c-myc mRNA在成釉细胞瘤中的表达

目的:研究成釉细胞瘤(AB)和牙源性角化囊肿(OKC)中c-mycmRNA的表达,探讨c-myc在AB和OKC中的发生、发展及其生物学意义。方法:使用原位杂交法检测54例AB、16例OKC和7例口腔正常黏膜(NOM)组织中c-mycmRNA的表达,并将AB按原发、复发、恶变分组,结果使用χ2检验进行统计分析。结果:AB、OKC及NOM组织中c-mycmRNA的阳性表达率分别为81.5%(44/54)、75.0%(12/16)和14.3%(1/7),3组比较有显著性差异(χ2=15.488,P<0.05)。原发组AB中c-mycmRNA的阳性表达率为71.0%,复发组为94.7%,恶变组为100.0%,伴随原发、复发、恶变,差异有显著性(χ2=16.912,P﹤0.05)。结论:c-myc表达在AB的发生、发展中有重要作用;c-mycmRNA的表达与AB的临床生物学行为有关,伴随其生物学行为变化,c-mycmRNA表达增强;提示c-myc有可能成为评价预后的有效指标。     

Solid variant of odontogenic keratocyst

A case of an unusual lesion from the maxilla is presented. Macroscopically, the lesion was solid and histologically consisted of 'multiple separate keratocysts' of varying size that infiltrated into the surrounding bone and soft tissues. Panoramic image and CT scans showed a multilocular honeycomb ill-defined radiolucency with infiltration into the maxillary sinus and floor of orbit. This lesion should be differentiated from similar odontogenic lesions, such as keratoameloblastoma and papilliferous keratoameloblastoma. As there was no evidence of follicles, islands of ameloblastoma, or papilliferous structures in the entire specimen, the lesion could not be diagnosed as either a keratoameloblastoma or a papilliferous keratoameloblastoma. The invasive and destructive growth behavior, the histopathological features, and the histochemical pattern of the collagen stroma imply that this solid lesion is a neoplasia. It is suggested that the proper term for this lesion is solid variant of odontogenic keratocyst.     

Human papillomavirus type 16 DMA in an odontogenic keratocyst

DNA was extracted from an odontogenic keratocyst and assayed for the presence of human papilloma virus (HPV) type 16 DNA sequences using high stringency Southern blot hybridization. HPV type 16 homologous DNA sequences were detected at a copy number of 50-100 genome copies per diploid cell. The oral HPV DNA was not identical to the prototype HPV 16 when cleaved with the restriction enzyme Pst-I, since it appeared to lack the Pst-I C fragment (L2/L1 ORFs) and contained "off-sized" high molecular weight fragments suggestive of integration events into the host cell chromosome.     

Non-neoplastic jaw cysts: a 30-year epidemiological study of 2150 cases in the Italian population

Non-neoplastic jaw cyst (NJC) is one of the most common lesions in oral cavity, but there are only few detailed and extended epidemiological data based on the 2017 WHO classification. The aim of this study was to perform an epidemiological analysis of all NJCs treated from 1990 to 2019 at the Marche Polytechnic University, and to compare these data with those published in the literature. This retrospective study considered 2060 patients treated from 1990 to 2019. The NJCs were classified according to the 2017 WHO classification, and the main clinicopathological variables were analysed (sex, age, diagnosis, site of onset, size, and recurrences). Of 2150 total lesions, there were 2095 primary cysts and 55 recurrences; men are more frequently affected than women (M/F ratio of 1.73:1). The mean age of occurrence was 46.6 years, with a peak of frequency in the fifth decade. The mandible was more frequently involved than the maxilla, with a mean size of 1.9 cm. Radicular cyst was the most frequently diagnosed cyst (56.6%), followed by dentigerous cyst (23.4%) and odontogenic keratocyst (12.9%). This is the first epidemiological study on NJCs in the Italian population according to 2017 WHO classification.     

Assessment of Hounsfield unit in the differential diagnosis of odontogenic cysts

Objectives:The purpose of this study was to evaluate the usefulness of Hounsfield unit (HU) assessment with multislice-CT in the differentiation of radicular cysts (RCs), dentigerous cysts (DCs) and odontogenic keratocysts (OKCs).Methods:In total, 307 odontogenic cysts (RCs, DCs and OKCs) were included in this study. Cysts with lesion diameter <10 mm, cysts with artefacts affecting measurement of HU values, cysts involving infection and recurrent cysts were regarded as exclusion criteria. Images were acquired in three different types of CT scanners: Aquilion ONE, Discovery CT750 HD and SOMATOM Definition Flash. Differences in HU values among scanners and among types of odontogenic cysts were assessed using one-way analysis of variance; multiple comparisons were performed post hoc, using the Tukey–Kramer honestly significant difference test.Results:In total, 164 cysts were analysed in this study (64 RCs, 57 DCs and 43 OKCs). Regardless of the type of lesion, the Aquilion ONE scanner demonstrated a significant difference in HU value, compared with the Discovery CT750 HD scanner. Regardless of CT scanner model, HU values significantly differed between DCs and OKCs (p < 0.0001), as well as between OKCs and RCs (p < 0.0001).Conclusions:HU values were found to vary among CT scanners and should always be associated with other lesion imaging features while interpreting and elaboration diagnostic hypothesis. Notably, the results suggested that OKCs might be able to be differentiated from DCs and RCs by using HU values.     

Survivin gene promoter polymorphism -31G/C as a risk factor for keratocystic odontogenic tumor development

Several single nucleotide polymorphisms in survivin gene promoters, notably -31G/C, have been shown to modulate the expression and activity of the survivin protein. Consequently, the -31G/C polymorphism has been identified as a risk factor for the development of several types of tumors. The aim of this study was to investigate a possible association between the -31G/C polymorphism and the risk for keratocystic odontogenic tumor (KCOT) development. DNA from 52 biopsy specimens of KCOTs and from 82 buccal swabs of healthy individuals was subjected to PCR restriction fragment length polymorphism analysis to identify individual genotypes. The distribution of genotypes in KCOT and control groups, respectively, was: GG: 30 (57.7%) vs. 26 (31.7%); CG: 17 (32.7%) vs. 45 (54.9%); and CC: 5 (9.6%) vs. 11 (13.4%), respectively. These differences were statistically significant. The G allele was more common in the KCOT group than in the control group: 76 (74%) vs. 96 (59%), respectively. Logistic regression analysis showed that GC heterozygotes had a considerably decreased susceptibility for KCOTs compared with GG homozygotes. The same was true for GC+CC vs. GG. The GG genotype of the -31G/C polymorphism might be a risk factor for KCOT development.     

PCR-SSCP和DNA测序检测牙源性角化囊肿中PTCH基因的突变

目的 检测牙源性角化囊肿（OKC）中PTCH基因突变的特点。方法 采用PCR-SSCP筛查与DNA直接测序的方法对12例OKC进行PTCH基因突变的检测, 其中2例为痣样基底细胞癌综合征（NBCCS）相关OKC,10例为散发OKC。 结果 在4例OKC中发现了4处突变,其中2处生殖细胞突变发生在2例NBCCS相关OKC,2处体细胞突变发生在2例散发OKC。另外,还在10例OKC中检测到了8处PTCH基因多态性。结论 NBCCS相关OKC和散发OKC均可发生PTCH基因突变,但突变水平不同,PTCH基因的突变在二者的发病中可能均起重要作用。