Rom J Morphol Embryol 2016, 57(2 Suppl):719–728 ISSN (print) 1220–0522 ISSN (online) 2066–8279 ORIGINAL PAPER Clinical, imagistic and histopathological study of chronic apical periodontitis ILEANA CRISTIANA CROITORU 1) , ŞTEFANIA CRĂIŢOIU 2) , CRISTIAN MARIAN PETCU 3) , OANA ANDREEA MIHĂILESCU 3) , ROXANA MARIA PASCU 1) , ADELINA GABRIELA BOBIC 2) , DORIANA AGOP FORNA 4) , MONICA MIHAELA CRĂIŢOIU 1) 1) Department of Prosthetic Dentistry, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, Romania 2) Department of Histology, Faculty of Medicine, University of Medicine and Pharmacy of Craiova, Romania 3) Department of Endodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, Romania 4) Department of Dentoalveolar Surgery, “Grigore T. Popa” University of Medicine and Pharmacy, Iassy, Romania Abstract Periapical lesions are among the most frequent periodontal pathologies in human teeth, generally called apical periodontitis. Apical periodontitis is a continuation of the endodontic space infection and it is manifested as a response of the host defense against the microbial action. It may determine local inflammation, hard tissue resorption, destruction of other periapical tissues. The preliminary diagnosis of chronic periapical lesions is based on the clinical symptoms and imagistic investigation, which represent a reliable diagnosis instrument, but the histological investigation remains essential for a certain diagnosis. We performed a clinical and histological study of the periapical lesions, evaluating the various clinical and imagistic aspects and we compared them with the results of the histological examination, in order to establish the correspondence between the clinical-imagistic aspects and the morphological ones. The relation between the histological aspects, the clinical signs and imagistic aspects may provide valuable data both for establishing an accurate diagnosis and for adopting the most efficient treatment. Keywords: chronic apical periodontitis, granuloma, radicular cyst, periapical lesions.  Introduction Chronic apical periodontitis, an inflammatory reaction of the apical periodontium, is a condition with a high incidence and whose treatment does not always lead to an improvement, which can represent an etiological factor of edentation. It is a destructive-proliferative inflammation, leading to the lysis and metaplasia of the periodontal components. It may have various clinical aspects, deter- mined by a diverse etiology, by an individual reactivity and by the diverse structure of the apical periodontium. In the studied cases, we found various clinical aspects, some of them presenting obvious manifestations, others having an asymptomatic progress. The pulpar and peri- apical pathologies are closely linked in most cases, as pulpar damage precedes the periodontal damage. That is why the specialty literature uses the term pulpo-periapical pathology. Periradicular lesions mainly involve the apical periodontium, with no predominance related to race, gender or age [1, 2]. Periapical lesions are usually classified according to their histological structure [3–8]. Thus, Spatafore et al. classifies them into: periapical granuloma, radicular cyst, periapical cicatrices and other lesions [9]. The treatment should be individualized and it must be applied after an accurate diagnosis, resulting from the corroboration between the clinical and imagistic aspects. The histological study of this pathology provides various aspects, due to multiple forms, being the only one that may validate or invalidate the accuracy of the clinical diagnosis. This leads to the necessity of knowing the histological aspects, their imagistic correspondents and the clinical manifestations of every clinical form of this pathology. The histopathological study is important because, in the same clinical and imagistic manifestations, the histo- logical aspect may have various forms (chronic fibrous apical periodontitis, hyperplastic or granulomatous forms, diffuse chronic apical periodontitis and forms of conden- sed chronic apical periodontitis). Also, it is important to detect the factors orienting the evolution towards one of the histopathological forms, so that it may contribute to the prevention and treatment of these lesions. The purpose of our study is to compare the results obtained through clinical, radiological and histopatho- logical investigations, in order to clarify some of the difficulties of diagnostication and to identify the predic- table post-treatment complications.  Patients, Materials and Methods The clinical study included a group of 132 patients diagnosed with chronic apical periodontitis, selected after the examination of 258 patients that presented for specialty treatment, between November 2012–March 2016, in the Clinic of Dental Prosthetics within the University of Medicine and Pharmacy of Craiova, and also in a Private Clinic in Craiova, Romania. In order to establish the degree of apical periodontium damage, and also for verifying the conservatory treatment, there was performed an imagistic investigation with retroalveolar dental X-rays, ortho- R J M E Romanian Journal of Morphology & Embryology http://www.rjme.ro/