Clinical Oral Investigations

, Volume 17, Issue 8, pp 1821–1827 | Cite as

Direct versus indirect loading of orthodontic miniscrew implants—an FEM analysis

  • C. HolbergEmail author
  • P. Winterhalder
  • N. Holberg
  • I. Rudzki-Janson
  • A. Wichelhaus
Original Article



The mesialization of molars in the lower jaw represents a particularly demanding scenario for the quality of orthodontic anchorage. The use of miniscrew implants has proven particularly effective; whereby, these orthodontic implants are either directly loaded (direct anchorage) or employed indirectly to stabilize a dental anchorage block (indirect anchorage). The objective of this study was to analyze the biomechanical differences between direct and indirect anchorage and their effects on the primary stability of the miniscrew implants.

Materials and methods

For this purpose, several computer-aided design/computer-aided manufacturing (CAD-CAM)-models were prepared from the CT data of a 21-year-old patient, and these were combined with virtually constructed models of brackets, arches, and miniscrew implants. Based on this, four finite element method (FEM) models were generated by three-dimensional meshing. Material properties, boundary conditions, and the quality of applied forces (direction and magnitude) were defined. After solving the FEM equations, strain values were recorded at predefined measuring points. The calculations made using the FEM models with direct and indirect anchorage were statistically evaluated.


The loading of the compact bone in the proximity of the miniscrew was clearly greater with direct than it was with indirect anchorage. The more anchor teeth were integrated into the anchoring block with indirect anchorage, the smaller was the peri-implant loading of the bone.


Indirect miniscrew anchorage is a reliable possibility to reduce the peri-implant loading of the bone and to reduce the risk of losing the miniscrew. The more teeth are integrated into the anchoring block, the higher is this protective effect.

Clinical relevance

In clinical situations requiring major orthodontic forces, it is better to choose an indirect anchorage in order to minimize the risk of losing the miniscrew.


Orthodontics Miniscrew implants Anchorage Molar mesialization Finite element method (FEM) 


  1. 1.
    Gainsforth BL, Higley LB (1945) A study of orthodontic anchorage possibilities in basal bone. Am J Orthod Oral Surg 31:406–417CrossRefGoogle Scholar
  2. 2.
    Kanomi R (1997) Mini-implant for orthodontic anchorage. J Clin Orthod 31:763–767PubMedGoogle Scholar
  3. 3.
    Crismani AG, Bertl MH, Celar AG, Bantleon HP, Burstone CJ (2010) Miniscrews in orthodontic treatment: review and analysis of published clinical trials. Am J Orthod Dentofacial Orthop 137:108–113PubMedCrossRefGoogle Scholar
  4. 4.
    Lehnen S, McDonald F, Bourauel C, Baxmann M (2011) Patient expectations, acceptance and preferences in treatment with orthodontic mini-implants. A randomly controlled study. Part I: insertion techniques. J Orofac Orthop 72:93–102PubMedCrossRefGoogle Scholar
  5. 5.
    Wiechmann D, Meyer U, Buchter A (2007) Success rate of mini- and micro-implants used for orthodontic anchorage: a prospective clinical study. Clin Oral Implants Res 18:263–267PubMedCrossRefGoogle Scholar
  6. 6.
    Wilmes B, Drescher D (2011) Impact of bone quality, implant type, and implantation site preparation on insertion torques of mini-implants used for orthodontic anchorage. Int J Oral Maxillofac Surg 40:697–703PubMedCrossRefGoogle Scholar
  7. 7.
    Chang JZ, Chen YJ, Tung YY, Chiang YY, Lai EH, Chen WP, Lin CP (2012) Effects of thread depth, taper shape, and taper length on the mechanical properties of mini-implants. Am J Orthod Dentofacial Orthop 141:279–288PubMedCrossRefGoogle Scholar
  8. 8.
    Mortensen MG, Buschang PH, Oliver DR, Kyung HM, Behrentz RG (2009) Stability of immediately loaded 3- and 6-mm miniscrew implants in beagle dogs—a pilot study. Am J Orthod Dentofacial Orthop 136:251–259PubMedCrossRefGoogle Scholar
  9. 9.
    Gracco A, Cirignaco A, Cozzani M, Boccaccio A, Pappalettere C, Vitale G (2009) Numerical/experimental analysis of the stress field around miniscrews for orthodontic anchorage. Eur J Orthod 31:12–20PubMedCrossRefGoogle Scholar
  10. 10.
    Mortensen MG, Buschang PH, Oliver DR, Kyung HM, Behrents RG (2009) Stability of immediately loaded 3- and 6-mm miniscrew implants in beagle dogs—a pilot study. Am J Orthod Dentofacial Orthop 136:251–259PubMedCrossRefGoogle Scholar
  11. 11.
    Suzuki A, Masuda T, Takahashi I, Deguchi T, Suzuki O, Takano-Yamamoto T (2011) Changes in stress distribution of orthodontic miniscrews and surrounding bone evaluated by 3-dimensional finite element analysis. Am J Orthod Dentofacial Orthop 140:e273–e280PubMedCrossRefGoogle Scholar
  12. 12.
    Chatzigianni A, Keilig L, Reimann S, Eliades T, Bourauel C (2011) Effect of mini-implant length and diameter on primary stability under loading with two force levels. Eur J Orthod 33:381–387PubMedCrossRefGoogle Scholar
  13. 13.
    Morarend C, Qian F, Marshall SD, Southard KA, Grosland NM, Morgan TA, McManus M, Southard TE (2009) Effect of screw diameter on orthodontic skeletal anchorage. Am J Orthod Dentofacial Orthop 136:224–229PubMedCrossRefGoogle Scholar
  14. 14.
    Liu TC, Chang CH, Wong TY, Liu JK (2012) Finite element analysis of miniscrew implants used for orthodontic anchorage. Am J Orthod Dentofacial Orthop 141:468–476PubMedCrossRefGoogle Scholar
  15. 15.
    Woodall N, Tadepalli SC, Qian F, Grosland NM, Marshall SD, Southard TE (2011) Effect of miniscrew angulation on anchorage resistance. Am J Orthod Dentofacial Orthop 139:e147–e152PubMedCrossRefGoogle Scholar
  16. 16.
    Pickard MB, Dechow P, Rossouw PE, Buschang PH (2010) Effects of miniscrew orientation on implant stability and resistance to failure. Am J Orthod Dentofacial Orthop 137:91–99PubMedCrossRefGoogle Scholar
  17. 17.
    Park KH, Lee EM, Shin SI, Kim SH, Park YG, Kim SJ (2011) Evaluation of the effect of force direction on stationary anchorage success of mini-implant with a lever-arm-shaped upper structure. Angle Orthod 81:776–782PubMedCrossRefGoogle Scholar
  18. 18.
    Stahl E, Keilig L, Abdelgader I, Jäger A, Bourauel C (2009) Numerical analyses of biomechanical behavior of various orthodontic anchorage implants. J Orofac Orthop 70:115–127PubMedCrossRefGoogle Scholar
  19. 19.
    Motoyoshi M, Ueno S, Okazaki K, Shimizu N (2009) Bone stress for a mini-implant close to the roots of adjacent teeth—3D finite element analysis. Int J Oral Maxillofac Surg 38:363–368PubMedCrossRefGoogle Scholar
  20. 20.
    Lemieux G, Hart A, Cheretakis C, Goodmurphy C, Trexler S, McGary C, Retrouvey JM (2011) Computed tomographic characterization of mini-implant placement pattern and maximum anchorage force in human cadavers. Am J Orthod Dentofacial Orthop 140:356–365PubMedCrossRefGoogle Scholar
  21. 21.
    Reynders R, Ronchi L, Bipat S (2009) Mini-implants in orthodontics: a systematic review of the literature. Am J Orthod Dentofacial Orthop 135:564–565PubMedCrossRefGoogle Scholar
  22. 22.
    Upadhyay M, Yadav S, Patil S (2008) Mini-implant anchorage for en-masse retraction of maxillary anterior teeth: a clinical cephalometric study. Am J Orthod Dentofacial Orthop 134:803–810PubMedCrossRefGoogle Scholar
  23. 23.
    Kim SH, Hwang YS, Ferreira A, Chung KR (2009) Analysis of temporary skeletal anchorage devices used for en-masse retraction: a preliminary study. Am J Orthod Dentofacial Orthop 136:268–276PubMedCrossRefGoogle Scholar
  24. 24.
    Singh S, Mogra S, Shetty VS, Shetty S, Philip P (2012) Three-dimensional finite element analysis of strength, stability and stress distribution in orthodontic anchorage: a conical, self-drilling miniscrew implant system. Am J Orthod Dentofacial Orthop 141:327–336PubMedCrossRefGoogle Scholar
  25. 25.
    Fritz U, Ehmer A, Diedrich P (2004) Clinical suitability of titanium microscrews for orthodontic anchorage—preliminary experiences. J Orofac Orthop 65:410–418PubMedCrossRefGoogle Scholar
  26. 26.
    Nagaraj K, Upadhyay M, Yadav S (2008) Titanium screw anchorage for protraction of mandibular second molars into first molar extraction sites. Am J Orthod Dentofacial Orthop 134:583–591PubMedCrossRefGoogle Scholar
  27. 27.
    Cattaneo PM, Dalstra M, Melsen B (2005) The finite element method: a tool to study orthodontic tooth movement. J Dent Res 84:428–433PubMedCrossRefGoogle Scholar
  28. 28.
    Ammar HH, Ngan P, Crout RJ, Mucino VH, Mukdadi OM (2011) Three-dimensional modeling and finite element analysis in treatment planning for orthodontic tooth movement. Am J Orthod Dentofacial Orthop 139:e59–e71PubMedCrossRefGoogle Scholar
  29. 29.
    Chen F, Terada K, Handa K (2005) Anchorage effect of various shape palatal osseointegrated implants: a finite element study. Angle Orthod 75:378–385PubMedGoogle Scholar
  30. 30.
    Geramy A (2009) Stresses around a miniscrew. 3-D analysis with the finite element method (FEM). Aust Orthod J 25:104–109PubMedGoogle Scholar
  31. 31.
    Lombardo L, Gracco A, Zampini F, Stefanoni F, Mollica F (2010) Optimal palatal configuration for miniscrew applications. Angle Orthod 80:145–152PubMedCrossRefGoogle Scholar
  32. 32.
    Motoyoshi M, Yano S, Tsuruoka T, Shimizu N (2005) Biomechanical effect of abutment on stability of orthodontic mini-implant. A finite element analysis. Clin Oral Implants Res 16:480–485PubMedCrossRefGoogle Scholar
  33. 33.
    Kojima Y, Mizuno T, Fukui H (2007) A numerical simulation of tooth movement produced by molar uprighting spring. Am J Orthod Dentofacial Orthop 132:630–638PubMedCrossRefGoogle Scholar
  34. 34.
    Chatzigianni A, Keilig L, Duschner H, Götz H, Eliades T, Bourauel C (2011) Comparative analysis of numerical and experimental data of orthodontic mini-implants. Eur J Orthod 33:468–475PubMedCrossRefGoogle Scholar
  35. 35.
    Holberg C, Holberg N, Rudzki-Janson I (2008) Sutural strain in orthopedic headgear therapy: a finite element analysis. Am J Orthod Dentofacial Orthop 134:53–59PubMedCrossRefGoogle Scholar
  36. 36.
    Wilmes B, Ottenstreuer S, Su YY, Drescher D (2008) Impact of implant design on primary stability of orthodontic mini-implants. J Orofac Orthop 69:42–50PubMedCrossRefGoogle Scholar
  37. 37.
    Alves M Jr, Baratieri C, Nojima LI (2011) Assessment of mini-implant displacement using cone beam computed tomography. Clin Oral Implants Res 22:1151–1156PubMedCrossRefGoogle Scholar
  38. 38.
    Zhang Q, Zhao L, Wu Y, Wang H, Zhao Z, Xu Z, Wei X, Tang T (2011) The effect of varying healing times on orthodontic mini-implant stability: a microscopic computerized tomographic and biomechanical analysis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 112:423–429PubMedCrossRefGoogle Scholar
  39. 39.
    Deguchi T, Takano-Yamamoto T, Kanomi R, Hartsfield JK, Roberts WE, Garetto LP (2003) The use of small titanium screws for orthodontic anchorage. J Dent Res 82:377–381PubMedCrossRefGoogle Scholar
  40. 40.
    Buchter A, Wiechmann D, Koerdt S, Wiesmann HP, Piffko J, Meyer U (2005) Load-related implant reaction of mini-implants used for orthodontic anchorage. Clin Oral Implants Res 16:473–479PubMedCrossRefGoogle Scholar
  41. 41.
    Brettin BT, Grosland NM, Qian F, Southard KA, Stuntz TD, Morgan TA, Marshall SD, Southard TE (2008) Bicortical vs monocortical orthodontic skeletal anchorage. Am J Orthod Dentofacial Orthop 134:625–635PubMedCrossRefGoogle Scholar
  42. 42.
    Melsen B, Lang NP (2001) Biological reactions of alveolar bone to orthodontic loading in oral implants. Clin Oral Implants Res 12:144–152PubMedCrossRefGoogle Scholar
  43. 43.
    Woods PW, Buschang PH, Owens SE, Rossouw PE, Opperman LA (2009) The effect of force, timing, and location on bone-to-implant contact of miniscrew implants. Eur J Orthod 31:232–240PubMedCrossRefGoogle Scholar
  44. 44.
    Wehrbein H, Gollner P (2007) Skeletal anchorage in orthodontics—basics and clinical application. J Orofac Orthop 68:443–461PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • C. Holberg
    • 1
    Email author
  • P. Winterhalder
    • 1
  • N. Holberg
    • 1
  • I. Rudzki-Janson
    • 1
  • A. Wichelhaus
    • 1
  1. 1.Department of OrthodonticsUniversity of MunichMunichGermany

Personalised recommendations