Oral Biology and Oral Pathology Commons^™

Human Oral Mucosa And Gingiva: A Unique Reservoir For Mesenchymal Stem Cells, Q Z. Zhang, A L. Nguyen, W H. Yu, A D. Le

Departmental Papers (Dental)

Mesenchymal stem cells (MSCs) represent a heterogeneous population of progenitor cells with self-renewal and multipotent differentiation potential. Aside from their regenerative role, extensive in vitro and in vivo studies have demonstrated that MSCs are capable of potent immunomodulatory effects on a variety of innate and adaptive immune cells. In this article, we will review recent experimental studies on the characterization of a unique population of MSCs derived from human oral mucosa and gingiva, especially their immunomodulatory and anti-inflammatory functions and their application in the treatment of several in vivo models of inflammatory diseases. The ease of isolation, accessible tissue source, …

Oral Lichen Planus, Eric T. Stoopler, Thomas P. Sollecito

Departmental Papers (Dental)

No abstract provided.

Non-Exposed Bisphosphonate-Related Osteonecrosis Of The Jaw: A Critical Assessment Of Current Definition, Staging, And Treatment Guidelines, S Patel, S Choyee, J Uyanne, A L. Nguyen, P Lee, P P. Sedghizadeh, S K S Kumar, J Lytle, S Shi, A D. Le

Departmental Papers (Dental)

Non-exposed bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a newly reported complication arising from bisphosphonate therapy that presents with atypical symptoms and no apparent mucosal fenestration or exposure of necrotic bone. The clinical observation of the presence of necrotic bone underneath normal epithelial coverage was not conclusive for the diagnosis of BRONJ based on current guidelines established by the American Association of Oral and Maxillofacial Surgeons (AAOMS) and the American Society for Bone and Mineral Research (ASBMR), which specify the presence of clinically exposed necrotic bone for more than 8weeks. Hence, the purpose of this review is to critically assess …

Etiology Of Noncarious Cervical Lesions, Caren M. Barnes

Faculty Publications, College of Dentistry

As the number of older adults in the United States continues to grow, this change in patient demographics will profoundly affect the practice of dental hygiene. Not only are there more older adults, but they are also retaining more of their natural teeth than ever before. The risk of alveolar bone loss; gingival recession, which can lead to exposed cervical and root areas of the teeth; and tooth wear all increase with age. The confluence of these factors raises the risk of noncarious cervical lesions (NCCLs).

The prevalence of NCCLs is growing, largely due to the rising numbers of older …

Morphology And Fracture Of Enamel, Sangwon Myoung, James Lee, Paul Constantino, Peter Lucas, Herzl Chai, Brian Law

Paul J. Constantino

This study examines the inter-relation between enamel morphology and crack resistance by sectioning extracted human molars after loading to fracture. Cracks appear to initiate from tufts, hypocalcified defects at the enamel–dentin junction, and grow longitudinally around the enamel coat to produce failure. Microindentation corner cracks placed next to the tufts in the sections deflect along the tuft interfaces and occasionally penetrate into the adjacent enamel. Although they constitute weak interfaces, the tufts are nevertheless filled with organic matter, and appear to be stabilized against easy extension by self-healing, as well as by mutual stress-shielding and decussation, accounting at least in …

Mesenchymal Stem Cells: A Double-Edged Sword In Regulating Immune Responses, Wenzhao Li, Guangwen Ren, Yan Huang, Juanjuan Su, Yanyan Han, Jiao Li, Xiaodong Chen, Kai Cao, Qing Chen, Peishun Shou, Liying Zhang, Zengrong Yuan, Arthur I. Roberts, Songtao Shi, Anh D. Le, Yufang Shi

Departmental Papers (Dental)

Mesenchymal stem cells (MSCs) have been employed successfully to treat various immune disorders in animal models and clinical settings. Our previous studies have shown that MSCs can become highly immunosuppressive upon stimulation by inflammatory cytokines, an effect exerted through the concerted action of chemokines and nitric oxide (NO). Here, we show that MSCs can also enhance immune responses. This immune-promoting effect occurred when proinflammatory cytokines were inadequate to elicit sufficient NO production. When inducible nitric oxide synthase (iNOS) production was inhibited or genetically ablated, MSCs strongly enhance T-cell proliferation in vitro and the delayed-type hypersensitivity response in vivo. Furthermore, iNOS-/- …

[Studies On Keratocystic Odontogenic Tumors], T. Li, L. Sun, H. Luo, J. Luan, L. Gao, Xiaomei Gu, X. Li, L. Xu

Xiaomei Gu

Keratocystic odontogenic tumors (KCOTs, previously known as odontogenic keratocysts) are aggressive, noninflammatory jaw lesions with a putative high growth potential and a propensity for recurrence. This article puts together a summary of the serial studies related to KCOTs undertaken by the author's research group in recent years. Intraosseous jaw cysts with a solely orthokeratinized lining epithelium have been suggested to differ from the typical KCOTs. We report 20 cases of such cyst type under the term of 'orthokeratinized odontogenic cyst (OOC)'. Apart from the presence of a keratinizing epithelial lining, the OOC lacks the other histological features of KCOT, exhibits …

Ptch Mutations In Sporadic And Gorlin-Syndrome-Related Odontogenic Keratocysts, Xiaomei Gu, H. Zhao, L. Sun, T. Li

Xiaomei Gu

Odontogenic keratocysts are relatively common lesions that may occur in isolation or in association with nevoid basal cell carcinoma syndrome (or Gorlin syndrome). The PTCH gene has been reported to be associated with Gorlin syndrome. We investigated 10 cases of non-syndromic keratocysts and two other cases associated with Gorlin syndrome, looking for PTCH mutations. Four novel and 1 known PTCH mutations were identified in five individual patients. Of the 5 mutations identified, 2 were germ-line mutations (2619C>A; 1338_1339insGCG) in 2 cysts associated with Gorlin syndrome, and 3 were somatic mutations (3124_3129dupGTGTGC; 1361_1364delGTCT; 3913G>T) in 3 non-syndromic cysts. This …

Ptch Germline Mutations In Chinese Nevoid Basal Cell Carcinoma Syndrome Patients, T. Li, J. Yuan, Xiaomei Gu, L. Sun, H. Zhao

Xiaomei Gu

Objectives: PTCH, the human homologue of the Drosophila segment polarity gene, patched, has been identified as the gene responsible for nevoid basal cell carcinoma syndrome. The aim of this study was to investigate PTCH gene mutation in Chinese patients with nevoid basal cell carcinoma syndrome. Materials and methods:  DNA was isolated from both odontogenic keratocyst tissue and peripheral blood of five patients with syndrome and one patient with only multiple odontogenic keratocysts, and mutational analysis of the PTCH gene performed by direct sequencing after amplification of all 23 exons by polymerase chain reaction (PCR). Results:  A previously reported germline mutation …

[Detection Of Ptch Gene Mutations In Odontogenic Keratocysts By Sscp And Dna Sequencing], Xiaomei Gu, T Li

Xiaomei Gu

OBJECTIVE: To investigate PTCH gene mutations in odontogenic keratocysts (OKC). METHODS: PCR-SSCP and DNA sequencing were used to analyze the PTCH gene mutations in 12 OKCs, including 10 sporadic and 2 nevoid basal cell carcinoma syndrome (NBCCS) associated OKC. RESULTS: Four mutations were identified in 4 cysts, among which two germline mutations were associated with NBCCS and 2 somatic mutations were in 2 unrelated sporadic cases. In addition, eight previously reported polymorphisms in the PTCH gene were also found in 10 cases. CONCLUSION: The present study indicated that both sporadic and NBCCS-related OKCs could carry PTCH gene mutation. Thus, mutational …

Analysis Of Periapical Biopsies Submitted For Histopathological Evaluation: A Retrospective Study, Abdullah I. Alqaied

Master's Theses

Apical periodontitis is the most common pathological process in the periapical region. Disciplined clinical and radiographic evaluations and appropriate diagnostic tests can detect lesions related to apical periodontitis. Aside from this, lesions mimicking pulp-related pathology but unrelated to pulpal infection and necrosis are occasionally discovered in the periapical region. The objective of this study was two-fold: (1) to determine the prevalence of diverse periapically located pathological entities, and (2) to apply that information to evaluate the rationale for routine submission of surgically obtained tissue for histological examination and diagnosis. Methods: A 5-year retrospective analysis of pathology reports from the UCONN …

Racemization Of Amino Acids In Teeth For The Determination Of Age, Andrea Lee Toll

Masters Theses & Specialist Projects

Instrumental to forensic investigations is the ability to identify unknown human remains providing key evidence to criminal cases, resolution to missing persons, and assistance in mass or natural disasters. Identification of remains in an effort to determine age is an area of forensics that has received considerable attention. Traditional methods in age determination such as morphology are often biased, antiquated, and frequently result in a large margin of error. Conversely, the emergence of new forensic techniques provide promise to reduce the margin of error in determining age. One such technique has focused on relating the extent of amino acid racemization …

Prevalidation Of Salivary Biomarkers For Oral Cancer Detection, David A. Elashoff, Hui Zhou, Jean Reiss, Jianghua Wang, Hua Xiao, Bradley Henson, Shen Hu, Martha Arellano, Uttam Sinha, Anh Le, Diana Messadi, Marilene Wang, Vishad Nabili, Mark Lingen, Darly Morris, Timothy Randolph, Fred Ziding, David Akin, Dragana A. Kastratovic, David Chia, Elliot Abemayor, David T W Wong

Departmental Papers (Dental)

Background: Oral cancer is the sixth most common cancer with a 5-year survival rate of approximately 60%. Presently, there are no scientifically credible early detection techniques beyond conventional clinical oral examination. The goal of this study is to validate whether the seven mRNAs and three proteins previously reported as biomarkers are capable of discriminating patients with oral squamous cell carcinomas (OSCC) from healthy subjects in independent cohorts and by a National Cancer Institute (NCI)-Early Detection Research Network (EDRN)-Biomarker Reference Laboratory (BRL). Methods: Three hundred and ninety-five subjects from five independent cohorts based on case controlled design were investigated by two …

The Effect Of Extracorporeal Shock Wave (Esw) On Cementoblasts In Vitro, Joshua Barta

Master's Theses (2009 -)

Root resorption is an adverse consequence of orthodontic treatment, and currently no effective treatment method exists. Extracorporeal shock wave (ESW) has been applied to enhance angiogenesis, growth and healing of bone, but the effects of ESW on root resorption have not been studied. Cementoblasts are the cells responsible for forming and repairing cementum covering the dental root, and ESW may enhance this reparative process. The purpose of this study was to investigate the effects of ESW on cementoblasts to determine if ESW could potentially be used to treat root resorption. OCCM.30 cementoblasts were prepared in suspension at a density of …

Animal Models To Study Host-Bacteria Interactions Involved In Periodontitis, Dana T. Graves, Jun Kang, Oelisoa Andriankaja, Keisuke Wada, Carlos Rossa Jr.

Departmental Papers (Dental)

Animal models have distinct advantages because they can mimic cellular complexities that occur in humans in vivo and are often more accurate than in vitro studies that take place on plastic surfaces with limited numbers of cell types present. Furthermore, cause and effect relationships can be established by applying inhibitors or activators or through the use of genetically modified animals. Such gain or loss of function studies are often difficult to achieve in human clinical studies, particularly in obtaining target tissue due to important ethical considerations. Animal models in periodontal disease are particularly important at this point in the development …

A Polymerase Chain Reaction Method For The Detection Of Selenomonas Noxia, Arthuro Mehretu

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent studies, periodontal health has been linked to being overweight and/or obese. Among common oral bacteria, Selenomonas noxia has been implicated in converting periodontal health to disease. Selenomonas spp. have also been found in gastric ulcers, and were misdiagnosed as Helicobacter -like organisms, but no further studies were conducted. The increasing clinical and epidemiological importance of S. noxia necessitates the development of a rapid detection method. In this study, a TaqMan 16S rRNA based real-time Polymerase Chain Reaction (PCR) method was developed, optimized and evaluated for the rapid and specific detection of S. noxia . The 16S PCR assay …

Retrospective Evaluation Of Microbial Presence In Existing Saliva Repository: A Pcr Based Molecular Survey Of Oral Microbial Populations From Existing Saliva Samples, Jay Ericksen Davis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The overall purpose of this research project is to explore the link between oral health and disease in the University of Nevada, Las Vegas - School of Dental Medicine (UNLV-SDM) clinic patient population. More specifically, the population of interest is the UNLV-SDM orthodontic clinic patient population, which is mostly composed of adults, females, and minorities. The University of Nevada, Las Vegas, School of Dental Medicine, with more than 70,000 active patients and a post-graduate specialty program in Orthodontics is uniquely positioned to perform this type of oral health epidemiology survey, as well as targeted oral microbial testing among populations within …

Bacterial Adherence Of Streptococcus Mutans And Lactobacillus Acidophilus On Poly-Methyl Methacrylate And Thermoplastic Polypropene Used In Orthodontic Retention, Lindsay Ann Pfepper

UNLV Theses, Dissertations, Professional Papers, and Capstones

Retention is required in the majority of orthodontic patients throughout the remainder of their life. The two primary removable appliances are known as the traditional Hawley retainer or the vacuum formed retainer. These appliances were developed to maintain the position of the dentition without sacrificing oral health. The orthodontic population is at a higher risk for caries due to plaque accumulation from poor diet, suboptimal oral hygiene and often lack of motivation. These two retainers occupy different niches and are comprised of different materials; therefore the retainers' effect on oral health could be very different. An understanding of which bacteria …

Gingival Crevicular Fluid (Gcf) Levels Of Interleukin-6 (Il-6), Soluble Glycoprotein 130 (Sgp130), And Soluble Interleukin-6 Receptor (Sil-6r) During Orthodontic Tooth Movement, Mathue Gene Faulkner

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Orthodontic tooth movement requires the precise coordination of a multitude of biological factors in order for proper bone remodeling to occur. Cytokines, such as Interleukin-6 (IL-6), play a critical role in the communication necessary for both bone resorption and bone apposition. IL-6 reacts with receptor proteins, such as soluble IL-6 receptor (sIL-6R), on target cells in order to transmit signals important to both osteoclast and osteoblast activities. Soluble glycoprotein 130 (sgp130), on the other hand, acts as a natural inhibitor to IL-6 activity. The purpose of this investigation was to evaluate the levels of IL-6, sIL-6R, and sgp130 …

Performance Of Melamine Modified Urea-Formaldehyde Microcapsules In A Dental Host Material, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Urea-formaldehyde (UF) microcapsules filled with dicyclopentadiene (DCPD) show potential for making self-healing dental restorative materials. To enhance the physical properties of the capsules, the urea was partially replaced with 0-5% melamine. The microcapsules were analyzed by different microscopic techniques. DSC was used to examine the capsule shell, and the core content was confirmed by (1)H NMR spectroscopy. Capsules in the range of 50-300 mu m were then embedded in a dental composite matrix consisting of bisphenol-A-glycidyl dimethacrylate (Bis-GMA) and triethylene-glycol dimethacrylate (TEGDMA). Flexural strength, microhardness, and nanoindentation hardness measurements were performed on the light-cured specimens. Optical microscopy (OM) examination showed …