|Year : 2015 | Volume
| Issue : 3 | Page : 255-258
Early treatment of Class III malocclusion by RME and modified Tandem appliance
Juhi Ansar1, Sandhya Maheshwari2, Sanjeev Kumar Verma2, Raj Kumar Singh3
1 Department of Orthodontics and Dentofacial Orthopedics, Institute of Dental Sciences Bareilly, Bareilly, Uttar Pradesh, India
2 Department of Orthodontics and Dental Anatomy, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
3 Department of Orthodontics and Dental Anatomy, Suda Rastogi Dental College, Faridabad, Haryana, India
|Date of Web Publication||9-Jul-2015|
Dr. Juhi Ansar
Department of Orthodontics and Dentofacial Orthopedics, Institute of Dental Sciences Bareilly, Bareilly - 243 006, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Patients with a skeletal Class III malocclusion and maxillary deficiency can be treated successfully using a combined protraction facemask and alternate rapid maxillary expansions and contractions (Alt-RAMEC). However, due to poor patient compliance during facemask therapy there has been growing interest in intraoral appliances for correcting Class III malocclusion. The tandem traction bow appliance (TTBA) is an intraoral appliance which has been used successfully for the treatment of growing Class III patients. This case report describes the management of a 10-year-old boy with a Class III malocclusion and maxillary deficiency treated with modified TTBA appliance.
Keywords: Class III skeletal pattern, maxillary expansion, orthopedic appliances
|How to cite this article:|
Ansar J, Maheshwari S, Verma SK, Singh RK. Early treatment of Class III malocclusion by RME and modified Tandem appliance. J Indian Soc Pedod Prev Dent 2015;33:255-8
|How to cite this URL:|
Ansar J, Maheshwari S, Verma SK, Singh RK. Early treatment of Class III malocclusion by RME and modified Tandem appliance. J Indian Soc Pedod Prev Dent [serial online] 2015 [cited 2020 Feb 17];33:255-8. Available from: http://www.jisppd.com/text.asp?2015/33/3/255/160405
| Introduction|| |
Class III malocclusion is characterized by deviation in the sagittal relationship of the maxilla and the mandible caused by a deficiency and/or a backward position of the maxilla, or by prognathism and/or forward position of the mandible.  In Asian societies, the frequency of Class III malocclusion is higher due to a large percentage of patients with maxillary deficiency. The incidence of Class III malocclusion in Asian populations can be as high as 14%. ,
Different treatment modalities have been advocated for treatment of Class III malocclusion. They include early orthopedic treatment using protraction facemask or chin cup therapy, orthodontic camouflage or combined surgical/orthodontic approach for patients with severe skeletal discrepancies. Early treatment of Class III malocclusion has been advocated to avoid complications like gingival recession with relation to lower incisors,  compromised dental and facial esthetics,  eliminating an anterior functional shift of the mandible,  and decreasing the chances of later orthognathic surgery.  Orthopedic treatment is usually carried out in children with active growth, with a goal of obtaining maximum skeletal and minimum dental change.
Protraction facemask therapy has been advocated in the treatment of Class III patients with maxillary deficiency. Protraction devices for the maxilla are used to promote the growth of a deficient maxilla by applying extraoral force to actively growing patients. Various authors have reported the forward movement of the maxilla with protraction devices in animals, and the formation of new bone by sutural apposition.  However, the major problem with extraoral anchorage has been of patient's compliance, due to the physical appearance of the extraoral appliance. This article presents an intraoral modified tandem appliance for maxillary protraction in the mixed dentition that has been used clinically to achieve successful results without relying on unusual patient cooperation.
| Diagnosis and Etiology|| |
A 10-year-old boy came to the Department of Orthodontics and Dentofacial orthopedics with a chief concern of "forwardly placed lower front teeth". Clinically, he had a concave facial profile, acute nasolabial angle, and a protrusive mandible and competent lips. Intraorally, he had crossbite i.r.t 11, 12, 21, and 22; mesial step on both left and right sides; a low anterior tongue posture; and carious left upper deciduous canine [Figure 1]a-f. The cephalometric radiograph and tracing showed a skeletal Class III malocclusion with maxillary deficiency, mandibular prognathism (A-point-Nasion-B-point (ANB) −3°), and hypodivergent growth pattern (Frankfort mandibular plane angle (FMA) 18°). The maxillary incisors were slightly proclined (upper incisor (U1) to nasion-A point (NA), 34°), and the mandibular incisors were retroclined (incisor mandibular plane angle (IMPA) 95°), compensating for the skeletal malocclusion [Figure 2] and [Table 1]. Patient had cervical vertebrae maturation index (CVMI) stage II and had no familial history of similar malocclusion.
|Table 1: Cephalometric measurements at pretreatment, and after protraction headgear treatment|
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| Treatment Alternatives|| |
Based on the objectives, two treatment options were proposed. The first option was an early phase of orthopedic treatment to induce harmonious skeletal growth and improve facial esthetics. This option would not eliminate the necessity for orthognathic surgery. The patient would be followed to determine the stability of treatment until growth is completed. The second option would be to wait until all growth was completed, and determine whether the malocclusion could be camouflaged by orthodontic treatment or a combination of surgical and orthodontic treatment. Patient opted for the first option.
| Treatment Progress|| |
Phase 1 treatment was started at age 10 years 4 months with a modified tandem traction bow appliance (TTBA). Modified TTBA comprises an upper splint, and a traction bow. The upper splint, includes HYRAX for rapid maxillary expansion (RME) and covers the palatal and occlusal surfaces of the maxillary teeth for retention [Figure 3]a-e. The traction bow is a modification of a conventional headgear outer facebow. The position of the elastic hooks on the upper splint and the tubes on the lower first permanent molar determines the direction of force. The maxillary hooks should be placed distal to the deciduous or permanent canines, so that the elastic force passes through the center of resistance of the maxilla. Maxillary protraction was started after 5 weeks of alternate rapid maxillary expansions and contractions (Alt-RAMEC), with a force of 300 cN per side applied for for 12-14 hours per day. A bionator was given as a retainer after appliance removal, and patient was instructed to wear it at night for 10-12 hours [Figure 4].
| Treatment Results|| |
Progress records taken after 9 months showed anterior crossbite correction and favorable growth between the maxilla and the mandible [Figure 5]a-f. Postprotraction cephalometric tracings showed 3 mm of forward movement of A-point (A-point to N perp. to Frankfort horizontal (FH)) and 5° of counterclockwise tipping of the palatal plane. The ANB angle changed from −3° to 2°. FMA opens from 18° to 21°. Slight labial tipping of the maxillary incisors and lingual tipping of the mandibular incisor were also observed [Figure 6] and [Table 1].
| Discussion|| |
The success of orthodontic treatment in patients with a developing Class III malocclusion depends on individual growth and timing of orthodontic or orthopedic intervention. For patients with moderate to severe Class III malocclusions, the decision of whether to treat early or to wait until the end of growth is difficult. The advantages of early treatment include minimizing dental compensation and overclosure of the mandible, which can lead to better facial esthetics during this important growth period. Takada et al., reported that the forward maxillary displacement with protraction is more favorable before or during acceleration of a child's pubertal growth spurt.  Similarly, Baccetti et al., reported that Class III treatment with maxillary expansion and protraction is effective in the maxilla only when it is performed before the peak (cervical Stage 1 or cervical Stage 2).  However, patient might still have to undergo a surgical procedure after early orthopedic and orthodontic treatment.
A combination of maxillary protraction and rapid maxillary expansion has been used to treat young Class III patients with maxillary deficiency. , Rapid maxillary expansion has been postulated as a means of disarticulating the maxilla from the surrounding bones connected by circumaxillary sutures.  The goal of combining RME with maxillary protraction was to facilitate the forward movement of the maxilla. It is suggested that Alt-RAMEC can increase the amount of maxillary protraction and result in a shorter period of protraction.  We used 5 weeks of Alt-RAMEC as suggested by Wang et al.  Maxillary protraction along the occlusal plane is usually accompanied by counterclockwise rotation of the palatal plane, and downward and backward rotation of the mandible, resulting in tentative improvement of the skeletal relationship.  In this case report, postprotraction radiographs showed a counterclockwise tipping of the palatal plane and slight increases in the mandibular plane and increased Lower facial height, thus overall improving the profile of the patient. As a result of the forward movement of the maxilla and the backward movement of the mandible, a significant increase was observed in ANB after TTBA treatment. Although positive overjet was achieved after treatment, careful monitoring is extremely important so that worsening of skeletal pattern can be detected. Ngan gave growth treatment response vector analysis (GTRV) to determine whether a Class III malocclusion can be camouflaged or if surgical treatment will be required at a later date.  Serial cephalometric radiographs of patients taken a few years apart after facemask treatment are superimposed to calculate GTRV. Class III patients having ratio below 0.38 should be warned of the future need for orthognathic surgery.
Although maxillary expander-facemask appliances achieve excellent orthopedic effects, they demand special patient compliance and are not as esthetic or comfortable due to both the physical appearance of the extraoral appliance and discomfort from the anchorage pads. The TTBA is more esthetic and comfortable than conventional devices because it is worn intraorally. Chun et al.,  in 1999 introduced the TTBA for the treatment of growing Class III patients. They defined the TTBA as a more esthetic and comfortable device than conventional appliances because it is removable, and worn intraorally. Its design allows the patient to open the mouth freely.
The traditional facemask has the advantage of generating maxillary protraction with pure extraoral anchorage. In contrast, the tandem appliance provides a tooth-borne anchorage system that combines skeletal and dentoalveolar movement.  Nevertheless, the increased level of patient cooperation with the tandem appliance, combined with the ability to protract the maxilla, and benefit from the Class III elastic dentoalveolar effect, makes this appliance valuable in nonsurgical Class III treatment.
| Conclusion|| |
Satisfactory correction can be obtained with modified TTBA appliance in patients having skeletal and dental Class III malocclusion with an average or decreased mandibular growth pattern. As the extraoral view of the appliance is more esthetic compared with a facemask, it could be a good alternative for noncompliant patients.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]