International J. of Healthcare & Biomedical Research, Volume: 1, Issue: 3, April 2013, Pages 180-189

“ACTIVATOR: SIMPLE YET EFFECTIVE FUNCTIONAL APPLIANCE FOR SKELETAL CLASS II

CORRECTION: CASE REPORT”

1Dr. Falguni Mehta *, 2Dr. Dolly Patel, 3Dr. Nishit Mehta

1Professor, Dept of & Dentofacial orthopaedics Govt Dental College & Hospital, Ahmedabad, Gujarat , India 2Professor & Head, Dept of orthodontics & Dentofacial orthopaedics Govt Dental College & Hospital, Ahmedabad, Gujarat , India 3Third year post graduate student Dept of orthodontics & dentofacial orthopaedics, Govt Dental College & Hospital, Ahmedabad, Gujarat, India *Corresponding author: Dr. Falguni Mehta ; Email id : [email protected] ...... ………… …………………………………………………………………………………... ABSTRACT:

A Class II may result from a mandibular deficiency, maxillary excess or a combination of both, but the most common finding is mandibular skeletal retrusion. Functionaljaw orthopaedic appliances are designed to encourageadaptive skeletal growth by maintaining the mandible in a corrected forward position. The activatordeveloped by Andresen is one of the most widely used. A 12-year-old boy with skeletal Class II malocclusion, a low mandibular planeangle was treated with growth modulation by activator followed by fixed orthodontics for detailing of occlusion.The major effects of the activator treatment in this case has been due to increase in condylar growth and in mandibular base length.Further non-extraction fixed orthodontic treatment for proper interdigitation of the dentition also help to maintain the stability of the satisfactory results achieved in this type of cases. KEY WORDS: class II Malocclusion , mandibular , functional jaw orthopaedics , Activator

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INTRODUCTION discrepancy 1. The success of treatment with a functional Class II are one of the most common appliance relies on the patient's cooperation and

problems in orthodontic treatment.Treatment of class favourable mandibular growth. Treatment with a II malocclusion has always been an enigma to the functional appliance usually lasts for 9 to 12 months and

orthodontic fraternity. It ranges from a simple requires a proper retention time to ensure complete functional appliance to surgical correction. There are musculoskeletal adaptation. A second stage of treatment

a variety of effective treatment modalities to correct with a full-fixed appliance is often required to achieve them, ranging from headgear and functional proper alignment and good interdigitation of the

appliances to surgical options, depending on the site , dentition 2. age of the patient and severity of problem. Functional By holding a deficient mandible forward and forcing the

appliances are commonly used for the treatment of patient to function with lower jaw forward , functional Class II malocclusions with mandibular deficiency. appliance can stimulate or accelerate the forward

The treatment goals for these appliances are to reduce mandibular growth .There are variety of removable the large overjet and correct the sagittal skeletal 180 www.ijhbr.com

International J. of Healthcare & Biomedical Research, Volume: 1, Issue: 3, April 2013, Pages 180-189 functional appliances including activator , Robins’ • aim was to correct the sagittal skeletal monobloc, bionator ,bass appliance ,twin block 1,etc. discrepancy with growth modulation with The activator and its successors provide a greater functional appliance. • contact area with the mandibular teeth and lingual To achieve and maintain Angle’s class I molar mucosa, and thus are more effective in stimulating the and canine relationship bilaterally patient to position the mandible forward constantly. • To achieve normal overjet and . Here, we are presenting a case of a class II • To align and level upper and lower arches and skeletal malocclusion treated by using the time-tested final finishing and detailing of the occlusion with activator appliance. Despite of simple design, fixed mechanotherapy. activator can be used to change dental relationship in TREATMENT PROGRESS 3 all three planes of space with proper adjustments . 12 year male with a Class II malocclusion and DIAGNOSIS retrognathic mandible was treated first withactivator for 1 A 12 year old male patient reported with the chief year and 1 month. Construction bite with single complaint of forwardly placed upper front teeth.There advancement was taken and activator was delivered with was history of trauma with Ellis class I fracture in proper patient instuctions. The patient had good relation to upper left central incisor. The patient had a compliance and maintained good oral hygiene. . After skeletal Class II malocclusion with severe mandibular treatment period of 1 year and 1 month with activator, retrognathism, and average mandibular plane patient showed improvement in soft tissue profile with angle(table-1,2,3). The lips were competent, with non- class I molar and canine relationship bilaterally(Fig 2-a to consonant smile arc and convex soft tissue profile(fig h).Selective trimming of acrylic portion was done to allow 1-a,b,c) . patient had mixed dentition in late eruption of posterior teeth to eliminate the excessive curve transitional period with Angle’s class II molar aswell of Spee in lower arch. The activator successfully resolved as canine relationship with increased overjet(14 mm) the problem of the retrognathicmandible with favourable andoverbite(8 mm)(fig 1-d,e.f,g,h) .curve of Spee of 4 mandibular growth. mm was present. His maxillary incisors were tipped After achieving the functional correction of skeletal labially of their bony base, and the mandibular incisors discrepancy, the full-fixed orthodontic appliance (022” were tipped lingually(table-1). There was spacing in MBT) along with inclined plane was put in place for 1 upper anterior region. Mesiobuccalrotations were year to stabilize the occlusion without extraction(fig 3- a present in upper premolars. The maxillary and to h). Once the occlusion was stabilized with good mandibular midline were coincident with facial posterior interdigitation , fixed appliances were removed 4 midline.patient was in CVMI stage III with positive and patient was kept under retention. Since the patient was VTO . in growing phase , along with upper Hawleys’ plate with TREATMENT PLANNING inclined plane , night time wear of activator was

• Since the patient was in growing stage with advocated. favourable growth pattern and positive VTO, 181 www.ijhbr.com

International J. of Healthcare & Biomedical Research, Volume: 1, Issue: 3, April 2013, Pages 180-189

TREATMENT RESULTS activator in correcting a class II malocclusion in this

At the end of the treatment the patient had good patient include : functional , mutually protected occlusion with canine • Stimulation of the mandibular growth. 5,6,7,8,9,13 and molar in Angles’ class I relationship , normal • Redirection of the anterior and overjet and overbite (fig 4-d,e,f,g,h) and good facial verticaldentoalveolar growth of maxilla. 6,10,11 proportions(fig 4-a,b,c , table-4). • Redirection of the anterior and Superimposing the pre and post-treatment lateral verticaldentoalveolar growth of mandible. 5,10,12 cephalograms (fig. 5) demonstrated a considerable • Remodelling changes in TMJ. 13 downward and forward growth of mandible reducing CONCLUSION

ANB angle to 2˚ from 6˚.Mandibular base length It is generally agreed that functional appliances can be increased from 76 mm to 85 mm(table-3). used successfully to treat skeletal class II malocclusions in DISCUSSION growing and cooperative patients. The ideal case for such Functional appliances are effective in treating skeletal treatment is: class II malocclusion, particularly in cases with • Class II division I malocclusion withretrognathic retrognathic mandible functional appliances are of mandible Low to average mandibular plane angle greatest clinical benefit in actively growing patients • Upright or linguallytipped lower incisors. with good compliance.In this case ,the muscular force The activator can solve many problems that become more generated by the forward mandibular positioning was severe if left untreated.The Activator cannot create a large transferred to the maxillary and the mandibular teeth mandible from a small one, but it can help the patient through the acrylic body and labial bow. These forces achieve the optimal size consistent with morphogenetic which were transmitted through the teeth to the pattern 14 . The restoration of the normal function is a major periosteum and bone were responsible in producing a contribution to improvement in the morphofunctional restraining effect on the forward growth of maxilla , interrelationship. while stimulating the mandibular growth and causing maxilla mandibular dentoalveolar adaptation. Both skeletal and dentoalveolar changes has been achieved

The major effects of the activator treatment in this case by activator therapy.Due to favourable growth and good has been due to increase in condylar growth and in compliance, his facial profile became orthognathic with mandibular base length. The combination of these treatment. The overbite decreased because of molar effects resulted in the permanent anterior displacement extrusion and inhibition of incisor eruption which level the of mandible. The activator also had an influence on curve of Spee. The uprighting of the upper incisors also dentition. By inhibiting the maxillary dentoalveolar helped to reduce the overjet. Further non-extraction fixed vertical growth and encouraging the mandibular orthodontic treatment for proper interdigitation of the dentoalveolar mesial and vertical development , the dentition will also help to maintain the stability of the activator resolved the class II malocclusion to class I satisfactory results achieved in this type of cases. malocclusion. The possible mechanisms for the 182 www.ijhbr.com

International J. of Healthcare & Biomedical Research, Volume: 1, Issue: 3, April 2013, Pages 180-189

LEGENDS:

Figure 1: Pre Treatment Photographs

Figure 2 : Post functional correction

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International J. of Healthcare & Biomedical Research, Volume: 1, Issue: 3, April 2013, Pages 180-189

Figure 3 : fixed appliances in situ

Figure 4 : Post Treatment Photographs

Figure 5 : Pre Treatment and Post treatment lateral cephalogram Super Imposition

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International J. of Healthcare & Biomedical Research, Volume: 1, Issue: 3, April 2013, Pages 180-189

TABLE 1 – CEPHALOMETRIC DATA

MEAN PRE POST TREATMENT TREATMENT

SNA 82° ± 2° 74° 73 0 SNB 80° ± 2° 68° 71 0 ANB 2° 6° 20 U1 -NA 22° 44° 25° U1 -NA 4mm 11mm 6mm L1 -NB 25° 18 0 25° L1 -NB 4mm 6mm 5mm Interincisal Angle 130° 114° 115°

GoGn -SN 32 ˚ 29 ˚ 31 ˚ Occ -SN 14 ˚ 18 ˚ 22 ˚ L1 -APog −1.2mm ± 1.4mm -1mm 3 mm

FMA 25° 19° 22 0 IMPA 90° 93° 98°

FMIA 65 ˚ 66 ˚ 60 ˚

NA -APg -8˚-10 ˚ 5˚ 0˚

NPg -AB -9˚-0˚ -12 ˚ -4˚

NPg -FH 82 ˚-95 ˚ 84 ˚ 96 ˚

Y-Axis 53 ˚-66 ˚ 60 ˚ 60 ˚

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International J. of Healthcare & Biomedical Research, Volume: 1, Issue: 3, April 2013, Pages 180-189 Table 2 - – Mc NAMARA ANALYSIS

MEAN PRETREATMENT POST TREATMENT

MAXILLA TO CRANIAL BASE

A) Nasolabial angle 102±8 100 108

A) Cant of upper lip Female: 10 0

Male:

A) Point A to N- perpendicular 0-1 mm -3 mm -6 mm

MAXILLA TO MANDIBLE

ANTEROPOSTERIOR

A) Maxillary length (Co-A) 90 mm 96 mm

A) Mandibular length (Co-Gn) 109 mm 121 mm

A) Maxilla mandibular differential Small:20-23 19 mm 25 mm

Medium 27- 30

Large:30-33

VERTICAL

A) Lower AFH (ANS-Me) 62 mm 71 M

B) Mandibular plane angle (FH-Go-Me) 22±4 19 22

C) Facial axis angle (Ptm-Gn-Ba-N perpendicular) 0±3.5mm -4 -5

MANDIBLE TO CRANIAL BASE

Pog to N perpendicular Small: -10 mm -12 mm

Medium:

Large:

DENTITION

A) Maxillary incisor to point A 4-6mm 7 mm 5 mm

A) Mandibular incisor to A-Pog 1-3mm -2 mm 3 mm

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Table 3-Rakosi’s Analysis

ANALYSIS OF FACIAL SKELETON

MEASUREMENT MEAN PRE-TREATMENT POST-TREATMENT

SADDLE ANGLE 123 +5 130 130

ARTICULAR ANGLE 143 +6 146 146

GONIAL ANGLE 128+ 7 119 121

U- GONIAL ANGLE 52 -55 51 mm 51 mm

L – GONIAL ANGLE 72 – 75 68 mm 70 mm

POSTERIOR FACE HEIGHT 76 mm 85 mm

ANTERIOR FACE HEIGHT 117 v 131 mm

JARABACK’S RATIO 62-65% 64.95 % 64.88 %

ANTERIOR CRANIAL BASE 71 mm 73 mm 78 mm LENGTH

POSTERIOR CRANIAL BASE 32-35 mm 39 mm 44 mm LENGTH

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International J. of Healthcare & Biomedical Research, Volume: 1, Issue: 3, April 2013, Pages 180-189

ANALYSIS OF THE JAW BASES

SNA ANGLE 81 74 73

SNB ANGLE 79 68 71

ANB ANGLE 2 6 2

BASAL PLANE ANGLE 25 21 23

INCLINATION ANGLE (Pn 85 81 81 TO ANS-PNS)

REFERENCES

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10. Öztürk Y, Tankuter N, Class II: a comparison of activator and activator headgear combination appliances. European Journal of Orthodontics 16: 149–157 , 1994. 11. Courtney M, Harkness M, HerbisonP ,Maxillary and cranial base changes during treatment with functional appliances. American Journal of Orthodontics and DentofacialOrthopedics 109: 616–624, 1996 12. HakanTurkkahraman and M. OzgurSayın, Effects of activator and activator headgear treatment: comparison with untreated Class II subjects :European Journal of Orthodontics28 (2006) 27–34 13. Arat ZM, GokalpH ,Erdem D , Erden I, Changes in the TMJ disc-condyle-fossa relationship following functional treatment of skeletal Class II division I malocclusion: A Magnetic Resonance Imaging study.American Journal of Orthodontics and DentofacialOrthopedics 119:316-319, 2001. 14. Graber TM ,Rakosi T , Petrovic AG; DentofacialOrthopedics with functional appliances.second Edition/ Mosbypublishers.

Date of submission: 2 March 2013 Date of provisional acceptance: 11 March 2013 Date of Final acceptance: 30 March 2013 Date of Publication: 03 April 2013 Source of support: Nil; Conflict of Interest: Nil

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