Simplified Classification System for Periodontally Involved Mandibular Furcations

Numerous authors have proposed furcation classification systems of various complexities.^1-3 We use the following simplified classification system for periodontally involved mandibular furcations, as it offers the advantage of direct applicability with regard to predictable treatment options:

1. Horizontal furcation involvement

1. Class I: Entrance into the furcation proceeds less than half of the horizontal dimension of the tooth (Figure 1).
2. Class II: Entrance into the furcation proceeds greater than half of the horizontal dimension of the tooth, but less than the full horizontal dimension of the tooth (Figure 2).
3. Class III: Entrance into the furcation proceeds around to complete horizontal dimension of the tooth, connecting the buccal and lingual furcation entrances (Figure 3).

2. Vertical furcation involvement

1. Loss of less than 25% of the vertical component of the attachment apparatus in the furcation.
2. Loss of between 25% and 50% of the vertical component of the attachment apparatus in the furcation.
3. Loss of more than 50% of the vertical component of the attachment apparatus in the furcation.

References

1. Pilloni A, Rojas MA. Furcation involvement classification. A comprehensive review and a new system proposal. Dent J (Basel). 2018;6:34.
2. Graetz C, Mann L, Krois J, et al. Comparison of periodontitis patients’ classification in the 2018 versus 1999 classification. J Clin Periodontol. 2019;46:908–917.
3. Tarnow D, Fletcher P. Classification of the vertical component of furcation involvements. J Perio.1984;55:283–234.

This information originally appeared in Brodsky A, Fugazzotto PA. Treatment approaches to periodontally furcated mandibular molars. Decisions in Dentistry. 2021;7(6)26–31.