Mandibular bilateral compound odontoma: histological and morphostructural features by confocal laser scanning microscopy

Objectives. Odontomas are the most common odontogenic tumors of the oral cavity. They account for 22-67% of all maxillary tumors with an increased prevalence in children and adolescents. They are asymptomatic and are generally diagnosed by radiographic examination. The chosen treatment is surgical excision of the lesion followed by a histo- pathological examination. The aim of this study is to show confocal laser scanning microscopic features in a case of compound odontoma not easily evident when using an optical traditional microscopy. Methods. A case of bilateral mandibular compound odontoma in young patient is presented. Radiographic analysis revealed two symmetrical radio-opaque masses with a surrounding thin radio-transparent halo, up to the first lower premolars. Surgical excision of the lesion under general anesthesia was performed. The specimens were fixed in a buffered solution of 10% formalin, embedded in paraffin, cut in 3 μm thick serial sections, stained with hematoxylineosin, observed by optical microscope and by Confocal Laser Scanning Microscope (CLSM). Results. Control at 2 weeks showed excellent healing of the tissues. Follow-up at 6 months showed the absence of recurrence and the eruption of the previously retained teeth. CLSM analysis in autofluorescence underlined a different fluorescence of soft and hard tissues showing different intensity of emission in autofluorescence due to different degrees of calcification. The odontogenetic components appeared strongly autofluorescent and presented foci of ectomesenchymal dentinogenetic multifocal differentiation that cause irregularities in the shape and structure of the tissue. Conclusions. Odontomas are frequent in childhood and are often responsible for dental retention. CLSM allows a careful histo-morphological analysis of odontomas and other odontogenic tumors. The morpho-structural organization of the cellular component is also observed with the possibility of three-dimensional reconstruction. References • Crincoli V, Scivetti M, Di Bisceglie MB, Lucchese A, Favia G. Complex odontoma: confocal laser scanning microscopy analysis of a case. Minerva Stomatol. 2007 Nov-Dec;56(11-12):611-20. • Da Silva LF, David L, Ribeiro D, Felino A. Odontomas: a clinico-pathologic study in a Portuguese population. Quintessence Int 2009; 40(1):61-72. • Tamme T, Soots M, Kulla A, Karu K, Hanstein S-M, Sokk A, et al. Odontogenic tumours, a collaborative retrospective study of 75 cases covering more than 25 years from Estonia. J Cranio-Maxillofacial Surgery 2004; 32:161-5.