Cancer stem cell markers in intraoral minor salivary gland tumors.

Emerging evidence suggests the existence of a tumorigenic population of cancer cells that demonstrate stem cell-like properties. Cancer stem cells have been associated with tumor initiation and progression. The purpose of this study is to evaluate whether cancer stem cells play a functional role in the tumorigenesis of salivary gland tumors. 24 malignant, 24 benign salivary gland tumors, and seven normal salivary gland tissues were immunohistochemically stained for cancer stem cell markers ALDH1, CD44, CD24, and CD166. We scored the expressions of these proteins based on staining intensity and the ratio of positive cells. ALDH1 expression was down-regulated in malignant tumors (p = 0.034), while CD166 expression was upregulated (p = 0.002). CD44 and CD24 showed decreased expression in malignant tumors. Downregulation of ALDH expression by age also showed statistical significance (p = 0.007). ALDH1, CD166, CD44, and CD24 are potential stem cell markers for salivary gland tumors. Particularly CD166 and ALDH1 have a role in the pathogenesis and prognosis of these tumors. Loss of ALDH1 by aging may play an essential biological role in malignancy. The potential diagnostic role of ALDH1 and CD44 should be investigated.

In vivo efficacy of low-level laser therapy on bone regeneration.

PURPOSE: In clinical use of low-level laser therapy for bone regeneration (LLLT), application protocol (dose, duration, and repetitions) has not been established. This study aimed to depict a reliable dosage of LLLT by evaluating the efficacy of different dosing of LLLT (diode) on the healing of rabbit cranial defects. METHODS: Critical size defects were prepared in calvarias of 26 New Zealand White Rabbits in such each animal containing both test and control groups. Test groups were irradiated with 4 Joule/cm2 (j/cm2), 6 j/cm2, and 8 j/cm2. The rabbits were subjected to six times of laser treatments in 10 days. At the end of the second week, 5 rabbits were sacrificed for histopathological and immunohistochemical analyses. At the 4th and 8th weeks, 20 rabbits (10 each) were sacrificed for micro-CT and histopathological analyses. RESULTS: Micro-CT evaluation revealed improved new bone formation in all test groups compared to the control group. 6 j/cm2 group demonstrated the highest bone formation. The highest bone morphogenic protein -2 levels were found in the 4 j/cm2 group. Osteocalcin expression was significantly higher in 4 j/cm2 group. CONCLUSIONS: Our findings indicate that LLLT have a positive effect on new bone formation. The high efficacy of doses of 4 j/cm2 and 6 j/cm2 is promising to promote early bone healing.

De-epithelialized gingival graft versus subepithelial connective tissue graft in the treatment of multiple adjacent gingival recessions using the tunnel technique: 1-year results of a randomized clinical trial.

AIM: To compare the clinical efficacy and postoperative morbidity of de-epithelialized gingival graft (DGG) with subepithelial connective tissue graft (SCTG) on treatment of multiple adjacent gingival recessions (MAGRs) with tunnel technique (TUN) and to evaluate histological characteristics of the palatal grafts. MATERIALS AND METHODS: Twenty-seven patients with MAGRs affecting at least 2 adjacent teeth were treated with either DGG + TUN or SCTG + TUN. Recession depth(RD) and width(RW), probing depth(PD), clinical attachment level(CAL), keratinized tissue height(KTH), gingival thickness(GT), and complete and mean root coverage(CRC, MRC) were evaluated at 6 and 12 months postoperatively. Multilevel analysis was performed to identify patient- and tooth/site-related predictors for the 12-month MRC outcomes. Postoperative patient morbidity and histological characteristics of palatal graft samples obtained during harvesting were investigated. RESULTS: At the 12-month follow-up, MRC was 91.72% ± 16.59% and 84.72% ± 19.72% in DGG + TUN and SCTG + TUN groups (p = .001). Multilevel regression analysis identified RD, KTH and GT as variables associated with MRC. No significant difference between the groups was observed regarding postoperative patient morbidity parameters. Cellularity was found significantly higher in the SCTG samples compared to the DGG samples (p < .05). CONCLUSIONS: Although DGG + TUN presented higher MRC and CRC compared to SCTG + TUN in the treatment of MAGRs, treatment method was not a significant predictive factor for the amount of MRC outcomes while RD, KTH and GT were significant predictive factors.

Effects of Piezoelectric Surgery on Bone Regeneration Following Distraction Osteogenesis of Mandible.

The aim of this study is to compare the bone healing in the distraction gap following the osteotomy performed with piezoelectric and conventional devices for the distraction osteogenesis in the rabbit mandibles. Twelve rabbits were randomly divided into 2 groups; 6 for piezoelectric device and 6 for rotary instruments. After 3 days of latency period, distraction was started at a rate of 1 mm per day for 10 days. All the animals were sacrificed after 4 weeks of consolidation phase for histological and histomorphological evaluation. Histological evaluation revealed thick trabecular bone formation in all of the specimens. Inflammation scores were chronic minimal. The mean percentages of the bone area in distraction gap are 62% in group P and 57% in group R. However, the difference between 2 groups was not statistically significant (P > 0.05). Our results revealed a slight increase in bone formation in the distraction gap in piezo-osteotomy groups histologically though not statistically supported. However, there is still a need for more histological studies with larger sample sizes evaluating the bone structure following piezo-osteotomies.

Experimental Evaluation of the Effectiveness of Demineralized Bone Matrix and Collagenated Heterologous Bone Grafts Used Alone or in Combination with Platelet-Rich Fibrin on Bone Healing in Sinus Floor Augmentation.

PURPOSE: The aim of this study was an experimental evaluation of the effectiveness of demineralized bone matrix (DBM) and collagenated heterologous bone graft (CHBG) used alone or in combination with platelet-rich fibrin on bone healing in sinus floor augmentation procedures. MATERIALS AND METHODS: In this study, 36 New Zealand rabbits were used. The bilateral sinus elevation was performed, and 72 defects were obtained. The rabbit maxillary sinuses were divided into four groups according to the augmentation biomaterials obtained: demineralized bone matrix (Grafton DBM Putty, Osteotech; DBM group), DBM combined with platelet-rich fibrin (PRF; DBM + PRF group), collagenated heterologous bone graft (CHBG; Apatos Mix, OsteoBiol, Tecnoss; CHBG group), CHBG combined with PRF (CHBG + PRF group). All groups were sacrificed at 2, 4, and 8 weeks after surgery for histologic, histomorphometric, and immunohistochemical analyses. RESULTS: The inflammatory reaction was moderate to intense at the second week in all groups and declined from 2 to 8 weeks. New bone formation was started at the second week and increased from 2 to 8 weeks in all groups. There was no significant difference in bone formation between the experimental groups that used PRF mixed graft material and control groups that used only graft material. The percentage of new bone formation showed a significant difference in DBM groups and DBM + PRF groups compared with other groups. There were osteoclasts around all the bone graft materials used, but the percentage of residual graft particles was significantly higher in CHBG groups and CHBG + PRF groups at the eighth week. CONCLUSION: There is no beneficial effect of the application of PRF in combination with demineralized bone matrix or collagenated heterologous bone graft on bone formation in sinus floor augmentation. The results of this study showed that both collagenated heterologous bone graft and demineralized bone matrix have osteoconductive properties, but demineralized bone matrix showed more bone formation than collagenated heterologous bone graft.

Osteocalcin and osteonectin expression after double application of platelet-rich plasma in rabbits.

PURPOSE: Platelet-rich plasma (PRP) is a novel method for transferring autogenous growth factors to the wound area. The aim of this study was to evaluate the efficacy of double-application of PRP (DA-PRP) on bone healing in rabbit cranial defects by examining osteonectin (ON) and osteocalcin (OC) expression. MATERIALS AND METHODS: Twenty-eight rabbits, each with two surgically prepared calvarial bone defects, were included in this study and divided into six groups: The defects (N=56) were treated with either a single-application of PRP (SA-PRP) (n=10), a combination of SA-PRP and betatricalciumphosphate (SA-PRP+ß-TCP) (n=10), only DAPRP (n=8), both DA-PRP and beta-tricalciumphosphate (DA-PRP+ß-TCP) (n=8), only beta-tricalciumphosphate (ß-TCP) (n=10), or controls (n=10). The animals were sacrificed at 30th day postoperatively and samples were immunohistochemically examined for ON and OC expressions. RESULTS: It was determined that DA-PRP did not significantly improve the ON and OC percentages achieved by SA-PRP or the controls. The three groups treated with ß-TCP showed a higher percentage of ON than those treated without ß-TCP (p<0.05). The ß-TCP treated groups and SA-PRP group demonstrated higher OC percentage than DA-PRP and control groups (p<0.05). CONCLUSION: The present findings suggest that DAPRP did not have a significant effect on the healing of non-critical size rabbit cranial bone defects.

Oral mucosal lesions: a retrospective review of one institution's 13-year experience.

BACKGROUND/AIM: To investigate the relative frequency of biopsied nonneoplastic oral mucosal lesions in Ankara, Turkey. MATERIALS AND METHODS: Biopsy records of a single center from 2000-2012 were retrospectively collected. Diagnosis was recorded and evaluated with respect to patient demographics (age, sex) and location of the lesion. RESULTS: Of 11,980 biopsies, 1732 (14.5%) were mucosal nonneoplastic lesions. Hyperplastic lesions (n= 1000, 57.7%) with fibroepithelial hyperplasia in 30.9% of patients were the most common type of oral nonneoplastic lesions. The mean age of patients differed with respect to type of mucosal lesion, tending to be lower in patients with reactive lesions. Dermatoses showed a female predominance. CONCLUSION: Our ,findings revealed that hyperplastic lesions were the most common among nonneoplastic oral mucosa lesions. Geographic and ethnic.differences of patients with various types of oral mucosal lesions require further investigation.

Multiple calcifying hyperplastic dental follicles: A case report.

This report describes a 31-year-old female patient with six impacted teeth. The crowns of the impacted teeth were surrounded with cyst-like lesions with a mixed internal structure and well-defined cortical borders. Microscopic examination of the specimen obtained from the follicle of the left mandibular third molar tooth revealed loose to moderately dense collagenous connective tissue with abundant calcified material and sparse epithelial islands. A diagnosis of multiple calcifying hyperplastic dental follicles was made.

Prevalence of herpes simplex, Epstein Barr and human papilloma viruses in oral lichen planus.

OBJECTIVES: The aim of the present study was to assess the prevalence of Herpes Simplex virus, Epstein Barr virus and Human Papilloma virus -16 in oral lichen planus cases and to evaluate whether any clinical variant, histopathological or demographic feature correlates with these viruses. STUDY DESIGN: The study was conducted on 65 cases. Viruses were detected immunohistochemically. We evaluated the histopathological and demographic features and statistically analysed correlation of these features with Herpes Simplex virus, Epstein Barr virus and Human Papilloma virus-16 positivity. RESULTS: Herpes Simplex virus was positive in six (9%) cases and this was not statistically significant. The number of Epstein Barr virus positive cases was 23 (35%) and it was statistically significant. Human Papilloma virus positivity in 14 cases (21%) was statistically significant. Except basal cell degeneration in Herpes Simplex virus positive cases, we did not observe any significant correlation between virus positivity and demographic or histopathological features. However an increased risk of Epstein Barr virus and Human Papilloma virus infection was noted in oral lichen planus cases. CONCLUSIONS: Taking into account the oncogenic potential of both viruses, oral lichen planus cases should be detected for the presence of these viruses.

Oral focal epithelial hyperplasia: report of 3 cases with human papillomavirus DNA sequencing analysis.

Focal epithelial hyperplasia (FEH), or Heck's disease, is a benign proliferative viral infection of the oral mucosa that is related to Human Papil-lomavirus (HPV), mainly subtypes 13 and 32. Although this condition is known to exist in numerous populations and ethnic groups, the reported cases among Caucasians are relatively rare. It presents as asymptomatic papules or nodules on the oral mucosa, gingiva, tongue, and lips. Histopathologically, it is characterized by parakeratosis, epithelial hyperplasia, focal acanthosis, fusion, and horizontal outgrowth of epithelial ridges and the cells named mitozoids. The purpose of this case report was to present 3 cases of focal epithelial hyperplasia in a pediatric age group. Histopathological and clinical features of cases are discussed and DNA sequencing analysis is reported in which HPV 13, HPV 32, and HPV 11 genomes are detected.