Objective: To investigate buccal and lingual bone thicknesses and fenestration rate of mandibular first and second molars using cone-beam computed tomography (CBCT).

Methods: A total of CBCT images of 41 patients were selected and overall 120 mandibular molars were investigated. The buccal and lingual alveolar bone widths were measured at apex of the roots. The prevalence of fenestration in mandibular molars was recorded. Statistical analyses were performed.

Results: The buccal bone widths of mesial root of second molars were significantly lower than the lingual (p<0.05). The lingual bone widths of mesial and distal root of second molars were lower than the buccal (p<0.05). The lowest thickness of buccal and lingual bone was observed in mesial root of first molar and distal root of second molar. The prevalence of fenestration in mandibular first and second molars was 5% and 10%.

Conclusion: The buccal bone widths were lower at the first molar than the second molar. All fenestrations in first molar were in buccal aspect, in second molar were in lingual aspect. Topographical proximity of the buccal side of first molar and the lingual side of second molar to bone plate create a risky region for endodontic treatment or spread of infection.


  1. Fragiskos D. (2007), Oral Surgery. 1st ed Springer - Verlag Berlin Heidelberg.
  2. Siqueira JF. Endodontic infections: concepts, paradigms, and perspectives. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2002;94(3):281-93.
  3. Glossary of Endodontic Terms - American Association of Endodontists. Accessed February 11, 2021. https://www.aae.org/specialty/clinical-resources/glossary-endodontic-terms/
  4. Rupprecht RD, Horning GM, Nicoll BK, Cohen ME. Prevalence of dehiscences and fenestrations in modern American skulls. J Periodontol. 2001;72(6):722-29.
  5. Boucher Y. Persistent pain related to root canal filling and apical fenestration: A case report. J Endod. 2000;26(4):242-4.
  6. Sun Z, Smith T, Kortam S, Kim DG, Tee BC, Fields H. Effect of bone thickness on alveolar bone-height measurements from cone-beam computed tomography images. Am J Orthod Dentofacial Orthop. 2011;139(2):117-27.
  7. Pan HY, Yang H, Zhang R, et al. Use of cone-beam computed tomography to evaluate the prevalence of root fenestration in a Chinese subpopulation. Int Endod J. 2014;47(1):10-9.
  8. Wang D, He X, Wang Y, Zhou G, Sun C, Yang L, et al. Topographic relationship between root apex of mesially and horizontally impacted mandibular third molar and lingual plate: cross-sectional analysis using CBCT. Sci Rep. 2016;6(1):1-10.
  9. Castro LO, Castro IO, De Alencar AHG, Valladares-Neto J, Estrela C. Cone beam computed tomography evaluation of distance from cementoenamel junction to alveolar crest before and after nonextraction orthodontic treatment. Angle Orthod. 2016;86(4):543-9.
  10. Ohshima A, Ariji Y, Goto M, Izumi M, Naitoh M, Kurita K, et al. Anatomical considerations for the spread of odontogenic infection originating from the pericoronitis of impacted mandibular third molar: Computed tomographic analyses. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004;98(5):589-97.
  11. Qahash M, Susin C, Polimeni G, Hall J, Wikesjö UME. Bone heali ng dy nam ics at buccal peri-implant sites. Clin Oral Implants Res. 2008;19(2):166-72.
  12. Braut V, Bornstein MM, Lauber R, Buser D. Bone dimensions in the posterior mandible: a retrospective radiographic study using cone beam computed tomography. Part 1--analysis of dentate sites. Int J Periodontics Restorative Dent. 2012;32(2):175-84.
  13. Nowzari H, Molayem S, Chiu CHK, Rich SK. Cone beam computed tomographic measurement of maxillary central incisors to determine prevalence of facial alveolar bone width ≥2 mm. Clin Implant Dent Relat Res. 2012;14(4):595-602.
  14. Chen I, Karabucak B, Wang C, Wang Hg, Koyama E, Kohli Mr, et al. Healing after root-end microsurgery by using mineral trioxide aggregate and a new calcium silicate-based bioceramic material as root-end filling materials in dogs. J Endod. 2015;41(3):389-99.
  15. von Arx T, Janner SFM, Hänni S, Bornstein MM. Agreement between 2D and 3D radiographic outcome assessment one year after periapical surgery. Int Endod J. 2016;49(10):915-25.
  16. Wang X, Chen K, Wang S, Tiwari SK, Ye L, Peng L. Relationship between the mental foramen, mandibular canal, and the surgical access line of the mandibular posterior teeth: A Cone-beam Computed Tomographic Analysis. J Endod. 2017;43(8):1262-6.
  17. Zahedi S, Mostafavi M, Lotfirikan N. Anatomic study of mandibular posterior teeth using cone-beam computed tomography for endodontic surgery. J Endod. 2018;44(5):738-43.
  18. Kim D, Ha JH, Jin MU, Kim YK, Kim SK. Proximity of the mandibular molar root apex from the buccal bone surface: a cone-beam computed tomographic study. Restor Dent Endod. 2016;41(3):182-8.
  19. Jin G-C, Kim KD, Roh BD, Lee CY, Lee SJ. Buccal bone plate thickness of the Asian people. J Endod. 2005;31(6):430-4.
  20. Uğur Aydın Z, Göller Bulut D. Relationship between the anatomic structures and mandibular posterior teeth for endodontic surgery in a Turkish population: a cone-beam computed tomographic analysis. Clin Oral Investig. 2019;23(9):3637-44.
  21. Jhaveri HM, Amberkar S, Galav L, Deshmukh VL, Aggarwal S. Management of mucosal fenestrations by interdisciplinary approach: A Report of Three Cases. J Endod. 2010;36(1):164-8.
  22. Jorgić-Srdjak K, Plancak D, Bosnjak A, Azinović Z. Incidence and distribution of dehiscences and fenestrations on human skulls. Coll Antropol. 1999;22 Suppl:111-6.
  23. Edel A. Alveolar bone fenest rations and dehiscences in dry Bedouin jaws. J Clin Periodontol. 1981;8(6):491-99.
  24. Davies RM, Downer MC, Hull PS, Lennon MA. Alveolar defects in human skulls. J Clin Periodontol. 1974;1(2):107-11.
  25. Abdelmalek RG, Bissada NF. Incidence and distribution of alveolar bony dehiscence and fenestration in dry human Egyptian jaws. J Periodontol. 1973;44(9):586-8.
  26. Nimigean VR, Nimigean V, Bencze MA, Dimcevici-Poesina N, Cergan R, Moraru S. Alveolar bone dehiscences and fenestrations: an anatomical study and review. Romanian J Morphol Embryol Rev Roum Morphol Embryol. 2009;50(3):391-7.
  27. Larato DC. Alveolar plate fenestrations and dehiscences of the human skull. Oral Surg Oral Med Oral Pathol. 1970;29(6):816-9



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