Periodontal probing of dental furcations compared with diagnosis by low-dose computed tomography: a case series

Therapeutic decisions in periodontal surgery are based on the accurate diagnosis of the furcation. Clinical probing is the basic diagnostic tool; however, the accuracy of clinical probing to distinguish Class II and Class III furcation defects is unknown. Therefore, this study compares clinical probing diagnoses to those of computed tomography (CT).

Seventy-five patients with severe periodontal disease were enrolled in this case series study. A total of 582 furcation sites in molars were assigned for the diagnosis of Class II and Class III furcation defects by clinical probing. Diagnosis based on CT served as a reference.

The degree of furcation involvement on clinical findings was confirmed in 57% of the sites, whereas 20% were overestimated and 23% were underestimated compared with the radiologic analysis. Only 32% of Class III furcations in the CT scan were detected clinically. The best correlation of CT scan and clinical probing was found at buccal furcation sites in the mandible, with a κ-coefficient of 0.52, and buccal furcation sites in the maxilla, κ = 0.38. The κ-coefficient was 0.35 for lingual furcations, 0.29 for mesial furcations, and 0.27 for distal furcations, showing weaker correlations.

CT scans offer more detailed information on furcation involvement than clinical probing. Especially before surgical treatment, three-dimensional radiographic imaging can be a useful tool to assess the degree of furcation involvement and optimize treatment decisions.