Background:Jaw bones might be potential locations for different lesions. Differences in prevalence and the type of lesions can help in designing and programming prevention procedures in health care centers.Objectives:The aim of the present study was to evaluate the prevalence of intraosseous lesions in the jaws of patients referred to diagnostic and therapeutic centers in Hamadan during 1990-2010.Patients and Methods:This cross-sectional descriptive analytical study was carried out in Hamadan in 2011. Data sheets of the subjects were used to collect all the data of patients with intraosseous lesions, including their age, gender, location of the lesion, the radiographic view of lesions, and their type and histopathological diagnoses. Data were analyzed with SPSS, using means and frequencies.Results:A total of 284 intraosseous lesions were reported in our study. The mean age of the subjects was 28.8 ± 15.2 years. The lesions were distributed in males and females almost similarly. The most prevalent lesions were cystic lesions (54.58%), manifestations of systemic conditions in jaw bones (18.3%), benign tumors (15.5%), malignant lesions (6.7%), and inflammatory lesions (4.92%), in a descending order. The most common cystic lesion was radicular cyst; the most common manifestation of systemic conditions in jaw bones was central giant cell granuloma; the most common benign tumor was ameloblastoma; the most common malignant lesion was osteosarcoma; and the most common inflammatory lesion was periapical granuloma.Conclusions:Our data provided information on the prevalence and types of intraosseous lesions among an Iranian population. This study provided baseline information to help in designing and programming procedures in health care centers in every community so that preventive therapeutic measures can be adopted.

Objective: In the present study expression of cyclin D1 in the epithelial lining of odontogenic keratocyst, radicular cyst, dentigerous cyst and glandular odontogenic cyst was investigated to compare proliferative activity in these lesions. Material and Method:Immunohistochemical staining of cyclin D1 on formalin-fixed, paraff in-embedded tissue sections of odontogenic keratocysts (n=23), dentigerous cysts (n=20), radicular cysts (n=20) and glandular odontogenic cysts (n=5) was performed by standard EnVision method. Th en, slides were studied to evaluate the following parameters in epithelial lining of cysts: expression, expression pattern, staining intensity and localization of expression.Results: Th e data analysis showed statistically significant diff erence in cyclin D1 expression in studied groups (p<0.001). Assessment of staining intensity and staining pattern showed more strong intensity and focally pattern in odontogenic keratocysts, but diff erence was not statistically significant among groups respectively (p=0.204, 0.469). Considering expression localization, cyclin D1 positive cells in odontogenic keratocysts and dentigerous cysts were frequently confined in parabasal layer, diff erent from radicular cysts and glandular odontogenic cysts. Th e diff erence was statistically significant (p<0.01). Conclusion:Findings showed higher expression of cyclin D1 in parabasal layer of odontogenic keratocyst and the entire cystic epithelium of glandular odontogenic cysts comparing to dentigerous cysts and radicular cysts, implying the possible role of G1-S cell cycle phase disturbances in the aggressiveness of odontogenic keratocyst and glandular odontogenic cyst.

Introduction: Calcifying odontogenic cyst (COC) is a unique and uncommon odontogenic cyst classified into four groups of cystic, odontoma producing, ameloblastomatous proliferating and neoplastic ones. Case Presentation: A 34-year-old Iranian man complaining of a painless facial and palatal swelling of the left side of the maxilla persisted for approximately three years was referred to the department of oral and maxillofacial surgery, Hamadan University, Iran. Panoramic film revealed a well-defined multilocular mixed radiolucent and radioopaque lesion of the maxilla at the left side. An incisional biopsy was obtained. Based on the histopathologic findings, ameloblastomatous COC was diagnosed. Discussion: We reported a rare case of COC. According to Praetorius et al. classification, this patient comes under the category of type 1C (ameloblastomatous proliferating). Many patients with ameloblastomatous COC should be reported to understand its biological behavior as possible.

Introduction:Malignant sinus mucosal melanoma is a rarely occurring melanoma in adults, with a poor prognosis. This study presents a rare case of a 33-year-old man suffering from headache and nasal obstruction for two weeks, and emphasizes the importance of immunohistochemical staining for diagnosis.