Methylation and Expression Status of <i>SOCS</i>1 and <i>SOCS</i>3 in Oral Lichen Planus

Oral lichen planus (OLP) is a disease of unknown etiology affecting oral mucosa by mediated chronic inflammation and is classified as a potentially malignant oral disorder. SOCS1 and SOCS3 in the SOCS family have been identified as negative regulators of the cytokine-activated JAK/STAT pathway responsible for inflammatory reaction. The DNA methylation in the promoter regions of SOCS1 and SOCS3 have been reported to correlate with carcinogenesis. In this study, we performed methylation-specific PCR (MSP) to investigate the methylation status of the promoter regions in SOCS1 and SOCS3 genes using biopsy samples from OLP and oral squamous cell carcinoma (OSCC) patients. SOCS1 was methylated in 14/29 (48.3%) cases with OLP and 7/15 (46.7%) cases with OSCC. At the same time, SOCS3 was methylated in 25/29 (86.2%) cases with OLP and 11/15 (73.3%) cases with OSCC. We didn’t recognize any DNA methylation in SOCS1 or SOCS3 genes from the exfoliated cytological specimens of normal buccal mucosa. Furthermore, mRNA expression level was analyzed using real-time RT-PCR method to evaluate the correlation with DNA methylation status. DNA methylation status of SOCS1 seemed not to affect the expression level of SOCS1 mRNA. At the same time, DNA methylation status of SOCS3 was negatively correlated with the expression level of SOCS3 mRNA (p < 0.05). We posit frequent methylation of the SOCS3 gene promoter, theoretically resulting in the increase of cytokines expression, might be associated with the etiological mechanism of OLP.

Successful surgical extraction of an impacted mandibular third molar in a patient treated with head & neck radiotherapy and chemotherapy for oral cancer

Osteoradionecrosis(ORN),a pathological condition characterized by a nonvital bone occurring in the site of radiation injury,is one of the significant risks following extraction of highly impacted third molar teeth in patients treated with head&neck radiotherapy for oral cancer.Therefore,the surgery’s meticulous planning is essential to avoid such complications.This case report describes a 63-year-old male patient diagnosed with an impacted lower third molar(tooth#38)with concurrent basal cell carcinoma of the right ear and squamous cell carcinoma of the right vocal cord treated with radiotherapy.Taking into account the patient’s health status,a minimally invasive osteotomy and a corono-radicular separation procedure were performed.This procedure allowed us to reduce the risk of mandibular ORN.Three years later,the healing was complete,and the situation was stable.

Functional and molecular mechanism of intracellular pH regulation in human inducible pluripotent stem cells

AIM To establish a functional and molecular model of the intracellular pH(pH_i) regulatory mechanism in human induced pluripotent stem cells(hiPSCs).METHODS hiP SCs(HPS0077) were kindly provided by Dr. Dai from the Tri-Service General Hospital(IRB No. B-106-09). Changes in the pH_i were detected either by microspectrofluorimetry or by a multimode reader with a pH-sensitive fluorescent probe, BCECF, and the fluorescent ratio was calibrated by the high K^+/nigericin method. NH_4Cl and Na-acetate prepulse techniques were used to induce rapid intracellular acidosis and alkalization, respectively. The buffering power(β) was calculated from the ΔpH_i induced by perfusing different concentrations of(NH_4)_2SO_4. Western blot techniques and immunocytochemistry staining were used to detect the protein expression of pH_i regulators and pluripotency markers.RESULTS In this study, our results indicated that(1) the steadystate pH_i value was found to be 7.5 ± 0.01(n = 20) and 7.68 ± 0.01(n =20) in HEPES and 5% CO_2/HCO_3^- buffered systems, respectively, which were much greater than that in normal adult cells(7.2);(2) in a CO_2/HCO_3^--buffered system, the values of total intracellular buffering power(β) can be described by the following equation: β_(tot) = 107.79(pH_i)~2-1522.2(pH_i) + 5396.9(correlation coefficient R^2 = 0.85), in the estimated pH_i range of 7.1- 8.0;(3) the Na^+/H^+ exchanger(NHE) and the Na^+/HCO_3^- cotransporter(NBC) were found to be functionally activated for acid extrusion for pHi values less than 7.5 and 7.68, respectively;(4) V-ATPase and some other unknown Na^+-independent acid extruder(s) could only be functionally detected for pHi values less than 7.1;(5) the Cl^-/OH^- exchanger(CHE) and the Cl^- /HCO_3 anion exchanger(AE) were found to be responsible for the weakening of intracellular proton loading;(6) besides the CHE and the AE, a Cl^--independent acid loading mechanism was functionally identified; and(7) in hiPSCs, a strong positive correlation was observed between the loss of pluripotency and the weakening of the intracellular acid extrusion mechanism, which included a decrease in the steady-state pH i value and diminished the functional activity and protein expression of the NHE and the NBC.CONCLUSION For the first time, we established a functional and molecular model of a pHi regulatory mechanism and demonstrated its strong positive correlation with hiPSC pluripotency.

Electron Probe Microanalysis of Exogenous Pigmentation of Oral Mucosa Originating from Dental Alloy: Two Case Reports

Pigmentation of the oral mucosa is relatively common and has a wide variety of etiologies. Although most pigmented lesions of the oral mucosa are associated with deposition of melanin and accidental displacement of a dental alloy, accurate differential diagnosis of a pigmented lesion is important, especially in the case of malignant melanoma. We report two cases of oral mucosal pigmentation associated with accidental displacement of a dental alloy in which malignant melanoma was suspected. Excisional biopsy was carried out in these cases with the incision line set at approximately 5 mm from the lesions. Histopathologically, brownish foreign substances were observed in the lamina propria. Metal quantitative analyses of the extracted specimens were carried out by electron probe microanalysis (EPMA). The metal components and the mass concentration revealed that the metals were derived from a dental casting silver alloy in Case 1 and from a gold-silver palladium alloy in Case 2. Although exogenous pigmentation originating from a dental alloy is not rare, differential diagnosis of oral pigmented lesions is sometimes very difficult. In such cases, histopathological examination may be necessary for the diagnosis to exclude melanocytic lesions and EPMA may be effective to identify the causative dental alloy.

A Case of Giant Epidermoid Cyst in the Floor of the Mouth That Caused Severe Obstructive Sleep Apnea Syndrome

We describe here, a case with a giant epidermoid cyst in the floor of the mouth that caused severe obstructive sleep apnea syndrome (OSAS). A 37-year-old man was referred to our clinic because of a swelling in the floor of his mouth and sleep apnea syndrome. The occurrence of breathing disorders and daytime drowsiness was monitored to evaluate his OSAS 1 day before and 7 days after surgery. Before surgery, the apnea-hyponea index (AHI) and Epworth Sleepiness Scale (ESS) were 45.7 and 22, respectively. The clinical diagnosis was a dermoid or an epidermoid cyst that caused severe OSAS. Under general anesthesia, the patient underwent intraoral surgical removal of the cyst, along with aspiration to reduce the mass. After surgery, his sleep apnea syndrome was significantly improved. The postoperative AHI and ESS were 5.5 and 7, respectively. As of 2 years after the operation, there was no evidence of recurrence.

An Experimental Study on the Effects of Platelet Rich Plasma on the Wound Healing of Tooth Extraction-Related Bone Defects

Platelet-rich plasma (PRP) has been used as a therapeutic tool to promote wound healing, in orthopedics, dermatology, oral surgery, etc. However, the mechanisms underlying the wound healing effects of PRP remain unclear. The purpose of this study was to evaluate the effectiveness of applying PRP, particularly in the management of tooth extraction sockets. Three upper molars of Fischer rats were extracted, and blood was drawn from the hearts of other rats to prepare PRP. The PRP was activated and applied to the bone defects of the experimental group, and nothing was applied to the bone defects of the control group. On day 3, fibrin network and granulation tissue, which are abundant in blood capillaries, were seen under the PRP layer in the experimental group. On the other hand, only inflammatory cells and a fibrin network were observed in the bone defects of the control group. On day 7, granulation tissue was seen in the bone defects in both the control group and experimental group, although excavation of granulation tissue was noted in the control group. The results demonstrated the presence of a rich fibrin network and early inflammatory reactions in the experimental group, which may lead to rise of thick, vessel-rich granulation tissue. The application of PRP may stimulate wound healing in tooth extraction bone defects, and PRP may confer some beneficial effects on the outcomes.

Survival of dental implants in patients with bone dysplasia:A systematic review

Objective:This study used published studies to assess the survival rate of dental implants placed in patients with bone dysplasia of the maxillofacial region.Material and methods:An electronic search without a specified date range was performed using the MEDLINE,PubMed,EMBASE,Web of Science,and Cochrane databases.No gender or age restrictions were applied.Results:Eighteen publications were found that met the study’s criteria,reporting data on 18 patients with bone dysplasia including cleidocranial dysplasia(CDD),fibrous dysplasia(FD),florid cemento-osseous dysplasia(FCOD),and odonto-maxillary segmental dysplasia(SOMD),who received a total of 130 implants,an average of 7.2 implants/patient(range 1 to 16).The mean age of the patients was 36.7 years(range 15 to 70 years).For implants placed in bone dysplasia,the survival rates were 100% for patients with CDD(n=8),FD(n=5),SOMD(n=2),FCOD with implants inserted far from the lesions(n=2)and 0% for dental implants inserted within FCOD(n=1).The mean follow-up was 38.2 months(min 6,max 60).Conclusions:Dental implants placed in patients with dysplastic bone lesions show high survival rates,similar to those in the general population for CDD,FD,and SOMD.For FCOD,the failure rate was 100%.

Advanced Hydrogel systems for mandibular reconstruction

Mandibular defect becomes a prevalent maxillofacial disease resulting in mandibular dysfunctions and huge psychological burdens to the patients.Considering the routine presence of oral contaminations and aesthetic restoration of facial structures,the current clinical treatments are however limited,incapable to reconstruct the structural integrity and regeneration,spurring the need for cost-effective mandibular tissue engineering.Hydrogel systems possess great merit for mandibular reconstruction with precise involvement of cells and bioactive factors.In this review,current clinical treatments and distinct mode(s)of mandible formation and pathological resorption are summarized,followed by a review of hydrogel-related mandibular tissue engineering,and an update on the advanced fabrication of hydrogels with improved mechanical property,antibacterial ability,injectable form,and 3D bioprinted hydrogel constructs.The exploration of advanced hydrogel systems will lay down a solid foundation for a bright future with more biocompatible,effective,and personalized treatment in mandibular reconstruction.

Collagen membrane functionalized with magnesium oxide via room-temperature atomic layer deposition promotes osteopromotive and antimicrobial properties

Artificial bone grafting materials such as collagen are gaining interest due to the ease of production and implantation.However,collagen must be supplemented with additional coating materials for improved osteointegration.Here,we report room-temperature atomic layer deposition(ALD)of MgO,a novel method to coat collagen membranes with MgO.Characterization techniques such as X-ray photoelectron spectroscopy,Raman spectroscopy,and electron beam dispersion mapping confirm the chemical nature of the film.Scanning electron and atomic force microscopies show the surface topography and morphology of the collagen fibers were not altered during the ALD of MgO.Slow release of magnesium ions promotes bone growth,and we show the deposited MgO film leaches trace amounts of Mg when incubated in phosphate-buffered saline at 37◦C.The coated collagen membrane had a superhydrophilic surface immediately after the deposition of MgO.The film was not toxic to human cells and demonstrated antibacterial properties against bacterial biofilms.Furthermore,in vivo studies performed on calvaria rats showed MgO-coated membranes(200 and 500 ALD)elicit a higher inflammatory response,leading to an increase in angiogenesis and a greater bone formation,mainly for Col-MgO500,compared to uncoated collagen.Based on the characterization of the MgO film and in vitro and in vivo data,the MgO-coated collagen membranes are excellent candidates for guided bone regeneration.

下颌骨骨折的固定处理

颌间结扎、外固定和外科夹板曾是治疗下颌骨骨折的常用技术。自从使用开放复位、坚强内固定以来，我们对下颌骨骨折治疗效果的预测能力明显提高了。手术器械的改进使骨折复位手术可以从口内或通过内镜入路，术后的美学效果令患者更加满意。目前多数下颌骨骨折采用口内入路进行开放复位和骨折内固定治疗。准确的解剖复位避免了术后的颌间固定，患者恢复口腔功能的时间可缩短，合并的髁突损伤可及时恢复，减轻了患者的痛苦。

Autologous bone graft harvested during implant site preparation: histological study

Aim:The bone particles harvested during osteotomy could be used as autogenous bone graft materials to correct a bony defect prior to implant placement.Methods:A simple surgical procedure was described in which autogenous bone was harvested from the drills during the preparation of implant sites.Eleven samples were obtained from bone drilling duringfixture installation in 11 patients(5 men and 6 women)with an average age of 57 years.These samples were subjected to histological preparation,in order to evaluate for the presence of viable osteoblasts.Results:Histological evaluation of the samples suggested that the viability of the bone tissue was maintained.Conclusion:The results show that this method of harvesting autogenous bone may be useful in situations where small amounts of bone are required.