The Prevalence of EBV and KSHV in Odontogenic Lesions.

OBJECTIVES: Odontogenic lesions evolve as a result of altered dental development. This study aimed to evaluate the prevalence and the coinfection of Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) in radicular cysts, dentigerous cysts, odontogenic keratocysts, and ameloblastomas. METHODS: Polymerase chain reaction (PCR) was used to analyse 66 cases of odontogenic lesions for the presence of EBV-DNA and KSHV-DNA. These lesions were 15 radicular cysts, 16 dentigerous cysts, 18 odontogenic keratocysts, and 17 ameloblastomas. RESULTS: EBV-DNA was detected in 24 (36.4%) of the studied samples as follows: 6 samples (40.0%) of radicular cysts, 4 (25.0%) of dentigerous cysts, 10 (55.6 %) of odontogenic keratocysts, and 4 (23.5%) of ameloblastomas (P = .168). KSHV-DNA was found in 16 (24.2%) of the studied samples as follows: 1 sample (6.7%) of radicular cysts, 6 (37.5%) of dentigerous cysts, 8 (44.4 %) of odontogenic keratocysts, and 1 (5.9%) of ameloblastomas (P = .001). Additionally, EBV and KSHV were positively correlated in all studied samples (P = .002). CONCLUSIONS: Both EBV and KSHV are found in odontogenic cysts and ameloblastomas. KSHV and EBV are more prevalent in odontogenic keratocysts than in other studied odontogenic lesions. Further, there is a high prevalence of EBV and KSHV coinfection in odontogenic cysts and ameloblastomas.

P63 and Ki-67 expression in radicular cyst.

Objectives: The aim of the current study was to identify the expression of P63 and its relation to odontogenic epithelial cell proliferation, severity of the inflammatory infiltrate and size of radicular cysts (RCs). Methods: In this retrospective cross-sectional study, 30 cases of paraffin-embedded RCs were randomly selected from the archive. P63 and Ki-67 expression was assessed by immunohistochemistry. Results: Epithelial P63 expression was absent in four (13.3%), weak in 10 (33.3%), and moderate in 16 (53.3%) cases. In the connective tissue wall of RC, P63 expression was absent in two (6.7%) cases, weak in 24 (80.0%) cases, and moderate in four (13.3%) cases. Ki-67 was found to be weakly expressed in 12 (40.0%) cases, moderately expressed in 13 (43.3%), and strongly expressed in five (16.7%) cases. No correlation was found between Ki-67 expression in odontogenic epithelium and P63 expression in the odontogenic epithelium (rho = 0.110, p = .563) or fibrous capsule (rho = 0.160, p = .399). Nevertheless, we found a positive correlation between Ki-67 expression in the odontogenic epithelium and the size of the RC (rho = 0.450, p = .013). The inflammatory infiltrate was negatively correlated with P63 expression in the odontogenic epithelium (rho = -0.428, p = .018), and with the size of cysts (rho = -0.728, p < .001). Conclusions: There is a high expression of P63 throughout the odontogenic epithelium and connective tissue capsule of the RC. P63 expression in the odontogenic epithelium is negatively correlated with the degree of the inflammatory infiltrate but not with epithelial cell proliferation or the size of the cyst.

The correlated expression of COX-2 and keratin 15 in radicular cysts.

Background: The expression of cyclooxygenase-2 (COX-2) and Keratin-15 (K15) in radicular cysts (RCs) is poorly understood. Identifying the expression of these two markers may modify the current treatment of RC. The objective of this study was to evaluate the expression of COX-2 and its relationship to K15 expression in the odontogenic epithelial cells of the RC. Material and Methods: A total of 18 RCs were immunohistochemically analyzed for COX-2 and K15 expression. The cellular inflammatory reaction in the cyst wall was also assessed by measuring the percentage of inflammatory cells to the total number of cells. Results: COX-2 expression in the odontogenic epithelium of RC was absent in 11.1 % (n=2), mild in 27.8 % (n=5), moderate in 22.2% (n=4) and strong in 38.9% (n=7). Meanwhile, K15 expression was absent in 27.8% (n=5), mild in 16.7% (n=3), moderate in 44.4% (n=8), and strong in 11.1% (n=2) of the cases. The inflammatory infiltrate was mild in 2 cases (11.1%), moderate in 6 cases (33.3%), and high in 10 cases (55.6%). Spearman's correlation test revealed significant correlation (rho= .533; p= .023) between COX-2 and K15 expression in the odontogenic epithelium of RC. However, no correlation was noted between inflammation and expression of COX-2 (rho= 0.248, p=.321) or K15 (rho= -0.162, p= .520). Conclusions: There is high and correlated expression of COX-2 and K15 in the odontogenic epithelium of RC. COX-2 could therefore be involved in epithelial cell differentiation of the cyst. Additionally, the expression of K15 in RC may be an indicator of epithelial cell differentiation. Key words:Cyclooxygenase, COX-2, Keratin-15, K15, Radicular cyst.

Correlation between distribution of Helicobacter pylori in oral cavity and chronic stomach conditions.

In this study, the colonization and distribution of Helicobacter pylori (Hp) in patients with chronic gastric diseases were investigated and the relationship between the periodontal initial treatment and presence of Hp in oral cavity was examined to better understand the connection between Hp infection and chronic diseases. Primers for PCR amplification were designed according to ureC gene and cagA genes of Hp. Specimens were harvested from different sites of 96 patients with chronic gastric diseases and the specimens of dental plaques, gargles and dorsal mucosa were tested for Hp. The 96 patients were treated by bismuth triple therapy and among them, 52 subjects were additionally given periodontal initial therapy. The eradication rate of gastric Hp and oral Hp detection rate were determined 4 weeks and 1 year after the treatment. The results showed that the detection rates of oral specimens were in the order of dental plaques (82.3%), gargles (51.1%) and scrapings of dorsal mucosa of tongue (37.5%). One year after bismuth triple therapy or the triple therapy in combination with periodontal initial treatment, the eradication rate of gastric Hp was significantly higher in the combination treatment group than in group treated by the triple therapy alone (62.8% vs. 32.4%, P<0. 05). Moreover, the Hp detection rate was significantly lower in the combination group than in the group treated only with the triple therapy. We are led to conclude that Hp is present at various parts of oral cavity, oral Hp might be an important source of gastric Hp and the triple therapy plus periodontal initial treatment can enhance the long-term eradication rate of gastric Hp in patient with both chronic gastric diseases and chronic periodontitis.

Human cytomegalovirus is present in the odontogenic epithelium of ameloblastoma.

Background: The factor behind the activation of the remnant odontogenic tissues and development of odontogenic cysts and tumors is poorly understood.This study aimed to investigate the presence of human cytomegalovirus (HCMV) in dentigerous cyst (DC), odontogenic keratocyst (OKC), and ameloblastoma (AB). Methods: The study included 41 samples, which distributed into DC (n=13), OKC (n=12), and AB (n=16). Conventional PCR assay and IHC analysis were used to detect the HCMV-DNA and HCMV glycoprotein B (HCMV-gB) respectively. Results: HCMV-DNA was detected in 10 samples (62.5%) of AB, four samples (30.8%) of DC, and three samples (25 %) of OKC respectively (χ2 test = 1.195, p= 0.247). Meanwhile, HCMV-gB was found in 12 (75%) of AB, in 2 (15.4%) of DC, and absent in OKC (0.0%) (χ2 test = 4.122, p= 0.042). Conclusions: The high prevalence of HCMV inside the odontogenic epithelium of AB could indicate a possible role of the virus in the oncogenesis and/or oncomodulation of the AB. Additionally, we recommend the IHC for the detection of HCMV in the odontogenic tumors like AB.

p63 Expression and its Relation to Epithelial Cells Proliferation in Dentigerous Cyst, Odontogenic Keratocyst, and Ameloblastoma.

The current controversy about the classification of odontogenic keratocyst reflects the shortage in the understanding of the odontogenic cysts and tumors. The aim of the present study was to investigate p63 immunoexpression and its relation to the proliferation of the epithelial lining in dentigerous cyst (DC), odontogenic keratocyst (OKC), and follicular type of ameloblastoma (AB). The study involved 36 samples, which are DC (n = 12), OKC (n = 9), and AB (n = 15). p63 protein expression was evaluated by immunohistochemistry. The results on Ki-67 expression were obtained from our previous studies and correlated with p63 expressions. p63 was expressed differently in the studied lesions with various distribution in different study samples. Statistical analysis using Kruskal-Wallis test showed a significant difference in the expression of p63 protein among DC, OKC, and AB (p = 0.048). Subsequently, Mann-Whitney U test revealed the expression of p63 protein was significantly higher in OKC than DC (p = 0.018). Interestingly, Spearman's correlation analysis showed a positive correlation between the expression of p63 and Ki-67 in the odontogenic epithelium of DC (σ = 0.757, P = 0.004) and OKC (σ = 0.741, P = 0.022). While no such a positive correlation was found between the two studied markers in AB group (σ = 0.006, P = 0.983). In conclusion, the present results indicated various expression and correlation of p63 with the proliferation of odontogenic epithelial cells in DC, OKC, and AB. This diversity could reflect a different role and pathways of ΔNp63 in odontogenic tumor than that in odontogenic cyst. These together will help in better understanding the pathogenesis and biological behavior of odontogenic cysts and tumors.

Expression of keratin 15 in dentigerous cyst, odontogenic keratocyst and ameloblastoma.

The etiology and pathogenesis of odontogenic lesions are poorly understood. Keratin 15 (K15) is a type I cytoskeletal protein that provides structural support to the cells and has been considered to be a stem cell marker. The aim of the present study was to evaluate the expression of K15 in the epithelial lining of dentigerous cysts (DCs), odontogenic keratocysts (OKCs) and ameloblastomas (ABs). The study included 41 samples of DCs (n=13), OKCs (n=12), and AB tissues (n=16). K15 protein expression was evaluated via immunohistochemistry and data were statistically analyzed using a Kruskal-Wallis test. K15 was expressed in the majority of the studied lesions with various distributions in the different study samples. The Kruskal-Wallis test revealed non-significant differences in the expression of K15 among the three odontogenic lesions (P=0.380). The present study confirmed the high expression of K15 in the different epithelial layers of DC, OKC and AB. This type of expression excludes the reliability of regarding K15 as a stem cell marker in DC, OKC and AB. However, K15 may reflect the abnormal differentiation of pathological epithelial cells in these lesions.

Third-molar development in relation to chronologic age in young adults of central China.

The estimation of chronologic age based on the stages of third-molar development was evaluated by using the eight stages (A-H) method of Demirjian and the third-molar development was compared, in terms of sex and age, with results of previous studies. The samples consisted of 291 orthopantomograms from young Chinese subjects of known chronologic age and sex (including 139 males with a mean age of 14.67+/-3.62 y and 152 females with a mean age of 14.85+/-3.70 y). Statistical analysis was performed by employing the Mann-Whitney U-test and the t-test. Regression analysis was conducted to obtain regression formulas for calculating dental age from the chronologic age. Our results showed statistically significant differences (P<0.05) in third-molar development between males and females, at the calcification stages D, E and H. And a strong correlation was found between age and third-molar development in both males (r (2)=0.65) and females (r (2)=0.61). New equations (Age=8.76+1.32 Development stage) for estimating chronologic age were derived. It is concluded that third-molar genesis took place earlier in males than in females. The use of third molars as a developmental marker is appropriate in young adults of Central China. The formula obtained in the present study can be used as a guide for estimation of dental maturity and a standard for age estimation for young adults of Central China.

Expression of c-Src and comparison of cytologic features in cherubism, central giant cell granuloma and giant cell tumors.

Cherubism (CBM) and central giant cell granuloma (CGCG) of the jaw and giant cell tumor (GCT) of the long bone are clinically different diseases. Histologically, they are all multinucleated giant cell (MGC)-containing lesions. This study aims to evaluate the expression of c-Src and cytologic features in CBM, CGCG and GCT and to clarify whether there is a common mechanism underlying the formation of multi-nucleated giant cells (MGCs) in these lesions. Specimens and paraffin blocks were collected from patients with CBM (12 cases), CGCG (24 cases) and GCT (37 cases). Histomorpho-metric differences in MGCs were compared among the three types of lesions. The expression of c-Src by immunohistochemistry and in situ hybridization and the expression of TRAP by enzyme histochemical staining were examined. Expression of c-Src mRNA and protein, as well as TRAP staining, was detected in both MGCs and a fraction of mononuclear cells in all investigated lesions. There are no quantitative differences for cytologic features and c-Src expression among the lesions. The results suggested that CBM, CGCG and GCT have overlapping cytological features at the histological level, and c-Src may be involved in the formation of MGCs in the three different diseases.

The application of virtual endoscopy with computed tomography in maxillofacial surgery.

OBJECTIVE: To use virtual endoscopy to obtain detailed three-dimensional images of bone, soft tissue and paranasal sinus damage as well as images of adjacent unaffected areas for optimum surgical planning. METHODS: A spiral CT scanner was used to examine 46 cases of facial bone fractures, maxillary cysts, obstructive sleep apnea syndrome (OSAS) and maxillary bone tumours. Data were input into a navigator workstation to create images similar to those displayed by a fiberoptic endoscope. Various 3-D images were obtained when probe sites were changed. RESULTS: Virtual endoscopy can clearly display the anatomic structure of the paranasal sinuses, nasopharyngeal cavity and upper respiratory tract, revealing damage to the sinus wall caused by a bone tumor or fracture. In addition, the technique can be used to indicate volume changes of the upper respiratory tract in OSAS patients. These results were similar to those obtained through actual operations. CONCLUSIONS: Virtual endoscopy is a new method which produces very clear images. It is reliable to provide detailed information for optimal operative planning.

[The level of PPTA mRNA and its proteins expression in trigeminal ganglia in rats with occlusal recovery].

PURPOSE: To study the level of substance P(SP) and preprotachykinin A(PPTA) mRNA in trigeminal ganglia(TG)in rats with occlusal recoveryìand to discuss the mechanism of temporomandibular disorders. METHODS: 48 Wistar male rats were randomly divided into 3 experimental groups and 3 control groupsì8 rats in each group. The right maxillary and mandibular molars in the experimental groups were ground to the gingival level without occlusal contact. The occlusal contact was recovered by stoping grinding the molars gradually. The section of trigeminal ganglia were used for immunohistological and in situ hybridization study. Light microscope and microscoic photo analytic software were employed to detect the percentage of SP and PPTA mRNA positive neurons in the frozen section of TGs in 48 rats. SPSS10.0 software package were used for statistical analysis. RESULTS: The percentage of SP positive neurons in TG with unilateral chew experimental group decreased significantly compared to the control group (P<0.01,P<0.05).The decreased extent in the non-chewing side was much higher than that in the chewing side(P<0.05).The percentage of PPTA mRNA positive neurons was significantly higher in both of the chewing and non-chewing sides of the unilateral chew experimental group than that in the control group (P<0.05,P<0.01)ì and that non-chewing side was significantly higher than that in the chewing side(P<0.01).There was no significant difference in the percentage of SP and PPTA mRNA positive neurons between the early occlusal reconstruction the experimental group and the control group(P>0.05), and there was no significant difference of those between the non-chewing side and the chewing side(P>0.05). The results of later occlusal recovery in the experimental group was same to that of the unilateral chew experimental group. CONCLUSIONS: The expressions of SP and PPTA mRNA in TG can recover normal in the early occlusal recovery but can not in the later occlusal recovery. SP and PPTA mRNA might participate in the histopathologic mechanism of temporomandibular disorders.

[The study of magnetic resonance sialography in diagnosing parotid diseases].

OBJECTIVE: To study the feasibility of diagnosing parotid disease with magnetic resonance sialography (MRS) and to select the optimal scanning sequence. METHODS: Twenty-three patients with parotid gland disease and 5 normal adults received sialography using magnetic resonance imaging technique and several sequences (including IR-FSE, FSE, SS-IR-FSE, SS-FSE) were used. After first scanning, the patients were scanned respectively 3 and 10 minutes after buccal application of vitamin C. And MR images of duct obtained. The images of parotid duct system were analysed and evaluated according to their displaying effects. Qualitative diagnosis was made based on MRI and those diagnosis were compared with pathological diagnosis after operation. RESULTS: Images of MR sialography clearly displayed the main duct and its branches of parotid gland and the pathological changes of duct, such as narrow, expanded, stoppage. Of the scanning sequences, IR-FSE was superior to others in manifesting the parotid gland duct (P < 0.05). The performance of images after being given vitamin C did not significantly improve the displaying effect. The accurate rate of qualitative diagnosis was 95.6%. CONCLUSIONS: MR sialography can clearly display the parotid ducts and their pathological changes. The accurate rate of qualitative diagnosis of parotid disease was higher than that X-ray sialography.