Cone Beam Computer Tomography and Histological Evaluation of Dental Follicle of Impacted Lower Third Molar Germs in Teens: A Histo-Radiographic Correlation Study in a Case Series

The dental follicle (DF) is the tissue that surrounds the crown of the developing tooth. In X-ray, images it appears as a radiolucent area. The removal of an impacted mandibular third molar is a common procedure in oral surgery. The radiographic evidence of pathology, commonly defined as a pericoronal radiolucency measuring at least mm 2.5 mm in any dimension, is accepted for the extraction of impacted mandibular third molars. Mesioangular impactions are usually more closely placed to the inferior alveolar canal, and the use of cone beam computer tomography (CBCT) before the removal of impacted mandibular third molars has been reported to be appropriate in these cases. The aim of this study was to evaluate the microscopic features of radiographically normal DFs associated with mesioangular impacted mandibular third molars examined through CBCT. Thirteen mesioangular impacted third molars from ten patients (5 males and 5 females, mean age ± SD: 15.1 ± 1.66) with a maximum width of the DF <2.5 mm, as digitally established by CBCT, were included in this study. All the DFs associated with the removed third molars were examined histologically through the analysis of different variables. The mean (±SD) and range of the maximum width of the DFs were 1.35 (±0.47) mm and 0.71–2.21 mm, respectively. Nine (69.23%) DFs showed odontogenic remnants, five (38.46%) showed focal squamous metaplasia and eight (61.53%) mild mesenchymal myxoid degeneration. The maximum width of the DF failed to show any significant correlation with all the histological variables considered in this study. Aware of the limited number of patients included in this study, the histo-radiographic correlation in our case series confirm data in the literature, according to which normal pericoronal imaging may be associated with DF tissue changes/variations that in turn are potentially associated with the development of pathologies including odontogenic cysts and tumors. Whether these changes/variations are enough to make prophylactic germectomy of impacted third molars the standard by themselves remains to be established. However, they require accurate correlations with the radiographic data for the appropriate histologic assessment of a DF.