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					Feature                       Micro Implants in Orthodontics
                                                                                                              By A. Korrodi Ritto, DDS, PhD

       everal temporary osseous anchor systems have been                   tions and more implant sites. Among the problems we can

S      introduced into the market as orthodontic anchorage
       during recent years.
    Implant orthodontics is in rapid expansion and devel-
                                                                           describe are loosening, break and failure rate.
                                                                               Following are photos highlighting many solutions for
                                                                           orthodontic purposes with mini implants.
oping in eastern Asian countries and will become an indis-
pensable modality in modern orthodontic therapy within                           1—Mesialization of lower molars (fig 1-8)
the next ten years.                                                              2—Canine retraction (fig 9-11)
    Success or failure of the traditional edgewise treatment                     3—Upper incisor retraction (fig 12-16)
depends on careful consideration to anchorage for tooth                          4—Lower Incisor intrusion (fig 17-18)
movement. The use of implant anchorage simplifies ortho-                         5—Upper molar intrusion (fig 19-20)
dontic treatment by sparing us the need for patient compli-                      6—Close the bite (fig 21)
ance and the complexity of treatment.                                            7—Premolar retraction (fig. 22- 27)
    Among different type of anchor implants, the bone                            8—Upper molar mesialization (fig 28-31)
screws seemed to be more popular and widely accepted by
orthodontists, because they offer several advantages over                       In this article we describe many solutions for orthodon-
the other systems: smaller fixture, easier surgical procedures             tic purposes with mini implants.
and less trauma, lower cost and risk, more clinical indica-

Mesialization of lower molars (Figures 1-8)

Figure 1. First lower molars extracted.   Figure 2. Lateral view.          Figure 3. Implant with traction.       Figure 4. Molar is advanced.

Figure 5. Stabilization.                  Figure 6. Decay on lower first   Figure 7. Pre-orthodontics.             Figure 8. Molars have been
                                          molars.                                                                  advanced.
     The big advantage of the mini-implants as anchorage                        It is also very easy to control root parallelism during
for lower molars mesialization is that the lower front teeth               mesialization, if we use a segmented arch with the point of
don’t change their position. With conventional anchorage, it               the coil spring fixation near to the center of resistance.
is a hard work to control the lower incisors torque, and                        In this case, the #37 moved to the #36 position with a
sometimes we spend more 6 months to correct this prob-                     good parallelism, however, on the other side, a conventional
lem. Also due to reverse curve arches and heavy arches,                    technique was used and it takes more time and more diffi-
root resorption happen.                                                    culties to get the same result.
22                                                                                                              IJO • VOL. 15 • NO. 3 • FALL 2004
Canine retraction (Figures 9-11, 11a)

Figure 9. Implant with traction.   Figure 10. Canine retracted.     Figure 11. Elastic for finishing.      Figure 11a.
     The canine distalization can be done in different ways, depending on the conditions. It is possible to use a spring coil, or
an elastomeric ligature, as well as different high of the mini-implant or the fixation system to the canine. If it is important to
get a root parallelism, it is better to attach the coil to a segmented wire, which passes through the vertical slot of the bracket.

Upper incisor retraction (Figures 12-16)
                                                                                                                Upper canine retraction
                                                                                                           can be done with crimpable
                                                                                                           or weld clasps to the straight
                                                                                                           wire in lingual or vestibular
                                                                                                           fixed technique, or attached
                                                                                                           directly to the loops or even
                                                                                                           to a segmented retrusion
Figure 12. Traction in place.      Figure 13. Frontal view.         Figure 14. Retraction with looped      arch.
                                                                    wire from the implant.

                                                                    Lower incisor intrusion (Figures 17-18,
                                                                    18a, 18b)

Figure 15. Retraction from the     Figure 16. Finishing the case.
palatal implants.

Upper molar intrusion (Figures 19-20)
molar intru-
sion is one of                                                      Figure 17. Intrusion of laterals and   Figure 18. Intrusion done.
the most diffi-                                                     cuspids.
cult move-
ments to
achieve with
when there is
no tooth dis-
tal to the                                                          Figure 18a.                            Figure 18b.
                Figure 19. Location of   Figure 20. Traction in
molar. This implants.                    place.
problem caus-                                                           Lower incisor intrusion can be done with spring coils
es many difficulties when we need to mesialize lower molars,        or elastomeric ligatures to the mini-implant placed
and a premature contact is present. Here, the orthodontist can      between the roots of the incisors. On the upper arch, the
also prepare the space necessary for a prosthesis or implant.       mini-implant can also be placed near to the nasal spine.
     With only one implant in the palatal area, and an
implant on the vestibular area or even the fixed appliance we
achieve nice results.
IJO • VOL. 15 • NO. 3 • FALL 2004                                                                                                       23
Case 6. Bite closure (Figure 21)
                                           Skeletal anchorage in
                                       one jaw is important to close
                                       the bite, or used for Class II
                                       or Class III elastics, without
                                       unwanted dental move-

Figure 21. Anchorage to close a lat-
eral open bite.

Premolar retraction (Figures 22-27)

Figure 22. Initial bite.               Figure 23. Traction in place.         Figure 24. Distalizing the 2nd pre-     Figure 25. Distalizing the 1st
                                                                             molar.                                  premolar.

                                                                                 With mini-implants it is now very easy to distalize pre-
                                                                             molars, or any other teeth, using spring coils attached to it.
                                                                             However it is imperative to decide the correct site of place-
                                                                             ment no avoid a root contact with the mini-implant during
                                                                             the distalization.

Figure 26. Distalizing the canine.      Figure 27. Need to distalize upper

Upper molar mesialization (Figures 28-31)

Figure 28. Initial bite.               Figure 29. Implant with               Figure 30. Traction done.               Figure 31. Case finishing.
    Like the distalization, the molars mesialization is also                                             A. Korrodi Ritto, DDS, PhD, the inventor of
possible to achieve with the mini-implants, to close extrac-                                             the Ritto Appliance, received his dental
tions spaces, or in cases of missing lateral incisors where                                              degree, orthodontic training and PhD in
we want to move all the teeth forward.                                                                   orthodontics from the Oporto Dentistry
                                                                                                         University. He is invited professor in the
                                                                                                         department of orthodontics, and in exclusive
                                                                                                         practice in Leiria, Portugal. Dr. Ritto can be
                                                                                                         contacted at or at
                                                                             A. Korrodi Ritto, DDS,
24                                                                                                                 IJO • VOL. 15 • NO. 3 • FALL 2004

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