Furcation Defect

Usually, when we picture a tooth, we see its crown and its root, with the long root trunk separating into two or three points at the bottom. The area where a tooth separates into these cementum-coated points is known as the tooth’s bifurcation or trifurcation, depending on the number of roots contained within the root trunk. Only multi-rooted teeth have furcation, which means that furcation defects can only involve the premolars and the molars. When bone loss occurs in a location or depth adjacent to this area of bifurcation or trifurcation, which can happen as a result of periodontal disease, this is known as a furcation defect. Furcation defects can vary significantly in both severity and configuration, which are two significant factors in diagnosing furcation defects and in planning their treatment. Furcation defects carry with them an increased risk of tooth loss, as the area of the furcation is often deeply and complexly nestled in among soft tissue and bone and is therefore very difficult to keep clean. Because the accumulation of bacterial plaque is a key contributor to periodontal disease, it is of the utmost importance that the levels of bacterial plaque in a person with advanced periodontal disease be managed, lest greater destruction occur. The complicated position and characteristics of a furcation defect may necessitate surgical periodontal treatment, either to close the affected area with skin grafts or to create a larger open to increase access to the furcation defect, thereby either sealing the area to protect it from periodontal pathogens, or creating a clearer pathway for removing periodontal pathogens that may enter the area.

Furcation defects are classified based on the levels of clinical attachment loss and bone loss; the deeper the bone loss, the more exposed the furcation defect. The area where the cementum, which is the calcified substance that protectively coats the roots of each tooth, meets the enamel, which coats the tooth’s crown, is called the cementoenamel junction. The distance between this cementoenamel junction and the area of furcation is the root trunk length. Both the root trunk length and the horizontal measurements of attachment loss are used to measure, and therefore classify, furcation defects. The first classification system was created in 1953 by Irving Glickman, who is referred to as the father of periodontology.

According to Glickman’s classifications, a grade I furcation defect indicates incipient furcation involvement. This means that a periodontal pocket is present, but the tissue that is affected is predominantly soft tissue, and the periodontal pocket remains coronal to the alveolar bone. The most significant classification of furcation defect is grade IV, which indicates a furcation defect that is characterized by such significant bone loss that the furcation itself is entirely probeable. Grades II and III bridge these first and final grades. While Glickman’s classification system has been adjusted somewhat to include the measurement of probeable depth and to factor in such technological advances as cone beam computerized technology, its guidelines remain critical in the diagnosis and treatment of furcation defects. Treatment aims to remove bacteria from exposed root surfaces and modification of the area anatomy, if necessary, to facilitate access to the area for continued bacteria removal and hygiene maintenance. Treatments may include scaling and polishing, debridement, tunnel preparation, root resection, furcationplasty, guided tissue regeneration, enamel matrix derivative, or extraction, depending on the location and classification of the furcation involvement. Extraction is ideally only considered if attachment loss is severe or if other treatments are unlikely to succeed.