UNASSIGNED: Limited statistically and clinically significant studies have been down on connective tissue factors in the odontogenic tumors. Therefore, the aim of this study was to determine the biological behavior of two selected epithelial odontogenic tumors (Ameloblastoma and Adenomatoid odontogenic tumor) by detecting CD34, VEGFR3 and eosinophil densities.
UNASSIGNED: In this cross-sectional study, paraffin blocks including 20 cases of ameloblastoma and 20 (AOT), were selected. Totally, 4 sections were prepared for hematoxylin-eosin, Congo red staining, immunohistochemistry with CD34 and VEGFR3. Expression of VEGFR3, CD34 and lymphatic, blood vessels and eosinophil densities was examined.
UNASSIGNED: The mean of blood, lymphatic vessels and eosinophils densities in ameloblastoma were 14.9 ± 6.4, 4.4 ± 2 and 3.2 ± 2.7, respectively; and in AOT, they were 8.9 ± 3.4, 3.6 ± 1.3 and 1.2 ± 07, respectively. There was a significant difference in eosinophils and blood vessels densities between the two lesions (p = 0.005; p = 0.003). By increasing the density of eosinophils, the density of the blood vessels increased in both lesions (r = 0.539, P = 0.001) There was no positive relationship between eosinophils and lymphatic vessels densities in the two above mentioned odontogenic lesions (p = 0.288, R = 0.191).
UNASSIGNED: It can be suggested that tumor angiogenesis and eosinophil densities may play a more effective role than lymphangiogenesis in local invasive behavior of ameloblastoma rather than AOT.

BACKGROUND: This retrospective study was planned to ascertain the relative frequency of odontogenic tumors (OTs) in an Indian population in the light of the latest World Health Organization (WHO) classification.
OBJECTIVE: To compare data with various reports from other parts of the world.
METHODS: Retrospective study.
METHODS: The histopathology records and archived slides of all lesions diagnosed as \"OT\" in the Department of Oral Pathology and Microbiology of Government Dental teaching institute, Mumbai, Maharashtra, India, were recovered from the period January 1981-December 2016. A total of 250 lesions thus classified were reviewed for age, gender, site of tumor, and histopathologic typing. The tumors were reclassified according to the WHO 2017 criteria.
METHODS: Microsoft Excel 2010 was used for statistical analysis.
RESULTS: In all, 250 cases of OTs were reported in a 35-year period. OTs in this study constituted 7.14% of all the 6797 registered biopsies. The most frequent histological type was ameloblastoma (AML) (30.8%), followed by odontoma (19.2%), unicystic ameloblastoma (18.4%), adenomatoid OT (14%), cementifying fibroma (6%), odontogenic myxoma and cementoblastoma (2.4% each), calcifying epithelial OT and odontogenic fibroma (2% each), ameloblastic fibroma (1.2%), squamous OT, dentinogenic ghost cell tumor, peripheral ameloblastoma, ameloblastic carcinoma and ameloblastic fibrosarcoma (odontogenic sarcoma) (0.4% each).
CONCLUSIONS: A frequency of 7.14% of OTs was observed in this study. AML comprised the single most common tumor of all OTs. This study observed geographic variations in the frequency and distribution of OTs.

OBJECTIVE: Since its recognition as a physiologic process associated with tumor, among molecular mechanisms involved in tumor progression, defects in regulation of apoptosis have generated an accelerating volume of research that has sought to elucidate the role of programed cell death in pathogenesis and treatment of various tumors. Therefore, this study was performed to understand better the diverse biological profile of epithelial odontogenic tumors with the help of immunohistochemical expression of Bcl-X protein.
METHODS: We studied Bcl-X protein expression in 45 cases of epithelial odontogenic tumors which included 15 cases each of ameloblastomas, keratocystic odontogenic tumor (KCOT) and adenomatoid odontogenic tumor (AOT) and correlated the expression with their growth pattern.
RESULTS: Cytoplasmic staining of Bcl-X revealed overexpression in ameloblastoma when compared to KCOT and AOT. Percentage of positive cells showed a statistically significant difference, P = 0.007 between ameloblastoma and KCOT, whereas P < 0.001 between ameloblastoma and AOT. However, no significance was observed between KCOT and AOT (P = 0.132).
CONCLUSIONS: The present study supports the fact that epithelial odontogenic tumors show diverse growth profiles. An increased Bcl-X expression was seen in ameloblastoma compared to KCOT and least expression in case of AOT which could be indicative of more aggressive biological behavior and increased cell survival activity of ameloblastoma than KCOT and AOT. This signifies the diagnostic relevance of this biomarker and also could be a possible regulator of the proliferative compartment by contributing in tumor progression and cytodifferentiation of epithelial odontogenic tumors.

OBJECTIVE: To determine the distribution and clinicopathologic characteristics of adenomatoid odontogenic tumors from Tamil Nadu, India, to provide meaningful data for comparison among different population groups, mainly in the Asian context.
METHODS: Forty-three adenomatoid odontogenic tumors were reviewed from 493 odontogenic tumors recorded between 1970 and 2008. The data pertaining to age, sex, anatomic site, associated impacted teeth and radiographic details, provisional diagnoses, and macroscopic and microscopic details of the 43 odontogenic tumors were reviewed.
RESULTS: The relative frequency of adenomatoid tumors comprised 8.72% of the total odontogenic tumors. The age range was 9-30 years, with a mean age of 16.88 years for combined adenomatoid odontogenic tumors. The mean age for other variants of adenomatoid odontogenic tumors assessed in this study differed slightly between sexes. Forty occurred within the bone and three peripherally. In general, the maxilla was the predominant site of involvement (72.5%), and the anterior region of jaw was affected in 92.5%. For combined adenomatoid odontogenic tumors, the male-to-female ratio was 1:1.26, and the maxilla-to-mandible ratio was 2.9:1. Microscopically, cystic lesions comprised 37.5% and occurred more often in males with a lower mean age.
CONCLUSIONS: The present study shows variations in the distribution of adenomatoid odontogenic tumors within the population assessed, but no definite conclusion emerged with regard to regional or ethnic effect.

OBJECTIVE: To compare the polarization colors of collagen fibers of odontogenic keratocyst (OKC), radicular cyst, dentigerous cyst, and adenomatoid odontogenic tumor (AOT) with reference to their biological behavior.
METHODS: Twenty cases each of OKC, radicular cyst, dentigerous cyst, and AOT were stained with picrosirius red stain and studied under polarized light.
RESULTS: A predominance of green to greenish yellow thick fibers was noted in OKC and AOT as compared to dentigerous cyst and radicular cyst. There was no significant difference between the polarization colors of the thin fibers in all the three groups.
CONCLUSIONS: The stroma of OKC and AOT consists of poorly packed or pathologic collagen and plays a role in its neoplastic behavior.

OBJECTIVE: To investigate the role of c-Myc oncogene in selected odontogenic cysts and tumors.
METHODS: Ten cases each of ameloblastoma, adenomatoid odontogenic tumor (AOT), odontogenic keratocyst (OKC), dentigerous cyst, and radicular cyst were selected and primary monoclonal mouse anti-human c-Myc antibody was used in a dilution of 1: 50. Statistical Analysis was performed using Mann Whitney U test.
RESULTS: 80% positivity was observed in ameloblastoma, AOT and OKC; 50% positivity in radicular cyst and 20% positivity in dentigerous cyst. Comparison of c-Myc expression between ameloblastoma and AOT did not reveal significant results. Similarly, no statistical significance was observed when results of OKC were compared with ameloblastoma and AOT. In contrast, significant differences were seen on comparison of dentigerous cyst with ameloblastoma and AOT and radicular cyst with AOT.
CONCLUSIONS: From the above data we conclude that (1) Ameloblastoma and AOT have similar proliferative potential and their biologic behavior cannot possibly be attributed to it. (2) OKC has an intrinsic growth potential which is absent in other cysts and reinforces its classification as keratocystic odontogenic tumor.

BACKGROUND: Solid ameloblastoma (SAB) is an invasive tumor which infiltrates adjacent normal tissues. Adenomatoid odontogenic tumor is a noninvasive tumor and never infiltrates surrounding normal tissues. The purpose of this study was to determine the biological behavior of these two epithelial odontogenic neoplasm by detecting Ki-67 and Bcl-2, which are mitotic and anti apoptotic markers respectively.
METHODS: In this analytical retrospective study, 16 samples of SAB and 16 samples of adenomatoid odontogenic tumor were selected. The samples were deparafinized and antigens were retrieved. Immunohistochemistry technique was applied for evaluation of these two markers. Monoclonal antibodies MIB1 and Bcl-2 were used to detect Ki-67 and Bcl-2 protein respectively, then the labeling index (LI) was calculated for both markers according to cellular staining. Data were analyzed by \"t\" test, (P<0.05).
RESULTS: The mean values of LI for Ki-67 in SAB and Adenomatiod odontogenic tumor (AOT) were 4 and 1% respectively and for Bcl-2 in SAB and AOT were 63 and 26% respectively. The indices of both markers were higher in SAB compared to AOT (P <0.05).
CONCLUSIONS: Higher percentage of these two markers in SAB compared to AOT confirms the aggressive behavior of SAB and the hamartomatosis behavior of AOT.