Background. Periodontal attachment loss around multi-rooted teeth can lead to exposure of furcation sites and colonization of periodontopathogens. Furcation-involved teeth are often given a poor prognosis and are considered unpredictably responsive to conventional treatments. Objective. To determine radiographic bone loss patterns over time, testing the hypothesis that bone loss in furcation sites is more rapid and extensive than that at interproximal sites. Methods. Existing radiographs were analyzed to compare rate of bone loss between furcation and interproximal sites of the same tooth. Selection criteria included mandibular molars with furcation involvement and a minimum follow-up of 5 years. Using ImageJ software, anatomical landmarks (CEJ, furca, apex) were located and measured corono-apically. P-values for differences between interproximal and furcation bone loss and sub-groups associations were calculated using Wilcoxon signed-rank test. Results . Follow-up time for 29 teeth from 19 patients ranged from 5 to 12 years (mean = 6.3 years). Bone level change over time averaged 4.22 % ± 2.49 (range: 0.04 – 13.9) for interproximal sites and 4.55% ± 2.84 (range: 0.49 – 15.52) for furcation sites. Significant bone loss (p < 0.05) was noted in furcation sites for the non-compliant sub-group. No other sub-group variables were associated with bone loss. Conclusion . In this study, there were no overall significant differences in bone loss over time between furcation sites and interproximal sites of the same tooth.