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Furcation-involved molar teeth - part 1: prevalence, classification and assessment


Furcation-involved molars are a common presentation in general dental practice. Teeth with increasing degrees of furcation involvement are at a higher risk of requiring extraction. The assessment and management of these teeth may be complicated by difficulties in accessing the furcation for both the clinician and patient. However, with appropriate supportive therapy, these teeth have been shown to have acceptable survival rates. This first article reviews and discusses the classification, assessment and the non-surgical management of furcation-involved molar teeth. An improved understanding of how to appropriately manage these teeth can result in improved outcomes for patients.

Key points

  • The presence of a furcation involvement will considerably increase the risk of tooth loss, whether patients are undergoing supportive periodontal care or not.

  • Professional mechanical plaque removal of the furcation region of a molar is challenging, often owing to the discrepancy between a narrow furcation entrance and the width of the instruments available for treatment.

  • Both the horizontal and vertical components of a furcation involvement should be considered and classified according to sub-categories, as this can help to assess the tooth's prognosis.

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  1. Kassebaum N J, Bernabé E, Dahiya M, Bhandari B, Murray C J L, Marcenes W. Global burden of severe periodontitis in 1990-2010: a systematic review and meta-regression. J Dent Res 2014; 93: 1045-1053.

  2. Caton J G, Armitage G, Berglundh T et al. A new classification scheme for periodontal and peri-implant diseases and conditions - Introduction and key changes from the 1999 classification. J Clin Periodontol 2018; DOI: 10.1111/jcpe.12935.

  3. Rasperini G, Majzoub J, Tavelli L et al. Management of Furcation-Involved Molars: Recommendation for Treatment and Regeneration. Int J Periodontics Restorative Dent 2020; DOI: 10.11607/prd.4341.

  4. Nordland P, Garrett S, Kiger R, Vanooteghem R, Hutchens L H, Egelberg J. The effect of plaque control and root debridement in molar teeth. J Clin Periodontol 1987; 14: 231-236.

  5. Wang H L, Burgett F G, Shyr Y, Ramfjord S. The influence of molar furcation involvement and mobility on future clinical periodontal attachment loss. J Periodontol 1994; 65: 25-29.

  6. Loos B, Nylund K, Claffey N, Egelberg J. Clinical effects of root debridement in molar and non-molar teeth. A 2-year follow-up. J Clin Periodontol 1989; 16: 498-504.

  7. Salvi G E, Mischler D C, Schmidlin K et al. Risk factors associated with the longevity of multi-rooted teeth. Long-term outcomes after active and supportive periodontal therapy. J Clin Periodontol 2014; 41: 701-707.

  8. Fleischer H C, Mellonig J T, Brayer W K, Grey J L, Barnett J D. Scaling and root planing efficacy in multirooted teeth. J Periodontol 1989; 60: 402-409.

  9. Nibali L, Shemie M, Li G et al. Periodontal furcation lesions: A survey of diagnosis and management by general dental practitioners. J Clin Periodontol 2021; 48: 1441-1448.

  10. Najim U, Slotte C, Norderyd O. Prevalence of furcation-involved molars in a Swedish adult population. A radiographic epidemiological study. Clin Exp Dent Res 2016; 2: 104-111.

  11. Svärdström G, Wennström J L. Prevalence of furcation involvements in patients referred for periodontal treatment. J Clin Periodontol 1996; 23: 1093-1099.

  12. Masters D H, Hoskins S W Jr. Projection of cervical enamel into molar furcations. J Periodontol 1964; 35: 49-53.

  13. Lim H-C, Jeon S-K, Cha J-K, Lee J-S, Choi S-H, Jung U-W. Prevalence of Cervical Enamel Projection and Its Impact on Furcation Involvement in Mandibular Molars: A Cone-Beam Computed Tomography Study in Koreans. Anat Rec (Hoboken) 2016; 299: 379-384.

  14. Moskow B S, Canut P M. Studies on root enamel (2). Enamel pearls. A review of their morphology, localization, nomenclature, occurrence, classification, histogenesis and incidence. J Clin Periodontol 1990; 17: 275-281.

  15. Mandelaris G A, Wang H L, MacNeil R L. A morphometric analysis of the furcation region of mandibular molars. Compend Contin Educ Dent 1998; 19: 113-122.

  16. Wang H L, Burgett F G, Shyr Y. The relationship between restoration and furcation involvement on molar teeth. J Periodontol 1993; 64: 302-305.

  17. Hamp S E, Nyman S, Lindhe J. Periodontal treatment of multirooted teeth. Results after 5 years. J Clin Periodontol 1975; 2: 126-135.

  18. Tarnow D, Fletcher P. Classification of the vertical component of furcation involvement. J Periodontol 1984; 55: 283-284.

  19. Tonetti M S, Christiansen A L, Cortellini P. Vertical subclassification predicts survival of molars with class II furcation involvement during supportive periodontal care. J Clin Periodontol 2017; 44: 1140-1144.

  20. Al-Shammari K F, Kazor C E, Wang H L. Molar root anatomy and management of furcation defects. J Clin Periodontol 2001; 28: 730-740.

  21. Gher M W Jr, Dunlap R W. Linear variation of the root surface area of the maxillary first molar. J Periodontol 1985; 56: 39-43.

  22. Horwitz J, Machtei E E, Reitmeir P, Holle R, Kim T-S, Eickholz P. Radiographic parameters as prognostic indicators for healing of class II furcation defects. J Clin Periodontol 2004; 31: 105-111.

  23. Roussa E. Anatomic characteristics of the furcation and root surfaces of molar teeth and their significance in the clinical management of marginal periodontitis. Clin Anat 1998; 11: 177-186.

  24. Bower R C. Furcation morphology relative to periodontal treatment. Furcation entrance architecture. J Periodontol 1979; 50: 23-27.

  25. Dos Santos K M, Pinto S C S, Pochapski M T, Wambier D S, Pilatti G L, Santos F A. Molar furcation entrance and its relation to the width of curette blades used in periodontal mechanical therapy. Int J Dent Hyg 2009; 7: 263-269.

  26. Matthews D C, Tabesh M. Detection of localized tooth-related factors that predispose to periodontal infections. Periodontol 2000 2004; 34: 136-150.

  27. Parashis A O, Anagnou-Vareltzides A, Demetriou N. Calculus removal from multirooted teeth with and without surgical access. II. Comparison between external and furcation surfaces and effect of furcation entrance width. J Clin Periodontol 1993; 20: 294-298.

  28. Dietrich T, Ower P, Tank M et al. Periodontal diagnosis in the context of the 2017 classification system of periodontal diseases and conditions - implementation in clinical practice. Br Dent J 2019; 226: 16-22.

  29. Eickholz P, Kim T S. Reproducibility and validity of the assessment of clinical furcation parameters as related to different probes. J Periodontol 1998; 69: 328-336.

  30. Mardam-Bey W, Majzoub Z, Kon S. Anatomic considerations in the aetiology and management of maxillary and mandibular molars with furcation involvement. Int J Periodontics Restorative Dent 1991; 11: 398-409.

  31. Pilloni A, Rojas M A. Furcation Involvement Classification: A Comprehensive Review and a New System Proposal. Dent J (Basel) 2018; 6: 7-23.

  32. Papapanou P N, Sanz M, Buduneli N et al. Periodontitis: Consensus report of workgroup 2 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Periodontol 2018; DOI: 10.1002/JPER.17-0721.

  33. Tonetti M S, Greenwell H, Kornman K S. Staging and grading of periodontitis: Framework and proposal of a new classification and case definition. J Periodontol 2018; DOI: 10.1002/JPER.18-0006.

  34. Khasnis S A, Kidiyoor K H, Patil A B, Kenganal S B. Vertical root fractures and their management. J Conserv Dent 2014; 17: 103-110.

  35. See W-K, Ho J-C, Huang C-F, Hung W-C, Chang C-W. The association between clinical diagnostic factors and the prevalence of vertical root fracture in endodontic surgery. J Formos Med Assoc 2019; 118: 713-720.

  36. Vertucci F J, Williams R G. Root canal anatomy of the mandibular first molar. J N J Dent Assoc 1974; 45: 27-28.

  37. Barkhordar R A, Stewart G G. The potential of periodontal pocket formation associated with untreated accessory root canals. Oral Surg Oral Med Oral Pathol 1990; 70: 769-772.

  38. Harrel S K. Occlusal forces as a risk factor for periodontal disease. Periodontol 2000 2003; 32: 111-117.

  39. Zhang W, Foss K, Wang B-Y. A retrospective study on molar furcation assessment via clinical detection, intraoral radiography and cone beam computed tomography. BMC Oral Health 2018; 18: 75.

  40. Graetz C, Plaumann A, Wiebe J-F, Springer C, Sälzer S, Dörfer C E. Periodontal probing versus radiographs for the diagnosis of furcation involvement. J Periodontol 2014; 85: 1371-1379.

  41. Walter C, Weiger R, Zitzmann N U. Accuracy of three-dimensional imaging in assessing maxillary molar furcation involvement. J Clin Periodontol 2010; 37: 436-441.

  42. Pitale U, Mankad H, Pandey R, Pal P C, Dhakad S, Mittal A. Comparative evaluation of the precision of cone-beam computed tomography and surgical intervention in the determination of periodontal bone defects: A clinicoradiographic study. J Indian Soc Periodontol 2020; 24: 127-134.

  43. Tal H, Lemmer J. Furcal defects in dry mandibles. Part II: Severity of furcal defects. J Periodontol 1982; 53: 364-367.

  44. Eskow R N, Kapin S H. Furcation invasions: correlating a classification system with therapeutic considerations. Part I. Examination, diagnosis, and classification. Compend Contin Educ Dent (Lawrenceville) 1984; 5: 479-487.

  45. Hou G L, Chen Y M, Tsai C C, Weisgold A S. A new classification of molar furcation involvement based on the root trunk and horizontal and vertical bone loss. Int J Periodontics Restorative Dent 1998; 18: 257-265.

  46. Walter C, Kaner D, Berndt D C, Weiger R, Zitzmann N U. Three-dimensional imaging as a pre-operative tool in decision making for furcation surgery. J Clin Periodontol 2009; 36: 250-257.

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To Dr Kitichai Janaphan for providing clinical cases for this publication.


Thomas Gill and Priya Bahal are National Institute for Health and Care Research-funded academic clinical fellows.

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Thomas Gill and Priya Bahal contributed to design, article writing and approval of the article. Luigi Nibali contributed to review of the article.

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Correspondence to Thomas Gill.

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Gill, T., Bahal, P. & Nibali, L. Furcation-involved molar teeth - part 1: prevalence, classification and assessment. Br Dent J 233, 847–852 (2022).

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