Incidence and effect of an extra root on the crown morphometry of the maxillary second molars among Malaysian Mongoloids
Abstract
Background: This study aimed to investigate whether the presence of two palatal roots on permanent maxillary second molars (MSMs) can affect the crown size and crown’s buccolingual and mesiodistal diameters.
Materials and methods: A retrospective study was conducted using 592 CBCT scans to investigate 1120 MSMs of Mongoloid Malaysians. 3D models were created to assess the four-rooted MSMs and other related teeth carefully. Crown size and crown’s buccolingual and mesiodistal diameters were measured for the four-rooted MSM, the adjacent maxillary first molar (MFM), and their antimeres to investigate the effect of the presence of an extra root on the size and morphological features of the crown of these associated teeth.
Results: Only six out of the 1120 MSMs displayed four roots (0.53%). The incidence was 0.67% (2/298) for the Malay males and 0.4% (1/247) for the Malay females, with the Malay male having a bilateral occurrence of four-rooted MSM. The incidence was 0.34% (1/294) for the Chinese males, while 0.71% (2/281) was detected in Chinese females. Interestingly, the four-rooted MSMs showed a wider mesiodistal distance than their three-rooted antimeres in three out of four cases. The presence of two palatal roots may also increase the crown’s buccolingual diameter.
Conclusions: The presence of anatomical variations and the dramatic change in crown measurements can be good indicators of the presence of extra roots, including in some of their related neighbours. This might help dentists to take precautionary measures when performing tooth extractions and endodontic therapy.
Keywords: crown morphometrymaxillary second molarsMalaysian
References
- Ahmed HMA, Abbott PV. Accessory roots in maxillary molar teeth: a review and endodontic considerations. Aust Dent J. 2012; 57(2): 123–131; quiz 248.
- Carlsen O, Alexandersen V. Radix mesiolingualis and radix distolingualis in a collection of permanent maxillary molars. Acta Odontol Scand. 2000; 58(5): 229–236.
- Aydın H. Relationship between crown and root canal anatomy of four-rooted maxillary molar teeth. Aust Endod J. 2021; 47(2): 298–306.
- Azim AA, Azim KA, Deutsch AS, et al. Acquisition of anatomic parameters concerning molar pulp chamber landmarks using cone-beam computed tomography. J Endod. 2014; 40(9): 1298–1302.
- Baratto-Filho F, Fariniuk LF, Ferreira EL, et al. Clinical and macroscopic study of maxillary molars with two palatal roots. Int Endod J. 2002; 35(9): 796–801.
- Borghesi A, Michelini S, Tononcelli E, et al. Five-rooted permanent maxillary second molar: CBCT findings of an extremely rare anatomical variant. Radiol Case Rep. 2019; 14(9): 1113–1116.
- Candeiro GT, Gonçalves SD, Lopes LL, et al. Internal configuration of maxillary molars in a subpopulation of Brazil's Northeast region: A CBCT analysis. Braz Oral Res. 2019; 33: e082.
- Christie WH, Peikoff MD, Fogel HM. Maxillary molars with two palatal roots: A retrospective clinical study. J Endod. 1991; 17(2): 80–84.
- Nardo DDi. 3D clinical evaluation of unusual anatomy of a maxillary second molar: a case report. Biomed J Sci & Tech Res. 2018; 2(1).
- Gu Y, Wang W, Ni L. Four-rooted permanent maxillary first and second molars in a northwestern Chinese population. Arch Oral Biol. 2015; 60(6): 811–817.
- Harris EF. Carabelli's trait and tooth size of human maxillary first molars. Am J Phys Anthropol. 2007; 132(2): 238–246.
- Hennekam R, Biesecker L, Allanson J, et al. Elements of morphology: General terms for congenital anomalies. Am J Med Genet A. 2013; 161(11): 2726–2733.
- Hitij T, Štamfelj I. The role of clinical examination in the detection of permanent maxillary molars with two palatal roots. Folia Morphol. 2020; 79(1): 127–133.
- Hitij T, Štamfelj I. The role of clinical examination in the detection of permanent maxillary molars with two palatal roots. Folia Morphol. 2015; 79(1): 127–133.
- Inoue T, Saito M, Nishimura F, et al. Unusual root canal anatomy in a maxillary second molar. Int J Case Rep Imag. 2017; 8(5): 352–354.
- Kanazawa E, Sekikawa M, Ozaki T. A quantitative investigation of irregular cuspules in human maxillary permanent molars. Am J Phys Anthropol. 2005; 83(2): 173–180.
- Kim Y, Lee SJ, Woo J. Morphology of maxillary first and second molars analyzed by cone-beam computed tomography in a korean population: variations in the number of roots and canals and the incidence of fusion. J Endod. 2012; 38(8): 1063–1068.
- Kondo S, Townsend GC. Associations between Carabelli trait and cusp areas in human permanent maxillary first molars. Am J Phys Anthropol. 2006; 129(2): 196–203.
- Kraus B. Occurrence of the carabelli trait in southwest ethnic groups. Am J Phys Anthropol. 2005; 17(2): 117–123.
- Libfeld H, Rotstein I. Incidence of four-rooted maxillary second molars: literature review and radiographic survey of 1,200 teeth. J Endod. 1989; 15(3): 129–131.
- Madhuram K, Dhanavel C, Naveen V, et al. Corono radicular anomaly in a maxillary first molar – a rare case report. 2012. J Integr Dent. 2012; 1: 41–44.
- Magnucki G, Mietling SVK. Four-Rooted maxillary first molars: a systematic review and meta-analysis. Int J Dent. 2021; 2021: 8845442.
- Manjunatha BS, Soni NK. Estimation of age from development and eruption of teeth. J Forensic Dent Sci. 2014; 6(2): 73–76.
- Nikhil V, Jha P, Mishra P, et al. Two palatal roots in maxillary first molar, a rare entity: report of two cases. J Dent. 2024; 25(2): 178–182.
- Ramasamy S. A rare clinical phenomenon of four rooted maxillary second molar: A case report. Saudi J Dent Res. 2015; 6(1): 30–32.
- Scott GR, Irish J. Human tooth crown and root morphology. 2017.
- Silva EJ, Nejaim Y, Silva AIV, et al. Evaluation of root canal configuration of maxillary molars in a Brazilian population using cone-beam computed tomographic imaging: an in vivo study. J Endod. 2014; 40(2): 173–176.
- Slowey RR. Radiographic aids in the detection of extra root canals. Oral Surg Oral Med Oral Pathol. 1974; 37(5): 762–772.
- Versiani MA, Pécora J, Sousa-Neto Mde. Root and root canal morphology of four-rooted maxillary second molars: a micro–computed tomography study. J Endod. 2012; 38(7): 977–982.
- Vertucci FJ. Root canal morphology and its relationship to endodontic procedures. Endodontic Topics. 2005; 10(1): 3–29.
- Yu X, Guo B, Li KZ, et al. Cone-beam computed tomography study of root and canal morphology of mandibular premolars in a western Chinese population. BMC Medical Imaging. 2012; 18: 1–5.
- Zhao J, Li Y, Yang Z, et al. Three‐dimensional computed topography analysis of a patient with an unusual anatomy of the maxillary second and third molars. Int J Oral Sci. 2011; 3(4): 225–228.
