Furcation

Furcation refers to the area on a multirooted tooth where the roots divide. In human dentition, furcation areas most commonly involve molars and, less frequently, multirooted premolars. The furcation region lies on the root trunk at or near the level where the roots separate, and its health is an indicator of periodontal status.

Clinically, furcation involvement is commonly staged using the Glickman classification: Grade I denotes incipient involvement with a detectable entry of a probe into the furcation, typically less than 1 mm. Grade II indicates a partial penetration or cul-de-sac defect, where the probe enters more than 1 mm but does not pass through to the opposite side. Grade III describes a through-and-through defect with loss of interradicular bone, where the furcation can be probed from buccal and lingual aspects but may be clinically hidden by soft tissue. Grade IV is a through-and-through defect with gingival recession, making the furcation entrance clinically visible.

Assessment relies on periodontal probing at the furcation area, along with radiographs for orientation. Conventional radiographs may underestimate furcation involvement; advanced imaging such as cone-beam computed tomography can provide a three-dimensional view of the defect.

Management depends on defect severity. Early furcation involvement may respond to non-surgical periodontal therapy and meticulous plaque control. More advanced defects often require surgical debridement and, in suitable cases, regenerative procedures (bone grafts, guided tissue regeneration). In extensive defects, options include root resection, hemisection, or tooth extraction. Prognosis correlates with the degree of furcation involvement, overall bone support, and patient hygiene.

Beyond dentistry, furcation can refer to the branching point of a stem or other structures in botany and anatomy. In dental literature, it denotes the tooth-root bifurcation or trifurcation region.