Abstract
Transversal asymmetries of the dental arches are common orthodontic problems. Significant
asymmetries needed a surgical approach for their correction before the introduction
of skeletal anchorage. This paper presents two different approaches to correct dental
transversal asymmetries, using skeletal anchorage both directly and indirectly. The
direct use of skeletal anchorage requires careful planning of the desired dental movement
and the estimation of the line of action of the needed force to achieve it. This information
can be used to orientate the orthodontist in the screw placement, since it should
be inserted, if possible, along the line of action of this force. In this way, it
is possible to design appliances that do not deliver to the screw moments, which can
compromise their stability. In the direct approach, the screw can be placed in the
palatal vault or between the dental roots. The indirect use of skeletal anchorage
implies the connection of the screw with one or some of the teeth which are required
to maintain their position. Since the connecting wire should be rather short, it is
recommendable to place the screw in the interradicular bone, rather than in the palate.
This approach can be used with both fixed appliances, and with aligners. Four clinical
cases illustrate these modalities of asymmetric expansion or contraction.
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References
- Precision adjustment of the transpalatal lingual arch: Computer arch form predetermination.Am J Orthod. 1981; 79: 115-133
- Efficient palatal expansion with a quadhelix appliance: an in vitro study using an experimental dental arch model.Eur J Orthod. 2012; 34: 442-446
- Expansion with transpalatal arch or continuous arch mechanics.Am J Orthod Dentofacial Orthop. 2020; 157: 611-618
- A randomized controlled trial comparing the quadhelix and the expansion arch for the correction of crossbite.J Orthod. 2005; 32: 29-35
- Efficiency of upper arch expansion with the Invisalign system.Angle Orthod. 2020; 90 (Jan): 23-30
- Three-dimensional evaluation of surgically assisted asymmetric rapid maxillary expansion.Am J Orthod Dentofacial Orthop. 2019; 155: 620-631
Pary A., Cal-Neto J.P.: A simple method to treat asymmetric expansions in three-segment surgically assisted rapid maxillary expansion. J Oral Maxillofac Surg. 71(12):2130-6, 201
- Different orthodontic anchorage systems.A critical examination (German): Fortschr Kieferorthop. 1993; 54: 156-157
- T-loop position and anchorage control.Am J Orthod Dentofacial Orthop. 1997; 112 (Jul): 12-18
- Different approaches to anchorage: a survey and an evaluation.Angle Orthod. 1997; 67: 23-30
- Occlusion management in orthodontic anchorage control.J Clin Orthod. 2013; 47 (Mar): 188-197
- Asymmetric maxillary expansion (AMEX) appliance for treatment of true unilateral posterior crossbite.Am J Orthod Dentofacial Orthop. 2002; 122: 164-173
- Symmetric and asymmetric expansion of molars using a Burstone-type transpalatal arch. Biomechanical and clinical analysis.J Orofac Orthop. 2015; 76: 377-390
Fiorelli G., Melsen B.: Biomechanics in Orthodontics, Multimedia Textbook. Rel 4. Chapter 5, www.ioss-ortho.com, IOSS GmbH, Wollerau, 1992-2022
- What Is the Safety Zone for Palatal Soft Tissue Graft Harvesting Based on the Locations of the Greater Palatine Artery and Foramen? A Systematic Review.J Oral Maxillofac Surg. 2019; 77 (Feb): 271
- Statically determinate appliances and creative mechanics.Burstone and Choy “The biomechanical foundations of clinical orthodontics. 2nd Ed. Quintessence, Batavia, IL2022 (Chapter 15)
- The “3-D occlusogram” software.Am J Orthod Dentofac Orthop. 1999; 116: 363-368
- Visualizing Treatment Objectives and Treatment Planning Using 2D and 3D Occlusograms.in: Retrouvey JM. Abdallah MN. 3D Diagnosis and Treatment Planning in Orthodontics. Springer, Cham.2021
- Le repositionnement mandibulaire: une alternative à la chirurgie chez des patients adultes? Un suivi sur deux ans.Orthodontie Française June. 2018; 89: 123-135
- Comparison of effectiveness of quad helix appliance with other slow maxillary expanders in children with posterior crossbite: A systematic review.J Indian Soc Pedod Prev Dent. 2018; 36 (Jul-Sep): 225-233
- Efficacy and predictability of maxillary and mandibular expansion with the Invisalign system.J Clin Exp Dent. 2021; 13 (Jul 1)
- Guidelines for the use of rigid indirect anchorage mechanics.Am J Orthod Dentofacial Orthop. 2017; 152: 413-419
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Published online: October 27, 2022
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