|Year : 2016 | Volume
| Issue : 1 | Page : 42-47
A severe skeletal Class II correction by activator headgear combination
Shivam Agrawal1, Prashant Gupta2, Nandini Venkatesh Kamat3
1 Senior Resident, Department of Orthodontics and Dentofacial Orthopedics, Goa Dental College and Hospital, Bambolim, Goa, India
2 Consultant Orthodontist, Department of Orthodontics and Dentofacial Orthopedics, Goa Dental College and Hospital, Bambolim, Goa, India
3 Professor and Head, Department of Orthodontics and Dentofacial Orthopedics, Goa Dental College and Hospital, Bambolim, Goa, India
|Date of Submission||27-Jul-2015|
|Date of Acceptance||08-Oct-2015|
|Date of Web Publication||4-Feb-2016|
Department of Orthodontics and Dentofacial Orthopedics, Goa Dental College and Hospital, Bambolim, Goa - 403 202
Source of Support: None, Conflict of Interest: None
Skeletal Class II malocclusion with mandibular deficiency and maxillary excess is a severe skeletal problem encountered in growing individuals. Correction of mandibular deficiency and maxillary excess in a skeletal Class II patient with a vertical growth pattern poses a great challenge. The control of vertical dimension becomes very important as downward and backward rotation of mandible will exaggerate the facial convexity. The present case signifies the importance of functional jaw orthopedic treatment in a vertically growing female patient with mandibular deficiency and maxillary vertical excess. Activator headgear combination was used for skeletal correction which was followed by fixed mechanotherapy. Superimposition of pretreatment and posttreatment cephalometric tracings shows desired treatment outcomes.
Keywords: Activator headgear therapy, Skeletal Class II correction, Vertical maxillary excess correction
|How to cite this article:|
Agrawal S, Gupta P, Kamat NV. A severe skeletal Class II correction by activator headgear combination. J Indian Orthod Soc 2016;50:42-7
|How to cite this URL:|
Agrawal S, Gupta P, Kamat NV. A severe skeletal Class II correction by activator headgear combination. J Indian Orthod Soc [serial online] 2016 [cited 2019 May 19];50:42-7. Available from: http://www.jios.in/text.asp?2016/50/1/42/175722
| Introduction|| |
Class II malocclusion may result from a mandibular deficiency, maxillary excess, or a combination of both, but the most common finding is mandibular skeletal retrusion.  Skeletal Class II malocclusion with mandibular deficiency and maxillary excess is a severe skeletal problem encountered in growing individuals. Functional jaw orthopedic appliances are designed to encourage adaptive skeletal growth by maintaining the mandible in a corrected forward position.  The activator developed by Andersen is one of the most widely used functional appliances. A high-pull face-bow attached to activator is indicated in those patients in whom an increase in vertical dimension should be minimized or avoided.  The combination appliance is also used to provide greater cumulative skeletal growth than either appliance alone.  In general, Class II, Division I malocclusion correction using high-pull headgear activator combination therapy produces restriction of forward maxillary growth, inhibition of the mesial and vertical displacement of the maxillary teeth, improvement of the mandibular posterior teeth, condylar and glenoid fossa remodeling, and improvement in muscle pattern. 
| Case Report|| |
A 13-year-old female patient presented with a chief complaint of excessive gum show both at rest and on smile. Clinical examination revealed convex profile, acute nasolabial angle, incompetent lips, nonconsonant smile, increased interlabial gap, increased maxillary incisor show at rest and smile, short upper lip length, and hyperactive mentalis activity [Figure 1]a-d]. Intraorally, she had a Class II canine relationship by 6 mm on the right side, 5 mm on the left side, and a Class II molar relationship bilaterally by 6 mm. The patient presented with spacing in the maxillary anterior, an increased overjet, (13 mm) and deep bite (7 mm). Teeth 16, 26 were root canal treated. The patient had a Bolton's discrepancy of 1.9 mm mandibular anterior tooth material excess and 1.92 mm total mandibular tooth material excess [Figure 1]e-i]. On the basis of cephalometric measurements, the patient was diagnosed as a case of skeletal Class II malocclusion with vertical growth pattern, prognathic, and vertically excess maxilla, retrognathic mandible [Figure 1]j and k]. There were no signs and symptoms of temporomandibular disorders.
|Figure 1: (a) Pretreatment frontal at rest, (b) pretreatment oblique at rest, (c) pretreatment profile at rest, (d) pretreatment frontal dynamic smile, (e) pretreatment right buccal dental photograph, (f) pretreatment frontal dental photograph, (g) pretreatment left buccal dental photograph, (h) pretreatment maxillary occlusal dental photograph, (i) pretreatment mandibular occlusal dental photograph, (j) pretreatment lateral cephalogram, (k) pretreatment orthopantomogram|
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Treatment objectives included the following:
- Correction of anteroposterior skeletal discrepancy to obtain a pleasing facial profile
- Control of vertical dimension and elongation of mandible
- Achieving neuromuscular balance by elimination of aberrant musculature
- Achieving Class I canine and molar relationship bilaterally
- Level and align the upper and lower teeth
- Achieving ideal overjet and overbite relationships
- To achieve a consonant smile
- To correct Bolton's discrepancy.
The first alternative was an orthosurgical management after the patient's growth was completed. This option had the disadvantage of patient waiting for a few years.
The second alternative was the extraction of maxillary first premolars and a camouflage treatment for Class II, Division 1 malocclusion. However, this treatment option would not improve the patient's facial frontal and profile features. It would also not inhibit the vertical growth of maxilla. This treatment alternative, therefore, was avoided.
To improve patients profile by controlling the vertical maxillary excess and backward rotation of the mandible, activator-headgear combination therapy was opted as an next treatment option. Alternative treatment using twin block with greater vertical block height was considered, but activator headgear combination was preferred due to well-documented skeletal results of this combination.
Benefits and disadvantages of each were explained to the patient and the patient opted for the third treatment alternative, as the patient wanted an immediate solution to her facial esthetics.
To improve the profile and control the backward rotation of the mandible, activator headgear combination was used. Construction bite for the activator was taken with 5 mm of vertical opening and 6 mm of horizontal advancement. After 1 week of activator wear the headgear was attached to the activator tubes in premolar-molar region of the acrylic blocks. High-pull headgear was used with the force of 400 g per side for 12-16 h daily for 11 months. The outer bow and extraoral force were adjusted such that force passed through the center of maxilla approximately between the root tips of maxillary first and second premolars. In the support phase, a maxillary anterior inclined plane to promote vertical eruption of premolars was given [Figure 2]a-j.
|Figure 2: (a) Post activator headgear therapy frontal at rest, (b) post activator headgear therapy oblique at rest, (c) post activator headgear therapy profile at rest, (d) post activator headgear therapy frontal dynamic smile, (e) post activator headgear therapy right buccal dental photograph, (f) post activator headgear therapy frontal dental photograph, (g) post activator headgear therapy left buccal dental photograph, (h) post activator headgear therapy maxillary occlusal dental photograph, (i) post activator headgear therapy mandibular occlusal dental photograph, (j) post activator headgear therapy lateral cephalogram|
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The patient was shifted to fixed mechanotherapy after achieving Class I molar relationship.
Fixed preadjusted appliance with MBT prescription (0.022ʺ × 0.028ʺ slot) was placed. An initial 0.014 nickel-titanium archwire was placed for aligning and leveling. Anchorage in this stage was reinforced using lacebacks and bendbacks in both the arches. The patient was progressively shifted to heavier archwires. After the alignment and leveling, coordinated 0.019ʺ × 0.025ʺ stainless steel wires were placed with weldable retraction hooks to close the spaces and for tip and torque expression. The interproximal reduction was carried out simultaneously in the mandibular anterior region to relieve Bolton's discrepancy.
After the space closure, settling of occlusion was achieved using a sectional maxillary 0.019ʺ × 0.025ʺ wire from 12 to 22 and lower 0.014ʺ stainless steel wire with short settling elastics. Upper circumferential retainer with a mild anterior biteplate and a lower circumferential retainer were delivered [Figure 3]a-k.
|Figure 3: (a) Posttreatment frontal at rest, (b) posttreatment oblique at rest, (c) posttreatment profile at rest, (d) posttreatment frontal dynamic smile, (e) posttreatment right buccal dental photograph, (f) posttreatment frontal dental photograph, (g) posttreatment left buccal dental photograph, (h) posttreatment maxillary occlusal dental photograph, (i) posttreatment mandibular occlusal dental photograph, (j) posttreatment lateral cephalogram, (k) posttreatment orthopantomogram|
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The total treatment time was 23 months.
The patient's profile had significantly improved, although there was excess gingival show on smile. There was a significant reduction in the soft tissue facial convexity with downward and forward mandibular growth, and a restraint of maxillary growth during the activator headgear therapy phase. A consonant smile was obtained at the end of treatment. Class I dental occlusion was achieved bilaterally with optimal overjet and overbite [Figure 3]a-i. Posttreatment cephalometric tracing revealed significant improvement in the skeletal discrepancy (SNA pretreatment: 83° and posttreatment 81°; SNB pretreatment: 76° and posttreatment 77°), inclination of the maxillary and mandibular incisors (upper incisors to SN angle, pretreatment: 110° and posttreatment: 102°; IMPA pretreatment: 102° and posttreatment 101°). The nasolabial angle was mildly acute at the end of treatment but showed a great improvement from its pretreatment value (pretreatment: 78° and posttreatment: 90°) [Figure 3]j and k. Superimposition of pre- and post-treatment cephalometric tracings confirmed the inhibition of maxillary growth, attainment of mandibular growth, and retraction of anterior teeth as desired
[Figure 4] [Figure 5] [Figure 6] and [Table 1].
|Figure 4: Superimposition of cephalometric tracings pretreatment (black), post activator headgear therapy (blue), and posttreatment (red). Along SN plane at S|
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|Figure 5: Superimposition of cephalometric tracings pretreatment (black), post activator headgear therapy (blue), and posttreatment (red). Nasion Basion at Cc point|
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|Figure 6: Superimposition of cephalometric tracings pretreatment (black), post activator headgear therapy (blue), and posttreatment (red). Nasion Basion at N|
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|Table 1: Pretreatment, postmyofunctional, and posttreatment cephalometric data |
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| Discussion|| |
The nature of a Class II malocclusion is related to many factors, such as facial structure, maxillary and mandibular growth patterns, and dentoalveolar development. Individual variations of these factors have to be considered in relation to treatment procedures to correct the malocclusion. Correction of mandibular deficiency in a skeletal Class II patient with a vertical growth pattern poses a great challenge. The control of vertical dimension becomes very important as downward and backward rotation of mandible will exaggerate the facial convexity. It appears that the control of vertical dimension is imperative for an optimal forward displacement of the correction of a skeletal Class II malocclusion. Activator headgear appliance used in combination is one of the most widely used functional appliances for the sagittal advancement of the mandible with vertical control. This appliance increases the activity of protractor and elevator muscles with concomitant relaxation and stretching of retractors. This produces a more favorable muscle pattern and also a change in bony structures as muscles adapt to new functional stresses.
The effects of functional appliances in a skeletal Class II malocclusion includes reduction of ANB angle, restriction of maxillary growth, advancement of mandible, increase in lower facial height, correction of overjet, improvement in overbite, uprighting of the maxillary incisors, protrusion of mandibular incisors, correction of dental Class II malocclusion, correction of facial convexity, and reduction of mentolabial fold. 
Oztόrk and Tankuter in their study have reported that restriction on the sagittal displacement of the maxillary complex with activator headgear appliance was more apparent than with activator alone. Katsavrias and Halazonetis found that posteriorly directed forces acting on the maxilla during activator wear were generally in the range of 100 g, whereas with activator headgear appliances the forces generated were generally in orthopedic range. The evidence suggests more orthopedic changes with the activator headgear appliance.  One of the major side effects of functional appliances including the activator and activator headgear combination is the protrusion of mandibular incisors, but the inclination of lower incisors is better controlled with an activator headgear combination.  The vertical development is better controlled by the activator headgear combination as it can induce clockwise mandibular rotation. 
Our patient had skeletal Class II pattern along with vertical growth pattern. As she was in growing stage, our objective was functional advancement of the mandible and inhibition of further maxillary growth. The best treatment plan for the patient would have been an orthosurgical management, but as the patient was not interested in surgery and moreover, her growth was yet to be completed, activator headgear treatment option was presented to her. High-pull headgear was used with the force of 400 g per side for 12-16 h daily for 11 months. The patient wore the appliance regularly. The skeletal correction was achieved by mandibular base lengthening and restriction of increase in maxillary basal length. The profile of the patient was improved drastically as seen from the postmyofunctional therapy photographs and the cephalometric readings [Table 1] and [Figure 2]. Although we could not prevent the maxillary down growth, its forward growth was restricted using the headgear. There was a great amount of improvement in the nasolabial angle. The maxillary incisor display at rest decreased from 9 to 6 mm post activator headgear therapy.
The patient was taken up for fixed mechanotherapy. After alignment and leveling, the spaces were closed, and the interproximal reduction was done to correct Bolton's discrepancy. A consonant smile was obtained at the end of treatment. Class I dental occlusion was achieved bilaterally with optimal overjet and overbite. The posttreatment cephalometric readings confirm the changes.
| Conclusion|| |
This case report elaborated on the use of activator headgear therapy for the correction of a severe skeletal Class II with vertical maxillary excess. After attaining the desired facial changes, fixed appliance mechanotherapy was used to correct the dental discrepancy. The result obtained was a marked improvement in the facial features and the correction of dental disharmony. Thus, by using activator headgear therapy, the results were obtained which helped the patient gain pleasing profile and better esthetic results.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]