Clinicopathologic study on a rare variant of ameloblastoma with basal cell features.

OBJECTIVES: To investigate the clinical features, pathologic manifestations, and biologic behaviors of a variant of ameloblastoma with basal cell features (AM-BC). MATERIALS AND METHODS: Following retrospective review of the clinical and pathological data of six cases of AM-BC, we described their histological and immunohistochemical (IHC) features and discussed the biologic behaviors, prognoses, pathogenesis, and clinical relevance of AM-BC. Direct sequencing of polymerase chain reaction products was also performed in all cases. RESULTS: The six cases of AM-BC involved four women and two men, aged 22-82 years. Four lesions occurred in the maxilla and two in the mandible. Histologically, the basal cells tended to be arranged as unequally sized follicles, strands, or cords of odontogenic epithelium in the connective tissue stroma. Little or no stellate reticulum was present in the central portion of the nest. Expression of CKs was consistent with other histological variants of ameloblastoma (AM), but AM-BC had significantly higher p53 and Ki-67 (p < 0.05) labeling indices than other histological variants of AM. Two patients had BRAF gene mutations. CONCLUSION: Ameloblastoma with basal cell features is a very rare variant of AM. Our study showed the differences and relationships that exist between AM-BC and other variants of AM, which could enhance understanding of AM-BC.

Effectiveness of Drainage in Mandibular Third Molar Surgery: A Systematic Review and Meta-Analysis.

PURPOSE: The purpose of this study was to provide an evidence-based evaluation of the impact of surgical drainage after the removal of mandibular third molars. MATERIALS AND METHODS: The Medline (PubMed), Cochrane Library, and Web of Science databases were searched to identify randomized controlled trials up to September 1, 2017. Postoperative variables, including facial swelling, trismus, and pain, were calculated early (2 to 3 days) and late (5 to 7 days) after the removal of impacted mandibular third molars. Weighted mean differences for trismus and standardized mean differences (SMDs) for swelling and pain were pooled for the included studies. RESULTS: The samples consisted of 592 extractions (297 with surgical drainage and 295 controls) in 409 participants. The included studies were published from 1988 to 2016. Participants who received surgical drainage had significantly less facial swelling during the early stage (SMD, -0.46; 95% confidence interval [CI], -0.67 to -0.26; P < .0001) and the late stage (SMD, -0.36; 95% CI, -0.55 to -0.16; P = .0004) after the removal of an impacted mandibular third molar. They also had better mouth opening than controls during the early and late stages (early MD, 5.55 mm; 95% CI, 2.31-8.79; P = .0008; late MD, 2.38 mm; 95% CI, 1.47-3.29; P < .0001). The level of pain was significantly different between the 2 groups in the early stage (SMD, -0.55; 95% CI, -1.00 to -0.10; P = .01); however, there were no significant differences in the late stage (SMD, -0.13; 95% CI, -0.38 to 0.12; P = .30). CONCLUSION: The use of surgical drainage has an obviously positive effect on postoperative reactions after the removal of a mandibular third molar. Given the need for additional time for clinic visits, surgical drainage presents an alternative for the perioperative management of impacted mandibular third molar surgery, especially in cases of a fully bony tooth with poor drainage.

Expressions of GLUT-1, PK-M2 and HIF-1α and Mutation Status of BRAF in Odontogenic Keratocysts.

OBJECTIVE: To investigate the expressions and clinicopathological features of glucose transporter 1 (GLUT-1), pyruvate kinase M2 (PK-M2) and hypoxia-inducible factor 1α (HIF-1α) in odontogenic keratocysts (OKCs), and to investigate the mutation status of v-raf murine sarcoma viral oncogene homolog B1 (BRAF). METHODS: Following a retrospective review of the clinicopathological data of 28 OKC cases, the expressions of GLUT-1, PK-M2 and HIF-1α in these tissue samples were detected through immunohistochemistry. The BRAF mutation statuses of all cases were examined using polymerase chain reaction amplification and direct sequencing. RESULTS: The expression levels of HIF-1α varied in 96.4% of OKC tissues, and there were higher positive rates of PKM2 (100%) and GLUT-1 (100%) in these tissues. None of the 28 OKC samples carried the BRAF mutation. CONCLUSION: The positive expressions of GLUT-1, PK-M2 and HIF-1α indicate that patients with OKCs undergo anaerobic glycolysis to a certain extent, but these processes appear to be irrelevant to clinicopathological features and to the BRAF mutation.

Study of the electrospun PLA/silk fibroin-gelatin composite nanofibrous scaffold for tissue engineering.

In this article, a nanofibrous composite scaffold of poly L-lactic acid(PLA)/silk fibroin(SF)-gelatin was fabricated by multilayer electrospinning. To investigate the feasibility of PLA/SF-gelatin use as scaffolds, the porosity and mechanical properties were examined; in particular, the biocompatibilities were evaluated in vivo and in vitro by the means of cell adhesion and cytotoxicity testing, short-term subcutaneous implantation testing, and acute hemolysis testing according to the requirements of ISO 10993. The results showed the scaffold achieved the desirable levels of pliability (elastic up to 7.3% strain) and the appropriate breaking strength (2.22 MPa). The porosity of the SF-gelatin layer was 87% and the pore diameter was 142 nm. After 12 days of cultivation, SEM observation demonstrated the scaffold was nontoxic, biocompatible, and capable of supporting 3T3 mouse fibroblasts attachment, spreading, and growth. The hemolysis test proved the scaffolds with hemolytic rates from 3.1 to 4.5%. The subcutaneous implantation test indicated minor inflammatory reactions surrounding the scaffolds and biodegradation were initially observed in about 3 months. The desired porous structure, strong and pliable properties, combined with the ability of PLA/SF-gelatin scaffold to support cell growth in vitro, especially excellent biocompatibility in vivo, suggested potential application for tissue engineering scaffolds.