|Year : 2014 | Volume
| Issue : 2 | Page : 102-104
Treatment of skeletal class II malocclusion with the combination of twin-block and combination-pull headgear
Sameer S Patil, Sandesh S Baralay, Sheetal S Potnis
Department of Orthodontics and Dentofacial Orthopaedics, Sinhgad Dental College and Hospital, Pune, Maharashtra, India
|Date of Web Publication||18-Jun-2015|
Dr. Sameer S Patil
Department of Orthodontics and Dentofacial Orthopaedics, Sinhgad Dental College and Hospital, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
The patient was a girl with a Class II division 1 malocclusion, a large overjet, an excessively deep overbite, and a slightly increased mandibular plane angle. Treatment started with the Twin-block appliance combined with combination-pull headgear to promote growth of the mandible, restrain the maxilla in the anteroposterior plane, and improve her profile. This was later, followed by fixed appliance therapy.
Keywords: Class II malocclusion division 1, combination-pull headgear, functional appliance, twin-block
|How to cite this article:|
Patil SS, Baralay SS, Potnis SS. Treatment of skeletal class II malocclusion with the combination of twin-block and combination-pull headgear. J Dent Allied Sci 2014;3:102-4
|How to cite this URL:|
Patil SS, Baralay SS, Potnis SS. Treatment of skeletal class II malocclusion with the combination of twin-block and combination-pull headgear. J Dent Allied Sci [serial online] 2014 [cited 2019 Dec 12];3:102-4. Available from: http://www.jdas.in/text.asp?2014/3/2/102/159094
| Introduction|| |
Twin-blocks are basically bite-blocks that effectively induce favorably directed occlusal forces by causing a functional mandibular displacement with the use of modified occlusal inclined plane. Upper and lower bite-blocks are made at a 45° angle. They are designed for full-time wear and take advantage of all functional forces applied to the dentition including the forces of mastication. Bite-blocks allow the patients to eat comfortably even with the appliances in place. Occlusal inclined planes give greater freedom of movement in anterior and lateral excursion and cause less interference with normal function, in comparison to other functional appliances. The change in the appearance is immediately seen when the appliance is fitted and can be an additional motivating factor. With twin-blocks full functional correction of occlusal relationships can be achieved in many cases without the addition of any orthopedic or traction forces. 
In cases with severe skeletal discrepancy, an orthopedic traction system can be used in conjunction to support the action of occlusal inclined planes. The indications for treatment include maxillary protrusion, mandibular retrusion, and vertical growth discrepancies. A functional orthopedic approach can help in controlling the uncertain treatment response that is sometimes associated with purely functional techniques. Rapid correction of malocclusion can be achieved even in cases with severe malocclusions that are unfavorable for conventional fixed or functional appliance therapy. 
| Case Report and Results|| |
A 12-year-old girl visited the Department of Orthodontics and Dentofacial Orthopedics with a chief complaint of proclined upper anterior teeth. The patient had Class II skeletal pattern with a slightly large Frankfort-mandibular planes angle and lower anterior face height. There was no facial asymmetry and the lips were incompetent. In the intra-oral assessment, the oral hygiene was good.
A convex profile was observed with protruded lips and moderate exposure of maxillary incisors. The midline of the mandible was shifted 2 mm to the right. She had a Class II division 1 malocclusion (full cusp Class II molars on the right side and end-on relationship of the molars on the right side) with 11 mm overjet and an excessive overbite. The pretreatment intra-oral and extra-oral photographs are shown in [Figure 1]. The cephalometric analysis confirmed a skeletal Class II jaw relationship with a retrognathic mandible. Additionally, the maxillary incisors were labially inclined and mandibular incisors were slightly retroclined on the mandibular base. The lateral radiographs of the patient are shown in [Figure 2].
The twin-block appliance was used to correct the sagittal mandibular discrepancy. Meanwhile, the combination-pull headgear was worn for 9 months to restrict forward growth of the maxilla. The patient was instructed to wear the twin-block appliance 24 h a day, even during eating, and to wear the headgear at least 12-14 h/day. The patient was initially seen 10 days after the first visit, then monthly so that the blocks and the headgear could be adjusted for retention and stability as needed.
When the treatment with the functional appliance ended, the patient's mandible was positioned forward, and the profile was greatly improved. The posttreatment photographs are shown in [Figure 3]. A skeletal anteroposterior reduction was significant with 6° change in the ANB angle (the SNA angle had decreased from 86° to 84°). The posttreatment lateral cephalogram is shown in [Figure 4].
| Discussion|| |
Since the patient had a skeletal Class II pattern with a retrognathic mandible, the functional appliance with extra-oral forces were used to correct the skeletal anteroposterior discrepancy. Some studies have shown that the anteroposterior correction accomplished is more through dentoalveolar changes than skeletal changes. , In this patient the skeletal changes were confirmed by the restrained maxilla and the advanced mandible and a decrease in the ANB angle. There was a slight increase in the Frankfort-mandibular planes angle which was undesirable in this case.
Several studies have shown that twin-block produces retroclination of maxillary incisors and proclination of the mandibular incisors. , In the study done by Tortop and Yüksel, they showed a decrease in the SNA and ANB values with the use of combination-pull headgear.  Similar combined findings have been observed in our patient. The maxillary incisors retroclined by 6° (U1-NA) and the mandibular incisors proclined from 21° to 24° (L1-NB). Furthermore, the nasolabial angle increased from 87° to 99°. The values of selected parameters before and after functional appliance therapy are shown in [Table 1]. Studies making the use of twin-block and bionator with a high pull headgear in patients with steep mandibular plane angle and increased vertical dimensions to correct Class II malocclusions were done. , Short-term skeletal effects include a small restriction in forward maxillary growth with headgear and a small forward positioning of B point with functional appliances, leading to an ANB improvement in Class II patients with either appliance.  Similar results were obtained in our study with the use of twin-block and combination-pull headgear.
|Table 1: Pre- and post- functional appliance cephalometric measurements |
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Following the treatment with the functional appliance, fixed appliance therapy was planned for leveling, aligning and finishing of the dentition without extraction of any teeth.
| Conclusion|| |
The use of twin-block together with the combination-pull headgear produced desirable effects in our patient with skeletal Class II malocclusion. However, other adverse effects like increase in Frankfort-mandibular planes angle were also seen. This treatment modality is case specific and cannot be routinely used in all patients having Class II malocclusions.
| References|| |
Clark WJ. The twin block technique. A functional orthopedic appliance system. Am J Orthod Dentofacial Orthop 1988;93:1-18.
O'Brien K, Wright J, Conboy F, Sanjie Y, Mandall N, Chadwick S, et al
. Effectiveness of early orthodontic treatment with the Twin-block appliance: A multicenter, randomized, controlled trial. Part 1: Dental and skeletal effects. Am J Orthod Dentofacial Orthop 2003;124:234-43.
Huang GJ. Twin-block appliance is effective for the correction of Class II Division I malocclusion during mixed dentition. J Evid Based Dent Pract 2004;4:222-3.
Mills CM, McCulloch KJ. Posttreatment changes after successful correction of Class II malocclusions with the twin block appliance. Am J Orthod Dentofacial Orthop 2000;118:24-33.
Illing HM, Morris DO, Lee RT. A prospective evaluation of Bass, Bionator and Twin Block appliances. Part I - The hard tissues. Eur J Orthod 1998;20:501-16.
Tortop T, Yüksel S. Treatment and posttreatment changes with combined headgear therapy. Angle Orthod 2007;77:857-63.
Lv Y, Yan B, Wang L. Two-phase treatment of skeletal class II malocclusion with the combination of the twin-block appliance and high-pull headgear. Am J Orthod Dentofacial Orthop 2012;142:246-55.
Freeman CS, McNamara JA Jr, Baccetti T, Franchi L, Graff TW. Treatment effects of the bionator and high-pull facebow combination followed by fixed appliances in patients with increased vertical dimensions. Am J Orthod Dentofacial Orthop 2007;131:184-95.
Southard TE, Marshall SD, Allareddy V, Moreno Uribe LM, Holton NE. An evidence-based comparison of headgear and functional appliance therapy for the correction of Class II malocclusions. Semin Orthod 2013;19:174-95.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]