Comparison between orthodontic micro-implants and dental units as anchorages for tooth retraction in dogs


  • Omer Fawzi Chawshil Department of P.O.P, College of Dentistry, Hawler Medical University, Erbil, Iraq.
  • Rafah Hatam AlMaarof Department of Oral Diagnosis, College of Dentistry, Hawler Medical University, Erbil, Iraq.
  • Fadhil Yasen Jasim Department of P.O.P, College of Dentistry, Mousul University, Erbil, Iraq.



Mini-implants, Dental anchorage, Tooth retraction, Dogs


Background and objective: Dental units, extra oral devices and mini-implants are the main types of anchorage that are used in orthodontic treatment. The aim of this study was to compare between mini-implants and dental unites as anchorage. Methods: This study used seven dogs wearing orthodontic appliances in the right and left sides of the maxilla for 40 days to retract the 3rd incisors toward the canines. On right side, canine was used as dental anchorage to retract the 3rd incisor by nickel-titanium closed coil spring along a straight arch wire. On the left side, mini-implant between the roots of canine and 1st premolar was used as skeletal anchorage. Different clinical measurements were done on the stone casts and photographs of maxillary dental arch for each dog before and after tooth retraction to assess the effectiveness of each anchorage type on the same animal. Results: Clinical measurements revealed a highly significant difference between dental and mini-implant sides. The mini-implant side showed less loss of anchorage than dental side, while the extrusion was higher in retracted tooth of mini-implant side than in dental side Conclusion: This study showed that the mini-implants provide more stable anchorage units than the teeth but cause more extrusion in the moving tooth.


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Proffit WR. Contemporary orthodontics, 2nd ed. St Louis: Mosby-year book; 2000. P. 308.

Graber LW, Vanarsdall RL, Vig KWL. Orthodontics, current principles and techniques, 5th ed. Philadelphia: Mosby; 2012. P. 13.

Deguchi T, Kurosaka H, Oikawa H, Kuroda S, Takahashi I Yamashiro T, et al. Comparison of orthodontic treatment outcomes in adults with skeletal open bite between conventional edgewise treatment and implant-anchored orthodontics. Am J Orthod Dentofacial Orthop 2011; 139:S60-8.

Upadhyay M, Yadav S, Nagaraj K, Uribe F, Nanda R. Mini-implant vs fixed functional appliances for treatment of young adult class II female patients. Angle Orthod 2012; 82:294-303.

Lee JS, Kim KJ, Park YC, Vanarsdell RL. Applications of orthodontic mini-implants, 1st ed. Canada: Quintessence Publishing; 2007.

Yao CCJ, Lai EHH, Chang JZC, Chen I, Chena YJ. Comparison of treatment outcomes between skeletal anchorage and extraoral anchorage in adults with maxillary dentoalveolar protrusion. Am J Orthod Dentofacial Orthop 2008; 134:615-24.

Chen F, Terada K, Hananda K, Saito I. Anchorage Effect of Osseointegrated vs. Nonosseointegrated Palatal Implants. Angle Orthod 2006; 76:660-5.

Ohashi E, Pecho OE, Moron M, Lagravere MO. Implant vs. Screw Loading Protocols in Orthodontics, A Systematic Review. Angle Orthod 2006; 76:721-7.

Asscherickx K, Vannet BV, Wehrbein H, Sabzevar MM. Success rate of miniscrews relative to their position to adjacent roots. Eur J Orthod 2008; 30:330-5.

Kim JW, Baek SH, Kim TW, Chang YII. Comparison of Stability between Cylindrical and Conical Type Mini-Implants. Angle Orthod 2008; 78:692-8.

Poggio PM, Incorvati C, Velo S, Carano A. ‘‘Safe Zones’’: A guide for mini-screw positioning in the maxillary and mandibular arch. Angle Orthod 2006; 76:191-7.

Serra G, Morais LS, Elias CN, Meyers MA, Andrade L, Muller CA, et al. Sequential bone healing of immediately loaded mini-implants: Histomorphometric and fluorescence analysis. Am J Orthod Dentofacial Orthop 2010; 137:80-90.

Leung MTC, Rabie ABM, Wong RWK. Stability of connected mini-implants and mini-plates for skeletal anchorage in orthodontics. Eur J Orthod 2008; 30:483-9.

Chung KR, Kim SH, Kang YG, Nelson G. Orthodontic mini-plate with tube as an efficient tool for borderline cases. Am J Orthod Dentofacial Orthop 2011; 139:551-62.

Cornelis MA, Scheffler NR, De Clerck HJ, Tulloch JF, Behets CN. Systematic review of the experimental use of temporary skeletal anchorage devices in orthodontics. Am J Orthod Dentofacial Orthop 2007; 131:S52-8.

Park HM, Kim BH, Yang IH, Baek SH. Preliminary three-dimensional analysis of tooth movement and arch dimension change of the maxillary dentition in Class II division 1 malocclusion treated with first premolar extraction: conventional anchorage vs. mini-implant anchorage. Korean J Orthod 2012; 42(6):280-90.

Huja SS, Litsky AS, Beck FM, Jhonson KA, Larsen PE. Pull-out strength of monocortical screws placed in the maxillae and mandibles of dogs. Am J Orthod Dentofac Orthop 2005; 127:307-13.

Carrillo R, Buschang PH, Opperman LA, Franco PF, Rossouw PE. Segmental intrusion with mini-screw implant anchorage: A radiographic evaluation. Am J Orthod Dentofacial Orthop 2007; 132:576.e1-576.e6.

Koyama I, Iino S, Abe Y, Takano-Yamamoto T, Miyawaki S. Differences between sliding mechanics with implant anchorage and straight-pull headgear and intermaxillary elastics in adults with bimaxillary protrusion. Eur J Orthod 2011; 33:126-31.

Ohmae M, Saito S, Morohashi T, Seki K, QU H, Kanomi R, et al. A clinical and histological evaluation of the titanium mini-implants as anchorage for orthodontic intrusion in beagle dogs. Am J Orthod Dentofac Orthop 2001; 119:489-97.

Feldmann L, Bondemark L. Anchorage capacity of osseointegrated and conventional anchorage systems: A randomized controlled trial. Am J Orthod Dentofac Orthop 2008; 133: 339.e19-339.e28.

Liou EJW, Chang PMH. Apical root resorption in orthodontic patients with en-masse maxillary anterior retraction and intrusion with miniscrews. Am J Orthod Dentofac Orthop 2010; 137:207-12.

Motoyoshi M, Uemura M, Ono A, Okazaki K, Shigeeda T, Shimizue N. Factors affecting the long-term stability of orthodontic mini-implants. Am J Orthod Dentofacial Orthop 2010; 137: 588.e1-588.e5.




How to Cite

Chawshil, O. F., AlMaarof, R. H., & Jasim, F. Y. (2014). Comparison between orthodontic micro-implants and dental units as anchorages for tooth retraction in dogs. Zanco Journal of Medical Sciences (Zanco J Med Sci), 18(1), 611_617.



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