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OBJECTIVE: This prospective study was performed to evaluate whether the distal-triangular flap was a practical alternative surgical approach for extracting mandibular third molars. METHODS: Sixty participants with impacted mandibular third molars were randomly divided into three groups: group A, distal-triangular flap; group B, Szmyd flap; and group C, envelope flap. The impacted third molars were extracted by the corresponding flapping method. During a three-month follow-up observation after the extraction, the postoperative pain, swelling, mouth opening, and periodontal status were recorded and analyzed by ANOVA and chi-square tests. RESULTS: The 60 participants had successful extraction and 3-month follow-up observation. No participant suffered from postoperative infections, lower lip disorder, or tongue sensory disorders. No statistical differences were found in the postoperative symptoms and signs of the three flap designs, such as postoperative pain, swelling, mouth opening, and periodontal status (P>0.05). CONCLUSION: The distal-triangular flap was as safe and reliable as the Szmyd and envelope flaps but more advantageous because of its convenient operative field exposure and low requirement for the patient's mouth opening. Thus, the distal-triangular flap is one of the alternative flap options for extracting impacted mandibular third molars.

OBJECTIVE: The present study aimed to explore the innervation of the anterior hard palatine and its relationship with individual development stage. Specifically, the effects of anesthesia on patients of different ages were observed, and neurodevelopment in the maxillofacial region was invesitgated. References that are helpful in selecting local anesthesia were provided. METHODS: A total of 182 patients with mixed dentition were randomly divided into the nasopalatine nerve block and greater palatine nerve block groups. Then, 219 patients with permanent dentition were divided into an adolescent group (13–18 years old) and adult group (over 19 years old), all of whom underwent bilateral greater palatine nerve block. Palatal mucosal pain sensation was tested pre- and post-anesthesia with Von Frey hairs. RESULTS: Among the children with mixed dentition, bilateral greater palatine nerve block tended to result in better anesthetic effects than nasopalatine nerve block (P0.05). The bilateral greater palatine nerve block was more effective in inducing an anesthestic effect in the anterior hard palatine in mixed dentition than in permanent dentition (over 13 years old; P

This study aimed to investigate the prognosis of permanent teeth with external root resorption (ERR) caused by adjacent impacted teeth.A total of 75 ERR teeth (permanent teeth) caused by adjacent impacted teeth of 63 patients were included. The prognosis of ERR teeth was analyzed followed by minimally invasive extraction of the adjacent impacted teeth. The time of follow-up was six months. The relationship between prognosis of ERR teeth and patients' age, gender, root number, type of root resorption and degree of root resorption were analyzed.In the 75 ERR teeth, 67 teeth (89.3%) did not show pulpitis symptoms. The clinical outcome was found to be related with age (r=0.330, P0.05), whereas no relationships with gender, root number, as well as type and degree of root resorption were observed (P0.05). Pulpitis symptom was not found in ERR teeth of patients under 30 years old.For ERR teeth caused by adjacent impacted teeth, keeping the pulp vital after surgical removal of impacted teeth is highly probable. Post-operative follow-up instead of preventive root canal therapy of ERR teeth is recommended.目的 探讨埋伏阻生牙导致邻牙（恒牙）牙根外吸收（ERR）时，阻生牙拔除术后邻牙的预后。方法 以埋伏阻生牙导致邻牙（恒牙）ERR但可以正常行使功能的63例患者的75颗ERR邻牙作为研究对象，微创拔除埋伏阻生牙后，术后随访6月，观察ERR邻牙的预后情况，并分析预后与患者年龄、性别、牙根数量、牙根吸收类型、牙根吸收程度的关系。结果 在75颗ERR邻牙中，67颗（89.3%）为无症状活髓牙。ERR邻牙的预后与患者的年龄相关（r=0.330，P0.05），年龄低于30岁者ERR邻牙均保持了无症状活髓。ERR邻牙的预后与性别、牙根数量、牙根吸收类型、牙根吸收程度无相关性（P0.05）。结论 对于因相邻埋伏阻生牙导致的牙根外吸收而无临床症状的恒牙，有较大概率在阻生牙拔除术后保存活髓，建议密切随访观察，不必行预防性根管治疗。.

This article provides an overview of metastases to jaws (MJ), mainly concerning the differences between American and Chinese patients, and exploring the relationship between the primary tumors' prevalence (PTP) and constituent ratio of MJ. Information concerning of 399 MJ cases in 215 papers, including one new case in our hospital, was subjected to statistic analysis. The main clinical features of MJ, such as constituent ratio of PTP and that of MJ, metastatic sites, treatments, and prognosis were summarized. Breast, lung, kidney, prostate and thyroid (in descending order) were the leading primary sites of MJ. Furthermore, the constituent ratio of MJ was found to be correlated with that of PTP in all subjects including American and Chinese subjects in our study. As to metastatic sites in the mandible, a specific “M” shaped pattern appeared regardless of the tumor type or constituent ratios of MJ were in all subjects. Almost all subjects received traditionally palliative treatments, and the prognosis was quite poor. The PTP had a significant impact on the constituent ratio of MJ. However, it was the properties of the microenvironment rather than characteristics or constituent ratios of tumor cells, that decided the metastatic sites in various tumor subjects.

Objective The purpose of this study was to investigate the expression of Twist in salivary adenoid cystic carcinoma (SACC) and the relations between Twist expression and the clinicopathological characteristics.

To explore the effects of peer-assisted learning (PAL) for evidence-based dentistry (EBD) teaching.Four hundred and eleven students who attended EBD class were randomly classified into PAL group (n=75) and traditional teaching group (n=326) via a ratio of 1:5. Students in traditional teaching group received traditional theoretical teaching; while PAL group received traditional theoretical teaching and group study with tutors introduced and finished study protocols given by the teachers. Teaching effects were evaluated by final examinations, questionnaires and published articles via bibliographic searching. Statistical analysis was carried out with STATA 11.0 software package.In the final examination, students in PAL group had 6.9 higher scores than traditional teaching group (P0.05). The results of questionnaires showed that students in PAL group had higher interests and contentments in EBD class (P0.05), and PAL had positive effects on their usage of EBD methodology and involvement in EBD research (P0.05). In publication of articles, the number and ratios of article publication in PAL group were significantly higher than the traditional group (P0.05).PAL has positive effects on EBD teaching.

Vascularization is thought to be a principle obstacle in the reconstruction of skeletal muscle defects. Long-term survival of reconstructed skeletal muscle is dependent on good vascularization. In this study, we upregulated angiogenic gene expression in myoblasts in an attempt to promote vascularization during repair of skeletal muscle defects. Skeletal myoblasts were isolated and expanded from newborn male Sprague-Dawley (SD) rats. The cells were transfected with human vascular endothelial growth factor 165 (VEGF-165) or human stromal cell-derived factor 1 (SDF-1), using Lipofectamine™ 2000 transfection reagent, prior to seeding onto calf collagen scaffolds. Gene and protein overexpression was verified by ELISA, RT-PCR and western blot analysis. Cell-seeded scaffolds were transplanted into back muscle defects in female SD rats. At weeks 2, 4 and 8 after transplantation, Y chromosome detection was used to observe the survival of growth factor-producing cells within the scaffolds in vivo. Capillary density was investigated using microvessel density detection, haematoxylin and eosin (HE) staining and immunohistochemical staining. We found that vascularization was enhanced by transfected myoblasts compared with non-transfected myoblasts. In addition, VEGF-165 and SDF-1 had a synergistic effect on vascularization during repair of skeletal muscle defects in vivo. In conclusion, we have combined myoblast-seeded collagen sponge with gene therapy, resulting in a promising approach for the construction of well-vascularized skeletal muscle.

Mesenchymal stem cells (MSCs) have the potential for differentiating into vascular endothelial cells. Stromal cell-derived factor-1α (SDF-1α) plays an important role in neovascularization of ischemic flaps. The authors evaluated the feasibility of applying MSCs transduced by SDF-1α gene to the treatment of early and partial ischemic free flaps survival. MSCs were isolated from Lewis rats and cultured in vitro. Recombinant adenovirus encoding SDF-1α gene (Ad-SDF-1α) was transduced into the MSCs. Lewis rats that underwent epigastric free flaps based on medial and lateral branches of superficial inferior epigastric vessels and femoral vessels were equally randomized into 4 groups, and injected with Ad-SDF-1α-transduced MSCs, MSCs, Ad-SDF-1α, and normal saline, respectively. Gene transduction, flaps survival, neovascularization, and expression level of SDF-1a protein were detected. The results showed that Ad-SDF-1α-transduced MSCs expressed higher SDF-1α both in vitro and in vivo, yielded more survival area, and resulted in higher neovascularization than any other groups. Interestingly, the necrotic sites of all free flaps were in the proximal end rather than in the distal end. In conclusion, Ad-SDF-1α-transduced MSCs can increase neovascularization of early and partial ischemic free flaps and augment the surviving areas.

To investigate the effect of vascular bundle implantation in autogenous bone graft on angiogenesis.Thirty-six New Zealand white rabbits were evaluated in this study. A portion of bilateral radial bones of a rabbit were removed as free bone grafts, whose periostea were peeled off. In test group, the external maxillary artery bundle was passed through the marrow cavity of the bone. In control group, there was no vascular bundle implantation. Each bone was placed in masseter muscle separately. The rabbits were sacrificed and the specimens were procured at 3 days, 1, 2, 3, 4 and 6 weeks after surgery for histological observation, Chinese ink perfusion and CD34 immunohistochemistry. Microvessel density (MVD) was assessed in order to evaluate angiogenesis of autogenous bone grafts.The bone grafts were found revascularization in 3 days after surgery in the test group, whereas at 2 weeks in the control group. In 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks after surgery, the MVD of test group was significantly higher than that of control group. In 4 weeks after surgery, angiogenesis of test group reached to peak.Vascular bundle implantation improved angiogenesis in non-vascularized autogenous bone graft in this study.

Summary This study aims to investigate the effect of arterial pedicle implantation on angiogenesis and osteogenesis of autogenous bone graft. In this study, 36 New Zealand white rabbits were evaluated, in which free radial bone grafts without periosteum were harvested and implanted into the masseter muscles. In group 1, on the one side, the external maxillary artery pedicle was passed through the bone marrow cavity. In group 2, on the other hand, as control, no arterial pedicle was implanted. Microvessel density was assessed by India ink perfusion and integrated optical density of tetracycline fluorescence labelling was used to evaluate angiogenesis and new bone formation at 3 days and 1, 2, 3, 4 and 6 weeks postoperatively. The bone grafts were found to be re-vascularised at 3 days postoperatively in group 1, and at 2 weeks in group 2. At 2, 3 and 4 weeks postoperatively, the microvessel densities of group 1 were significantly higher than those of group 2. At 4 weeks postoperatively, angiogenesis of group 1 reached a peak. The tetracycline fluorescence labelling integrated optical densities of group 1 were significantly higher than those of group 2 from 2 to 6 weeks postoperatively. Implantation of arterial pedicle into non-vascularised autogenous bone graft enhances angiogenesis, and increased angiogenesis enhances osteogenesis.

The aim of this article was to obtain an overview of metastatic tumors to the oral and maxillofacial (OMF) region, especially the differences in the constituent ratios of primary cancers between the United States and China.Clinical findings of 19 cases encountered in West China Hospital of Stomatology were summarized and the English and Chinese literature were reviewed and analyzed. The main clinical features of OMF metastases were summarized, with an emphasis on primary cancers' constituents.The lung, breast, kidney, liver, and prostate were the top 5 common primary sites of cancer. However, there was a significant difference in the primary cancers' constituents between United States and China (P.001). The breast, kidney, prostate cancers, and melanoma of skin were more frequent primary cancers in United States than in China, whereas that of the lung, thyroid, liver, esophagus, and the stomach were more common in China than in United States. The proportions of the OMF metastatic lesions originating in the lung, kidney, liver, thyroid, and esophagus in all OMF metastatic tumors were higher than the corresponding primary cancers' prevalent proportions.The frequency of developing OMF metastasis is not always consistent with primary cancers' prevalence, which suggests that different cancers have different potentiality to develop OMF metastasis. Cancers of the kidney, liver, lung, thyroid, and esophagus were more likely to spread to the OMF region. In general screening of primary cancer, it would be helpful to take into account the metastatic potentiality of different cancers and primary cancers' prevalence in different countries in the case of occult primary.

To investigate the evidences of the presence of tumor stem cells and its impact on the tumorigenesis of adenoid cystic carcinoma cell (ACC)-2 cell line by analyzing the biologic characteristics of different sub-clones of adenoid cystic carcinoma cell line.In vitro individual cell culture was employed to observe the proliferating character of ACC-2 cells. The expression of CD44(+) and CD24(-) of ACC-2 cells were investigated by immunohistochemical. Immunomagnetic isolation of different phenotype of ACC-2 cells, followed by cell culture, was used to study the proliferating abilities of different clusters of the cell line. The hetero-transplanted tumor mold was established using BALB/C nude mice by subcutaneous injection of tumor cells. The tumorigenic and differentiating properties of the different cluster were investigated.Only 4.41% of cultured ACC-2 cell had ability of division, proliferation and establishment of cell clone. CD44(+)-CD24(-) cluster accounted for about 8.1% of total ACC-2 cells, among which, 25.71% cells could divide and proliferate. All of CD44 and CD44(+)-CD24(+) cells were failure to be eternal alive in the condition of in vitro individual cell culture. According to the results of in vivo tumorigenic study, the minimal cell quantity to develop a subcutaneous transplanted tumor by CD44(+)-CD24(-) cells was 1 x 10(3), where as the needed cell amount were 1 x 10(5) and 1 x 10(4) as to non-isolated ACC-2 cells and CD44(+) cells, respectively. The CD44(-) and CD44(+)-CD24(+) did not develop transplanted tumors. CD44(+)-CD24(-) ACC-2 cell could differentiate into cells of other phenotypes.CD44(+)-CD24(-) ACC-2 cells consist of a very small portion of all ACC-2 cells (about 4%). They have remarkable proliferating ability and can bear special phenotypes, The tumorogenic ability of CD44(+)-CD24(-) cells are stronger than that of CD44(+) and non-isolated ACC-2 cells. Eliminating of this cluster from ACC-2 would actually deprive the tumorogenic ability of the cell line.

To investigate the effects of cyclic biaxial mechanical stimulation on adhesion of salivary adenoid cystic carcinoma(SACC) extracellular matrix (ECM) and expression of E-cadherin/cateninin complex in the SACC high metastasis cell lines ACC-M, SACC low metastasis cells line ACC-2, we observed the functions of mechanical stimulation in the adhesion of SACC cell-ECM and investigate the mechanism in the adhesion of ACC.Mechanical stimulation were applied to the cells for periods of 1, 3 and 6 hours every day, lasting for 2 days. The amplitude of mechanical stimulation applied to the cells were 1000, 4000 micro strain, at a frequency of 3 Hz. Unstrained cells were used as control. The expression of E-cadherin/cateninin complex on the cell of ACC-M, ACC-2 were studied with laser scanning confocal microscope and image analysis. SACC cell-ECM adhesion was assayed by MTT technique.The results showed that expressions of alpha, beta, gamma-cateninin on the cell of ACC-2 were obviously higher than that ACC-M and E-cadherin on the cell of ACC-M were obviously higher than that ACC-2 without mechanical stimulation. Mechanical stimulation can change the expression of E-cadherin/cateninin complex on the cell of ACC-2 and ACC-M with time. The results also showed that cell-ECM adhesion on the cell of ACC-2 were obviously higher than that of ACC-M without mechanical stimulation. Mechanical stimulation can change the cell-ECM adhesion of ACC-2 and ACC-M with time.Mechanical stimulation can change the adhesion of the SACC cell-ECM and expression of E-cadherin/cateninin complex of the SACC cell. We think it played an important role in metastasis of the cancer.

To investigate the functional expression of a truncated VEGF-C gene in mammalian cells.A truncated VEGF-C cDNA (with 5'-terminal cleaved between residues 207/208) was used to construct a pcDNA3.1(+)-VEGF-C recombined plasmid, which was cloned into a lingual SCC cell line (Tca8113) by lipid-mediated transfection. The expression of VEGF-C was detected by Western blotting and immunohistochemical staining.The VEGF-C fragment was successfully ligated into the pcDNA3.1(+) between EcoR I and Xho I multiclone sites. By Western blotting, the relative molecular mass 53 x 10(3) and 29 x 10(3) forms of VEGF-C were detected in cell lysates of VEGF-C transfected cells (VcTca), while the relative molecular mass 29 x 10(3) form of VEGF-C presented the only band in culture media. According to immunohistochemistry, the VcTca cells showed intensive cytoplasm positive reaction to VEGF-C, whereas faint reaction was found in non-transfected cells and pcDNA3.1(+) mock transfected cells.The results indicated that the truncated VEGF-C cDNA was sufficient for expression, secretion and activation when it was transfected into Tca8113 cell.