A conservative approach for an adult patient with a fractured tooth and crowding: Autotransplantation at the fracture site.

Autotransplantation of a mature premolar in adults can be a treatment of choice for tooth replacement when combined with well-planned orthodontic treatment. This case report describes the successful treatment of a 39-year-old patient with severe crowding and a hopelessly fractured tooth on the maxillary left side. Maxillary dental crowding was relieved by extraction of a premolar on the right side, and this extracted tooth was autotransplanted to replace the fractured tooth. A mandibular incisor was extracted to correct anterior crossbite. The total treatment period was 20 months. The treatment results showed a good long-term prognosis after transplantation of a mature premolar with normal surrounding alveolar bone level for over 6 years of follow-up. Occlusion and periodontal health were excellent in the long term.

Identifying genetic variants underlying medication-induced osteonecrosis of the jaw in cancer and osteoporosis: a case control study.

BACKGROUND: Bisphosphonate-induced osteonecrosis of the jaw (BRONJ) presents with a typical pattern of jaw necrosis in patients who have been prescribed bisphosphonates (BPs) and other antiangiogenetic drugs to treat osteoporosis or bone-related complications of cancer. METHODS: This study divided 38 patients with BRONJ into two groups according to the prescribing causes: cancer (n = 13) and osteoporosis (n = 25), and underwent whole exome sequencing and compared them with normal controls (n = 90). To identify candidate genes and variants, we conducted three analyses: a traditional genetic model, gene-wise variant score burden, and rare-variant analysis methods. RESULTS: The stop-gain mutation (rs117889746) of the PZP gene in the BRONJ cancer group was significantly identified in the additive trend model analysis. In the cancer group, ARIDS, HEBP1, LTBP1, and PLVAP were identified as candidate genes. In the osteoporosis group, VEGFA, DFFA, and FAM193A genes showed a significant association. No significant genes were identified in the rare-variant analysis pipeline. Biologically accountable functions related to BRONJ occurrence-angiogenesis-related signaling (VEGFA and PLVAP genes), TGF-ß signaling (LTBP1 and PZP genes), heme toxicity (HEBP1) and osteoblast maturation (ARIDS)-were shown in candidate genes. CONCLUSION: This study showed that the candidate causative genes contributing to the development of BRONJ differ according to the BP dose and background disease.

Identification of N-(5-(phenoxymethyl)-1,3,4-thiadiazol-2-yl)acetamide derivatives as novel protein tyrosine phosphatase epsilon inhibitors exhibiting anti-osteoclastic activity.

Cytosolic protein tyrosine phosphatase epsilon (cyt-PTPε) plays a central role in controlling differentiation and function of osteoclasts, whose overactivation causes osteoporosis. Based on our previous study reporting a number of cyt-PTPε inhibitory chemical compounds, we carried out a further and extended analysis of our compounds to examine their effects on cyt-PTPε-mediated dephosphorylation and on osteoclast organization and differentiation. Among five compounds showing target selectivity to cyt-PTPε over three other phosphatases in vitro, two compounds exhibited an inhibitory effect against the dephosphorylation of cellular Src protein, the cyt-PTPε substrate. Moreover, these two compounds caused destabilization of the podosome structure that is necessary for the bone-resorbing activity of osteoclasts, and also attenuated cellular differentiation of monocytes into osteoclasts, without affecting cell viability. Therefore, these findings not only verified anti-osteoclastic effects of our cyt-PTPε inhibitory compounds, but also showed that cyt-PTPε expressed in osteoclasts could be a putative therapeutic target worth considering.

Distalization of the mandibular dentition with a ramal plate for skeletal Class III malocclusion correction.

The retromolar fossa is an anatomically suitable skeletal anchorage site. The aim of this report was to introduce a novel appliance for the correction of skeletal Class III malocclusions with mandibular dentition distalization. The placement site and the procedure of the ramal plate are described. The resulting force vectors are parallel to the functional occlusal plane leading to efficient molar distalization. This approach is demonstrated with 2 adult patients who refused a surgical treatment option. This ramal plate may be indicated for total arch distalization for nonextraction and nonsurgical cases.

The effects of tetracycline-loaded silk fibroin membrane on proliferation and osteogenic potential of mesenchymal stem cells.

BACKGROUND: The main objective of this study was to investigate the effect of tetracycline-loaded silk fibroin membranes (TC-SFMs) on the proliferation and the osteogenic differentiation of human mesenchymal stem cells. MATERIALS AND METHODS: Four groups (0, 1, 5, and 10% concentration) of TC-SFMs were prepared for the experiments. We investigated cumulative tetracycline (TC) release profile for 7 d. Human gingiva-derived mesenchymal stem cells (GMSCs) were isolated from our previous study and seeded to the TC-SFMs. WST-8 assay (Cell Counting Kit-8; SigmaeAldrich Co, St. Louis, MO), staining of Phalloidin-FITC, and scanning electron microscope analyzed the cellular attachment and viability. Staining of Alizarin Red S (Sigma-Aldrich Co.) and osteogenic marker (osteocalcin) analyzed osteogenic differentiation. Additionally, quantitative polymerase chain reaction measured the expression of osteogenic lineage genes, including bone gamma-carboxyglutamic acid protein, bone sialoprotein, runt-related transcription factor 2, and collagen type I α1 according to TC concentration (0.05, 0.1, 0.25, and 0.5 mg/mL). RESULTS: The release of TC from TC-SFMs plateaued and neared completion in 24 h. Significantly higher viability was noted achieved in 1% and 5% TC-SFMs. The morphology of GMSCs on TC-SFMs at 0% and 1% concentration showed spindle shapes, but cells in 10% TC-SFMs appeared spheroid. During Alizarin Red S staining at 21 d of osteogenic differentiation, calcium and osteocalcin formation were significantly lower in the 10% TC-SFM group than in the 0, 1, and 5 groups. Compared with the control group, bone gamma-carboxyglutamic acid protein showed significantly low expression rate at TC concentration ≥0.05 mg/mL. Bone sialoprotein was low at TC concentration ≥0.1 mg/mL. Likewise, runt-related transcription factor 2 and collagen type I α1 were low at TC concentration of 0.5 mg/mL. CONCLUSIONS: Within the limits of this study, 1% and 5% TC-SFMs showed higher proliferation and osteogenic potential of GMSCs than 10% TC-SFM. Therefore, the use of 1% to 5% range of TC may be more suitable to silk fibroin membrane for stem cell tissue engineering.

Identification of 3-acyl-2-phenylamino-1,4-dihydroquinolin-4-one derivatives as inhibitors of the phosphatase SerB653 in Porphyromonas gingivalis, implicated in periodontitis.

The serine phosphatase SerB653 plays a crucial role in the infection of Porphyromonas gingivalis, which contributes to the pathogenesis of periodontitis, an inflammatory disease of teeth-supporting tissues. Because functional loss of SerB653 eliminates the virulence of P. gingivalis, SerB653 inhibitors are considered potential periodontitis therapeutic or preventive agents. To identify SerB653 inhibitors with potent anti-periodontitis activity, we conducted a high-throughput screen of a representative 6800-compound subset of a synthetic chemical library of the Korea Chemical Bank (KCB) for compounds with activity against SerB653. The primary screening yielded 150 hits, and subsequent confirmatory studies identified eight compounds, mainly within a single cluster of 3-acyl-2-phenylamino-1,4-dihydroquinolin-4-one derivatives, that showed greater than 50% inhibition of SerB653 activity at a concentration of 50µM. A second screening with a focused library identified 10 compounds with IC(50) values less than 10µM. In antibacterial tests, three of these compounds showed a minimum inhibitory concentration against P. gingivalis growth of 5-50nM.

Expression of E-cadherin, P-cadherin and N-cadherin in oral squamous cell carcinoma: correlation with the clinicopathologic features and patient outcome.

PURPOSE: Alteration of cadherin expression is associated with the loss of cellular differentiation, the acquisition of an invasive phenotype and a poor prognosis in many types of cancer. This study aimed to evaluate the immunoreactivity of E-, P- and N-cadherins (cad) in oral squamous cell carcinoma and to correlate their expression with clinicopathological features and clinical outcome. The interaction between the cadherins was also investigated. METHODS: A total of 71 tissue samples were examined by immunohistochemical methods on paraffin sections using specific antibodies. RESULTS: In the primary lesions and lymph node metastases, the immunoreactivity of E-cad was reduced and P-cad was over-expressed, but the expression of N-cad was negative (p<0.001, 0.01 and 0.05, respectively). The reduced primary E-cad expression was related to the invasion pattern and lymph node metastasis (p=0.046 and 0.037, respectively). However, the expression of cadherins did not appear to differ significantly in relation to the histological grade, invasion, tumour size, stage of oral SCC or tumour recurrence. A much greater reduction in the expression of E-cad was found in the positive N-cadherin group (p=0.008). Nonetheless, cadherin expression was not significantly associated with failure-free survival or overall survival in this experiment subset. CONCLUSION: The reduced E-cad expression and the aberrant N-cad expression are closely associated with each other in oral cancer cases, and this suggests that cadherin switching from E. cad to N. cad may play a critical role in cancer development and metastasis.

Treatment effects of mandibular total arch distalization using a ramal plate.

OBJECTIVE: The purpose of this study was to evaluate treatment effects after distalization of the mandibular dentition using ramal plates through lateral cephalograms. METHODS: Pre- and post-treatment lateral cephalograms and dental casts of 22 adult patients (11 males and 11 females; mean age, 23.9 ± 5.52 years) who received ramal plates for mandibular molar distalization were analyzed. The treatment effects and amount of distalization of the mandibular molars were calculated and tested for statistical significance. The significance level was set at p < 0.001. RESULTS: The mandibular first molar distalization at the crown and root were 2.10 mm (p < 0.001) and 0.81 mm (p = 0.011), respectively. In the evaluation of skeletal variables, there was a significant increase in the Wits appraisal (p < 0.001). In the evaluation of the soft tissue, there was no significant effect on upper lip position, but the lower lips showed a significant retraction of 2.2 mm (p < 0.001). CONCLUSIONS: The mandibular molars showed a significant amount of distalization accompanied by limited extrusion and mesiobuccal rotation of the crowns. A ramal plate may be a viable device for mandibular total arch distalization in Class III patients who are reluctant to undergo orthognathic surgery.

Comparative effects of chlorhexidine and essential oils containing mouth rinse on stem cells cultured on a titanium surface.

Chlorhexidine (CHX) and Listerine (LIS), an essential oil compound, are the two commonly used adjunctive agents for mechanical debridement, for reducing the bacterial load in the treatment of peri-implant inflammation. However, antimicrobial agents have been reported to be cytotoxic to the alveolar bone cells and gingival epithelial cells. The present study was performed to examine the effects of antiseptics CHX and LIS, on the morphology and proliferation of stem cells. Stem cells derived from the buccal fat pad were grown on machined titanium discs. Each disc was immersed in CHX or LIS for 30 sec, 1.5 min or 4.5 min. Cell morphology was evaluated with a confocal laser microscope and the viability of the cells was quantitatively analyzed with the cell counting kit-8 (CCK-8). The untreated cells attached to the titanium discs demonstrated well-organized actin cytoskeletons. No marked alterations in the cytoskeletal organization were observed in any of the treated groups. The treatment with CHX and LIS of the titanium discs decreased the viability of the cells grown on the treated discs (P<0.05). The stem cells derived from the buccal fat pad were sensitive to CHX and LIS, and a reduction in cellular viability was observed when these agents were applied to the discs for 30 sec. Further studies are required to determine the optimal application time and concentration of this antimicrobial agent for maximizing the reduction of the bacterial load and minimizing the cytotoxicity to the surrounding cells.