Appearance of Mandibular Para-radicular Third Molar Radiolucencies on Cone-Beam Computed Tomography

AIMS: Mandibular para-radicular third molar radiolucencies (MPRs) may be mistaken for pathological lesions, leading to misdiagnosis and mistreatment. This study sought to assess the appearance of MPRs on cone-beam computed tomography (CBCT). SETTINGS AND DESIGN: This was a descriptive, cross-sectional study. MATERIALS AND METHODS: This study evaluated 770 CBCT of patients presenting to the dental school of Hamadan University of Medical Sciences. Demographic information, unilateral or bilateral presence, shape and prevalence of MPRs observed on axial and sagittal sections, their density, thinning of cortical margin, internal trabeculation, bony expansion, and mean height and width of MPRs were all evaluated. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS version 22.0 and descriptive statistics. Chi-square test was used. RESULTS: Seventy (9.1%) patients had a total of 82 MPRs, including 51 (72.86%) females. The prevalence of MPRs in females was more than males (P = 0.011). The majority of MPRs were unilateral 58 (70.73%), mostly round in shape 48 (58.54%), and were mostly associated with third molars with distoangular impaction 47 (57.31%); this difference was statistically significant (P < 0.001). Furthermore, in 47 (57.32%) patients, MPRs had less density than the surrounding bone. MPRs were not associated with expansion or root resorption in any patient. CONCLUSION: Differentiation of MPRs from the pathological lesions is important to make a decision about further imaging or referral for surgical treatment. MPRs are often considered normal since they do not cause root resorption or bone expansion and do not affect the lamina dura. MPRs are more commonly found adjacent to third molars with distoangular impaction.