Pneumomediastinum and subcutaneous emphysema secondary to dental extraction: Two case reports.

BACKGROUND: Dental extraction is a common operation in oral surgery and is usually accompanied by pain, swelling, and local infection. The application of high-speed air turbines increases the comfort of alveolar surgery and makes it more minimally-invasive. However, high-speed gas can enter the subcutaneous tissue of the face and neck or even the chest and mediastinum, which is a serious iatrogenic complication. CASE SUMMARY: We describe two cases of severe subcutaneous and mediastinal emphysema caused by high-speed turbine splitting during dental extraction. The first case involved a 34-year-old man who complained of swelling of the face, mild chest tightness, and chest pain after dental extraction. Computed tomography (CT) scan showed a large amount of gas in the neck, chest wall, and mediastinum. The second case involved a 54-year-old woman who complained of swelling and pain of the neck after dental extraction. CT showed a large amount of gas collected in the neck and mediastinum. Both of them used high-speed turbine splitting during dental extraction. CONCLUSION: High-speed turbine splitting during dental extraction may lead to severe subcutaneous and mediastinal emphysema. Dentists should carefully operate to avoid emphysema. If emphysema occurs, CT can be used to improve the diagnosis. The patient should be informed, and the complications dealt with carefully.

Clinical and histological evaluations of the effects of concentrated growth factor combined with deproteinated bovine bone mineral in site preservation / 口腔疾病防治

Objective@#To evaluate the osteogenic effect of concentrated growth factor (CGF) combined with deproteinated bovine bone mineral (DBBM) in site preservation using clinical and histomorphometric observations.@*Methods @#A total of 26 patients who needed extraction of affected teeth and received staged implantation after site preservation were selected. The patients were randomly divided into the DBBM group (Bio-Oss was implanted simultaneously after extraction) and CGF+DBBM group (CGF+Bio-Oss was implanted simultaneously after extraction), with 13 patients in each group, and both groups were covered with Bio-Gide collagen membrane. Cone beam computed tomography (CBCT) was performed preoperatively and 6 months later to measure the changes in alveolar bone height and width, and the bone specimens were drilled 6 months after site preservation during implant surgery for histological analyses.@*Results@# CBCT showed that the height and width of alveolar bone were absorbed 6 months after site preservation in the CGF+DBBM and DBBM groups, and the reduction in alveolar ridge width in the CGF+DBBM group was statistically less than the DBBM group (P <0.05). The histomorphometry results showed that the percentage of new bone in the CGF+DBBM and DBBM groups were 35.30% ± 3.56% and 26.38% ± 5.04%, respectively, and the amount of new bone in the CGF+DBBM group was statistically higher than the DBBM group (P<0.05). @*Conclusion @#CGF combined with DBBM is superior to DBBM in maintaining the alveolar bone volume and shape in site preservation, which creates favorable conditions for implant restoration.

Horizontal bone augmentation and simultaneous implant placement using xenogeneic bone rings technique: a retrospective clinical study.

This study evaluated the use of bone ring technique with xenogeneic bone grafts in treating horizontal alveolar bone defects. In total, 11 patients in need of horizontal bone augmentation treatment before implant placement were included in this retrospective study. All patients received simultaneous bone augmentation surgery and implant placement with xenogeneic bone ring grafts. We evaluated the postoperative efficacy of the bone ring technique with xenogeneic bone grafts using radiographical and clinical parameters. Survival rates of implants were 100%. Cone-beam computed tomography revealed that the xenogeneic bone ring graft had significantly sufficient horizontal bone augmentation below the implant neck platform to 0 mm, 1 mm, 2 mm, and 3 mm. It could also provide an excellent peri-implant tissue condition during the 1-year follow-up after loading. The bone ring technique with xenogeneic bone ring graft could increase and maintain horizontal bone mass in the region of the implant neck platforms in serious horizontal bone defects.

The TGF-ß1/COX-2-dependant pathway serves a key role in the generation of OKC-induced M2-polarized macrophage-like cells and angiogenesis.

An odontogenic keratocyst (OKC) is a common oral cyst arising from the odontogenic epithelium, which has the characteristics of a tumor. Previous studies have demonstrated that M2-polarized macrophages and angiogenesis have important roles in the progression of OKCs. As transforming growth factor (TGF)-ß1 is important in growth and developmental processes, and early studies have indicated that TGF-ß1 is upregulated in OKCs, the present study aimed to investigate the expression levels of TGF-ß1 as a first step. Flow cytometric analysis suggested that TGF-ß1 induced M2-polarization of macrophages in a dose-dependent manner. Expression levels of cyclooxygenase (COX)-1 and -2 were measured after treatment of M2 macrophages with TGF-ß1 and OKC homogenate supernatant. COX-2 expression was influenced by TGF-ß1 in a concentration-dependent manner and in OKC induction. In addition, inhibition of COX-2 resulted in the induction of M2-polarization of macrophages via TGF-ß1 and OKC disruption. Because the extracellular matrix (ECM) is altered in individuals with chronic diseases, the present study analyzed the expression of matrix metalloproteinase (MMP)-9, which is able to degrade the ECM. The present study observed a decrease in MMP-9 activity following treatment with TGF-ß1 and OKC homogenate supernatant. Additionally, the present study analyzed tube formation caused by OKC with or without a COX-2 inhibitor. The results of the present study suggested that angiogenesis increased following treatment with OKC homogenate supernatant but decreased after treatment with a COX-2 inhibitor. These findings indicated that the TGF-ß1/COX-2 pathway may have an important role in the progression of OKC.

Photodynamic therapy versus systemic antibiotic for the treatment of periodontitis in a rat model.

BACKGROUND: To compare the therapeutic effect of photodynamic therapy (PDT) with Toluidine blue O hydrogel versus systemic antibiotic (SA) in treating periodontitis on rats. METHODS: Thirty-two Wistar rats were divided into four groups and treated differently: Negative control (NC) group, normal rats; positive control (PC) group, rats with periodontitis; SA group, rats with periodontitis treated with systemic antibiotic; PDT group, rats with periodontitis treated with PDT. After treatment, gingival sulcus bacterial load was measured by counting the colony forming units per milliliter (CFU mL-1 ). The tooth and periodontal tissues were histologically processed to analyze histological and immunohistochemical profile. Gingival samples were obtained to quantify interleukin-1 beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) levels. RESULTS: Gingival sulcus bacteria load is significantly lower in PDT group compared with the SA group. The histological analysis showed that some extremely effective repair signs of periodontal tissue were presented in PDT group, such as no periodontal pocket, no bone resorption, few inflammatory cells, massive fibroblasts and collagen fibers. Several effective repair signs of periodontal tissue were also observed in SA group, such as shallow periodontal pocket, small amount of inflammatory cells, substantial fibroblasts and collagen fibers. There were lower cyclooxygenase-2, matrix metalloproteinase -8 (MMP-8) and RANK immunolabeling, higher osteoprotegerin immunolabeling in PDT group compared with SA group. The IL-1ß and TNF-α levels in PDT group were lower than those in NC group, but higher than those in SA group. CONCLUSION: PDT was effective to treat experimental periodontitis and was superior to systemic metronidazole as a treatment for periodontitis.