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CASE REPORT |
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| Year : 2012 | Volume
: 30
| Issue : 2 | Page : 161-165 |
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New design space regainers: 'Lingual arch crossbow' and 'Double banded space regainer'
P Chalakka1, AM Thomas1, F Akkara2, R Pavaskar3
1 Department of Pedodontics and Preventive Dentistry, Christian Dental College and Hospital, Ludhiana, Punjab, India
2 Department of Oral and Maxillofacial Surgery, Dental College and Hospital, Bambolim, Goa, India
3 Department of Conservative Dentistry and Endodontics, Index Institute of Dental Sciences, Indore, Madhya Pradesh, India
| Date of Web Publication | 23-Aug-2012 |
Correspondence Address:
P Chalakka
Department of Pedodontics and Preventive Dentistry, Goa Dental College and Hospital, Bambolim, Goa 403202
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0970-4388.100001
 Abstract | | |
This article highlights the use of two new design space regainers - the "lingual arch crossbow" and the "double-banded space regainer." The former may be used for distalizing a mesially migrated mandibular first premolar, if it erupts prior to the canine. The latter may be used in conventional cases of interdental space loss. They both contain assemblies that function through the action of NiTi open coil springs.
Keywords: Crossbow, lingual arch, NiTi, space regainer
How to cite this article:
Chalakka P, Thomas A M, Akkara F, Pavaskar R. New design space regainers: 'Lingual arch crossbow' and 'Double banded space regainer'. J Indian Soc Pedod Prev Dent 2012;30:161-5 |
How to cite this URL:
Chalakka P, Thomas A M, Akkara F, Pavaskar R. New design space regainers: 'Lingual arch crossbow' and 'Double banded space regainer'. J Indian Soc Pedod Prev Dent [serial online] 2012 [cited 2021 Mar 1];30:161-5. Available from: https://www.jisppd.com/text.asp?2012/30/2/161/100001 |
| Introduction | |  |
The transition from mixed dentition to a permanent one is seldom accurate, the hurdles being space loss, tooth size arch length discrepancy, early exfoliation of primary teeth, or premature eruption of permanent teeth. When the usual sequence of eruption of permanent teeth does not occur, it must warn the clinician of monitoring the arches and intervening with extractions, space maintainers, or space regainers.
This article highlights the use two new design space regainers, the "lingual arch crossbow" (LAC) and the "double-banded space regainer" (DBSR). LAC can be used on the lower arch if the first premolar erupts prior to the canine and needs to be distallized to prevent it from encroaching into the canine space. The DBSR may be used in conventional cases of interdental space loss.
| Materials and Methods | | |
An 8-year-old boy reported to the department of Pedodontics and Preventive Dentistry with the complaint of misaligned teeth.
His mandibular arch contained all permanent incisors and first molars, primary right first molar, primary left second molar and the left first premolar [Figure 1]. The reason for exfoliation of the primary canines and the primary right second molar was unknown and the boy gave no history of extractions. This had resulted in mesial migration of the left first premolar, limiting the canine space to just 3 mm [Figure 2]. It was decided to regain the canine space using a space regainer by distalizing the first-left premolar after extracting the primary second-left molar. A lingual arch space maintainer was constructed to prevent mesial migration of the permanent first molars [Figure 3]. Molar tubes (1.1 mm diameter, 10 mm length) were welded to molar bands (0.006 × 0.180 in) on the lingual arch, buccally and lingually. A stainless steel curved wire (0.9 mm width) was constructed angled medially forward with its free ends passing posteriorly through molar tubes and NiTi open coil springs (GAC Int Inc, Central Islip, NY; 0.012 in diameter; 0.045 in lumen; 10 mm length) on the permanent left first molar [Figure 4],[Figure 5] and [Figure 6]. This wire was medially angled to enable distalization of the premolar along the ridge, preventing any buccal or lingual displacement. The primary second left molar was extracted and the LAC was cemented on to the mandibular first permanent molars. After cementation, the curved wire was pulled forwards to engage the first premolar at its mesio-cervical margin [Figure 7]. In doing so, the NiTi open coil springs got compressed to half their original lengths. Under compression, the springs exerted forces between stops anteriorly (molar tubes) and posteriorly (wire tags). These forces tend to push the wire tags posteriorly, while simultaneously pulling the first premolar distally. After 5 months, the space gained mesial to the first-left premolar was 4 mm, improving the canine space to 7 mm [Figure 8],[Figure 9],[Figure 10] and [Figure 11]. Following this, self-cure acrylic was added to the springs to prevent further space gain, as further distalization would compromise the space available for eruption of the second-left premolar.
His maxillary arch showed mild anterior crowding. It contained all permanent incisors and first molars; all primary molars except the left second primary molar [Figure 12]. The reason for its exfoliation was unknown. This had resulted in mesial migration of the permanent left first molar [Figure 13] resulting in 3.5 mm of space between it and the primary left first molar, compared to 8.8 mm on the contralateral side. A space regainer was designed to regain the space as follows [Figure 14]. The permanent left first molar was banded (0.006 × 0.180 in) with molar tubes (1.1 mm diameter, 10 mm length) welded to it buccally and palatally. The primary first-left molar was also banded (0.005 × 0.180 in) with two stainless steel wires (0.9 mm width) soldered to it buccally and palatally, extending posteriorly to insert into the molar tubes of the permanent first molar. NiTi open coil springs (GAC Int Inc, Central Islip, NY; 0.012 in diameter; 0.045 in lumen; 15 mm length) were incorporated into the wires between stops anteriorly (solder joints) and posteriorly (molar tubes). The assembly (DBSR) was cemented on to the teeth with the springs held in compression to half their lengths [Figure 15]. After 6 months, the space gained was 5.1 mm, making the total space available between the permanent first-left molar and the primary left first molar to be 8.6 mm [Figure 16] and [Figure 17]. The appliance was removed soon after, because the second-left premolar had erupted into the space up to its mesial and distal heights of contour [Figure 18] and the primary left first molar was nearing exfoliation [Figure 8]. | Figure 3: Mandibular arch with a noncemented lingual arch before constructing the space regainer
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 | Figure 12: Maxillary arch showing mesially migrated 26 onto the space of 65 (exfoliated)
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 | Figure 13: Periapical view showing mesially migrated 26 onto the space of 65 (exfoliated)
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 | Figure 15: Maxillary arch showing space regainer on 26 and 64 before distalization
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 | Figure 16: Maxillary arch showing space regainer on 26 and 64 after distalization
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 | Figure 18: Post-treatment maxillary view after removal of space regainer
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| Discussion | | |
NiTi coils have a long range of the superelastic activity with minimal load fluctuation in spite of large deflection due to excellent springback and superelasticity. [1] This property makes it possible to achieve large tooth movements without having to replace the springs.
In the mandibular arch, noticeable amount of distal tipping had occurred on the first-left premolar following distalization. However, it will most probably self-correct following appliance removal after the eruption of the permanent left canine. Although it is generally not advised to orthodontically move a tooth with incomplete root formation, the premolar showed continuation of root formation during the course of distalization. There was no radiographical evidence of root resorption or ankylosis. Distalization of the permanent first-left molar may be required after the eruption of the permanent left canine, if the space available for eruption of the left second premolar is found to be insufficient. There is negligible risk of anchorage loss while using the "lingual arch crossbow," as the entire lingual arch takes the role of anchorage distributing force over a large number of teeth. On the right side, the radiograph suggests the eruption of the first premolar ahead of the canine. If this happens, the treatment protocol would be similar to that undertaken on his left side.
In the maxillary arch, a resorbing primary first molar was used as anchorage to distalize a permanent first molar. It is certain that the anchor tooth must have transmitted considerable force to the teeth anterior to it, contributing to the already existent anterior crowding. A distal movement rate of approximately 1 mm per month has been reported for permanent first molars, but there is marked individual variation. [2],[3],[4],[5],[6] However, in this case, 5.1 mm of space was gained over a period of 6 months. Distalizing the permanent first molar was easily possible in this case because the permanent second molar had not erupted and its crown was at the midroot level of the permanent first molar. Since both, the permanent first molar and the primary first molar were banded for space regaining, and the wires were soldered to pass paralleling the molar tubes, there was no observable tipping on the permanent first molar. This is an advantage of the DBSR over the conventionally used Gerber space regainer, where only one of the two teeth is banded allowing a possibility for tipping.
The boy is currently being monitored at three month intervals to ensure successful transition to a permanent dentition. He has been advised a unitufted brush to help in brushing efficiently throughout the course of treatment.
| References | | |
| 1. | Miura F, Mogi M, Ohura Y, Karibe M. The super-elastic Japanese NiTi alloy wire for use in orthodontics. Part III studies on the Japanese NiTi alloy coil springs. Am J Orthod Dentofacial Orthop 1988;94:89-96. 
[PUBMED] |
| 2. | Bondemark L, Karlsson I. Extraoral vs intraoral appliance for distal movement of maxillary first molars: A randomized controlled trial. Angle Orthod 2005;75:699-706.
[PUBMED] |
| 3. | Papadopoulos MA, Mavropoulos A, Karamouzos A. Cephalometric changes following simultaneous first and second maxillary molar distalization using a non-compliance intraoral appliance. J Orofac Orthop 2004;65:123-36.
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| 4. | Bondemark L. A comparative analysis of distal maxillary molar movement produced by a new lingual intra-arch Ni-Ti coil appliance and a magnetic appliance. Eur J Orthod 2000;22:683- 95.
[PUBMED] |
| 5. | Paul LD, O'Brien KD, Mandall NA. Upper removable appliance or Jones jig for distalizing first molars? A randomized clinical trial. Orthod Craniofac Res 2002;5:238-42.
[PUBMED] |
| 6. | Gianelly AA. Distal movement of the maxillary molars. Am J Orthod Dentofacial Orthop 1998;114:66-72.
[PUBMED] |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13], [Figure 14], [Figure 15], [Figure 16], [Figure 17], [Figure 18]
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