|Year : 2013 | Volume
| Issue : 3 | Page : 92-96
An innovative technique to distalize maxillary molar using microimplant supported rapid molar distalizer
Meenu Goel1, Anup Holla2, Sukant Sahoo3, Rakesh Mittal4
1 Department of Orthodontics, Institute of Dental Studies and Technologies, Modinagar, Ghaziabad, Uttar Pradesh, India
2 Kanti Devi Dental College and Hospital, Mathura, Uttar Pradesh, India
3 Department of Prosthodontics, Shree Bankey Bihari Dental College, Ghaziabad, Uttar Pradesh, India
4 Department of Pediatric Dentistry, NIMS Dental College, Jaipur, Rajasthan, India
|Date of Web Publication||8-Aug-2013|
Department of Orthodontics, Institute of Dental Studies and Technologies, Modinagar, Ghaziabad
Source of Support: None, Conflict of Interest: None
Introduction: In recent years, enhancements in implants have made their use possible as a mode of absolute anchorage in orthodontic patients. In this paper, the authors have introduced an innovative technique to unilaterally distalize the upper left 1 st molar to obtain an ideal Class I molar relationship from a Class II existing molar relationship with an indigenous designed distalizer. Clinical Innovation: For effective unilateral diatalization of molar, a novel cantilever sliding jig assembly was utilized with coil spring supported by a buccally placed single micro implant. The results showed 3 mm of bodily distalization with 1 mm of intrusion and 2° of distal tipping of upper left 1 st molar in 1.5 months. Discussion: This appliance is relatively easy to insert, well-tolerated, and requires minimal patient cooperation compared to other present techniques of molar distalization. Moreover, it is particularly useful in cases that are Class II on one side and Class I on the other, with a minor midline discrepancy and nominal overjet. Patient acceptance level was reported to be within patients physiological and comfort limits.
Keywords: Implant, molar distalization, headgear
|How to cite this article:|
Goel M, Holla A, Sahoo S, Mittal R. An innovative technique to distalize maxillary molar using microimplant supported rapid molar distalizer. Dent Hypotheses 2013;4:92-6
|How to cite this URL:|
Goel M, Holla A, Sahoo S, Mittal R. An innovative technique to distalize maxillary molar using microimplant supported rapid molar distalizer. Dent Hypotheses [serial online] 2013 [cited 2019 Jul 16];4:92-6. Available from: http://www.dentalhypotheses.com/text.asp?2013/4/3/92/116339
| Introduction|| |
Over the past few years, non-extraction treatment and non-compliance therapies have become more popular in correction of Class II malocclusion and several methods have been proposed to distalize maxillary molars in Class II cases without the need for patient cooperation. These include fixed appliances such as magnets, the Jones Jig, Distal jet appliance and the Pendulum Appliance, and removable appliances such as headgear and removable plates. ,,,,,, Treatment of Class II cases sometimes requires distal movement of maxillary molars in order to achieve Class I molar and canine relationship. The areas of particular concern in such cases are molar tipping and anterior movement of the anchorage teeth. If the 1 st molar is tipped back rather than moved bodily, it will not only pose occlusal problems, but may not provide sufficient anchorage for distalizing the teeth anterior to it.  With the advent of micro implants in orthodontics as a mode of absolute anchorage, significant strides have been made in their use for the distalization of molars. Mainly, the micro implants have been placed palatally and distalization achieved by activating the arms connecting the molar to the implant. These include implant supported distal jet appliance, distalization with a midpalatal mini-screw, Graz implant supported pendulum appliance. ,, This article describes a novel mechanism for Class II non-compliance treatment wherein the distalization of the Class II molar was accomplished by the use of a cantilever sliding jig assembly with coil spring supported by a buccally placed single micro implant.
| Clinical Innovation|| |
Appliance design/materials and method
- A stainless steel micro implant (2 mm wide and 6 mm long, with long head and hexagonal in shape (Leone, Sesto Fiorentino [Firenze], Italy) [Figure 1].
- An adaptor for implant head (Leone, Sesto Fiorentino [Firenze], Italy) [Figure 2]a.
- A Ni-Ti open coil spring in a sliding assembly (Ni-Ti open coil assembly of a Forsus appliance, 3M Unitek, Monrovia, California, USA) [Figure 3]a.
- 18 gauge wire inserted into the distal aspect of the sliding jig and the headgear tube (Ortho Organizers, Carlsbad, California, USA).
- Molar band with 0.0453 headgear tube (0.0223 Roth, Gemini, 3M Unitek, Monrovia, California, USA).
| Fabrication|| |
The head of the micro implant as well as the adapter is hexagonal in shape and they fit rigidly on each other and the shape of the head also prevents the rotation of the assembly [Figure 1], and [Figure 2]a, b. The Ni-Ti open coil spring has two parts the tube and the plunger. The spring is divided into 2 pieces and the tube soldered to the adaptor head [Figure 3]a, b and [Figure 4]a, b. The jig is prepared by placing the 18 gauge wire into the Ni-Ti open coil spring assembly distally and is then bent forward to enter into the headgear tube on the molar to be distalized. A 3-4 mm space is to be left for reactivation [Figure 5]a and b. The headgear tube portion should be annealed to bend it during activation. The length of the assembly could be adjusted by cutting the tube portion such that, when fully activated, the distal portion of the assembly would coincide with that of the distal surface of the molar to be distalized [Figure 6]. The maximum force that can be generated by the appliance would be in the range of 200-250 g.
| Mechanism of Action|| |
Since, the head of the micro implant as well as the adapter was hexagonal in shape they fit snugly on each other and the shape of the head also prevented the rotation of the assembly. The assembly can finally be secured in place by ligating it through the hole on the implant head and activation is carried out by pulling the 18 gauge wire through the headgear tube on the molar band and turning it gingivally. This appliance can achieve bodily movement as the force would be passing through the center of resistance of the tooth.
The appliance was placed in a 13-year-old female patient with skeletal Class II malocclusion and hyperdivergent growth pattern for unilateral maxillary molar distalization by 3 mm on the left side [Figure 7]. In the present case, extraction of all first premolars was done for leveling and aligning and for the correction of crowding. Considering hyper-divergent growth pattern maxillary left 2 nd molar was extracted to prevent the wedging effect as the 1 st molar was distalized to correct Class II molar relation. An implant was inserted between the roots of the second premolar and 1 st molar from the buccal aspect and the adaptor of Ni-Ti open coil spring assembly was placed over the implant head after 1 week [Figure 8]. The appliance was activated by pulling 18 gauge wires through the headgear tube and turning it gingivally. [Figure 9] and [Figure 10]a and b show pre- and post-distalization photographs and panoramic image respectively. Cephalometric superimposition showed 3 mm of molar distalization with 1 mm of intrusion and 2° of distal tipping of the molar [Figure 1]0]a-c]. According to Ricketts analysis the position of upper first molar in relation to Pterygoid vertical is 25 mm and post-distalization is 22 mm. No anchorage loss, tipping of premolar and mobility of implant was seen.
|Figure 7: Microimplant placed on left side between the roots of the second premolar and first molar|
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|Figure 8: Pre-distalization (a) and Post-distalization occlusal views (b),|
Pre-distalization (c) and Post-distalization buccal view (d)
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|Figure 10: Cephalometric superimposition showed 3 mm of molar distalization. (a) Overall superimposition, (b) Maxillary superimposition, (c) Mandibular superimposition)|
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| Discussion|| |
The molar distalization seen in this case was almost entirely a bodily movement, with slight distal tipping and rotation without any associated root resorption. There were no complaints of pain during tooth movement. Recently, mini-screws have gradually gained acceptance for use in stationary anchorage because they provide clinical advantages such as minimal anatomic limitation on placement, lower medical cost and simpler placement with less traumatic surgery. ,,,,,,,, Success rates of mini-screws are reported as 80-90%. ,, Palatal implants were developed as temporary orthodontic skeletal anchorage elements, particularly for the maxilla.  Palatal screws are placed in the anterior part of the palatal vault and the screws must be precisely behind the incisive canal toward spinanasalis anterior to prevent possible perforation of the nasal floor or nasal mucosa (or both).  Mild mucositis or a hyperplastic reaction around the implant is commonly seen in case of palatal implants whereas placement of mini-screws in the buccal interradicular bone is one of the most common approaches used to provide skeletal anchorage. ,,,,, The interradicular space is a potentially advantageous region for insertion because the mini-screw would cause fewer complications related to soft-tissue irritation, especially if placed through the attached gingiva. However, mini-screws inserted into the interradicular space should not interfere with tooth movement when adjacent teeth are moved in an anterior-posterior direction.  In the present case, buccal approach was used and 3 mm of distalization was seen in 1.5 months with a negligible amount of distal tipping. Yamada et al., also used the buccal approach, but the distalization was 2.8 mm in 8.4 months with distal tipping of 4.8°.  This appliance is especially useful in cases that are Class II on one side and Class I on the other, with a slight midline discrepancy and minimal overjet. Another appliance can be used simultaneously in the lower arch with the bite opened by the occlusal rests of the upper appliance, utility arches can be placed to level, align, or intrude the lower incisors. Rate of distalization by various appliances are tabulated in [Table 1]. ,,,,,,,, Although, the 1 st molars can be distalized with this appliance without much loss of anchorage even after the eruption of the 2 nd molars, they are easier to move before the second molars erupt. If a significant amount of distal movement is required in a young patient, one might even consider extracting the 2 nd molars. Assuming the 3 rd molars are of good size and shape and the 2 nd molars are extracted in time, the 3 rd molars will drift and erupt into proper occlusion.  Patient side level of tolerance of the appliance has been excellent; most adapt to the appliance within a week. There was no difficulty with mastication and swallowing or any ulceration. Initial clinical findings have been encouraging; however, there was only little anterior displacement of the incisors if any and no clinical evidence of increased overjet. Post-treatment retention is solely aided by the cusp to fossa relationship brought about by the correction of Class II molar relation. The various other advantages of the appliance are its simplicity and efficiency, control of the moment-to-force ratio to produce bodily movement, controlled tipping or uncontrolled tipping as desired, ease of fabrication and placement, hygiene and comfort for the patient, minimal patient cooperation, and its low cost. Conversely, implant related complications will always be there that may severe the treatment outcome and could be best avoided by strict sterilization during surgical placement, infection control, cautious, and successive force application.
| Conclusion|| |
A novel mechanism of distalization of molars using a single buccally placed implant-supported friction-less assembly with 2 nd molar extraction respectively was attempted. A bodily distalization of upper left 1 st molar of 3 mm to an overcorrected Class I molar relationship was achieved in 1.5 months. The buccal approach is convenient and comfortable for the operator. The appliance can be easily activated and can be used for either unilateral or bilateral Class II correction. Further, improvements are being attempted towards making the appliance less bulky, and to achieve larger corrections. Long-term evaluations in larger samples needs to be carried out to further evaluate the clinical efficacy of this appliance.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10]