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Two Phase for a Better Face!! Twin Block and Headgear Followed by Fixed Therapy for Class II Correction
Correspondence: Vivek Bhaskar Post Graduate, Department of Orthodontics & Dentofacial Orthopaedics A.B. Shetty Memorial Institute of Dental Sciences, Nitte University, Mangalore - 575 018, Karnataka, India. E-mail: vivek.libra@gmail.com
This article was originally published by Thieme Medical and Scientific Publishers Private Ltd. and was migrated to Scientific Scholar after the change of Publisher.
Abstract
Correction of a skeletal sagittal Class II in a growing child can be done either in one single phase of treatment, or in two phases, i.e a first phase of functional appliance to reduce the severity of the skeletal discrepancy, followed by fixed appliance therapy to refine the occlusion. This 2 phase treatment has quite a few advantages such as early correction of the facial profile is seen by the child and parent, which motivates them, as well as, reduces the social handicap produced as a result of the malocclusion. Hence, this case report describes the treatment of a Class II child, with a Twin block appliance followed by fixed orthodontic treatment.
Keywords
Two phase treatment
Twin block
Headgear
Introduction:
Class II malocclusions can be due to prognathic maxilla, or retrognathic mandible, or both. In a growing patient, functional appliances are most widely chosen to correct the skeletal discrepancy making use of the natural growth potential. Usually, it is a 2 phase treatment, where in the skeletal discrepancy is corrected first, followed by detailing of the occlusion using fixed mechanotherapy.
A variety of functional appliances are at our foray to correct class II malocclusions like activator, functional regulator, twin block etc. The twin block, given by Clark (1), is a very commonly used appliance for many reasons; it has reduced bulk unlike other appliances, patient adjusts to speech and other functions very quickly, it can be fixed to the teeth in non-compliant cases, patient immediately sees the changes upon wearing the appliance which acts as a positive reinforcement. Compared to other appliances, twin block seems to be more useful in causing sagittal and vertical changes.(2)
This case report is of an 11 year old boy, who presented with a skeletal Class II, who was successfully treated in 2 phases- first phase of functional therapy using Twin Block, followed bya second phase of fixed mechanotherapy.
Case Report:
An 11 year old boy, Nidhin, reported to the Department of Orthodontics, A.B.Shetty Memorial Institute of Dental Sciences with a chief complaint of forwardly placed upper front teeth.
He had no significant medical or dental history.
On extra oral examination (FIGS 1-4), he presented to be Mesomorphic, Brachycephalic and Euryproscopic, with a convex profile, consciously competent lips, Class II apical bases, and recessive chin.
On intraoral examination (FIGS 5-10), dentition was in the mixed dentition stage. Generalised spacing was seen in the anterior segment of the maxillary arch.On occlusion, Molar relation was Class II bilaterally, with overjet of 12mm and overbite of 4mm, and the lower dental midline was shifted to the right side by 3mm.
The cephalometric analysis of the patient (Image 10) revealed him to bea Skeletal Class II with a prognathic maxilla, retrognathic mandible, recessive chin, horizontal growth, proclined anterior teeth and an acute nasolabial angle.
An analysis of the hand wrist radiograph (FIG 11) revealed the patient to be in the SMI 3 stage of skeletal maturation indicating 65-85% growth was still remaining.
- PRE TREATMENT OPG
| Measurement | Values |
|---|---|
| SNA | 87 |
| SNB | 78 |
| ANB | 9 |
| WITT'S APPRAISAL | 5mm |
| FMA | 20 |
| Sn-Go-Gn | 30 |
| Upper Incisor- NA | 40/9 |
| Lower incisor - NB | 32/6 |
| Lower incisor- Mandibular plane | 103 |
| Interincisal angle | 100 |
| Nasolabial Angle | 80 |
Diagnosis:
Using the above, the diagnosis was arrived to be:
Skeletal- Class II apical bases.
Dental- Class II div 1 malocclusion.
Soft tissue- Everted lips with acute nasolabial angle.
Visual Treatment Objective (VTO): (FIGS 13, 14)
The VTO was positive, indicative that mandibular advancement would benefit the patient.
TREATMENT OBJECTIVES:
Based on the above pre- treatment findings, the treatment objectives were to:
Correction of Class II Skeletal relationship
Correction of overjet and overbite
Obtain Class I molar and canine relationship.
Achieveoptimal facial balanceand esthetics.
TREATMENT PLAN:
Phase 1- Growth modification- Using Twin Block and Headgear.
Phase 2- Fixed mechanotherapy using Pre Adjusted Edgewise brackets (MBT 0.022 slot).
TREATMENT PROGESS:
-
Twin Block plus headgear:
Twin block was fabricated with a bite opening of 5mm in the pre molar region with sagittal advancement of 7mm.(FIGS15-19)
The appliance was delivered and the patient was asked to wear the appliance full time.
Alongside, from the second month onwards, a high pull headgear was given (FIGS 20,21) with a force of 400g bilaterally. The headgear was used to restrain the prognathic maxilla.(4)
Headgear:
The appliance was worn full time for a period of 12 months. Post Twin Block-Headgear Intra Oral Images: (FIGS 22-26)
Post Twin Block-Headgear Extra Oral Images (Figs 27-31)
PHASE 2- FIXED ORTHODONTIC TREATMENT
Following 12 months of functional and orthopaedic therapy, fixed orthodontic treatment was started with Pre Adjusted Edgewise (MBT 0.022” prescription).
Levelling and alignment was done from initial 0.016 NiTi wires till the final arch wire of 19x25 S.S was in place.
Mid Treatment Intra Oral Photographs (Figs 32-36)
The fixed orthodontic treatment was completed in a period of 20 months, with the total treatment time being 32 months.
Post Treatment Photographs (Figs 37-46)
- Post Treatment Cephalogram
- Post Treatment OPG
Superimposition shows reduced nasolabial angle, increased growth of mandible, reduced proclination, achievement of a Class I relation.
| Measurement | Values |
|---|---|
| SNA | 85 |
| SNB | 84 |
| ANB | 1 |
| WITT'S APPRAISAL | 1mm |
| FMA | 29 |
| Sn-Go-Gn | 30 |
| Upper Incisor- NA | 20/4 |
| Lower incisor - NB | 30/5 |
| Lower incisor- Mandibular plane | 98 |
| Interincisal angle | 125 |
| Nasolabial Angle | 95 |
RETENTION: (FIGS49-53)
The patient was given a modified Hawley's retainer, which was worn for a period of12 months.
- Superimposition
Discussion:
Correction of sagittal discrepancies in children can be either one phase or two phase treatment. Two phase treatment offers the advantages of earlier correction of the discrepancy, followed by a reduced period of fixed appliance treatment, reduced chances of surgery at a later date. (3)
We chose the twin block appliance as it offers many advantages such as better patient acceptance, reduced hygienedemands, growth patternofthe patient etc.
Conclusion:
In this patient, the two phase therapy with twin block and headgear helped us achieve satisfactory results. However, long term studies with large sample sizes are needed to validate this method.
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