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Can lower third molar position indicate the need for preoperative cone beam computed tomography exploration of retromolar canal?

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Abstract

Objectives

This study aims to reveal whether and which position of lower third molar (M3), assessed on a 2D image, indicates or potentially exclude the need for the CBCT exploration of the retromolar canal (RMC). We hypothesized that some positions of M3 are associated with overall higher incidence of the RMC, and particularly clinically relevant ones, thus justifying additional CBCT diagnostics.

Methods

CBCT exam of 186 hemi-mandibles with present M3 were selected for the study. Explorations were made during the 2-year period from January 1th 2018 to December 31th 2019 with Scanora 3Dx Sorodex (Tussula, Finland). The following variables were assessed: the presence and width of the RMC, eruption status, and angulation of the M3. The RMC presence in relation to the M3 eruption status and angulation was analyzed using appropriate statistical tests.

Results

RMC was present in 89 (47.8%) out of 186 hemi-mandibles. Mean canal width was 1.51 mm. 22.5% of detected canals had the diameter exceeding 2 mm. Third molar’s eruption status showed no statistical correlation with the occurrence of RMC. We observed significantly higher occurrence of RMC in the hemi-mandibles containing distally angulated M3 in comparison to other orientations (p = 0.025).

Conclusion

Based upon our findings, we recommend preoperative CBCT in cases where distal angulation of M3 is observed on 2D images, for the purpose of RMC exploration. Lower resolution CBCT mode and limited field of view (XS or S) are sufficient for the visualization of potentially clinically relevant RMCs, with as much reducing the patient dose.

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References

  1. Schejtman R, Devoto FC, Arias NH. The origin and distribution of the elements of the human mandibular retromolar canal. Arch Oral Biol. 1967;12:1261–7.

    Article  Google Scholar 

  2. Bilecenoglu B, Tuncer N. Clinical and anatomical study of retromolar foramen and canal. J Oral Maxillofac Surg. 2006;64:1493–7.

    Article  Google Scholar 

  3. Alves N, Deana NF. Anatomical and radiographical study of the retromolar canal and retromolar foramen in macerated mandibles. Int J Clin Exp Med. 2015;15:4292–6.

    Google Scholar 

  4. Moreno Rabie C, Vranckx M, Rusque MI, Deambrosi C, Ockerman A, Politis C, Jacobs R. Anatomical relation of third molars and the retromolar canal. Br J Oral Maxillofac Surg. 2019;57:765–70.

    Article  Google Scholar 

  5. Gamieldien MY, Van Schoor A. Retromolar foramen: an anatomical study with clinical considerations. Br J Oral Maxillofac Surg. 2016;54:784–7.

    Article  Google Scholar 

  6. Kikuta S, Iwanaga J, Nakamura K, Hino K, Nakamura M, Kusukawa J. The retromolar canals and foramina: radiographic observation and application to oral surgery. Surg Radiol Anat. 2018;40:647–52.

    Article  Google Scholar 

  7. Hou Y, Feng G, Lin W, Wang R, Yuan H. Observation of retromolar canals on cone beam computed tomography. Oral Radiol. 2020;36:365–70.

    Article  Google Scholar 

  8. Patil S, Matsuda Y, Nakajima K, Araki K, Okano T. Retromolar canals as observed on cone-beam computed tomography: their incidence, course, and characteristics. Oral Surg Oral Med Oral Pathol Oral Radiol. 2013;115:692–9.

    Article  Google Scholar 

  9. Truong MK, He P, Adeeb N, Oskouian RJ, Tubbs RS, Iwanaga J. Clinical anatomy and significance of the retromolar foramina and their canals: a literature review. Cureus. 2017;9: e1781.

    PubMed  PubMed Central  Google Scholar 

  10. Capote TS, Gonçalves MA, Campos JA. Retromolar canal associated with age, side, sex, bifid mandibular canal, and accessory mental foramen in panoramic radiographs of Brazilians. Anat Res Int. 2015;2015:434083.

    PubMed  PubMed Central  Google Scholar 

  11. Sisman Y, Sekerci AE, Payveren-Arikan M, Sahman H. Diagnostic accuracy of cone-beam CT compared with panoramic images in predicting retromolar canal during extraction of impacted mandibular third molars. Med Oral Patol Oral Cir Bucal. 2015;20:74–81.

    Article  Google Scholar 

  12. De Oliveira-Santos C, Souza PH, de Azambuja B-C, Stinkens L, Moyaert K, Rubira-Bullen IR, Jacobs R. Assessment of variations of the mandibular canal through cone beam computed tomography. Clin Oral Investig. 2012;16:387–93.

    Article  Google Scholar 

  13. Iida S, Hassfeld S, Reuther T, Nomura K, Mühling J. Relationship between the risk of mandibular angle fractures and the status of incompletely erupted mandibular third molars. J Craniomaxillofac Surg. 2005;33:158–63.

    Article  Google Scholar 

  14. Antic S, Milicic B, Jelovac DB, Djuric M. Impact of the lower third molar and injury mechanism on the risk of mandibular angle and condylar fracture. Dent Traumatol. 2016;32:286–95.

    Article  Google Scholar 

  15. Winter G. Principles of Exodontia as applied to the impacted third molars. St. Louis: American Medical Book Company; 1926.

    Google Scholar 

  16. Ludlow JB, Davies-Ludlow LE, White SC. Patient risk related to common dental radiographic examinations: the impact of 2007 International Commission on Radiological Protection recommendations regarding dose calculation. J Am Dent Assoc. 2008;139:1237–43.

    Article  Google Scholar 

  17. Shin HS, Nam KC, Park H, Choi HU, Kim HY, Park CS. Effective doses from panoramic radiography and CBCT (cone beam CT) using dose area product (DAP) in dentistry. Dentomaxillofac Radiol. 2014;43:20130439.

    Article  Google Scholar 

  18. Qiang W, Qiang F, Lin L. Estimation of effective dose of dental x-ray devices. Radiat Prot Dosimetry. 2019;183:417–21.

    Article  Google Scholar 

  19. Ludlow JB, Timothy R, Walker C, Hunter R, Benavides E, Samuelson DB, Scheske MJ. Effective dose of dental CBCT-a meta analysis of published data and additional data for nine CBCT units. Dentomaxillofac Radiol. 2015;44:20140197.

    Article  Google Scholar 

  20. Oenning AC, Jacobs R, Pauwels R, Stratis A, Hedesiu M, Salmon B, DIMITRA Research Group. Cone-beam CT in paediatric dentistry: DIMITRA project position statement. Pediatr Radiol. 2018;48:308–16.

    Article  Google Scholar 

  21. Luangchana P, Pornprasertsuk-Damrongsri S, Kitisubkanchana J, Wongchuensoontorn C. The retromolar canal and its variations: Classification using cone beam computed tomography. Quintessence Int. 2018;49:61–7.

    PubMed  Google Scholar 

  22. Nikkerdar N, Golshah A, Norouzi M, Falah-Kooshki S. Incidence and anatomical properties of retromolar canal in an Iranian population: a cone-beam computed tomography study. Int J Dent. 2020;9:9178973.

    Google Scholar 

  23. von Arx T, Hänni A, Sendi P, Buser D, Bornstein MM. Radiographic study of the mandibular retromolar canal: an anatomic structure with clinical importance. J Endod. 2011;37:1630–5.

    Article  Google Scholar 

  24. Narayana K, Nayak UA, Ahmed WN, Bhat JG, Devaiah BA. The retromolar foramen and canal in south Indian dry mandibles. Eur J Anat. 2002;6:141–6.

    Google Scholar 

  25. Schneider T, Filo K, Kruse AL, Locher M, Grätz KW, Lübbers HT. Variations in the anatomical positioning of impacted mandibular wisdom teeth and their practical implications. Swiss Dent J. 2014;124:520–38.

    PubMed  Google Scholar 

  26. Quek SL, Tay CK, Tay KH, Toh SL, Lim KC. Pattern of third molar impaction in a Singapore Chinese population: a retrospective radiographic survey. Int J Oral Maxillofac Surg. 2003;32:548–52.

    Article  Google Scholar 

  27. Matzenn LH, Wenzel A. Efficacy of CBCT for assessment of impacted mandibular third molars: a review – based on a hierarchical model of evidence. Dentomaxillofac Radiol. 2015;44:20140189.

    Article  Google Scholar 

  28. Kim TS, Caruso JM, Christensen H, Torabinejad M. A comparison of Cone-Beam Computed Tomography and direct measurement in the examination of the mandibular canal and adjacent structures. J Endodont. 2010;36:1191–4.

    Article  Google Scholar 

  29. Maret D, Telmon N, Peters OA, Lepage B, Treil J, Inglese JM, Peyre A, Kahn JL, Sixou M. Effect of voxel size on the accuracy of 3D reconstructions with cone beam CT. Dentomaxillofac Radiol. 2012;41:649–55.

    Article  Google Scholar 

  30. Palma LF, Buck AF, Kfouri FA, Blachman IT, Lombardi LA, Cavalli MA. Evaluation of retromolar canals on cone beam computerized tomography scans and digital panoramic radiographs. Oral Maxillofac Surg. 2017;21:307–12.

    Article  Google Scholar 

  31. Ngeow WC, Chai WL. The clinical significance of the retromolar canal and foramen in dentistry. Clin Anat. 2021;34:512–21.

    Article  Google Scholar 

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Correspondence to Svetlana Antic.

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Antic, S., Markovic-Vasiljkovic, B., Radivojević, O. et al. Can lower third molar position indicate the need for preoperative cone beam computed tomography exploration of retromolar canal?. Oral Radiol 38, 618–624 (2022). https://doi.org/10.1007/s11282-022-00597-z

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  • DOI: https://doi.org/10.1007/s11282-022-00597-z

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