Histopathology of furcation lesions associated with pulp degeneration in primary molars.

Abstract

The purpose of this report is to describe the histopathology of radiolucent lesions associated with pulp necrosis in primary molars. Twenty-one carious, previously untreated, primary molars with radiolucent lesions were extracted with forceps under local anesthesia. If a lesion remained attached to the root, the specimen was transferred to 10% neutral buffered formalin. The sockets were gently curretted and the tissue transferred to formalin fixative. Specimens were processed, stained with hematoxylin and eosin and viewed under a light microscope. Most specimens contained a mixed response including granulomatous inflammation, chronic proliferative inflammation, acute inflammation, and epithelium. Granulomatous inflammation was the predominant response. The cellular population varied as to the relative amounts of lymphocytes, plasma cells, monocytes, macrophages, and polymorphonuclear leukocytes. Odontogenic epithelium was observed in 10 of the 21 specimens. Radiolucent lesions associated with nonvital primary molars may be classified as furcation granulomas, granulomas with epithelium suggesting potential for cystic transformation or furcation cysts. A radiolucent lesion in the root furcation is a classic radiographic sign of pulp necrosis in a primary molar (Winter 1962; Moss and Addelston 1965). In contrast, lesions associated with pulp necrosis in a permanent molar usually appear as a periapical radiolucency (Lalonde and Lueke 1968). These lesions may be diagnosed as either a granuloma or a cyst and histological examination is required to establish a final diagnosis.’ Granulomatous inflammation is a consistent feature of the periapical radiolucent lesions associated with permanent teeth (Weiner et al. 1982) and consists of a classical fasicular or swirling pattern of mononuclear series cells