The Effect of Variations in the Vertical Position of the Bracket on the Crown Inclination

브라켓의 수직적 위치변동에 따른 치관경사도변화에 관한 연구

  • Chang, Yeon-Joo (Department of Orthodontics, College of Dentistry, Seoul National University) ;
  • Kim, Tae-Woo (Department of Orthodontics, College of Dentistry, Seoul National University) ;
  • Yoo, Kwan-Hee (Department of Computer Education, Chungbuk National University)
  • 장연주 (서울대학교 치과대학 치과교정학 교실) ;
  • 김태우 (서울대학교 치과대학 치과교정학 교실) ;
  • 유관희 (충북대학교 컴퓨터교육과)
  • Published : 2002.12.01

Abstract

Precise bracket positioning is essential in modem orthodontics. However, there can be alterations in the vertical position of a bracket due to several reasons. The purpose of this study was to evaluate the effect of variations in the vertical bracket position on the crown inclination in Korean patients with normal occlusion. From a larger group of what was considered to be normal occlusions obtained from the Department of Orthodontics, College of Dentistry, Seoul National University, each of the final 10 subjects (6 males and 4 females, with an average age of 22.3 yews) was selected. The dental models of each of the subjects were scanned three-dimensionally by a laser scanner, and measurements drawn from these were made on the scanned dental casts of the subjects were input into the computer program. From this the occlusal plane and the bracket plane were determined. The tooth plane was then constructed to measure the crown inclination on the bracket plane of each tooth. From a practical standpoint, information was obtained on the extent to which the torque of a tooth would be changed as the bracket position was to be moved vertically (in ${\pm}0.5mm,\;{\pm}1.0mm,\;{\pm}1.5mm$) from its ideal position. A one way analysis of the variance (ANOVA) was used to compare each group of the different vertical distances from the bracket plane on a specific tooth. Duncan's multiple comparison test was then performed. There were statistically significant differences in the crown inclination among the groups of different vertical distances for the upper central incisor, upper lateral incisor, upper canine, upper first and second molars, lower first and second premolars, and lower first and second molars (p<0.05). On the upper anterior teeth, upper molars, lower premolars and lower molars, the resultant torque values due to the vertical displacement of the bracket were different depending on the direction of the displacement, occlusal or gingival. This study implies that the torque of these teeth should be handled carefully during the orthodontic treatment. In circumstances in which the bracket must be positioned more gingivally or occlusally due to various reasons, it would be useful to provide the chart of torque alteration of each tooth referred to in this study with its specified bracket prescription.

정교한 교합을 달성하기 위해서는 브라켓을 정확하게 위치시키는 것이 필수적이다. 그러나, 많은 원인에 의해 브라켓의 위치가 변할 수 있다. 본 연구는 브라켓의 수직적 위치에 변화가 있을 때 이것이 치관경사도에 미치는 영향을 연구하고자 함이다. 연구대상으로는 서울대학교 치과대학 교정학교실의 정상교합자 표본 중 상태가 양호한 10명(남자 6명, 여자 4명, 평균 연령 22.3세)을 대상으로 하였으며 , 이들의 치아모형을 laser scanner를 이용, 3차원적으로 스캔을 시행하였고, 컴퓨터 프로그램 상에서 스캔된 치아모형에 대한 계측을 실시하였다. 각 모형에 대하여 Bracket plane을 설정하였고, 각 치아에서 Bracket plane에 수직이며 치아의 장축을 지나는 Tooth plane을 순협면에서 결정한 뒤 Bracket plane상에서의 치관경사도를 계측하였다. 이로부터 Bracket plane을 상하로 0.5mm, 1.0mm, 1.5mm 변위시켰을 때의 치관경사도를 계측하였다. 각 계측 항목에 대해 일원분산분석 (oneway ANOVA)과 Duncan's multiple comparison test를 시행하였다. 이상의 연구로부터 다음과 같은 결과를 얻었다. 1. 상악중절치, 측절치, 견치, 대구치와 하악소구치, 대구치에 있어서 브라켓의 수직적 위치가 변화함에 따라 치관경사도가 통계적으로 유의성 있게 차이 있는 것으로 나타났다(p<0.05). 2. 상악전치와 대구치, 하악소구치와 대구치에서는 기준평면으로부터 수직적으로 같은 양만큼 변위되었다 할지라도 보다 교합면쪽에 위치하는지, 보다 치은쪽에 위치하는지에 따라 치관경사도의 변화량이 다르게 나타났다. 3. 브라켓의 수직적 위치변화가 있을 경우 상악전치부와 대구치, 하악구치부, 이 중 특히 하악구치부의 치관경사도는 임상적으로 영향을 받게 되므로 브라켓을 위치시킬 때 주의를 요해야 할 것으로 생각된다.

Keywords

References

  1. Proffit WR. Comtemporary orthodontics. St Louis: CV Mosby, 1986
  2. Balut N, Klapper L, Sandrik J, Bowman D. Variations in bracket placement in the preadjusted orthodontic appliance. Am J Orthod Dentofac Orthop 1992 : 102 : 62-7 https://doi.org/10.1016/0889-5406(92)70015-3
  3. Swain BF. Interview by Sidney Bradt Dr Brainerd F. Swain on current appliance therapy. J Clin Orthod 1980 : 14 : 250-64
  4. Andrews LF. The straight-wire appliance. Br J Orthod 1979: 6 : 125-43 https://doi.org/10.1179/bjo.6.3.125
  5. Howells DJ. The straight-wire appliance. Dental Update 1986: 13 : 367-376
  6. Magness WB. The straight-wire concept. Am J Orthod 1978 : 73: 541-50
  7. McLaughlin RP. Case set-up, In : Course notes for the straight-wire appliance. San-Diego, 11-19
  8. Meyer M, Nelson G. Preadjusted edgewise appliances: theory and practice. Am J Orthod 1978 ; 73: 485-498 https://doi.org/10.1016/0002-9416(78)90239-7
  9. Ress LC. A finishing technique for the straight-wire appliance. J Clin Orthod 1988; 22 : 29-31
  10. Roth RH. Five year clinical evalution otlhe Andrews straight-wire appliace. J Clin Orthod 1976; 10: 836-850
  11. Carlson SK, Johnson E. Bracket positioning and resets: Five steps to align crowns and roots consistently. Am J Orthod Dentofac Orthop 2001 : 119 : 76-80 https://doi.org/10.1067/mod.2001.111220
  12. Andrews LF. Straight-wire: the concept and appliance, L.A. Wells 1989
  13. Alexander RG. The Vari-Simplex discipline, part I concept and appliance design. J Clin Orthod 1983 : 17: 380-392
  14. McLaughlin RP, Bennett JC. Bracket placement with the preadjusted appliace. J Clin Orthod 1995 : 29 : 302-311
  15. 이동주 Oriental Bracket. 대치교정지 1991 : 21 : 495-50
  16. 이선복,이동주. 한국인의 bracket위치에 관한 연구. 대치교정지 1986: 16 : 107-14
  17. Taylor NG, Cook PA. The reliability of positioning pre-adjusted brackets: An in vitro study. Br J Orthod 1992: 19 : 25-34 https://doi.org/10.1179/bjo.19.1.25
  18. Andrews LF. The straight-wire appliance, arch form, wire bending and an experiment. J Clin Orthod 1976 : 10 : 581-588
  19. Dellinger EL. A scientific assessment of the straight wire appliance. Am J Orthod 1978 : 73: 290-9 https://doi.org/10.1016/0002-9416(78)90135-5
  20. Thurow CR. Edgewise orthodontics. 3rd. ed. St. Louis: CV mosby, 1972
  21. Miethke RR, Melsen B. Effect of variation in tooth morphology and bracket position on first and third order correction with preadjusted appliances. Am J Orthod Dentofac Orthop 1999: 116 : 329-35 https://doi.org/10.1016/S0889-5406(99)70246-5
  22. 임성훈,윤영주,김광원. 변연융선평면을 계측기준으로 한 정상교합자의 구치부 치관경사도에 관한 연구. 대치교정지 1998 : 28 : 731-39
  23. 정돈영,손병화,박영철 정상교합자의 치관경사도에 관한연구. 대치교정지 1986: 16: 155-65
  24. 황해상,권오원. 정상교합자의 안이평면에 대한 개개 치아의 순,협설 측경사와 근원심경사. 대치교정지 1998 : 28 : 791-801
  25. Miethke RR. Third order tooth movements with straight wire appliances. Influence of vestibular tooth crown morphology in the vertical plane. J Orofac Orthop 1997: 58 : 186-97 https://doi.org/10.1007/BF02679959
  26. 김은정,황현식. 컴퓨터를 이용한 치아크기계측시 재현도와 정확도에 관한 연구. 대치교정지 1999 : 29 : 563-573
  27. 이원유,박영절,임경수. Straight Wire Appliance를 위한 한국인 정상 교합자의 치관형태에 관한 연구. 대치교정지 1998 : 28 : 601 -609
  28. Richmond S. Recording the dental cast in three dimensions. Am J Orthod Dentofac Orthop 1987 : 92 : 199-206 https://doi.org/10.1016/0889-5406(87)90412-4
  29. 문성철,장영일. 위상측정기를 사용한 상악치아 순. 협면의 형태학적분석. 서울대학교 대학원 박사학위청구논문 2000
  30. Sohmura T, Kojima T, Wakabayashi K. Takahashi J. Use of an ultrahigh-speed laser scanner for constructing three-dimensional shapes of dentition and occlusion. J Prosthet Dent 2000 : 84 : 345-52 https://doi.org/10.1067/mpr.2000.109786
  31. Yukio S, Minoru Y, Naohide S, Hiroyuki M, Masanori S, Kimio S, Hirokazu N, Kohki O, Ryohei K. Application of a high accuracy three-dimensional optical measurement system for dental casts using the grid pattern projection method. Orthod Waves 2001 : 60: 247-255
  32. Andrews LF. Straight-wire appliance, origin, controversy, commentary. J Clin Orthod 1976: 10:99-114
  33. 김종성, 진근호,홍성준. 한국인 정상교합자의 치관경사도에 관한 임상통계학적 연구. 대치교정지 1992: 22 : 715-33
  34. Vardimon AD, Lambertz W. Statistical evaluation of torque angles in reference to straight-Wire appliance(SWA) theories. Am J Orthod Dentofac Orthop 1986 : 89 : 56-66
  35. Vardimon AD, Lambertz W. Statistical evaluation of torque angles in reference to straight-Wire appliance(SWA) theories. Am J Orthod Dentofac Orthop 1986 : 89 : 56-66
  36. Hixson ME, Brantley WA, Pincsak JJ, Conover JP. Changes in bracket slot tolerance following recycling of direct-bond metallic orthodontic appliances. Am J Orthod 1982 : 81 : 447-54 https://doi.org/10.1016/0002-9416(82)90422-5
  37. Creekmore TD, Kunik RL. Straight-wire: the next generation. Am J Orthod Dentofac Orthop 1993 : 104 : 8-20 https://doi.org/10.1016/0889-5406(93)70023-H
  38. Ugur T, Yukay F. Normal faciolingual inclinations of tooth crowns compared with treatment groups of standard and pretorqued brackets. Am J Orthod Dentofac Orthop 1997 : 112 : 50-7 https://doi.org/10.1016/S0889-5406(97)70273-7