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How does a fixed functional appliance correct a Class II malocclusion?

Fixed functional appliances are used to correct Class II malocclusions and have supplanted their predecessors, that are removable functional appliances, such as bionator, Frankell, Twin Block, to name just a few.

Yet, it has been shown that no removable functional appliances could make the mandible grow (lengthen) even if these appliances move the lower jaw anteriorly to correct the Class II discrepancy between both jaws.

It was also shown that removable functional appliances are efficient. They correct most of Class II malocclusions, but it is due to dental (dentoalveolar) movements rather than skeletal changes (mandibular lengthening).

What about how fixed functional appliances work?

Review of literature

Let’s look at the articles one by one.

Xbow®

Flores-Mir et coll.1, in a retrospective cohort study, compared 69 patients treated consecutively with the Xbow® (crossbow) appliance with a historical control group of 30 individuals. The Xbow® appliance was used during 4.5 months in average and the cephalometric X-ray at time T2 was taken 6.5 months in average after the removal of the Xbow® appliance.

Consequently, the measurements taken at time T2 include the relapse of most of the side effects that could have been caused by the Xbow® appliance.

Results showed no mandibular changes (no advancement or different growth from the control group). However, a decrease in maxillary protrusion (maxilla that moved backward) and an increase in the vertical dimension were noted.

The dental changes observed were a decrease in the overjet caused by anterior tipping (proclination) of the lower incisors of about 5° (4.7 ± 4.1°). No significant changes were observed in the upper incisors. The upper molars moved backward by about 1 mm (0.9 ± 1.2 mm) and the lower molars moved forward by 1 mm (1.1 ± 1.3 mm).

Xbow® and Forsus™

The Xbow® appliance was then compared to the Forsus™ appliance. Miller et coll2 in a retrospective cohort study, compared 38 patients having received the Xbow® appliance (XB group) with 36 patients having received Forsus™ Class II correctors (FO group). T1 is prior to appliance placement (don’t know how many weeks) , T2 was 6 to 8 weeks after the end of the orthodontic treatment rather than at the removal of the functional appliances.

They found that both appliances produced the same amount of tipping of the lower incisors (no differences between both groups). The longer the treatment had been, the more the incisors tipped. The Xbow appliance and Full brackets averaged 24,18 ± 5,26 months and the Forsus with Full Brackets group averaged 30,17 ± 7,66. The difference between the 2 treatment protocol was significant (p = 0,37).

However, it is not clear if the XBow phase 1 treatment time is include phase 2 treatment time with fixed edgewise appliance but it seems so.  In the result section, we see that the treatment time with fixed appliance  in the XBow group is 16,68 months. I assume that the difference between 16 months and 24 months can be explained by a phase 1 of 8 months or so of XBow therapy.

Earlier report (Tullooch et al13) compared the treatment time of 2 phase treatment versus one phase treament.  They found that the total duration of treatment beyond phase 1, appears that this was shorter for patients who had had early treatment during phase 1. Therfore, it make sense that phase 2 therapy with full fixed brackets that followed phase 1 therapy with Xbow appliance would appears shorter than a full edgewise therapy with Forsus device.

Xbow®

A recent prospective study from Erbas et Kocadereli3 analyzed the changes of the Xbow® appliance and their observation time was at the removal of the functional appliance that was used 6 months in average (5.0 to 8.0 months). The radiographic method used was cone beam computed tomography (CBCT). Their result confirms a skeletal effect of maxillary backward movement (decrease in the SNA angle of 0.67 ± 1.35°) and no significant mandibular changes. The dental movements observed were significant backward tipping of the upper incisors (-3.58 ± 3.56°) and extrusion (egression) of 1.72 ± 1.87 mm. The lower incisors presented a significant anterior tipping of 10.87 ± 4.91°. The upper molars did not show any significant backward movement or intrusion. The lower molars presented a significant forward shift of 2.07 ± 1.24 mm and extrusion of 1.52 ± 1.08 mm.

Forsus™ and Class II elastics

Dubois et coll4 prospectively compared patients treated with Forsus™ Class II correctors with patients wearing Class II intermaxillary elastics. The observation time at T2 is at the removal of the Forsus™ Class II correctors and the observation duration is 6 months.

The results could not show evidence of any maxillary or mandibular skeletal changes. The use of Forsus™ correctors resulted in significant backward tipping of the upper incisors and forward tipping of the lower incisors, as well as a change in inclination of the occlusal plane.

Efficiency of the Forsus™ Class II correctors

Franchi L, Alvetro L et coll5 compared a retrospective cohort of 32 patients treated consecutively with a historical control group of 27 untreated patients.

The observation times are T0 before the orthodontic treatment and T1 after the orthodontic treatment. The average duration of treatment was 2.4 ± 0.4 years. The average duration of the use of Forsus™ Class II correctors was 5.2 ± 1.3 months.

87.5% of patients saw their Class II malocclusion being corrected successfully. The significant skeletal effect observed was a restriction of maxillary anterior growth (SNA is in average 1.6 ± 1.4° lower than the control value).

The effect on the mandible is mainly dentoalveolar:

1- Anterior movement of the incisors (6.1 ± 6.3°)

2- Anterior movement of the molars (2.4 ± 1.6 mm)

3- Extrusion of the lower molars (3.6 ± 1.5 mm)

A follow-up but retrospective cohort study from the same group of researchers (Cacciatore et coll6) analyzed 36 patients 2.3 ± 1.1 years in average (T3) after the end of the orthodontic treatment with Forsus™ Class II correctors compared to an historical control group of untreated individuals.

The results show that, during the observation period post treatment, the maxilla returns to a normal growth and position (SNA increases by 1.4°). The overjet and overbite increase significantly (1.3 mm and 1.5 mm respectively). The upper incisors show a significant intrusion of 1.2 mm.

When the changes between the beginning (time T1) and the end of the follow-up (time T3) are compared, there are no significant skeletal changes in the maxilla or mandible.

The significant dental changes are:

1- Reduction of the overjet (-3.8 mm) and overbite (-1.5 mm)

2- Improvement of the molar relationship (3.7 mm)

3- Retrusion (backward movement) of the upper incisors (-1.1 mm)

4- Intrusion of the lower incisors (-1.2 mm)

2 years after the orthodontic treatment, the efficiency rate of the Class II correction is 83.3% compared to an efficiency rate of 87.5% at the end of treatment.

Forsus™ and temporomandibular joint

Aras et coll7 compared 15 individuals before their pubertal growth peak with 14 individuals after their pubertal growth peak. These 29 patients received Forsus™ Class II correctors for a period of about 9 months. Cephalometric X-rays and magnetic resonance imageries were taken. Significant therapeutic effects are about the same as those previously discussed, namely backward tipping and extrusion of the upper incisors, protrusion, intrusion and anterior tipping of the lower incisors, a distal movement of the upper molars and a mesial movement of the lower molars.

Interesting fact, magnetic resonance imagery proved that there were no changes in the position of the articular disc, which is a good thing.

Twin Force® Bite Corrector™

Chhibber et coll8 retrospectively studied the therapeutic effect of the Twin Force® Bite Correctors™. Like Aras et coll7, they compared 23 individuals treated before their growth peak with 18 individuals treated after their pubertal growth peak.

Like the other fixed functional appliances, the skeletal change put in evidence, when the Twin Force® devices were removed, is a maxillary growth restriction (SNA decreases by 1.22°) and anterior tipping of the lower incisors (dentoalveolar movements) of 4,4 ± 5,5°.

At the end of the orthodontic treatment, there were no differences in the maxillary or mandibular skeletal parameters, no matter if patients were treated before or after their pubertal growth peak.

The orthodontic treatment was significantly longer in individuals whose treatment started earlier (3.67 years versus 2.75 years).

In conclusion, the efficiency of a fixed functional appliance is better in an individual after his/her puberty. Starting too early is not better and leads to a longer treatment.

SUS2 correctors

Oztoprak et coll10 compared, in a prospective study, SUS2 correctors with Forsus™ Class II correctors. A control group of untreated individuals was used as a reference. The duration of use of both appliances was 5 ± 1 months in average.

The dentoalveolar effects observed are:

1- Retrusion and extrusion of the upper incisors

2- Protrusion and intrusion of the lower incisors

No significant anteroposterior or vertical skeletal changes were observed for both appliances.

However, if dentoalveolar changes in the lower incisors are compared, the use of Forsus™ Class II correctors significantly leads to more anterior tipping of the lower incisors than SUS2 correctors (10.8 ± 3.07° versus 5.78 ± 3.91°).

Study model

Experimental groups

Observation Time Point

Sample size (>25)

Untreated Controls

T0 Baseline

T1 Prior Cl II device

T2 Post Cl II device

T3 End of Ortho

T4 Follow-up

Flores-Mir AJODO 2009 R

✔︎ 69

✔︎ 30

✔︎

6 m. post Xbow

Miller AO 2013 R

✔︎ 38/36

✔︎

✔︎

Erbas AO 2014 P

✔︎ 25

✔︎

✔︎

Dubois et al P

✔︎ 23 / 7

✔︎

✔︎

Franchi AO 2011 R

✔︎ 32

✔︎ 27

✔︎

✔︎

Cacciatore AO In press R

✔︎ 36

✔︎ 20

✔︎

✔︎

✔︎

Aras AJODO 2011 P

✔︎ 15 / 14

✔︎

✔︎

Chhibber AO 2013 R

✔︎ 23 / 18

✔︎

✔︎

Oztoprak EJD 2012 R

✔︎ 20 / 20

✔︎ 19

✔︎

✔︎

This table compares the study model of the studies previously discussed. The retrospective cohort studies are identified by the letter R and the prospective ones are identified by the letter P in the first column. Only 4 studies had an untreated control group. Only 3 studies have an observation time before the functional correctors were installed and when the correctors were removed. Only one study presents a follow-up 2 years post treatment.

Thus, there is room for more studies and the best study model will be the one with the most check marks on its row and which will be a prospective study of consecutively treated cases. Making such a study takes a minimum of 4 to 6 years and hundreds of hours of work.

Conclusion

Fixed functional appliances efficiently correct Class II malocclusions. They all function similarly. The correction is mainly done through dentoalveolar changes. No appliances make significant long-term skeletal maxillary and mandibular changes.

Bibliography

1- Flores-Mir C, Barnett G, Higgins DW, Heo G, and Major PW. Short-term skeletal and dental effects of the Xbow appliance as measured on lateral cephalograms. AJODO; 2009;136(6):822-832.

2- Miller, Robert A, Long Tieu, and Carlos Flores-Mir. “Incisor Inclination Changes Produced by Two Compliance-free Class II Correction Protocols for the Treatment of Mild to Moderate Class II Malocclusions.” Angle orthodontist 83, no. 3 (2013): doi:10.2319/062712-528.1.

3- Erbas, Banu, and Ilken Kocadereli. “Upper Airway Changes After Xbow Appliance Therapy Evaluated with Cone Beam Computed Tomography.” Angle Orthod 2014; 84, no. 4: doi:10.2319/072213-533.1

4- Dubois A, Rompré P, Rodrigue C, Remise C, Comparaison des effets sur la croissance des maxillaires de l’utilisation du Forsus versus celle des élastiques de classe II, Thèse de maîtrise

5- Franchi L, Lisa Alvetro, Veronica Giuntini, Caterina Masucci, Efisio Defraia, and Tiziano Baccetti. “Effectiveness of Comprehensive Fixed Appliance Treatment Used with the Forsus Fatigue Resistant Device in Class II Patients.” Angle orthodontist  2011; 81, no. 4: doi:10.2319/102710-629.1

6- Cacciatore, Giorgio, Luis Tomas Huanca Ghislanzoni, Lisa Alvetro, Veronica Giuntini, and Lorenzo Franchi. “Treatment and Posttreatment Effects Induced by the Forsus Appliance A Controlled Clinical Study.” Angle orthodontist (2014):doi:10.2319/112613-867.1

7- Aras, Ada, Saracoglu, Gezer, and Aras. “Comparison of Treatments with the Forsus Fatigue Resistant Device in Relation to skeletal maturity: A cephalometric and magnetic resonance imaging study. AJODO 2011; 140: 616-25: doi:10.1016/j.ajodo.2010.12.018.

8- Chhibber, Aditya, Madhur Upadhyay, Flavio Uribe, and Ravindra Nanda. “Mechanism of Class II Correction in Prepubertal and Postpubertal Patients with Twin Force Bite Corrector.” Angle Orthod. 2013; 83, n718-727: doi:10.2319/090412-709.1

9- Bassarelli T., Does an Anterior Bite Plane Change the Treatment Result Obtained with a Jasper Jumper in Class II Division 1 Growing Patients, Angle East 2013 scientific meeting, New York

10- Oztoprak MO, Nalbantgil D, Uyanlar A, and Arun T. A cephalometric comparative study of class II correction with Sabbagh Universal Spring. European journal of dentistry. 2012 Turkey;6(3):302-10

11- Giuseppe Perinetti, Jasmina Primožič, Giovanna Furlani, Lorenzo Franchi, and Luca Contardo (2014) Treatment effects of fixed functional appliances alone or in combination with multibracket appliances: A systematic review and meta-analysis. The Angle Orthodontist In-Press.

12-Tulloch, J F, C Phillips, and W R Proffit. “Benefit of Early Class II Treatment: Progress Report of a Two-phase Randomized Clinical Trial.” AJODO  1998;113: 62-72.

Questions and comments

Leave a comment

  1. Gurmukh Singh Sahi says:

    Thanks a lot .very quick .v simple….

  2. Duncan Higgins says:

    Under the heading: “Xbow® and Forsus™” the final sentence reads:”There were no differences in the total time of treatment between both appliances.”
    In Dr. Miller’s article in the Angle Orthodontist under Results in the Abstract he states:”The mean treatment time was 24.2 months for XB and 30.2 months for the FO group (P 5 .037).
    XB patients averaged 10 fewer months of fixed edgewise appliances compared to FO patients. (XB=Xbow group, FO=Forsus to the archwire group)

    At the recent AAO meeting in San Diego Dr.Proffit complimented you on your research. He also stated that as a profession we need to look at clinical significance over statistical significance.
    If there was ever a clinically significant difference found in a study it was that found in Dr. Miller’s.

    In an unpublished study from the University of Alberta in 2015 involving 172 consecutively treated patients with Xbow followed by full edgewise the lower incisor changes were as follows:
    L1MGo change from T1 (99.1) to T2 (102.2). Mean difference 3.1 degrees is significant (p<0.001).
    L1MGo change from T2 (102.2) to T3 (103.7) Mean difference 1.5 degrees is significant (p=0.01).
    L1MGo change from T1 (99.1) to T3 (103.7). Mean difference 4.6 degrees is significant (p<0.001).
    For every extra mm of OB (greater than the ideal overbite of 2mm) there is an increase in lower incisor inclination of 1.3 degrees.
    This result is similar to other studies done of inter arch Class II appliances.

    We have never taken a ceph right after spring removal.
    We know the lower incisor is in an unstable, over corrected, and overly proclined position that will relapse.
    I would not be comfortable exposing a patient to an extra radiograph and it would certainly be questioned by the ethics committee.
    Our protocol was developed after discussions with Dr. Hans Pancherz whom I have lectured with. He had shown over proclination and relapse with the non-edgewise Herbst. The important conclusions that he made were that overcorrection was important to end up with a solid Class I occlusion, and that there was no gingival recession.

    A spring is a spring is a spring. The difference in lower incisor proclination depends on whether there is torque control with an edgewise appliance as in the SUS2 to the archwire and Forsus to the archwire, or tipping, overcorrection, and rebound, as with Xbow. At the end of phase two it is the same 5 degrees.
    The advantages as I see them to the Xbow are:
    1. Xbow has a Hyrax screw which is useful in practically all Class II's.
    2. The unwanted side effects of posterior openbite, over proclination of lower incisors, occlusal plane tipping, and the overcorrection of the maxillary transverse and Class II mostly relapse before phase two.
    3. There is no buccal flaring of upper molars with Xbow.
    4. There is no anterior occlusal plane canting in asymmetric Class II's with Xbow.
    5. In many cases we do not need to proceed with phase two.
    6. In most cases phase two only takes approximately one year which decreases the rate of white spot lesions.
    7. Xbow opens space for the erupting maxillary canines and probably reduces the number of surgical exposures.

    1. Hi Dr. Higgins,

      Thank you for pointing out my error in the paragraph about Dr. Miller’s paper. I went back to the original paper and made the correction. I hope I got it right this time.

      Xbow® and Forsus™

      Maybe you can clarify if the mean treatment time of 24 months of the Xbow group included both phase 1 Xbow therapy and phase 2 with full edgewise brackets. Did the data of treatment time had a normal distribution?

      Dr Proffit’s lecture AAO 2017, San Diego

      Since you attended Dr. Proffit’s lecture at the AAO meeting in San Diego, you certainly noted that he said that for clinical significance, one should not only compare 2 means. The mean treatment time of the Xbow group was 24,18 ± 5,26 months and the mean for the Forsus group was 30,17 ± 7,66 months.

      It would be interesting to divide the treatment time in 3 groups: <24 months, 24 to 30 months, > 30 months, assess the number (or %) of patients Xbow and Forsus that were treated in less than 24, 24-30 or more than 30 months and find out if there is a difference in the number of patients for each treatment protocol in each strata of treatment time.

      I think the orthodontist clinician would benefit from knowing that using A or B protocol of treatment, chances are that Z% of the time the treatment time would be 24 months or less, Y% would be 24-30 months and so on…

      That is how Dr. Proffit told me to present the data on SARPE and the data of genioplasty. It gives a much clearer picture of the outcome, especially when the outcome data are not normally distributed, which almost always is the case.

      CAO 66th Annual Scientific Session, 2014

      This webpage is a resume of the lecture I did at the panel on Fixed Appliance Management of Class II Malocclusion at the 66th Annual Scientific Session of the Canadian Association of Orthodontist. The other panel members were Dr. Miller, Dr. Ramzi and Dr. Goodday.

      I was the outlier who was not promoting a Unitek product or a product in which I would have financial interest.

      My message was that all these appliances work about the same way.

      Most studies showed:

      • • Some restriction of Mx forward growth
      • • No significant increase of Md growth
      • • Significant dentoalveolar change at end of ortho
      • • Class II correction is maintained at 2 y follow up (83%)
      • • No significant skeletal change at 2 y follow up.

      Among the side effect, incisor proclination occurred in spite of arch wire cinchback and -6° torque in the brackets. Therefore, wire-slot interplay should be reduced by using full dimensional arch wire and posterior cinchback. The use of TADs along with Class II correction device reduces lower incisors proclination (Aslan B, et al AO 2014;84;76-87). Extraction and cl II correction device is good marriage when space is necessary along cl II correction.

      When comparing the cost, SUS2 was the least expensive followed by Esprit corrector. Forsus and Twin Force Bite Corrector (TFBC) are about the same price, but more expensive than SUS2 and Esprit. Xbow device was the most expensive as one has to pay for the Forsus and the Xbow device. You will likely argue that if it saves some months of treatment, it may be worth paying extra dollars.

      Nowadays, Carriere Motion appliance is gaining popularity. Dr. McNamara at the University of Michigan is conducting new studies with that appliance. The preliminary results are promising.  The cost is about 270$ per unit so it ranks at the same price of Forsus and TFBC.
      Carriere® Motion appliance permit the same advantage as Xbow reducing the treatment time of full fixed edgewise appliance. I am quite sure that side effect comes with the use of Carriere® Motion and this need to be managed.

      Universal claims

      Regarding the list of advantages to the Xbow appliance, many apply to other class II corrector devices :

      1- Hyrax appliance can be use with any Class II corrector device, not only Xbow device.

      3- If there is no buccal flaring, it is because there is a rigid trans-palatal device (an expansion device that is now not activated) maintain steady the molars. Any expansion device with any class II corrector device will do the same.

      4- Asymmetric class II or class II subdivision is often explained by asymmetric growth at the condyle, one side being more distal than the other or by more mesial position of maxillary teeth on one side. This implies more distalization on class II side in the maxilla or mesialization of the class II side in the mandible. How can this can be achieve with the hyrax and the labiolingual appliance in place?

      5- The need for phase 2. It is unlikely that despite adequate class II correction, there would not be other problems that need correction, like deep overbite, some rotation, some crowding. Therefore it depends on how much compromise the patient or the orthodontist is willing to accept. I doubt that a phase 1 only Xbow case would routinely meet the standards for satisfactory treatment, much less pass the requirements of ABO case or Angle case.

      6- The relationship of reduction of white spot lesion and Xbow is weak. White spot lesions are related to the maintenance of good oral hygiene whether the treatment is long or short.

      7- Xbow opens space for the erupting maxillary canines. This is true for any device that would distalise maxillary teeth to gain space for the canine.

      Regarding the relapse of side effect (item 2) that occur in phase 1 Xbow therapy, perhaps there should be thanks to God that relapse exists. You don’t take cephs at the end of phase 1, but I often do. This permits to see the true effect of a given appliance. It is sad you did not.

      Conclusion

      I want to thank you for generating this discussion. I changed the paragraph to reflect Dr. Miller’s paper.

      It gave me an opportunity to review cases that were treated with a labiolingual appliance.

      In a private practice, I don’t have an ethics committee to tell me what to do, but keeping in mind the ALARA principle, my own ethics tells me to know what I have done with this or that appliance and that is why I may take a ceph after a particular phase of treatment. This is helpful to guide the mechanics of the phase 2.

      In this sample of 3 selected cases, I can tell you that Phase 1 therapy with Labiolingual device (Xbow) and Forsus proclined the lower incisors by an average 17° ((15+14+22)/3) which is about 3 times what is reported because they did not look at it. The side effects relapse 2° in one case, 15° in the other and a class I occlusion was achieved in both treated cases.

      We can conclude that the Labiolingual appliance and Forsus device is effective to correct class II malocclusion, but other class II corrector device can do the same. I think that Carriere Motion appliance is gaining in popularity and less Forsus device is employed nowadays.

      Clinical case of Labiolingual appliance (Xbow)

      I would like to share some cases with you and the public

      Case 1

       

       

      The picture on the left show the dental change following 5 months of Labiolingual appliance & Forsus device. Superposition of the tracing (pict on the right) shows proclination of the lower incisors of 22°, clockwise rotation of the occlusal plane and retraction of the maxillary teeth.

      At the end of treatment, the red tracing show most side effect relapse and class I relationship was maintained.

      The total treatment time was 23 months.

      Case 2

      .

      This 11 y. 5 m. old girl was in late mixed dentition, had retroclined lower incisors, impacted 23 and lip trap. The labiolingual appliance was selected because we could afford proclination of the lower incisors during phase 1 treatment. Lower incisors (/1-MP) was 93° at the end of treatment which is a normal value.

      Case 3

      .

      This is a transfer case from a friend orthodontist in Toronto. Progress ceph was done at the removal of the Xbow device. The duration of phase 1 is 11 months. Like the other 2 cases, lower incisors proclined and the occlusal plane rotate clockwise.

  3. Dr Herb Hughes says:

    I’ve been using the Xbow/Forsus Combo treatment for over 10 years and have completed over 500 cases. Most of my class II cases I treat in less than 18 months (5-6 months Xbos followed by 10-12 months of braces or clear aligners). It is the most efficient class II corrector on the market today! Below are a couple of comments that I wanted to share with you about the article.

    1* Totally agree that the lion’s share of movement with a functional appliance is dentoalveolar.
    2• Xbow/Forsus Combo is the most efficient class II appliance on the market today.
    3• Goal is to achieve an excellent and stable result in the least amount of time. With that said, I try to correct several issues at the same time and at the right time. Don’t start too early wait until permanent teeth have fully erupted.
    4• Another advantage of the Xbow is correcting the transverse relationship. It has been shown that most class II malocclusions have a narrow maxilla and can benefit from lateral expansion which the Xbow delivers nicely.
    5• I believe (no research to back up my statement) that after expanding the maxillary expansion appliance it loosens both sutures and teeth. The net effect after inserting the Forsus Springs is a turbocharged movement of the dentoalveolar complex.
    6• The Xbow/Forsus Combo requires less patient cooperation than many other class II correctors while minimizing undesirable forces or movements such as the Carrier System which requires elastic wear can pull down the maxillary anterior occlusal plane leading to a gummy smile line.

    The Xbow/Forsus combo just like any other orthodontic appliance takes a little bit of time getting use to but it is well worth the effort and your patients will love the results!

    1. Pyramid of Clinical Evidence versus Pyramid of Denieal

      .

      .

      .
      The goal of this article was to review different fixed fonctionnal that  I have used over the last 20 years or so after using Bionator, Frankell and Head gear in the early years of my career. I did a literature review to discuss the different treatment effect of each appliance.

      I tried to do it objectively, but you are not objective in your comments. Your comments made me think of a blog of Kevin O’brien : Uncertainty and the pyramid of denial

      If I would rank your comment in the pyramid of clinical evidence and denial, it would be at the 1st level: case report/expert opinion/ I know best.

      I said in my article that Xbow device used with Forsus device is effective to correct class II malocclusion, but other class II corrector device can do the same.

      There is no study that support your claim that Xbow/Forsus combo is the most efficient class II appliance. This is a commercial claim, like Damon Bracket is best SLB, or Smartclip is the best invention since slice bread. Such claim has little value.

      In item #4 you mention correcting the transverse relationship is an advantage of Xbow combo. This is not unique to Xbow. Correcting the transverse relationship can be done with most other fixed functional appliances.

      I did not want to do the promotion of Carriere Motion either, as I did not use it yet, but I plan to try it.

      May be I did it wrong when I tried this labiolingual appliance, may be I should have ask to the magic man, may be your patients are different than mine, but I stopped using Xbow device because it flared too much the lower incisors even I I can count on God and relapse.

      Nevertheless I was able to correct class II malocclusion using differents appliances over the years. It was worth the effort and my patients loved the results.

       

       

       

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