Most clinicians dread seeing the patient presenting with a primary complaint of a burning pain on one or more oral mucosal surfaces. Unlike most other clinical conditions presenting in a dental office, burning mouth syndrome is poorly understood with few evidence based remedies. More recently, advances have been made towards clarifying the possible etiology of the disorder and testing the possible therapeutic modalities available. This article attempts to summarize the “state of the art” today.
Lymphatic metastasis is a continuous and complicated process. The detailed mechanisms of lymphatic metastasis are still not very clear, despite considerable research efforts in recent years. Previously, it was commonly accepted that there were no lymphatic vessels in the primary tumor. However, recent studies have demonstrated that lymphatic vessels are detectable in certain types of cancer, and more and more evidence has shown that cancer cells invade into local lymph nodes mainly via peritumoral lymphatic vessels. Moreover, activated endothelial cells may also be important, having an influence on lymphatic metastasis of cancer cells. This article, based on recent research findings, provides an in‐depth discussion of the relationship between lymphangiogenesis, tumor‐derived lymphatic endothelial cells and lymphatic metastasis in head and neck cancer.
The effect of Galla chinensis on de‐/re‐mineralization of advanced enamel lesions was investigated by using micro‐CT in a prolonged in vitro experiment.
Baseline mineral contents of sound enamels were first analyzed. Then lesions were produced in an acidic buffer solution (2.2 mmol·L−1 Ca(NO3)2, 2.2 mmol·L−1 KH2PO4, and pH=4.5) for 21 days, with thrice daily three‐minute treatments, divided into four groups: Group A, 4 000 ppm crude aqueous extract of Galla chinensis (GCE); Group B, 4 000 ppm gallic acid; Group C, 1 000 ppm F aq. (as NaF, positive control); Group D, deionized water (negative control). Next, the blocks were immersed in a remineralization solution (1.5 mmol·L−1 CaCl2, 0.9 mmol·L−1 KH2PO4, 0.1 ppm F, and pH=7.0) for 200 days. Mineral loss (ML) in each region of interest(ROI) and integrated mineral loss (IML) of the lesions were calculated (comparing with baseline mineral content of sound enamel) at different time points.
After 21 days demineralization, fluoride treatment showed a statistically significant demineralization‐inhibiting effect among the four groups, and after 200 days of remineralization, mineral content recovery was ordered (lowest to highest) as A=C<B<D.
GCE could slow down the remineralization of enamel in the surface layer and thereby facilitate ion transport into the lesion body. The mechanism of Galla chinensis in enhancing the remineralization of dental caries is different from fluoride.
The aim of this study was to confirm the multilineage differentiation ability of dental pulp stem cells (DPSCs) from green fluorescent protein (GFP) transgenic mice. The expression of GFP in DPSCs was also observed during differentiation.
DPSCs were harvested from the dental pulp tissue of transgenic nude mice, and then transferred to osteogenic, adipogenic, and chondrogenic media. The morphological characterization of induced cells was observed by microscopy and histological staining. The expression of marker genes was measured by RT‐PCR.
The endogenous GFP and multilineage potential of transgenic DPSCs had no influence on each other. Moreover, the results of fluorescence microscopic imaging suggest that there was no significant decline of GFP expression during DPSCs differentiation.
As the population of GFP labeled DPSCs can be easily identified, this will be a promising method for tracking DPSCs in vivo.
To evaluate the interactive effects of different self‐adhesive resin cements and tribochemical treatment on bond strength to zirconia.
The following self‐adhesive resin cements for bonding two zirconia blocks were evaluated: Maxcem (MA), Smartcem (SM), Rely X Unicem Aplicap (UN), Breeze (BR), Biscem (BI), Set (SE), and Clearfil SA luting (CL). The specimens were grouped according to conditioning as follows: Group 1, polishing with 600 grit polishing paper; Group 2, silica coating with 110 µm Al2O3 particles which modified with silica; and, Group 3, tribochemical treatment ‐ silica coating + silanization. Specimens were stored in distilled water at 37°C for 24 hours before testing shear bond strength.
Silica coating and tribochemical treatment significantly increased the bond strength of the MA, UN, BR, BI, SE and CL to zirconia compared to #600 polishing. For both #600 polished and silica coating treatments, MDP‐containing self‐adhesive resin cement CL had the highest bond strengths to zirconia.
Applying silica coating and tribochemical treatment improved the bond strength of self‐adhesive resin cement to zirconia, especially for CL.
To detect the expression of nerve growth factor (NGF) and vascular endothelial growth factor (VEGF) in salivary adenoid cystic carcinoma (SACC) tissues, as well as to determine the correlation between growth factor expression and prognosis in SACC.
Medical records of 63 patients surgically treated for SACC between January 1988 and October 2005 were reviewed. Immunohistochemistry was performed to examine the expression of NGF and VEGF in tumor tissues. Kaplan‐Meier analysis and Cox's proportional hazard regression model were applied to assess predictors of survival.
NGF and VEGF were overexpressed in SACC tissues, compared with those in normal salivary tissues (P<0.05), and the staining intensity of these two factors was stronger in groups of solid subtype, advanced TNM stage, perineural invasion and recurrence. Patients with high‐expression of NGF and VEGF, solid subtype, advanced stage, perineural invasion, recurrence and extended resection alone had worse survival rates (P<0.05).
NGF and VEGF are expressed increasingly in the tissues of SACC cases with invasion and metastasis. NGF expression and VEGF expression are independent prognosis factors for survival.
To analyse the cytomorphological features of keratinocytes in smears obtained from the oral mucosa of tobacco users and from oral squamous cell carcinoma lesions.
Oral smears were obtained from clinically, normal appearing mucosa of oral squamous cell carcinoma patients (n=20) and from the mucosa of smokers (n=20), and apparently healthy individuals (n=20) were used as controls. The smears were histochemically stained and cytomorphological assessment of the keratinocytes was carried out. One‐way ANOVA (Analysis of Variance) was used for comparing the parameters among multiple groups and Tukey‐HSD test was used to compare the mean values between groups.
The mean nuclear area of keratinocytes from the mucosa of tobacco users was 46 ± 2.57 and that of the oral squamous cell carcinoma lesion was 81.54 ± 4.31. While there was a significant (P=0.001) reduction in the cellular area of keratinocytes from oral squamous cell carcinoma lesion when compared with those from oral smears of tobacco users.
Cytomorphometric analysis of keratinocytes can serve as a useful adjunct in the early diagnosis of oral squamous cell carcinomas.
To investigate the role of the Chinese herbal medicine Xianhuayin on the reversal of 7,12‐dimethylbenz[a]anthracene (DMBA)‐induced premalignant mucosal lesions in the oral buccal pouch of golden hamsters.
The animals were randomly divided into a non‐diseased control group (n=5) and an experimental group including 50 animals in which the buccal mucosa had been painted with DMBA (0.5% in acetone) to generate an oral mucosa premalignant lesion. Animals in the experimental group were further divided into Xianhuayin‐treated group (n=30), untreated premalignant lesion group (n=10) and normal saline (NS)‐treated group (n=10). The cheek (buccal) pouch mucosa of the golden hamsters in each group was observed with light and electron microscopy eight weeks after intragastric administration with NS or Xianhuayin.
In the non‐diseased control group, the buccal mucosa was keratinized and stratified squamous epithelium under a light microscope. In the untreated premalignant lesion group, variable degrees of epithelial dysplasia was observed. The irregular epithelial mucosa gradually became distinct in the Xianhuayin‐treated group. Scanning electronic microscopic (SEM) analysis showed that surface of the cells exhibited honeycomb structures in the hamster of untreated‐group. The cells were morphologically irregular, overlapped and loosened in the untreated premalignant lesion group. Most of the cell surface exhibited honeycomb structure in the Xianhuayin‐treated group. Transmission electronic microscopic (TEM) analysis showed that buccal mucosal epithelial cells were morphologically regular in the non‐diseased control group. Desmosomes and tonofibrils were reduced and the nucleus was morphologically irregular in the untreated premalignant lesion group. In the Xianhuayin‐treated group, the widening intercellular gap was gradually reduced, desmosomes and the cells becoming morphologically regular. No significant difference was observed between the hamsters in NS‐treated group and those in the untreated premalignant lesion group. Significant therapeutic efficacy was observed in the group receiving Xianhuayin.
Xianhuayin is effective in the reversal of DMBA‐induced premalignant lesions in the buccal pouch of golden hamsters.