Immunohistochemical expression of Cyclooxygenase 2 reflects the proliferative activity in the epithelium of odontogenic lesions

Purpose: Odontogenic cysts and tumors comprise a major component of lesions of the oral and maxillofacial region. The pathogenesis of these lesions involves the interaction between the odontogenic epithelium and the ectomesenchyme. However, the clinical behavior of these biological entities is unpredictable. The aim of this study was to evaluate the role of Cyclooxygenase 2 (COX-2) in the pathogenesis and prognostication of odontogenic lesions.Material and method: : In this study formalin-fixed paraffin-embedded tissue section of Odontogenic Keratocyst (n=10) Dentigerous cyst (n=10), Radicular cyst (n=10) and unicystic ameloblastoma (n=10) were immunohistochemically stained with COX-2 (NCL2-COX-2- 4H12) and with Ki 67 (Ki-67 GM001) using standard staining protocols. The cytoplasmic expression of COX-2 in all the lesions was semi-quantitatively assessed. The pattern of expression of COX-2 among the different odontogenic lesions was statistical analyzed using the ANOVA test and the chi-square test.Results: All the 40 odontogenic lesions that were evaluated expressed COX-2 immunohistochemically. A high number of odontogenic epithelial cells expressed COX-2 in most of the odontogenic keratocyst, radicular cyst and unicystic ameloblastomas. The expression of COX-2 was significantly (p=0.036) higher in Unicystic Ameloblastomas and Radicular cyst compared to that of Odontogenic Keratocyst and the dentigerous cyst.Conclusion: The recognition that expression of COX-2 by odontogenic epithelial cells may indeed shed a new light on the biological mechanisms involved in the development of these benign yet aggressive lesions of the jaws. An insight into the molecular interactions occurring in the odontogenic epithelium will aid in better management of these lesions.

Maxillary Distomolar Associated with Dentigerous Cyst: An Unusual Entity

Supernumerary teeth may be encountered as an incidental finding on a radiograph. When impacted, they may be associated with clinical signs related to different problems such as failure of eruption, teeth displacement, root resorption or cystic lesions. They may occur in primary and permanent dentition, in both the maxilla and mandible and can be single or multiple in patients with syndromes. Mesiodens is the most commonly impacted tooth and appears between the central maxillary incisors in pediatric ages. Supernumerary teeth distal to the third molar are rare, usually impacted and referred to as a distomolar. A 46-year-old male consulted with the main complaint of pain on the left side of the maxilla. A panoramic radiograph revealed a right impacted maxillary fourth molar located posterior to the third molar associated with a pericoronal radiolucency. The supernumerary tooth was removed surgically under local anesthesia and the pericoronal lesion enucleated. Histopathological examination was consistent with the diagnosis of a dentigerous cyst associated with an impacted distomolar. Healing was uneventful, and the patients remained asymptomatic. The occurrence of a maxillary distomolar is rare and even rarer the association with a dentigerous cyst.

Odontogenic Cysts and Tumors of Maxilla and Maxillary Sinus (A Clinicopathological Analysis)

Background: Knowledge about the prevalence and distribution of pathologies in a particular location is important when a differential diagnosis is being formulated. The aim of this study was to describe the prevalence and the clinicopathological features of odontogenic cysts and tumors affecting the maxilla and to discuss the unusual presentation of those lesions within maxillary sinus. Materials and Methods: A multicenter retrospective analysis was performed on pathology archives of patients who were diagnosed with maxillary odontogenic cysts and tumors from 2010 to 2020. Data were collected with respect to age, gender and location. Result: A total of 384 cases was identified, 320 (83.3%) cases were diagnosed as odontogenic cysts and 64 (16.6%) as odontogenic tumors. The mean age was 30.5 years with a standard deviation of 16.2 years. Male patients were more commonly affected (n=220, 57.3%). Radicular cyst was the most common cyst (n=205, 64.1%), while the most common tumor was odontoma (n=14, 21.9%) and dentigerous cyst was the most common lesion to present within the maxillary sinus. Conclusion: This study indicates that there are some geographic similarities and differences in regard to distribution of odontogenic cysts and tumors in maxilla and it raises awareness of their presentation within maxillary sinus especially if there is an association with an ectopic or adjacent impacted tooth.