DOI QR코드

DOI QR Code

Radiographic assessment of clinical root-crown ratios of permanent teeth in a healthy Korean population

  • Yun, Hee-Jung (Department of Advanced General Dentistry, College of Dentistry, Yonsei University) ;
  • Jeong, Jin-Sun (Department of Advanced General Dentistry, College of Dentistry, Yonsei University) ;
  • Pang, Nan-Sim (Department of Advanced General Dentistry, College of Dentistry, Yonsei University) ;
  • Kwon, Il-Keun (Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University) ;
  • Jung, Bock-Young (Department of Advanced General Dentistry, College of Dentistry, Yonsei University)
  • Received : 2013.09.04
  • Accepted : 2014.05.15
  • Published : 2014.06.30

Abstract

PURPOSE. The aim of this study was to determine the absolute value of the root/crown ratio (R/C ratio) using panoramic radiographs (PRGs) in a healthy Korean population. MATERIALS AND METHODS. In total, 99 patient radiographs (of 50 males and 49 females subjects; aged 16 to 24 years old) were examined, and 2,770 teeth were analyzed. Crown lengths and root lengths were measured with modified Lind's measurements using PACS tools by two examiners in two separate sessions two months apart. All data were analyzed using SPSS. The independent t-test was used to assess for gender differences, and the paired t-test was used to compare both arches with a significance level of P<.05. RESULTS. The mean R/C ratios varied from 1.29 to 1.89 (male: 1.28-1.84; females: 1.31-1.94). The highest R/C ratios were recorded for the mandibular canines (1.89), followed by the maxillary canines (1.79). The lowest R/C ratios were recorded for the maxillary second molars (1.31). In comparison with the maxillary teeth (1.29-1.78), the mandibular teeth yielded the higher R/C ratio (1.47-1.89), and this difference was significant in the females (P<.05). The difference between the genders was not statistically significant, except for the maxillary central incisors, mandibular canines and mandibular first premolars. CONCLUSION. These data may enhance the understanding of the clinical R/C ratio as a useful guideline for determining the status of teeth and the ethnic difference.

Keywords

References

  1. Grossmann Y, Sadan A. The prosthodontic concept of crown-to-root ratio: a review of the literature. J Prosthet Dent 2005;93:559-62. https://doi.org/10.1016/j.prosdent.2005.03.006
  2. Reynolds JM. Abutment selection for fixed prosthodontics. J Prosthet Dent 1968;19:483-8. https://doi.org/10.1016/0022-3913(68)90064-4
  3. Nyman SR, Lang NP. Tooth mobility and the biological rationale for splinting teeth. Periodontol 2000 1994;4:15-22. https://doi.org/10.1111/j.1600-0757.1994.tb00002.x
  4. Nyman S, Lindhe J, Lundgren D. The role of occlusion for the stability of fixed bridges in patients with reduced periodontal tissue support. J Clin Periodontol 1975;2:53-66. https://doi.org/10.1111/j.1600-051X.1975.tb01726.x
  5. Sorensen JA, Martinoff JT. Endodontically treated teeth as abutments. J Prosthet Dent 1985;53:631-6. https://doi.org/10.1016/0022-3913(85)90008-3
  6. Goodacre CJ, Spolnik KJ. The prosthodontic management of endodontically treated teeth: a literature review. Part I. Success and failure data, treatment concepts. J Prosthodont 1994;3:243-50. https://doi.org/10.1111/j.1532-849X.1994.tb00162.x
  7. Johnston JF, Dykema RW, Goodacre CJ, Phillips RW, Johnston JF. Johnston's Modern practice in fixed prosthodontics. 4th ed. Philadelphia; Saunders; 1986. p. 8-21.
  8. Shillingburg HT. Fundamentals of fixed prosthodontics. 3rd ed. Chicago; Quintessence Pub. Co.; 1997. p. 85-103, 191-202.
  9. Rosenstiel SF. Contemporary fixed prosthodontics. 3rd ed. St. Louis; Mosby; 2000. p. 46-64.
  10. Carr AB, Brown DT, McGivney GP. McCracken's removable partial prosthodontics. 11th ed. St. Louis; MO; Mosby/ Elsevier; 2005. p. 189-229.
  11. Penny RE, Kraal JH. Crown-to-root ratio: its significance in restorative dentistry. J Prosthet Dent 1979;42:34-8. https://doi.org/10.1016/0022-3913(79)90327-5
  12. Jepsen A. Root surface measurement and a method for x-ray determination of root surface area. Acta Odontol Scand 1963;21:35-46. https://doi.org/10.3109/00016356309019777
  13. Schluger S, Schluger S. Periodontal diseases: Basic phenomena, clinical management, and occlusal and restorative interrelationships. 2nd ed. Philadelphia; PA; Lea & Febiger; 1990. p. 666-706.
  14. Wilson TG, Kornman KS. Fundamentals of periodontics. 2nd ed. Chicago; Quintessence Pub. Co.; 2003. p. 531-9.
  15. Lind V. Short root anomaly. Scand J Dent Res 1972;80:85-93.
  16. Holtta P, Nystrom M, Evalahti M, Alaluusua S. Root-crown ratios of permanent teeth in a healthy Finnish population assessed from panoramic radiographs. Eur J Orthod 2004;26: 491-7. https://doi.org/10.1093/ejo/26.5.491
  17. Lachin JM. The role of measurement reliability in clinical trials. Clin Trials 2004;1:553-66. https://doi.org/10.1191/1740774504cn057oa
  18. Larheim TA, Svanaes DB. Reproducibility of rotational panoramic radiography: mandibular linear dimensions and angles. Am J Orthod Dentofacial Orthop 1986;90:45-51. https://doi.org/10.1016/0889-5406(86)90026-0
  19. Pepelassi EA, Diamanti-Kipioti A. Selection of the most accurate method of conventional radiography for the assessment of periodontal osseous destruction. J Clin Periodontol 1997;24:557-67. https://doi.org/10.1111/j.1600-051X.1997.tb00229.x
  20. Brook AH, Holt RD. The relationship of crown length to root length in permanent maxillary central incisors. Proc Br Paedod Soc 1978;8:17-20.
  21. Laster WS, Ludlow JB, Bailey LJ, Hershey HG. Accuracy of measurements of mandibular anatomy and prediction of asymmetry in panoramic radiographic images. Dentomaxillofac Radiol 2005;34:343-9. https://doi.org/10.1259/dmfr/28020783
  22. Yim JH, Ryu DM, Lee BS, Kwon YD. Analysis of digitalized panorama and cone beam computed tomographic image distortion for the diagnosis of dental implant surgery. J Craniofac Surg 2011;22:669-73. https://doi.org/10.1097/SCS.0b013e31820745a7
  23. Avila G, Galindo-Moreno P, Soehren S, Misch CE, Morelli T, Wang HL. A novel decision-making process for tooth retention or extraction. J Periodontol 2009;80:476-91. https://doi.org/10.1902/jop.2009.080454
  24. Tylman SD. Theory and practice of crown and fixed partial prosthodontics (bridge). 6th ed. St. Louis; Mosby; 1970.

Cited by

  1. The Impact of the Crown-Root Ratio on Survival of Abutment Teeth for Dentures vol.94, pp.9_suppl, 2015, https://doi.org/10.1177/0022034515589710
  2. Cone-beam computed tomography for the assessment of root–crown ratios of the maxillary and mandibular incisors in a Korean population vol.47, pp.1, 2017, https://doi.org/10.4041/kjod.2017.47.1.39
  3. Analysis of the width ratio and wear rate of maxillary anterior teeth in the Korean population vol.9, pp.2, 2017, https://doi.org/10.4047/jap.2017.9.2.93
  4. Ethnic differences in the root to crown ratios of the permanent dentition pp.16016335, 2019, https://doi.org/10.1111/ocr.12288
  5. Reassessment of fluctuating dental asymmetry in Down syndrome vol.7, pp.None, 2014, https://doi.org/10.1038/s41598-017-16798-0
  6. Expanding torque possibilities: A skeletally anchored torqued cantilever for uprighting “kissing molars” vol.153, pp.4, 2018, https://doi.org/10.1016/j.ajodo.2017.12.006
  7. Orthodontic management in a female patient with an impacted incisor in the mandible - case report vol.14, pp.2, 2014, https://doi.org/10.5604/01.3001.0012.2034
  8. Root-crown ratio: a new method for measurement of orthodontic external apical root resorption vol.79, pp.1, 2020, https://doi.org/10.1080/13440241.2020.1712823
  9. Analysis of the distribution of supernumerary teeth and the characteristics of mesiodens in Bengbu, China: a retrospective study vol.37, pp.2, 2014, https://doi.org/10.1007/s11282-020-00432-3
  10. Association between Smoking during Pregnancy and Short Root Anomaly in Offspring vol.18, pp.21, 2014, https://doi.org/10.3390/ijerph182111662