JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL SCIENCES

Mathew T. Management of skeletal class II with twin block and fixed appliance for 12- year-old . Journal of pharmaceutical and biomedical sciences (J Pharm Biomed Sci .) 2013, March; 28 (28): 650-656. (Article no 14)

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ISSN NO- 2230 – 7885 CODEN JPBSCT NLM Title: J Pharm Biomed Sci .

Mathew T. J Pharm Biomed Sci . 2013, March; 28(28): 650-656. Available at jpbms.info

Case report Management of skeletal class II malocclusion with twin block and fixed appliance for 12- year-old

T Mathew *

*School Of , International Medical University, Bukit Jalil, Kuala Lumpur , Malaysia, 57000. Abstract: Introduction : Functional appliance is an effective way of treating skeletal Class II malocclusion in children and adolescents. A 12-month mandibular advancement protocol with Twin Block appliance has been proved to enhance the condylar growth and to improve the mandibular . Objective : The case report documented the treatment of a 12- year- old girl with skeletal class II malocclusion with over jet of 8mm, 100% Deep bite and Angle Class II molar, Class II canine and Class II incisor relationship. Method : The phase I Orthopedic stage treatment was done using Twin Block appliance for 12 months with mandibular advancement of 8mm including trimming of inter-occlusal bite plane of the Twin Block to facilitate the eruption of Mandibular molars. This was followed by a phase II Pre-adjusted Edgewise appliance therapy for finishing and detailing. Result: The treatment objective of normal and , skeletal class I by growth modification, class I molar relation, class I canine relation, class I incisor relation and lip competency were achieved. Conclusion : A stable harmonious was achieved after 20 months of treatment.

Key Words: Functional appliances. Angle Class II malocclusion. Pre-adjusted Edgewise appliance. Introduction: he prevalence of Skeletal Class II Malocclusion is common in permanent dentition. On extra- the Asian population. Although Maxillary protrusion and oral examination the patient had Tmandibular retrognathism are both found to be possible Mesoprosopic facial form and causative factors, Mcnamara [1] reported that mandibular Convex facial profile. The retrognathism is more common for Skeletal Class II malocclusion. Nasolabial angle was acute and There are various methods like, advancing the by the chin recessive with functional appliances, extra oral appliances, camouflage treatment incompetent lips (Figure 1 and and surgical repositioning of the jaws for the correction of skeletal Figure 2). class II . Functional appliances are more commonly used in the treatment of mandibular deficiency in growing children by stimulating the growth of the mandible [2] Functional appliances direct the pattern and direction of growth of the jaws by alteration of the forces produced by the neuromuscular complex. A restraining effect on the growth of the maxilla and the maxillary dento-alveolar complex is also seen along with the stimulation of mandibular growth and mandibular alveolar adaptation with functional appliance treatment. Twin block is a functional appliance which is well tolerated among the growing children and indicated in early permanent dentition. The following case report documented a 12-year-old Indian girl with 8 mm overjet treated by growth modification using Twin Block appliance for 12 months followed by a phase II pre-adjusted Edgewise appliance therapy for finishing and detailing.

Case Report: A-12-year- old Indian girl reported to the clinic with the complaint of proclined upper front teeth. The patient was in the early

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ISSN NO- 2230 – 7885 CODEN JPBSCT NLM Title: J Pharm Biomed Sci .

Mathew T. J Pharm Biomed Sci . 2013, March; 28(28): 650-656. Available at jpbms.info

The clinical FMA was low. She had positive VTO on advancement of the mandible to edge to edge bite (Figure 3). On Functional examination perioral muscle activity was normal. Incisor exposure on smile was 7mm (Figure 4 and Figure 5).

Intra-orally, patient presented with a Class II Division 1 incisor relationship and increased overjet of 8 mm (Figure 6).

The overbite was increased to 7 mm (100% Deep bite) (Figure 7) and the molar relationship (Figure 8) and canine relationships (Figure 9) were full unit Class II on both sides. There was disto-labial rotation of 11 and 21 in the Maxillary arch (Figure 10) and the Mandibular arch was well aligned. (Figure 11).

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ISSN NO- 2230 – 7885 CODEN JPBSCT NLM Title: J Pharm Biomed Sci .

Mathew T. J Pharm Biomed Sci . 2013, March; 28(28): 650-656. Available at jpbms.info

The lateral cephalometric findings (Figure 12) were an increased ANB (7°). The Wits appraisal (+7 mm) confirmed that the patient had a Class II skeletal pattern. The SNA angle was normal and SNB and SND were reduced indicating a Normal Maxillae and retrognathic mandible. The SN-mandibular plane angle and the lower facial proportion were reduced. The upper incisors were proclined while the lower incisors were normally angulated. According to Tanner and White [3,4] , skeletal maturation Index (Figure 13 and 14) was G stage which indicated peak pubertal growth spurt.

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ISSN NO- 2230 – 7885 CODEN JPBSCT NLM Title: J Pharm Biomed Sci .

Mathew T. J Pharm Biomed Sci . 2013, March; 28(28): 650-656. Available at jpbms.info

The lateral cephalometric findings were summarized as “A case of Treatment plan: skeletal class II malocclusion with orthognathic maxillae and The Orthodontic treatment plan retrognathic mandible with Angle class II molar relation and comprised of orthopedic phase horizontal growth pattern”. of Twin block appliance and orthodontic phase of Pre– The Treatment objectives were to adjusted edgewise 0.022” Roth o Achieve normal over jet and overbite. prescription. The upper o Achieve skeletal class I by growth modification with Hawley’s appliance and lower functional appliance. lingual bonded was o Achieve class I molar, Canine and Incisor relation. decided as retainers. o Achieve lip competency.

Treatment progress: The phase I Orthopedic stage An acrylic twin block (Figure 13) was inserted for full time wear. The mandibular advancement of 8 mm to achieve an edge to edge incisor relation and vertical opening of 5 mm in between the premolars was done. The phase I orthopedic stage treatment with Twin Block appliance was continued for 12 months. The inclined plane was at 70 degree angulation and extended from mesial of lower first permanent molar to distal of upper first pre- molar. The lower incisors were capped to prevent proclination of lower incisors. After 6 months of full time wear, the trimming of inter-occlusal bite plane of the Twin Block was done to facilitate the eruption of mandibular molars (Figure 14 and Figure 15).

The twin block appliance was discontinued after 12 months of relation, class I canine relation, treatment. The treatment objectives of normal over jet and class I incisor relation and lip overbite, skeletal class I by growth modification, class I molar competency were achieved by

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ISSN NO- 2230 – 7885 CODEN JPBSCT NLM Title: J Pharm Biomed Sci .

Mathew T. J Pharm Biomed Sci . 2013, March; 28(28): 650-656. Available at jpbms.info stage I orthopaedic stage(Figure 15 and Figure 16). The lateral class I were achieved(Figure 17). suggests treatment objective of skeletal

Phase II: Fixed Appliance stage The 0.022” Roth prescription brackets were bonded on both upper and lower arches and alignment was initiated with 0.014” Ni-Ti wires. The arch wires were subsequently changed to 0.018” x0.025” Stainless steel wire for torque control and class II was used to maintain the class I relation. The generalized spacing in the upper arch was closed using elastic chain. After 8 months of finishing and detailing the fixed appliance treatment was completed (Figure 18 and Figure 19). Upper hawleys’s and lower lingual bonded retainer were issued after 20 months of treatment.

Treatment Assessment : The treatment duration was 20 months and all the treatment objectives were achieved. The overjet and overbite was reduced to 1mm. The Class II molar, class II canine and class II incisor relation was changed to class I relation. The lip competency was achieved. The lateral cephalometric superimposition was compared between pre–treatment, post twin block and post fixed appliance treatment (Table 1). The super-imposition cephalometric tracing indicates that the mandibular to cranial base relation improved by 5 degree and effective mandibular length increased by 5

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ISSN NO- 2230 – 7885 CODEN JPBSCT NLM Title: J Pharm Biomed Sci .

Mathew T. J Pharm Biomed Sci . 2013, March; 28(28): 650-656. Available at jpbms.info mm by forward growth of mandible and maxillary growth was restrained. The ANB Angle was reduced to 2 degree. The upper incisor proclination was reduced and lower incisor proclination was marginally increased after twin block treatment by 1 degree, but eventually decreased after fixed appliance treatment. The lower facial height increased by 4 degree and soft tissue “S Line to lower lip” improved by 3mm(Figure 20 and Figure 21).

Composite analysis: Table 1. Lateral cephalometric assessment Parameter Mean Pretreatment Post Post Twin block Fixed Appliance

Skeletal SNA 82 83 83 83 SNB 80 76 81 81 ANB 2 7 2 2 Go -Gn to Sn 32 27 31 31 Effective Maxillary Length 89 85 86 87 Effective Mandibular Length 105 96 101 102 Y axis 66 68 65 65 Facial axis angle 90 87 90 91 Sum of Posterior Angle 396 385 390 391 Dental U* -1 to NA angle 22 28 26 22 U-1 to NA (mm) 4mm 6 5 4 U-1 to SN angle 102 108 104 102 L* -1 to NB angle 25 27 28 27 L-1 to NB mm 4mm 6 7 6 L-1 to A pog angle 22 25 27 24 L-1 to A pog mm 1-2mm 3 5 4 L1 to Mand plane angle 90 98 102 100 Inter incisal a ngle 130 109 115 128 Soft Tissue S line to U lip -2mm 1 behind 1 1 S line to lower lip 0 2 behind 2 1ahead

Discussion: The case reported in this article is a young female patient who is in The 0.022” Roth prescription was the acceleration stage of growth. The patient was an ideal choice for used for final finishing and twin block functional appliance treatment. She presented with detailing. The post treatment skeletal class II with mandibular retrognathism and low FMA, results showed significant Overjet of 8mm, 100% deep bite and class II dental malocclusion. improvement in the facial profile. Other treatment options like Orthodontic camouflage were not The molar relationship was considered as patient was in the pubertal growth spurt according corrected to class I and increased to the hand wrist and cervical maturation index [4,5] . The treatment overjet and overbite was effect by the functional appliance could be maximized during this corrected to ideal relation [10] . The period [6] . The step wise mandibular advancement has been proved success of functional appliance effective in correction of mandibular retrognathism[7] . The was assessed using cephalometric compliance of the patient to the Twin block is also very important assessment [11] . for the success of the treatment. Lower incisor proclination is an important side effect of functional appliance treatment. In this case, Conclusion: the acrylic lower incisor capping was done to reduce the This case report documented a proclination of lower incisors. The total duration of treatment was successful treatment of a skeletal 20 months with 12 months being growth modification using twin Class II malocclusion with block [7] . The main aim of the two phase orthodontic treatment was mandibular retrognathism for a to enhance the patient’s potential for favourable mandibular 12-year-old female patient using growth and improve her skeletal and soft tissue profile [8-10] . The Twin Block appliance and 0.022” two phase therapy used the functional appliance and fixed Pre- Adjusted edge wise appliance for management of skeletal class II relation.

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ISSN NO- 2230 – 7885 CODEN JPBSCT NLM Title: J Pharm Biomed Sci .

Mathew T. J Pharm Biomed Sci . 2013, March; 28(28): 650-656. Available at jpbms.info appliance. The long-term clinical effects of such treatment should 8. Hägg U, Rabie AB, Bendeus M, Wong be monitored on longer follow up period with more samples. RW, Wey MC, Du X, et al. Condylar growth and mandibular positioning with stepwise vs maximum advancement. Am J Orthod References 9. Larry C F L, Ricky W K W. Management 1. McÑamara J A. Components of Class II malocclusion in children 8-10 years of age. of severe Class II malocclusion with Angle Orthod. 1981; 51:177-202. sequential removable functional and 2. Graber T M, Rakosi T, Petrovic A. Dento-facial Orthopedics with Functional orthodontic appliances: A case for Appliances. St Louis, Mo: Mosby; 1997:346-52. MOrthRCSEd examination Dental Press J 3. Hägg U, Taranger J. Maturation indicators and the pubertal growth spurt. Am J Orthod 46.e1 2011 Sept-Oct;16(5):46e.1- Orthod. 1982;82(4):299-309. 11. 4. Baccetti T, Franchi L, James A, McNamara JA Jr. The cervical vertebral maturation 10.Shen G, Hagg U, Darendeliler M. (CVM) method for assessment of optimal treatment timing in dentofacial Skeletal effects of bite jumping therapy on orthopaedic. Semin Orthod. 2004;11:119-29. the mandible— removable vs. fixed 5. Khal HA, Wong RW, Rabie AB. Elimination of hand-wrist radiographs for maturity functional appliances. Orthod Craniofac assessment in children needing orthodontic therapy. Skeletal Radiol. Res 2005;8:2-10. 2008;37(3):195-200. Epub 2007 Oct 3. 11. Patel HP, Moseley HC, Noar JH. 6. Hägg U, Pancherz H. Dentofacial orthopaedics in relation to chronological age, Cephalometric determinants of successful growth period and skeletal development. An analysis of 72 male patients with Class functional appliance therapy. Angle II division 1 malocclusion treated with the Herbst appliance. Eur J Orthod. Orthod. 2002;72: 410-17. 1988;10(1):169-76. 7. Bakr A, Rabie AB, Al-Kalaly A. Does the degree of advancement during functional appliance therapy matter? Eur J Orthod. 2008;30(3):274-82.

Conflict of interest: - Author has not declared any conflict of interest.

Source of funding: - None

Correspondence address: T Mathew, School of Dentistry, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia, 57000. Contact no: - 0060164844537

Copyright © 2013 Mathew T. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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