Class II malocclusion treatment changes with the Jones jig, Distal jet and First Class appliances

Lorena VILANOVA José Fernando Castanha HENRIQUES Mayara Paim PATEL Rachelle Simões REIS Roberto Henrique da Costa GREC Aron ALIAGA-DEL CASTILLO Silvio Augusto BELLINI-PEREIRA Guilherme JANSON About the authors

Abstract

Objective

Maxillary molar distalization with intraoral distalizer appliances is a non-extraction orthodontic treatment used to correct molar relationship in patients with Class II malocclusion presenting maxillary dentoalveolar protrusion and minor skeletal discrepancies. This study compares the changes caused by three distalizers with different force systems.

Methodology

71 patients, divided into three groups, were included. The Jones jig group (JJG, n=30; 16 male, 14 female, 13.17 years mean age) was treated with the Jones jig for 0.8 years. The Distal jet group (DJG, n=25; 8 male, 17 female, 12.57 years mean age) was treated with the Distal jet for 1.06 years. The First Class group (FCG, n=16; 6 male, 10 female, 12.84 years mean age) was treated with the First Class for 0.69 years. Intergroup treatment changes were compared using one-way ANOVA, followed by post-hoc Tukey’s tests.

Results

Intergroup comparisons showed significantly greater maxillary incisor protrusion in DJG than in FCG (2.56±2.24 mm vs. 0.74±1.39mm, p=0.015). The maxillary first premolars showed progressive and significantly smaller mesial angulation in JJG, FCG and DJG, respectively (14.65±6.31º, 8.43±3.99º, 0.97±3.16º; p<0.001). They also showed greater mesialization in JJG than FCG (3.76±1.46 mm vs. 2.27±1.47 mm, p=0.010), and greater extrusion in DJG compared to JJG (0.90±0.77 mm vs 0.11±0.60 mm, p=0.004). The maxillary second premolars showed progressive and significantly smaller mesial angulation and mesialization in JJG, FCG and DJG, respectively (12.77±5.78º, 3.20±3.94º, -2.12±3.71º and 3.87±1.34 mm, 2.25±1.40 mm, 1.24±1.26 mm, respectively; p<0.001). DJG showed smaller distal angulation of maxillary first molars (-2.14±5.09º vs. -7.73±4.28º and -6.05±3.76º, for the JJG and FCG, respectively; p<0.001) and greater maxillary second molars extrusion (1.17±1.41 mm vs -0.02±1.16 mm and 0.16±1.40 mm, for the JJG and FCG, respectively; p=0.003). Overjet change was significantly larger in DJG compared to FCG (1.79±1.67 mm vs 0.68±0.84; p=0.046). Treatment time was smaller in FCG (0.69±0.22 years vs 0.81±0.33 years and 1.06±0.42 years, comparing it with the JJG and DJG, respectively; p=0.005).

Conclusion

The three appliances corrected the Class II molar relationship by dentoalveolar changes. The Distal jet produced smaller molar distal angulation than the Jones jig and First Class. The First Class appliance showed less anchorage loss, greater percentage of distalization and shorter treatment time than the Jones jig and Distal jet.

Cephalometry; Angle Class II malocclusion; Corrective orthodontics; Orthodontic appliances

Introduction

Distalization of maxillary molars is indicated to treat Class II malocclusion without extractions in patients with maxillary dentoalveolar discrepancy and minor skeletal discrepancies. 11 - Runge ME, Martin JT, Bukai F. Analysis of rapid maxillary molar distal movement without patient cooperation. Am J Orthod Dentofacial Orthop. 1999;115(2):153-7. doi: 10.1016/S0889-5406(99)70343-4
https://doi.org/10.1016/S0889-5406(99)70...
Headgear 22 - Kloehn S. Evaluation of cervical anchorage force in treatment. Angle Orthod. 1961;31(2):91-104. and Wilson maxillary bimetric distalizing arch system 33 - Wilson WL, Wilson RC. Modular orthodontics (Wilson) manual. Denver: Rocky Mountain Orthodontics; 1981. have been widely used in the past, however these distalizing appliances require the patient’s compliance to achieve molar distal movement. Protocols that require less patient cooperation are more effective and predictable. 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...

Several fixed and intraoral appliances for maxillary molars distalization have been described as an option to reduce the need of patient compliance. Most of these appliances involve an anchorage unit, commonly an acrylic Nance button, and an active unit. The active components can be repelling magnets, 55 - Gianelly AA, Vaitas AS, Thomas WM. The use of magnets to move molars distally. Am J Orthod Dentofacial Orthop. 1989;96(2):161-7. doi: 10.1016/0889-5406(89)90257-6
https://doi.org/10.1016/0889-5406(89)902...
superelastic nickel-titanium (NiTi) archwires, 66 - Locatelli R, Bednar J, Dietz VS, Gianelly AA. Molar distalization with superelastic NiTi wire. J Clin Orthod. 1992;26(5):277-9. coil springs on continuous archwire or on sectional archwire, 77 - Jones RD, White J. Rapid Class II molar correction with an open-coil jig. J Clin Orthod. 1992;26(10):661-4. , 88 - Carano A, Testa M. The distal jet for upper molar distalization. J Clin Orthod. 1996;30(7):374-80. springs in beta titanium alloy, 99 - Hilgers JJ. The pendulum appliance for Class II non-compliance therapy. J Clin Orthod. 1992;26(11):706-14. and vestibular screws associated with palatal NiTi coil springs. 1010 - Fortini A, Lupoli M, Giuntoli F, Franchi L. Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod Dentofacial Orthop. 2004;125(6):697-704.

These intraoral distalizers are practical resources to correct Class II molar relationship in a shorter time. 88 - Carano A, Testa M. The distal jet for upper molar distalization. J Clin Orthod. 1996;30(7):374-80. , 1111 - Haydar S, Üner O. Comparison of Jones jig molar distalization appliance with extraoral traction. Am J Orthod Dentofacial Orthop. 2000;117(1):49-53. The amount of maxillary molar movement and subsequent side effects could be directly associated with the biomechanics and particularities of each appliance. The Jones jig is a buccal distalization appliance whereas the Distal jet applies a palatal distalization force. Some advantages of the Distal jet have been reported such as the ability to promote molar distalization with less angulation effects, because the distalizing force applied is closer to the molar center of resistance. 88 - Carano A, Testa M. The distal jet for upper molar distalization. J Clin Orthod. 1996;30(7):374-80. More recently, the First Class was proposed as an intraoral appliance with a palatal and buccal force system. 1010 - Fortini A, Lupoli M, Giuntoli F, Franchi L. Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod Dentofacial Orthop. 2004;125(6):697-704.

The dentoalveolar and skeletal changes of these appliances have been previously investigated. 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...
, 77 - Jones RD, White J. Rapid Class II molar correction with an open-coil jig. J Clin Orthod. 1992;26(10):661-4. , 88 - Carano A, Testa M. The distal jet for upper molar distalization. J Clin Orthod. 1996;30(7):374-80. , 1010 - Fortini A, Lupoli M, Giuntoli F, Franchi L. Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod Dentofacial Orthop. 2004;125(6):697-704. , 1212 - Papadopoulos MA, Melkos AB, Athanasiou AE. Noncompliance maxillary molar distalization with the first class appliance: a randomized controlled trial. Am J Orthod Dentofacial Orthop. 2010;137(5):586.e1-586.e13. doi: 10.1016/j.ajodo.2009.10.033
https://doi.org/10.1016/j.ajodo.2009.10....
, 1313 - Patel MP, Janson G, Henriques JF, Almeida RR, Freitas MR, Pinzan A, et al. Comparative distalization effects of Jones jig and pendulum appliances. Am J Orthod Dentofacial Orthop. 2009;135(3):336-42. doi: 10.1016/j.ajodo.2007.01.035
https://doi.org/10.1016/j.ajodo.2007.01....
However, no previous studies directly compared the changes among treatments. Therefore, this study cephalometrically compares the dentoalveolar, skeletal and soft tissue effects of three appliances with different force systems (Jones jig, Distal jet and First Class) used for maxillary molar distalization in Class II malocclusion patients.

Methodology

This retrospective study was approved by the Research Ethics Committee of Bauru School of Dentistry, University of São Paulo. Informed consent was signed by all patients’ parents or legal guardians allowing their treatment and participation in the study.

Sample size was calculated considering a mean difference of 1.6 mm between groups for the amount of distal movement of maxillary molars in the sagittal plane, contemplated as the primary outcome, with a previously reported standard deviation of 1.5 mm, 1010 - Fortini A, Lupoli M, Giuntoli F, Franchi L. Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod Dentofacial Orthop. 2004;125(6):697-704. using 80% test power, at 5% alpha level. Then, a minimum of 16 patients was necessary in each group.

The selection criteria included patients with at least ¼ cusp Class II molar relationship, 1414 - Andrews LF. The straight-wire appliance: syllabus of philosophy and techniques. 2nd ed. San Diego: LF Andrews Foundation of Orthodontic Education and Research; 1975. all permanent teeth up to the first molars erupted, no severe mandibular crowding, no crossbite, no anterior open bite, no agenesis, supernumerary or tooth loss and no previous orthodontic intervention. Each group was treated in different periods. Patients were allocated to each group when they satisfied the selection criteria. The sample consisted of 71 patients divided into 3 groups. All groups were treated with distalization appliances using conventional anchorage. Most of the patients had erupted maxillary second molars.

The Jones jig group (JJG) consisted of 30 patients (16 male, 14 female) with 13.17±1.24 years initial mean age. The NiTi coil spring (G&H Wire Co, Greenwood, Indiana, USA) was activated 5 mm every 4 weeks to deliver 125 g of force. A Nance button, cemented on the second premolars, was used as anchorage ( Figure 1A ).

Figure 1
Distalization appliances. A: Jones jig; B: Distal jet; C: First Class

The Distal jet group (DJG) consisted of 25 patients (8 male, 17 female) with 12.57±1.43 years initial mean age. In this appliance, the Nance button was cemented on the maxillary first premolars serving as anchorage ( Figure 1B ). Different amounts of force (240g or 180g) were applied based on the clinical presence or absence of the second molars. The greatest force was used when second molars were erupted. 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...
The device was reactivated once a month in the same manner.

The First Class group (FCG) consisted of 16 subjects (6 male, 10 female) with 12.84±1.31 years initial mean age. The First Class appliance consisted of two buccal-activation screws (10 mm long) soldered to the first molar bands and placed in closed rings soldered to the second premolar bands, two 0.010x0.045-inch palatal open NiTi coil springs (10 mm long) and a modified Nance button ( Figure 1C ). The buccal screws were activated a quarter turn in a counterclockwise direction once a day, activating 0.1 mm per day. 1010 - Fortini A, Lupoli M, Giuntoli F, Franchi L. Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod Dentofacial Orthop. 2004;125(6):697-704.

Three orthodontic graduate students, supervised by the same professor, performed the treatment of all patients. Each group was treated by only one operator. In all groups, distalization was performed until a super-Class I molar relationship was obtained. 55 - Gianelly AA, Vaitas AS, Thomas WM. The use of magnets to move molars distally. Am J Orthod Dentofacial Orthop. 1989;96(2):161-7. doi: 10.1016/0889-5406(89)90257-6
https://doi.org/10.1016/0889-5406(89)902...

Lateral head films were obtained at pretreatment (T1) and after molar distalization (T2). They were analyzed with Dentofacial Planner 7.02 software (Dentofacial Planner, Toronto, Ontario, Canada). The image magnification factors were corrected by the software. A total of 30 variables were evaluated on each cephalogram ( Figures 2 and 3 ). Bilateral structures of interest were averaged.

Figure 2
Cephalometric measurements

Figure 3
Cephalometric variables. A: Skeletal and soft tissue variables (A. SNA; B.SNB; C. ANB; D. ANS-Me; E. A-PTV; F. B-PTV; G. FMA; H. SN.GoGn; I. SN.GoMe; J. SN.Occlusal plane; K. Nasolabial angle); B: Angular dental variables (A. Mx1.SN; B. Mx4.SN; C. Mx5.SN; D. Mx6.SN; E. Mx7.SN; F. Md6.MP); C: Linear dental variables (A. Mx1-PTV; B. Mx4-PTV; C. Mx5-PTV; D. Mx6-PTV; E. Mx7-PTV; F. Md6-PTV; G. Mx1-PP; H. Mx4-PP; I. Mx5-PP; J. Mx6-PP; K. Mx7-PP; L. Overjet; M. Overbite)

Error study

In total, 42 cephalograms were randomly selected and retraced by the same examiner (L.V.) after a 1-month interval. The random errors were evaluated using Dahlberg’s formula ( S 2 = Σd 2 /2n ), where S 2 is the error variance and d is the difference between two determinations of the same variable. The systematic errors were assessed with dependent t-tests at p<0.05. The random errors ranged between 0.50 mm (Mx1-PP) and 1.18 mm (LAFH) and between 0.52 (ANB) and 2.80 (NLA) degrees that were within acceptable limits, 1313 - Patel MP, Janson G, Henriques JF, Almeida RR, Freitas MR, Pinzan A, et al. Comparative distalization effects of Jones jig and pendulum appliances. Am J Orthod Dentofacial Orthop. 2009;135(3):336-42. doi: 10.1016/j.ajodo.2007.01.035
https://doi.org/10.1016/j.ajodo.2007.01....
and only one variable (A-PTV) demonstrated a significant systematic error.

Statistical analyses

Normal distributions were confirmed with Kolmogorov-Smirnov tests. Intergroup comparability regarding sex distribution, severity of Class II malocclusion and the number of erupted maxillary second molars were assessed with Chi-square tests.

Initial and final ages, treatment time, cephalometric statuses at pretreatment and treatment changes were compared between groups using one-way Analysis of Variance (ANOVA), followed by Tukey’s tests.

Statistica software (Statistica for Windows, version 6.0, Statsoft, Tulsa, Oklahoma, USA) was used to perform all statistical analyses. Statistical significance was set at p<0.05.

Considering the anchorage loss of premolars and incisors, the effect of molar distalization in the total movement in the sagittal dimension, as reported by Kinzinger, et al. 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...
(2008), were also calculated as percentages.

Results

The groups were comparable regarding sex and Class II malocclusion severity distributions, number of erupted maxillary second molars, initial and final mean ages ( Table 1 ). However, the First Class group presented a shorter treatment time than the Distal jet group.

Table 1
Comparison of sex and Class II malocclusion severity distributions, amount of erupted maxillary second molars, initial and final ages and treatment times

Mean values and standard deviations of all variables at pre-treatment (T1) and posttreatment (T2) are shown in Table 2 .

Table 2
Mean values and standard deviations (SD) of all variables at pretreatment (T1) and posttreatment (T2)

At pretreatment, the First Class group had significantly greater skeletal Class II relationship, maxillary length, and maxillary incisors protrusion than the other groups ( Table 3 ). The first premolar mesial angulation was progressive and significantly smaller in the Jones jig, Distal jet and First Class groups, respectively.

Table 3
Pretreatment intergroup cephalometric comparison (ANOVA followed by Tukey’s tests)

During treatment, the maxillary incisors showed significantly greater protrusion in the Distal jet than in the First Class group ( Table 4 ).

Table 4
Intergroup treatment changes comparison (ANOVA followed by Tukey tests)

The maxillary first premolars showed progressive and significantly smaller mesial angulation in the Jones jig, First Class and Distal jet groups, respectively. They also showed significantly greater mesialization in the Jones jig than in the First Class group, and significantly greater extrusion in the Distal jet than in the Jones jig group ( Table 4 ).

The maxillary second premolars showed progressive and significantly smaller mesial angulation and mesialization in the Jones jig, First Class and Distal jet groups, respectively ( Table 4 ).

The maxillary first molar distal angulation was significantly smaller in the Distal jet than in the other groups. The extrusion of maxillary second molars was significantly greater in the Distal jet than in the other groups ( Table 3 ).

The overjet change was significantly larger in the Distal jet than in the First Class group ( Table 4 ).

The First Class group showed greater percentages of maxillary molar distalization considering the anchorage loss of premolars and incisors, followed by the Jones jig and the Distal jet ( Tables 5 and 6 ).

Table 5
Percentages of molar distalization in the total movement in the sagittal dimension and anchorage loss considering premolars
Table 6
Percentages of molar distalization in the total movement in the sagittal dimension and anchorage loss considering the incisors

Discussion

Previous clinical studies and systematic reviews have investigated the changes resulting from intraoral molar distalizers. However, inter-study comparisons are limited because of their heterogeneity. 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...

16 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...
- 1717 - Costa Grec RH, Janson G, Branco NC, Moura-Grec PG, Patel MP, Henriques JF. Intraoral distalizer effects with conventional and skeletal anchorage: a meta-analysis. Am J Orthod Dentofacial Orthop. 2013;143(5):602-15. doi: 10.1016/j.ajodo.2012.11.024
https://doi.org/10.1016/j.ajodo.2012.11....
This study is relevant since it evaluates three distalizing appliances with different force systems to directly compare their treatment effects. The sample size on each group was similar to other previous studies. 11 - Runge ME, Martin JT, Bukai F. Analysis of rapid maxillary molar distal movement without patient cooperation. Am J Orthod Dentofacial Orthop. 1999;115(2):153-7. doi: 10.1016/S0889-5406(99)70343-4
https://doi.org/10.1016/S0889-5406(99)70...
, 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...
, 1111 - Haydar S, Üner O. Comparison of Jones jig molar distalization appliance with extraoral traction. Am J Orthod Dentofacial Orthop. 2000;117(1):49-53. , 1818 - Byloff FK, Darendeliler MA, Clar E, Darendeliler A. Distal molar movement using the pendulum appliance. Part 2: the effects of maxillary molar root uprighting bends. Angle Orthod. 1997;67(4):261-70. doi: 10.1043/0003-3219(1997)067<0261:DMMUTP>2.3.CO;2
https://doi.org/10.1043/0003-3219(1997)0...

19 - Nishii Y, Katada H, Yamaguchi H. Three-dimensional evaluation of the distal jet appliance. World J Orthod. 2002;3(4):321-7.
- 2020 - Polat-Ozsoy O, Gokcelik A, Güngör-Acar A, Kircelli BH. Soft tissue profile after distal molar movement with a pendulum K-loop appliance versus cervical headgear. Angle Orthod. 2008;78(2):317-23. doi: 10.2319/011107-10.1
https://doi.org/10.2319/011107-10.1...

Considering the number of variables used in this study, one could argue that Bonferroni corrections should be used. 2121 - Armstrong RA. When to use the Bonferroni correction. Opthalmic Physiol Opt. 2014;34(5):502-8. doi: 10.1111/opo.12131
https://doi.org/10.1111/opo.12131...
Nevertheless, this would decrease the probability of detecting slight significant differences between groups, which are very important in these comparisons. Since the focus of this study was to investigate whether there is a minimum difference in the treatment changes between the three groups, Bonferroni corrections were not performed.

The groups were reasonably similar at T1 ( Table 3 ). The more accentuated Class II maxillomandibular relationship in the First Class Group was probably due to the greater maxillary length that this group presented. Consequently, the maxillary incisor also presented greater protrusion in this group. The mesial angulation of the maxillary first premolars was progressive and significantly smaller in the Jones jig, Distal jet and First Class groups, respectively ( Table 3 ). However, these characteristics do not interfere with the comparison of results of the treatment changes since they do not affect the appliance performance.

The shorter treatment time in the First Class group was similar to previously reported results. 1212 - Papadopoulos MA, Melkos AB, Athanasiou AE. Noncompliance maxillary molar distalization with the first class appliance: a randomized controlled trial. Am J Orthod Dentofacial Orthop. 2010;137(5):586.e1-586.e13. doi: 10.1016/j.ajodo.2009.10.033
https://doi.org/10.1016/j.ajodo.2009.10....

Similar changes of the skeletal variables were observed between groups, as expected, because these treatment protocols do not promote significant changes on skeletal structures, as previously demonstrated 1313 - Patel MP, Janson G, Henriques JF, Almeida RR, Freitas MR, Pinzan A, et al. Comparative distalization effects of Jones jig and pendulum appliances. Am J Orthod Dentofacial Orthop. 2009;135(3):336-42. doi: 10.1016/j.ajodo.2007.01.035
https://doi.org/10.1016/j.ajodo.2007.01....
, 2222 - Brickman CD, Sinha PK, Nanda RS. Evaluation of the Jones jig appliance for distal molar movement. Am J Orthod Dentofacial Orthop. 2000;118(5):526-34. doi: 10.1067/mod.2000.110332
https://doi.org/10.1067/mod.2000.110332...
, 2323 - Lione R, Franchi L, Laganà G, Cozza P. Effects of cervical headgear and pendulum appliance on vertical dimension in growing subjects: a retrospective controlled clinical trial. Eur J Orthod. 2015;37(3):338-44. doi: 10.1093/ejo/cju061
https://doi.org/10.1093/ejo/cju061...
( Table 4 ).

Commonly, the undesirable effects produced by these appliances include mesialization and mesial angulation of premolars and protrusion and labial inclination of the anterior teeth, as reported by Kinzinger, et al. 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...
(2008), and Antonarakis and Kiliaridis 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...
(2008). The Distal jet presented significantly greater maxillary incisor protrusion compared to the First Class ( Table 4 ). This difference could be explained by the greater anchorage unit used in the First Class group. Since the modified Nance button is attached to the maxillary first molars and second premolars, more teeth are included as anterior anchorage for molar distalization. Furthermore, the Nance button is also larger in this appliance. 1212 - Papadopoulos MA, Melkos AB, Athanasiou AE. Noncompliance maxillary molar distalization with the first class appliance: a randomized controlled trial. Am J Orthod Dentofacial Orthop. 2010;137(5):586.e1-586.e13. doi: 10.1016/j.ajodo.2009.10.033
https://doi.org/10.1016/j.ajodo.2009.10....

Mesial angulation of maxillary first premolars was progressive and significantly smaller in the Jones jig, First Class and Distal jet groups, respectively. Significantly greater first premolars mesial angulation in the Jones jig group has been reported in previous studies as result of anchorage loss. 11 - Runge ME, Martin JT, Bukai F. Analysis of rapid maxillary molar distal movement without patient cooperation. Am J Orthod Dentofacial Orthop. 1999;115(2):153-7. doi: 10.1016/S0889-5406(99)70343-4
https://doi.org/10.1016/S0889-5406(99)70...
, 1313 - Patel MP, Janson G, Henriques JF, Almeida RR, Freitas MR, Pinzan A, et al. Comparative distalization effects of Jones jig and pendulum appliances. Am J Orthod Dentofacial Orthop. 2009;135(3):336-42. doi: 10.1016/j.ajodo.2007.01.035
https://doi.org/10.1016/j.ajodo.2007.01....
, 1717 - Costa Grec RH, Janson G, Branco NC, Moura-Grec PG, Patel MP, Henriques JF. Intraoral distalizer effects with conventional and skeletal anchorage: a meta-analysis. Am J Orthod Dentofacial Orthop. 2013;143(5):602-15. doi: 10.1016/j.ajodo.2012.11.024
https://doi.org/10.1016/j.ajodo.2012.11....
, 2222 - Brickman CD, Sinha PK, Nanda RS. Evaluation of the Jones jig appliance for distal molar movement. Am J Orthod Dentofacial Orthop. 2000;118(5):526-34. doi: 10.1067/mod.2000.110332
https://doi.org/10.1067/mod.2000.110332...
, 2424 - 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(2):123-36. doi: 10.1007/s00056-004-0317-z
https://doi.org/10.1007/s00056-004-0317-...
The maxillary first premolars showed significantly smaller mesial angulation in the Distal jet, despite these teeth served as the anchorage unit in this appliance. 1919 - Nishii Y, Katada H, Yamaguchi H. Three-dimensional evaluation of the distal jet appliance. World J Orthod. 2002;3(4):321-7. However, as the premolar bands were attached to the Nance button, this prevented them from excessive mesial tipping. 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...
, 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...

The significantly greater mesialization of the maxillary first premolars in the Jones jig than in the First Class could also be explained by the larger Nance button in the First Class, representing a greater anchorage unit. 1212 - Papadopoulos MA, Melkos AB, Athanasiou AE. Noncompliance maxillary molar distalization with the first class appliance: a randomized controlled trial. Am J Orthod Dentofacial Orthop. 2010;137(5):586.e1-586.e13. doi: 10.1016/j.ajodo.2009.10.033
https://doi.org/10.1016/j.ajodo.2009.10....
The First Class results are in accordance with a previous study. 1010 - Fortini A, Lupoli M, Giuntoli F, Franchi L. Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod Dentofacial Orthop. 2004;125(6):697-704.

The Distal jet presented greater extrusion of maxillary first premolars than the Jones jig. This is probably because the first premolars are attached to the appliance. As the resulting mesial force on these teeth finds resistance to mesial movement by the anterior teeth and their tipping is restricted, there is a resultant vertical vector which causes extrusion of these teeth. 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...
Vertical movements of premolars could be expected. 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...
However, they play a minor part and should not be considered clinically significant. 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...

Mesial angulation of maxillary second premolars were progressively smaller in the Jones jig and First Class, as expected because of the smaller and larger anchorage units, respectively. 11 - Runge ME, Martin JT, Bukai F. Analysis of rapid maxillary molar distal movement without patient cooperation. Am J Orthod Dentofacial Orthop. 1999;115(2):153-7. doi: 10.1016/S0889-5406(99)70343-4
https://doi.org/10.1016/S0889-5406(99)70...
, 1313 - Patel MP, Janson G, Henriques JF, Almeida RR, Freitas MR, Pinzan A, et al. Comparative distalization effects of Jones jig and pendulum appliances. Am J Orthod Dentofacial Orthop. 2009;135(3):336-42. doi: 10.1016/j.ajodo.2007.01.035
https://doi.org/10.1016/j.ajodo.2007.01....
, 1717 - Costa Grec RH, Janson G, Branco NC, Moura-Grec PG, Patel MP, Henriques JF. Intraoral distalizer effects with conventional and skeletal anchorage: a meta-analysis. Am J Orthod Dentofacial Orthop. 2013;143(5):602-15. doi: 10.1016/j.ajodo.2012.11.024
https://doi.org/10.1016/j.ajodo.2012.11....
, 2222 - Brickman CD, Sinha PK, Nanda RS. Evaluation of the Jones jig appliance for distal molar movement. Am J Orthod Dentofacial Orthop. 2000;118(5):526-34. doi: 10.1067/mod.2000.110332
https://doi.org/10.1067/mod.2000.110332...
, 2424 - 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(2):123-36. doi: 10.1007/s00056-004-0317-z
https://doi.org/10.1007/s00056-004-0317-...
In contrast to the these groups, the Distal jet showed distal angulation of the maxillary second premolar. Evaluation of dental casts in a previous study demonstrated similar results. 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...
Differently from the other two appliances, the second premolars are not attached to the appliance. Therefore, as the molars distalize, the second premolars are pulled by the transeptal fibers and experience some distal tipping. 2525 - Cetlin NM, Ten Hoeve A. Nonextraction treatment. J Clin Orthod. 1983;17(6):396-413.

The Jones Jig group presented significantly greater mesialization of the second premolars than the other groups. This could be explained by the smaller Nance button used in this group. Moreover, the smallest mesial movement of the second premolars in the Distal jet group was expected since these teeth were not incorporated in the anchorage unit in this appliance.

The Distal jet presented smaller distal angulation of maxillary first molars than the other groups. According to other studies, this could be explained by the appliance design. The force is applied on the palatal side, more cervically to the first molar crown, compared to the other appliances, producing forces parallel and closer to the center of resistance, resulting in greater bodily movement, 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...
, 88 - Carano A, Testa M. The distal jet for upper molar distalization. J Clin Orthod. 1996;30(7):374-80. , 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...
and smaller distal inclination, as mentioned by Antonarakis and Kiliaridis 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...
(2008). Even with the small amount of distal movement of this group, distal angulation was observed. This reflects that Distal jet appliances might decrease the distal angulation effect, but it cannot neutralize the effect. 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...
, 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...

It seems that decreasing the forces for maxillary molar distalization has not been effective to reduce the molar distal angulation. In this study, the Jones jig appliance used with 125g force, demonstrated similar maxillary molar distal angulation when compared with the 200g force used in the First Class appliance, and greater distal angulation when compared with the 180 or 240g force used with the Distal jet. Previous studies evaluating the Jones jig appliance exerting 75g of distal force demonstrated similar results. 11 - Runge ME, Martin JT, Bukai F. Analysis of rapid maxillary molar distal movement without patient cooperation. Am J Orthod Dentofacial Orthop. 1999;115(2):153-7. doi: 10.1016/S0889-5406(99)70343-4
https://doi.org/10.1016/S0889-5406(99)70...
, 1111 - Haydar S, Üner O. Comparison of Jones jig molar distalization appliance with extraoral traction. Am J Orthod Dentofacial Orthop. 2000;117(1):49-53. , 2222 - Brickman CD, Sinha PK, Nanda RS. Evaluation of the Jones jig appliance for distal molar movement. Am J Orthod Dentofacial Orthop. 2000;118(5):526-34. doi: 10.1067/mod.2000.110332
https://doi.org/10.1067/mod.2000.110332...

According to some authors, distal angulation of maxillary molars produces molar intrusion. 1818 - Byloff FK, Darendeliler MA, Clar E, Darendeliler A. Distal molar movement using the pendulum appliance. Part 2: the effects of maxillary molar root uprighting bends. Angle Orthod. 1997;67(4):261-70. doi: 10.1043/0003-3219(1997)067<0261:DMMUTP>2.3.CO;2
https://doi.org/10.1043/0003-3219(1997)0...
, 2626 - Bussick TJ, McNamara JA Jr. Dentoalveolar and skeletal changes associated with the pendulum appliance. Am J Orthod Dentofacial Orthop. 2000;117(3):333-43. doi: 10.1016/s0889-5406(00)70238-1
https://doi.org/10.1016/s0889-5406(00)70...
This could explain the greater, but not statistically significant, intrusive changes observed in the maxillary first molars with the Jones jig, since it presented greater amount of distal angulation. On the other hand, the Distal jet presented greater vertical development of the maxillary second molars in comparison to the other groups, similar to a previous study. 44 - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
https://doi.org/10.1043/0003-3219(2002)0...
This could be explained by the greater treatment time of this group, which probably resulted in greater amount of eruption of maxillary second molars at the end of the distalization phase.

The overjet increased significantly in the Distal jet than in the First Class. This probably occurs for the first premolars are included in the anchorage unit in the Distal jet and but not included in the First Class appliance. As mentioned, this increased overjet caused, as a consequence, the greatest and smallest incisor protrusions, in these appliances, respectively.

Since changes in maxillary incisor angulation were similar in all groups and only the maxillary incisor protrusion was significantly greater in the Distal jet compared to the First Class, the lack of statistically significant difference between groups regarding the nasolabial angle could be expected, as previously reported 2727 - Chiu PP, McNamara JA Jr, Franchi L. A comparison of two intraoral molar distalization appliances: distal jet versus pendulum. Am J Orthod Dentofacial Orthop. 2005;128(3):353-65. doi: 10.1016/j.ajodo.2004.04.031
https://doi.org/10.1016/j.ajodo.2004.04....
( Table 4 ).

The greater percentage of molar distal movement, considering the anchorage loss, observed in the First Class group ( Tables 5 and 6 ) could be expected since this group presented numerically but not statistically significant greater amount of maxillary molar distalization, in mm, than the other groups ( Table 4 ). Similar results were observed in previous studies. 1010 - Fortini A, Lupoli M, Giuntoli F, Franchi L. Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod Dentofacial Orthop. 2004;125(6):697-704. , 1212 - Papadopoulos MA, Melkos AB, Athanasiou AE. Noncompliance maxillary molar distalization with the first class appliance: a randomized controlled trial. Am J Orthod Dentofacial Orthop. 2010;137(5):586.e1-586.e13. doi: 10.1016/j.ajodo.2009.10.033
https://doi.org/10.1016/j.ajodo.2009.10....
, 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...

When analyzing the percentages of distal movement between the Jones jig and the Distal jet, both had similar percentages of molar distal movement, as expected, because the amount of distalization were very close. This was also reported by Antonarakis and Kiliaridis 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...
(2008) who compared buccal and palatal distalization appliances. Despite the similarity between buccal and palatal appliances, it is important to mention that the Distal jet presented smaller distal inclination of maxillary molars, as reported by Antonarakis and Kiliaridis 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...
(2008), as well.

Independently of the amount of maxillary molar distalization and anchorage loss, Class II molar relationship correction was observed in all patients after distalization mechanics with the three appliances.

The results indicate that the type of anchorage used in the studied appliances is insufficient to counteract the distalization forces. 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...
, 2828 - Ngantung V, Nanda RS, Bowman SJ. Posttreatment evaluation of the distal jet appliance. Am J Orthod Dentofacial Orthop. 2001;120(2):178-85. doi: 10.1067/mod.2001.114645
https://doi.org/10.1067/mod.2001.114645...
, 2929 - Fudalej P, Antoszewska J. Are orthodontic distalizers reinforced with the temporary skeletal anchorage devices effective? Am J Orthod Dentofacial Orthop. 2011;139(6):722-9. doi: 10.1016/j.ajodo.2011.01.019
https://doi.org/10.1016/j.ajodo.2011.01....
Side effects should be expected during maxillary molar distalization with conventional anchorage either in the distalized molar or in the anchorage unit. 1515 - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
https://doi.org/10.1093/ejo/cjn047...
, 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...
Recently, alternative anchorage designs using devices with skeletal anchorage have been described as reducing the side effects of distalization, thus they seem to be efficient alternatives for maxillary molar distalization. 1717 - Costa Grec RH, Janson G, Branco NC, Moura-Grec PG, Patel MP, Henriques JF. Intraoral distalizer effects with conventional and skeletal anchorage: a meta-analysis. Am J Orthod Dentofacial Orthop. 2013;143(5):602-15. doi: 10.1016/j.ajodo.2012.11.024
https://doi.org/10.1016/j.ajodo.2012.11....
, 2929 - Fudalej P, Antoszewska J. Are orthodontic distalizers reinforced with the temporary skeletal anchorage devices effective? Am J Orthod Dentofacial Orthop. 2011;139(6):722-9. doi: 10.1016/j.ajodo.2011.01.019
https://doi.org/10.1016/j.ajodo.2011.01....

30 - Kinzinger GS, Gülden N, Yildizhan F, Diedrich PR. Efficiency of a skeletonized distal jet appliance supported by miniscrew anchorage for noncompliance maxillary molar distalization. Am J Orthod Dentofacial Orthop. 2009;136(4):578-86. doi: 10.1016/j.ajodo.2007.10.049
https://doi.org/10.1016/j.ajodo.2007.10....
- 3131 - Cozzani M, Fontana M, Maino G, Maino G, Palpacelli L, Caprioglio A. Comparison between direct vs indirect anchorage in two miniscrew-supported distalizing devices. Angle Orthod. 2016;86(3):399-406. doi: 10.2319/040715-231.1
https://doi.org/10.2319/040715-231.1...

Nonetheless, it is important to know the effects of the several distalization systems with and without skeletal anchorage to choose the ideal alternative, depending on the singular requirements of the patient.

After distalization, orthodontic mechanics must be complemented with fixed appliances to preserve the results of distalization and to correct its side effects. In general, maxillary molar distalization can be achieved with the three studied appliances. The device selection should depend on predictability, minimal undesirable side effects, cost-efficiency, and patient need.

Further studies with greater sample sizes should be performed to confirm our results. Moreover, long-term studies should be performed to evaluate treatment stability of these types of appliances. 1616 - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
https://doi.org/10.2319/101507-406.1...

Conclusions

The three appliances efficiently corrected the Class II molar relationship by dentoalveolar changes with some undesirable effects;

The Distal jet presented significantly smaller molar distal angulation and smaller, but not statistically significant, amount of distalization than the Jones jig and First Class appliances;

The First Class appliance produced less anchorage loss, greater percentage of distalization, and shorter treatment time than the Jones jig and Distal jet appliances.

Acknowledgments

This study was financed in part by the Coordination of Higher Education and Graduate Training - Brasil (CAPES) – Finance Code 001 – and by the São Paulo Research Foundation (FAPESP, process #2005/04237-9 and #2009/04843-7).

References

  • 1
    - Runge ME, Martin JT, Bukai F. Analysis of rapid maxillary molar distal movement without patient cooperation. Am J Orthod Dentofacial Orthop. 1999;115(2):153-7. doi: 10.1016/S0889-5406(99)70343-4
    » https://doi.org/10.1016/S0889-5406(99)70343-4
  • 2
    - Kloehn S. Evaluation of cervical anchorage force in treatment. Angle Orthod. 1961;31(2):91-104.
  • 3
    - Wilson WL, Wilson RC. Modular orthodontics (Wilson) manual. Denver: Rocky Mountain Orthodontics; 1981.
  • 4
    - Bolla E, Muratore F, Carano A, Bowman SJ. Evaluation of maxillary molar distalization with the distal jet: a comparison with other contemporary methods. Angle Orthod. 2002;72(5):481-94. doi: 10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
    » https://doi.org/10.1043/0003-3219(2002)072<0481:EOMMDW>2.0.CO;2
  • 5
    - Gianelly AA, Vaitas AS, Thomas WM. The use of magnets to move molars distally. Am J Orthod Dentofacial Orthop. 1989;96(2):161-7. doi: 10.1016/0889-5406(89)90257-6
    » https://doi.org/10.1016/0889-5406(89)90257-6
  • 6
    - Locatelli R, Bednar J, Dietz VS, Gianelly AA. Molar distalization with superelastic NiTi wire. J Clin Orthod. 1992;26(5):277-9.
  • 7
    - Jones RD, White J. Rapid Class II molar correction with an open-coil jig. J Clin Orthod. 1992;26(10):661-4.
  • 8
    - Carano A, Testa M. The distal jet for upper molar distalization. J Clin Orthod. 1996;30(7):374-80.
  • 9
    - Hilgers JJ. The pendulum appliance for Class II non-compliance therapy. J Clin Orthod. 1992;26(11):706-14.
  • 10
    - Fortini A, Lupoli M, Giuntoli F, Franchi L. Dentoskeletal effects induced by rapid molar distalization with the first class appliance. Am J Orthod Dentofacial Orthop. 2004;125(6):697-704.
  • 11
    - Haydar S, Üner O. Comparison of Jones jig molar distalization appliance with extraoral traction. Am J Orthod Dentofacial Orthop. 2000;117(1):49-53.
  • 12
    - Papadopoulos MA, Melkos AB, Athanasiou AE. Noncompliance maxillary molar distalization with the first class appliance: a randomized controlled trial. Am J Orthod Dentofacial Orthop. 2010;137(5):586.e1-586.e13. doi: 10.1016/j.ajodo.2009.10.033
    » https://doi.org/10.1016/j.ajodo.2009.10.033
  • 13
    - Patel MP, Janson G, Henriques JF, Almeida RR, Freitas MR, Pinzan A, et al. Comparative distalization effects of Jones jig and pendulum appliances. Am J Orthod Dentofacial Orthop. 2009;135(3):336-42. doi: 10.1016/j.ajodo.2007.01.035
    » https://doi.org/10.1016/j.ajodo.2007.01.035
  • 14
    - Andrews LF. The straight-wire appliance: syllabus of philosophy and techniques. 2nd ed. San Diego: LF Andrews Foundation of Orthodontic Education and Research; 1975.
  • 15
    - Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. a literature review. Eur J Orthod. 2008;30(6):558-71. doi: 10.1093/ejo/cjn047
    » https://doi.org/10.1093/ejo/cjn047
  • 16
    - Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion: a systematic review. Angle Orthod. 2008;78(6):1133-40. doi: 10.2319/101507-406.1
    » https://doi.org/10.2319/101507-406.1
  • 17
    - Costa Grec RH, Janson G, Branco NC, Moura-Grec PG, Patel MP, Henriques JF. Intraoral distalizer effects with conventional and skeletal anchorage: a meta-analysis. Am J Orthod Dentofacial Orthop. 2013;143(5):602-15. doi: 10.1016/j.ajodo.2012.11.024
    » https://doi.org/10.1016/j.ajodo.2012.11.024
  • 18
    - Byloff FK, Darendeliler MA, Clar E, Darendeliler A. Distal molar movement using the pendulum appliance. Part 2: the effects of maxillary molar root uprighting bends. Angle Orthod. 1997;67(4):261-70. doi: 10.1043/0003-3219(1997)067<0261:DMMUTP>2.3.CO;2
    » https://doi.org/10.1043/0003-3219(1997)067<0261:DMMUTP>2.3.CO;2
  • 19
    - Nishii Y, Katada H, Yamaguchi H. Three-dimensional evaluation of the distal jet appliance. World J Orthod. 2002;3(4):321-7.
  • 20
    - Polat-Ozsoy O, Gokcelik A, Güngör-Acar A, Kircelli BH. Soft tissue profile after distal molar movement with a pendulum K-loop appliance versus cervical headgear. Angle Orthod. 2008;78(2):317-23. doi: 10.2319/011107-10.1
    » https://doi.org/10.2319/011107-10.1
  • 21
    - Armstrong RA. When to use the Bonferroni correction. Opthalmic Physiol Opt. 2014;34(5):502-8. doi: 10.1111/opo.12131
    » https://doi.org/10.1111/opo.12131
  • 22
    - Brickman CD, Sinha PK, Nanda RS. Evaluation of the Jones jig appliance for distal molar movement. Am J Orthod Dentofacial Orthop. 2000;118(5):526-34. doi: 10.1067/mod.2000.110332
    » https://doi.org/10.1067/mod.2000.110332
  • 23
    - Lione R, Franchi L, Laganà G, Cozza P. Effects of cervical headgear and pendulum appliance on vertical dimension in growing subjects: a retrospective controlled clinical trial. Eur J Orthod. 2015;37(3):338-44. doi: 10.1093/ejo/cju061
    » https://doi.org/10.1093/ejo/cju061
  • 24
    - 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(2):123-36. doi: 10.1007/s00056-004-0317-z
    » https://doi.org/10.1007/s00056-004-0317-z
  • 25
    - Cetlin NM, Ten Hoeve A. Nonextraction treatment. J Clin Orthod. 1983;17(6):396-413.
  • 26
    - Bussick TJ, McNamara JA Jr. Dentoalveolar and skeletal changes associated with the pendulum appliance. Am J Orthod Dentofacial Orthop. 2000;117(3):333-43. doi: 10.1016/s0889-5406(00)70238-1
    » https://doi.org/10.1016/s0889-5406(00)70238-1
  • 27
    - Chiu PP, McNamara JA Jr, Franchi L. A comparison of two intraoral molar distalization appliances: distal jet versus pendulum. Am J Orthod Dentofacial Orthop. 2005;128(3):353-65. doi: 10.1016/j.ajodo.2004.04.031
    » https://doi.org/10.1016/j.ajodo.2004.04.031
  • 28
    - Ngantung V, Nanda RS, Bowman SJ. Posttreatment evaluation of the distal jet appliance. Am J Orthod Dentofacial Orthop. 2001;120(2):178-85. doi: 10.1067/mod.2001.114645
    » https://doi.org/10.1067/mod.2001.114645
  • 29
    - Fudalej P, Antoszewska J. Are orthodontic distalizers reinforced with the temporary skeletal anchorage devices effective? Am J Orthod Dentofacial Orthop. 2011;139(6):722-9. doi: 10.1016/j.ajodo.2011.01.019
    » https://doi.org/10.1016/j.ajodo.2011.01.019
  • 30
    - Kinzinger GS, Gülden N, Yildizhan F, Diedrich PR. Efficiency of a skeletonized distal jet appliance supported by miniscrew anchorage for noncompliance maxillary molar distalization. Am J Orthod Dentofacial Orthop. 2009;136(4):578-86. doi: 10.1016/j.ajodo.2007.10.049
    » https://doi.org/10.1016/j.ajodo.2007.10.049
  • 31
    - Cozzani M, Fontana M, Maino G, Maino G, Palpacelli L, Caprioglio A. Comparison between direct vs indirect anchorage in two miniscrew-supported distalizing devices. Angle Orthod. 2016;86(3):399-406. doi: 10.2319/040715-231.1
    » https://doi.org/10.2319/040715-231.1

  • Ethical approval
    This retrospective study was approved by the Research Ethics Committee of the Bauru School of Dentistry, University of São Paulo, Brazil (Process number: 54857516.0.0000.5417. Approval number: 1.632.790).
  • Note
    This article is based on research submitted by Dr. Lorena Vilanova in partial fulfillment of the requirements for the degree of MSc. in Orthodontics at Bauru School of Dentistry, University of São Paulo.

Publication Dates

  • Publication in this collection
    27 Apr 2020
  • Date of issue
    2020

History

  • Received
    25 June 2019
  • Reviewed
    18 Nov 2019
  • Accepted
    19 Dec 2019
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