50 · a 0.022 * 0.028-inch slot straight wire appliance (mbt prescription; ormco) was placed in...

Chronicles of Dental Research, Dec2019, Vol 8, Issue 2 Chronicles of

Dental Research

50 www.cdronline .org

Official Publication of Kothiwal Dental

College & Research centre

CASE REPORT

Orthodontic camouflage treatment of skeletal class II malocclusion using

frictionless mechanics Prakash V S1, Santosh Verma2, Anil Sharma3, A K Chauhan3

INTRODUCTION

Class II malocclusion can be treated by several

means according to the characteristics associated

with the problem, such as antero-posterior

discrepancy, age, patient compliance.1

In adults with severe skeletal malocclusion involving

deficient mandible; orthognathic surgery is often the

possible treatment. However in Class II patients with

mild-to-moderate skeletal discrepancies, dental

compensation is the treatment of choice.2

Camouflage usually involves the extraction of

premolars. Variations in extraction sequence

including upper and lower first or second premolars

have been recommended by different authors.3

In patients who have their mandibular retrognathism

masked by their increased soft tissue chin thickness

along with moderate overjet , orthodontic

camouflage is indicated. Upper Ist premolars are

extracted followed by retraction of the upper anterior

teeth reducing the overjet, ending the canine relation

in class I. Variations in extraction sequence including upper

and lower first or second premolars have been

recommended by different authors.4

CASE REPORT

A 15 years old male reported to the Department of

Orthodontics for orthodontic treatment with the chief

complaint of forwardly placed upper front teeth and

inability to close the lips.

Extra-oral examination (Figure 1) revealed

dolichocephalic symmetrical face, convex profile, lip

incompetence and an acute nasolabial angle. The

patient showed no symptoms of TMJ disorder.

Intraorally (Figure 2) the patient had moderate

crowding and proclined maxillary incisors with an

overjet of 7 mm, 50% overbite,and high mandibular

plane angle. The molar and canine relationship was

class II bilaterally.

Abstract

Prevalence of Skeletal class II is quite high amongst the Indian population. With alarge variety of treatment

modalities available, choosing the right one becomes quite a challenge. A patient came to the department of

Orthodontics and Dentofacial Orthopedics at Kothiwal Dental college and Research center with a chief complain

of forwardly placed upper front teeth. On clinical examination the patient had a skeletal class II malocclusion.

This case report deals with the treatment of this particular case with camouflage with the help of frictionless

mechanics. Upper Ist premolars were extracted. Following treatment a class I canine relation was established

along with static and functional occlusion, good facial profile and patient satisfaction

Keywords:T loops, skeletal class II malocclusion, canine retraction

1. Post graduate student

2. Professor and H.O.D

3. Professor

Department of Orthodontics and Dentofacial

Orthopedics

Correspondence Address

Dr. Prakash V S (P.G. student)

Kothiwaldental college and research centre,

Moradabad.

[email protected]


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(d)

Figure 1

(a)

(b)

(e)

Figure 2

(b) (c)

(c)

(a)


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Figure 3 depicting pretreatment lateral cephalogram

Figure 4 depicting pretreatment Orthopentomogram


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Treatment Objectives

1) Relieve crowding and decrease proclination

2) To establish normal overjet and overbite.

3) To achieve a class I canine relationship

along with a class II molar relationship.

4) To decrease lip protrusion.

5) To establish a static and functional

occlusion.

Treatment Plan

Two treatment plans were established

The first treatment plan was to go for extraction of

lower Ist premolars along with upper 2nd premolars

followed by decompensation. After decompensation,

Bilateral split sagittal osteotomy of the mandible.

The second treatment plan was extraction of upper Ist

premolars followed by retraction of upper anterior

teeth therefore establishing a normal over jet,

overbite and a class I canine relationship.

The patient opted for the second treatment plan.

Treatment start and progress

A 0.022 * 0.028-inch slot straight wire appliance

(MBT Prescription; ORMCO) was placed in both

arches. Leveling and aligning were then commenced

with the use of round 0.012-inch nickel titanium

wire. (Figure 5). Leveling and alignment was

continued upto 19 * 25 ss wire. (Figure 6). The

canines had prominent roots, these would have

caused hindrance during retraction.

Since the canine bracket being used had a zero degree

torque, an additional lingual root torque of 30 degrees

was placed individually on the canines on a 19 * 25

TMA wire. (Figure 7)

Torque correction took 2 months

Since the patient was a vertical grower (a vertical

growing patient has more anchorage loss) and the

space requirementwas 11mm, we individually

retracted the canine on a 0.018 inch Australian arch

wire with stop loops given mesial to the molar to

prevent anchor loss. (Figure 8).Since retracting the

canine on a light wire leads to deepening of the bite,

an intrusion utility arch (17*25 TMA) was also

placed in the upper arch with a tip back bend to

counter act this side effect.After 4 months, canine

retraction was completed.(Figure 9)

A T loop5 was fabricated on a continuous TMA wire

(19*25) for retraction of the four upper anterior

teeth.(Figure 10)

After 4 months the upper anterior teeth were

retracted. Then a 19 * 25 ss wire was placed in the

upper arch for finishing (Figure 11)

Parameter Norms Pre-treatment Post-treatment

Skeletal SNA 82o 83.5o 800

SNB 80o 76o 77o

ANB 2o 7.5o 3o

Wits -1mm 2.5mm 1.5mm

GoGn-

SN

32o 37.5o 37.5o

Dental U1- SN 105o 112o 105o

U1-NA

(mm/Deg

rees)

4mm

/22o

7mm / 30o 3mm / 20o

L1-NB 4mm

/25o

11mm / 33o 9mm / 32o

IMPA 90o 99o 96.5o

Soft-Tissue S/Lin-

U/L

0 +2.5mm +0mm

L/L 0 +3mm +1mm

Table 1 Cephalometric

Comparisons


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Figure 5

Figure 6

Figure 7


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-

+

Figure 8

Figure 9

Figure 10


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Treatment results

The finishing stage photographs (Figure 11)depict a

class I canine relationship, normal overjet and

overbite with a class II molar relationship.

Canine guidance was present on the left and right

during lateral excursions, and incisal guidance was

present on protrusion. There were no nonworking

side interferences during functional movements. The

cephalometric analysis between pretreatment and

posttreatment cephalometric radiographs in the Table

I showed that sagittal skeletal relationship type II was

changed to type I (ANB was reduced from 7.5 to 3)

and the maxillary incisors were brought to their

normal inclination and positioned backward (U1-

NA was retracted from 30 degrees and7 mm to 20

degrees and 3 mm; U1-SN was decreased from 112

to 105

In terms of soft tissue changes, an acceptable facial

profile was achieved with H angle decreased from

22.5 to 20 degrees and nasolabial angle increased

from 100 to 108 degrees. All represented the changes

from a skeletal Class II pattern to a skeletal Class I

pattern.(Figure 12)

The active treatment time was 1 year 4 months.

Figure 11


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Figure 12

(a) (b)

Figure 13 depicting post treatment lateral cephalogram

(c)


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Discussion

A comprehensive extraction strategy should be based

on considerations on growth pattern, soft tissue

profile, degree of crowding, molar relationship and

mid-line discrepancy.6

Treatment of Class II patient requires careful

diagnosis and a treatment plan involving esthetic,

occlusal, and functional considerations.7

The non-extraction/distalization mechanics

unnecessarily prolongs treatment time and results in

redundant tooth movements that lead to irreversible

root damage and possible adverse periodontal

sequelae.8

Dentoalveolar camouflage of milder Class II cases is

possible in most instances without surgery.9

The patient was in CVMI stage 4 and had crossed his

peak pubertal growth stage but since the patient had a

high mandibular plane angle (37.5 degrees) we didn’t

opt for fixed functional appliance therapy.

References

1. Khan RS, Horrocks EN. A study of adult

orthodontic patients and their treatment. Br

J Orthod. 1991; 18(3):183–94.

2. Uribe F, Nanda. Treatment of Class II,

Division 2 Malocclusion in Adults:

Biomechanical Considerations. J Clin

Orthod. 2003; 11:599-606.

3. Staggers JA. A comparison of results of

second molar and first premolar extraction

treatment. Am J Orthod Dentofacial

Orthop. 1990: 98:430–6.

4. Basciftci FA, Usumez S. Effects of

extraction and non-extraction treatment on

Class I and Class II subjects. Angle

Orthodo. 2003; 73:36–42

5. Jie Chen, David L. Markham, and Thomas

R. Katona (2000) Effects of T-Loop

Geometry on Its Forces and Moments. The

Angle Orthodontist: February 2000, Vol.

70, No. 1, pp. 48-51.

6. Ackerman JL, Proffit WR. Soft tissue

limitations in orthodontics: treatment

planning guidelines. Angle Orthod. 1997;

67(5):327-36.

7. Nanda, R.: Biomechanics and Esthetic

Strategies in Clinical Orthodontics, W.B.

Saunders Co., Philadelphia, 2009.

8. Gianelly AA. The bi-dimensional technique:

Theory and practice. Bohemia (NY): GAC

International, 2002.

9. DeAngelis V. Atypical Orthodontic

Treatment of severe Class II malocclusions

in the Adult. J Massachusetts Dent Soc.

2008; 57:26-9.

50 · a 0.022 * 0.028-inch slot straight wire appliance (mbt prescription; ormco) was placed in...

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