The korean journal of orthodontics (대한치과교정학회지)

The Korean Association Of Orthodontists (대한치과교정학회)
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The changes of root length and form in immature teeth after orthodontic treatment

교정치료시 발생하는 미완성 치근의 길이와 형태변화

  • Kim, Heyon-A (Department of Orthodontics, Pusan National University) ;
  • Park, Soo-Byung (Department of Orthodontics, Pusan National University)
  • 김현아 (부산대학교 치과대학 교정학 교실) ;
  • 박수병 (부산대학교 치과대학 교정학 교실)
  • Published : 2004.06.01
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Abstract

Previous studies have focused on the causes of root resorption after orthodontic treatment and treatment methods to reduce this phenomenon, and have been mainly associated with developed, mature roots. As parents become increasingly interested in their children's' dentition, orthodontists are performing fixed orthodontic treatment on patients of less than 10 years and before the completion of the immature root. Thus, the author evaluated the changes of root length and root form of maxillary immature incisors after orthodontic treatment, compared with those of mature teeth, and investigated the correlation according to gender, treatment duration, and displacement of incisors. The sample consisted of an immature root group of twenty-eight persons (between 8 and 10 years old) and a mature root group of thirty-one persons (between 11 and 15 years old). The crown and root length of the maxillary four incisors were measured with a periapical radiograph, changes in root length and crown-root ratio were calculated, and root form was classified according to a scoring system. The results were as follows. 1. The development of immature roots was not affected by orthodontic treatment and mostly showed normal root length and apical form. 2. Root length of immature teeth was sustained or became shorter, partially in long treatment duration or with open bite patients. Even though the teeth reached their normal root length, they demonstrated a blunt form. 3. Most of the mature roots showed mild resorption, and the form of mature roots was more blunt than the developed form of the immature roots (p<0.05). 4. The developed form of the immature roots was statistically related to treatment duration, while the form of the mature roots was significantly related to the displacement of incisors (p<0.05). 5. In contrast, other variables such as gender, classification of malocclusion, changes in overbite, and changes of U1 to SN showed no correlation with the root resorption of both groups.

교정치료에 대한 인지도 변화 및 보호자의 관심증가로 조기에 내원하는 환자가 많으며 그 중 일부가 전치부 치근첨이 완성되기 전인 10세 이전에 고정식 교정장치가 필요하게 된다 따라서 본 연구에서는 미완성 치근의 치료 전후 치근의 길이 변화를 측정하고 형태변화를 관찰하여 완성된 치근의 교정력에 의한 변화양상과 비교하고, 환자의 성별, 기간, 이동양상 등과의 연관성을 조사하였다. 상악의 전치부 치근첨이 완성되지 않은 상태에서 고정식 교정치료를 시작한 8~10세 환자 28명을 실험군으로 하고, 치근첨이 완성된 상태에서 고정식 교정치료를 시작한 11~15세 환자 31명을 대조군으로 삼았다. 상악 4전치의 치료 전후 치근단 방사선사진상에서 치관, 치근길이를 측정해서, 치근길이의 변화량, 치관/치근 비의 변화량을 계산했고 분류체 계에 따라 치근형태에 점수를 부여했다. 결과는 다음과 같다. 1. 대부분의 미완성 치근은 교정치료 후에도 치근 길이가 증가하였으며 정상적인 치근첨 형태를 보였다. 2. 치료기간이 길어지거나 개방교합의 경우, 미완성 치근이라도 치근길이가 증가하지 않거나 더 짧아진 경우도 있었으며 정상적인 길이가 되더라도 치근첨의 완성 형태가 뭉툭한 흡수 형태를 보였다. 3. 완성치근에서는 교정치료에 의하여 대부분의 치근이 경미한 치근흡수를 보였으며, 흡수된 치근첨의 형태는 미완성 치근의 완성형태보다 더 뭉툭하였다(p<0.05). 4, 미완성 치근에서는 치료기간과, 완성치근에서는 치아의 이동거리(U1 to facial plane의 변화량)와 유의한 상관관계를 보였다(P<0.05). 5. 미완성 치근, 완성치근 모두 성별, 부정교합 분류, 수직피개의 변화량, 두개저에 대한 치아의 위치 변화(U1 to SN의 변화량)등과는 유의한 상관관계를 보이지 않았다.

Keywords

References

  1. McLaughlin KD. Quantitative determination of root resorption during orthodontic treatment. Am J Orthod 1964 : 50 : 143
  2. Rosenberg MN. An evaluation of the incidence and amount of apical root resorption and dilacerations occurring in orthodontically treated teeth, having incompletely formed roots at the beginning of Begg treatment. Am J Orthod 1972 : 61: 524-5
  3. Linge BO, Linge L. Apical root resorption in upper anterior teeth. Eur J Orthod 1983 : 5 : 173-83
  4. Levander E, Malmgren O. Evaluation of the risk of root resorption during orthodontic treatment : a study of upper incisors. Eur J Orthod 1988 : 10: 30-8
  5. Stenvik A, Mjor IA. Pulp and dentic reactions to experimental tooth Intrusion. A histologic study of the initial changes. Am J Orthod 1970 : 57 : 370-85
  6. Harry MR, Sims MR. Root resorption in bicuspid intrusion : A scanning electromicroscopic study. Angle Orthod 1982 : 52 : 235-58
  7. Alexander SA. Levels of root resorption associated with continuous arch and sectional arch mechanics. Am J Orthod Dentofac Onhop. 1996 : 110 : 321-4
  8. VonderAhe G. Postretention status of maxillary incisors with rootend resorption. Angle Orthod 1973 : 43 : 247-55
  9. Janson GRP. et. al. A radiographic comparison of apical root resorption after orthodontic treatment with 3 different fixed appliance technique. Am J Orthod Dentofac Orthop 1999 : 118 : 262-73
  10. Blake M, Woodside DG, Pharoah MJ. A radiographic comparison of apical root resorption after orthodontic treatment with the edgewise and speed appliances. Am J Orthod Dentofac Orthop 1995 : 108 : 76-84
  11. Harris EF, Hassankiadeh S, Harris JT. Maxillary incisor crown-root relationships in different angle malocclusions. Am J Orthod Dentofac Orthop 1993 : 103 : 48-53
  12. Parker RJ, Harris EF. Directions of orthodontic tooth movements associated with external apical root resorption of maxillary central incisor. Am J Orthod Dentofac Orthop 1998 : 114: 677-83
  13. Brezniak N, Wasseristein A. Root resorption after orthodontic treatment : Part 2. Literatane review. Am J Orthod Dentotac Orthop 1993 : 103 : 138-46 https://doi.org/10.1016/S0889-5406(05)81763-9
  14. Massier M, Malone AJ. Root resorption in human permanent teeth. Am J Orthod 1954 : 40 : 619-33
  15. Kennedy DB, Joondeph DR, Osterberg SK, Little RM. The effect of extraction and orthodontic treatment on dentoalveolar support. Am J Orthod 1983 : 84 : 183-90
  16. Rygh P. Orthodontic root resorption studied by electron microscopy. Angle Orthod 1977 : 47 : 1-16
  17. Newman WG. Possible etiologic factors in external root resorption. Am J Orthod 1975 : 67 : 522-39
  18. Linge L, Linge BO. Patient characteristic and treatment variables associated with apical root resorption during orthodontic treatment. Am J Orthod Dentofac Orthop 1991 : 99 : 35-43
  19. Slagsvold O, Bjercke B. Autotransplantation of premolars with partly-formed roots. A radiographic study of root growth. Am J Orthod Dentofac Orthop 1974: 66 : 355-66
  20. Baumund S, Korn EL, Boyd RL. Apical root resorption in orthodontically treated adults. Am J Orthod Dentofac Orthop 1996 : 110: 2311-20
  21. Sameshima GT, Sinclaic PW. Predicting and preventing root resorption : Part II. Treatment factors. Am J Orthod Dentofac Orthop2001 : 119 : 511-5
  22. DeShields RW. A study of root resorption in treated Class II Division 1 malocclusion. Angle Orthod 1969 : 39 : 231-45
  23. Chung-Ju Hwang, Young-yoon Song. A radiographic study on root resorption in the Malocclusion patients before orthodontic treatment. Korea J Orthod 1999 : 29 : 219-37
  24. McFadden WM, Engstrom C, Engstrom H . A study of the relationship between incisor intrusion and root shortening. Am J Orthod Dentofac Orthop 1989 : 96 : 390-6
  25. Dougherty HL. The effect of mechanical forces upon the mandibular buccal segments during orthodontic treatment. Part II. Am J Orthod 1968 : 54 : 83-103
  26. Dougherty HL. The effect of mechanical forces upon the mandibular buccal segments during orthodontic treatment. Part I. Am J Orthod 1968 : 54 : 29-49
  27. Harris EF, Hassankiadeh S, Harris JT. Maxillary Incisor crown-root relationships in different angle malocclusions. Am J Orthod Dentofac Orthop 1993 : 103 : 48-53
  28. Phillips JR. Apical root resorption under orthodontic therapy. Angle Orthod 1955 : 25 : 1-12
  29. Sameshima GT, Asgarifar KO. Assessment of root resorption and root shape periapical vs panoramic films. Angle orthod 2001 : 71 : 185-9