Retrospective evaluation of anatomical and topographic features of furcation defects in panoramic radiography and CONE-BEAM computed tomography

Objective: The first of the aims of this study; To evaluate and compare the anatomical and topographic features of furcation involvement (FT) in panoramic radiography (RG) and cone-beam computed tomography (CBCT) of mandibular first molars; To examine the relationship with bone defects in the mesial and distal sites. The second aim of the study is; The aim of this study is to evaluate the interobserver and intraobserver agreement of 3 observers consisting of a periodontology residency student, a professional periodontist and professional oral and maxillofacial radiologist. Materials and Methods: In our study, panoramic RG and furcation sites of patients who applied to Hacettepe University Faculty of Dentistry Oral, Dental and Maxillofacial Radiology and Hacettepe University Faculty of Dentistry Department of Periodontology were examined. While creating the research report, 95% confidence interval was used for the significance level. Results: In our study, 289 patients and 406 teeth were examined. 58.9% of the participants are female and 41.1% are male. The average age of the participants was determined as 52.73. In FT CBCT, it was determined as 10.6% class 1, 67.7% class 2 and 21.7% class 3. While there was a defect in the mesial site in 81.3% of the participants, this defect was associated with the furcation defect in 27.6%. While 86% of the participants had a defect in the distal site, this defect was found to be associated with the furcation defect in 28.3%, and the results were statistically significant In CBCT, the mean FT depth was 4.03 mm, the horizontal bone loss was 2.38 mm, the vertical bone loss was 3.02 mm, and the root-trunk height was 3.12 mm. In panoramic RG, 24.9% of the individuals had no defects, 58.1% were found to be subclass A, 11.8% to subclass B, and 5.2% to FT subclass C Bone loss %/age below 0.25% was found to be 2% in panoramic RG, 60.8% between 0.25 and 1, and 37.2% for 1 and above. Of those with FT class 1 on CBCT, 41.9% had no defects on panoramic RG, 55.8% were subclass A and 2.3% were subclass C. Of those with FT class 2 on CBCT, 26.9% had no defects on panoramic RG, 64% had subclass A, 6.2% had subclass B, and 2.9% had subclass C. Of those with FT class 3 on CBCT, 10.2% had no defects on panoramic RG, 40.9% had subclass A, 35.2% had subclass B, and 13.6% had subclass C. All these results were found to be statistically significant. Defect location and millimetric measurements were found to be in perfect agreement in intra- and inter-observer evaluation. Conclusion: In all cases, FT was not detected in panoramic RG and the severity of FT was underestimated in panoramic RG than in CBCT in complex cases where routine examinations and panoramic RG could not provide sufficient information in terms of diagnosis and/or treatment planning. In patients with CBCT for any reason, it was thought that the furcation sites should be examined in CBCT. Keywords: Furcation involvement, furcation defect classification, radiological bone loss