|Year : 2014 | Volume
| Issue : 1 | Page : 63-64
Modified support phase appliance after twin block therapy
Gautham Sivamurthy1, S Aravind Kumar2, Christine Samantha2
1 Department of Orthodontics, Penang International Dental College, Level 18-21, NB Tower, 5050, Jalan Bagan Luar, 12000 Butterworth, Penang, Malaysia
2 Department of Orthodontics, Saveetha Dental College, Vellapanchavadi, Chennai, Tamil Nadu, India
|Date of Web Publication||19-Mar-2014|
Penang International Dental College, Level 18-21, NB Tower, 5050, Jalan Bagan Luar, 12000, Butterworth, Penang
Source of Support: None, Conflict of Interest: None
Buccal segment occlusion is the cornerstone of stability after correction of Class II malocclusion using a twin block appliance. The following short communication is a modification of Clark's original support phase appliance, to achieve better retention after treatment.
Keywords: Retention, twin block, support phase appliance
|How to cite this article:|
Sivamurthy G, Kumar S A, Samantha C. Modified support phase appliance after twin block therapy. SRM J Res Dent Sci 2014;5:63-4
|How to cite this URL:|
Sivamurthy G, Kumar S A, Samantha C. Modified support phase appliance after twin block therapy. SRM J Res Dent Sci [serial online] 2014 [cited 2022 Jul 3];5:63-4. Available from: https://www.srmjrds.in/text.asp?2014/5/1/63/129077
| Introduction|| |
Twin block appliances are simple bite blocks that are designed to achieve rapid functional correction of malocclusion by the transmission of favorable occlusal forces to occlusal inclined planes that cover the posterior teeth. Conventionally, when using the twin block appliance to correct the anteroposterior relationship in Class II division 1 malocclusion, the appliance is replaced at the end of active treatment, with an upper Hawley type of appliance with an anterior inclined plane to support the corrected position as the posterior teeth settle completely into occlusion [Figure 1]. The design of the Hawley retainer which was introduced by Charles Hawley in 1919,  includes labial wire with adjustments loops at the canines and an acrylic base plate adapted to the palatal surfaces of the teeth.
|Figure 1: Hawley type support phase appliance inserted immediately after correction with twin block|
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Clark  recognized that a good buccal segment occlusion is the cornerstone of stability after correction of the arch to arch relationship. In an article 1997, Sauget et al.  demonstrated that Hawley retainer allows more settling of occlusal when compared to other commonly used designs of retainer, for example: Clear overlay retainer. In a similar study done by Littlewood et al. in 2006,  it was shown that Hawley retainer had weak and unreliable evidence that teeth settle better. Clinically, we also observed that the Hawley type appliance used to support the twin block effected advanced mandibular position, increased the time duration of the support phase and occasionally prevented the buccal segment occlusion to be completely established, as a consequence of its labial bow and clasps crossing over the occlusion [Figure 2].
| Discussion and Conclusion|| |
Due to this frequent disadvantage, we modified the support phase appliance by using a Begg's Wraparound type retainer along with an anterior inclined plane [Figure 3]. The Begg's retainer is named after the late Begg and Kesling,  who was responsible for popularizing this retainer. In this retainer the labial bow extends distally posterior to the last erupted molar. It is ideal for cases where settling of occlusion is required; especially in the posterior segment, as there is no wire framework crossing the occlusion [Figure 4]. The modification of the support phase appliance avoided all cross-over wires, resulting in unrestricted and quicker eruption of buccal segment into occlusion and stabilized the correction achieved [Figure 5].
|Figure 3: Appliance changed to Begg Wraparound type after 3 months due to slow settling on buccal segment|
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|Figure 5: Well established occlusion within 1 month of using Begg Wraparound type support phase appliance|
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| References|| |
|1.||Hawley CA. A removable retainer. Int J Orthod 1919;5:291-8. |
|2.||Clark WJ. Twin Block Functional Appliance Therapy: Applications in Dentofacial Orthopaedics. 2 nd ed. Edinburgh (Scotland): Mosby; 2002. |
|3.||Sauget E, Covell DA Jr, Boero RP, Lieber WS. Comparison of occlusal contacts with use of Hawley and clear overlay retainers. Angle Orthod 1997;67:223-30. |
|4.||Littlewood SJ, Millett DT, Doubleday B, Bearn DR, Worthington HV. Orthodontic retention: A systematic review. J Orthod 2006;33:205-12. |
|5.||Begg PR, Kesling PC. Begg Orthodontic Theory and Technique. Philadelphia: Saunders; 1977. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]