To improve the poor in vivo transport of gold nanoparticles through biological barriers, an efficient delivery strategy is needed. In this study, the improved penetration a ... [J. Biomed. Opt. 14, 034008 (2009)] published Tue May 12, 2009.
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    19. In vivo optical coherence tomography--based scoring of oral mucositis in human subjects: a pilot study

      Hilari Kawakami-Wong, Shuguang Gu, Marie J. Hammer-Wilson et al. A preliminary study to assess noninvasive optical coherence tomography (OCT) for early detection and evaluation of chemotherapy-induced oral mucositis in five patients. In five patients receiving neoadjuvant chemotherapy for primary breast cancer, oral mucositis was assessed clinically, and imaged u ... [J. Biomed. Opt. 12, 051702 (2007)] published Fri Sep 21, 2007.
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    1-19 of 19
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    1. (19 articles) UC Irvine
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    3. (13 articles) Zhongping Chen
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    6. (2 articles) Kenneth K. C. Lee
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    Detection of vesicant-induced upper airway mucosa damage in the hamster cheek pouch model using optical coherence tomography Potential of optical coherence tomography for early diagnosis of oral malignancies Overcoming barriers in topical administration of gold nanoparticles for optical coherence tomography using multimodal delivery Efficient and facile delivery of gold nanoparticles in vivo using dissolvable microneedles for contrast-enhanced optical coherence tomography Ability of optical coherence tomography to detect caries beneath commonly used dental sealants Novel Optical Coherence Tomography Parameters as Prognostic Factors for Stage 3 Epiretinal Membranes En-face OCT and OCT angiography analysis of macular choroidal macrovessel Three-dimensional live imaging of bovine embryos by optical coherence tomography Comparison of Subfoveal Choroidal Thickness and Retinal Nerve Fiber Layer Thickness in Patients with Coronary Slow Flow Phenomenon and Microvascular Angina: Optical Coherence Tomography based study Optical Coherence Tomography of the Orbit Through a Staphyloma: A View of Tenon's Capsule, Orbital Fat, and Inferior Oblique Muscle Line field Fourier domain optical coherence tomography based on a spatial light modulator Post-doctoral Scholar Position in OCT Endoscopy at the University of North Carolina at Chapel Hill