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3-D Force and Moment Analysis of Repulsive Magnetic Appliances to Correct Dentofacial Vertical Excess

The Maurice and Gabriela Goldschleger School of Dental Medicine, Department of Orthodontics, Tel Aviv University, Tel Aviv 69978, Israel

C. Bourauel

Poliklinik fur Kieferorthopadie, Rhein, Friedrich-Wilhelms-Universität, Welschnonnenstr. 17, 5300 Bonn 1, Germany

D. Drescher

Poliklinik fur Kieferorthopadie, Rhein, Friedrich-Wilhelms-Universität, Welschnonnenstr. 17, 5300 Bonn 1, Germany

G.P.F. Schmuth

Poliklinik fur Kieferorthopadie, Rhein, Friedrich-Wilhelms-Universität, Welschnonnenstr. 17, 5300 Bonn 1, Germany

Repulsive magnetic appliances can intrude posterior teeth, but create a lateral shift of the mandible and also decrease in force as the mouth opens. To model their optimal use, the 3-D spatial force/displacement (F/D) and moment/ displacement (M/D) diagrams of four magnetic repulsive appliances in diverse overlapping arrangements were characterized and compared. In this orthodontic measurement and simulation system, only the medial eccentric magnetic arrangement, of the four compared, partially met the criteria of an optimal repulsive force system, i.e., keeping a constant intruding force and excluding shearing force. The moment analysis found that eccentric arrangements, however, developed high Z-moment. Thus, a perplexing point was reached where the force analysis favored medial centric arrangement and the moment analysis favored centric arrangement. When the gap between juxtaposed magnets increased over 2 mm, the repulsive force declined and the attractive force was favorably eliminated. At gap distances of 3 to 6 mm, the intrusive force was almost constant. These data suggest that centric arrangement is indicated clinically when the gap is minute and Müller prongs are used to prevent deleterious lateral shearing forces.

Key Words: Orthodontic Appliances • Dental Models • Force and Moment Analyses

REFERENCES

• Akima HA (1978). Algorithm 526. Bivariated interpolation and smooth surface fitting for irregularly distributed data points. ACM Trans Math Software 4:160-164.
• Barbe RE, Sinclair PM (1991). A cephalometric evaluation of anterior openbite correction with the magnetic active vertical corrector. Angle Orthod 61:93-102.[Medline] [Order article via Infotrieve]
• Blechman AM (1985). Magnetic forces systems in orthodontics. Am J Orthod 87:201-210.[CrossRef][Medline] [Order article via Infotrieve]
• Blechman AM, Smiley M. (1978). Magnetic forces in orthodontics. Am J Orthod 74:435-443.[CrossRef][Medline] [Order article via Infotrieve]
• Bourauel C., Drescher D., Thier M. (1990). Kraft-Momenten-Aufnehmer für die Kieferorthopadie. Feinwerktechnik & Meßtechnik 98:419-422.
• Bourauel C., Drescher D., Thier M. (1992). An experimental apparatus for the simulation of three-dimensional movements in orthodontics. J Biomed Eng 14:371-378.[CrossRef][Medline] [Order article via Infotrieve]
• Dellinger E. (1986). A clinical assessment of the active vertical corrector-a nonsurgical alternative for skeletal openbite treatment. Am J Ort hod 89:428-436.
• Drescher D., Bourauel C., Thier M. (1991a). Application of the orthodontic measurement and simulation system (OMSS) in orthodontics. Eur J Orthod 13:169-178.[Abstract/Free Full Text]
• Drescher D., Bourauel C., Thier M. (1991b). Orthodontisches Meß- und Simulations-System zur statischen und dynamischen Analyse der Zahnbewegung. Fortschr Kieferorthop 52:133-140.[CrossRef][Medline] [Order article via Infotrieve]
• Gianely AA, Vaitas AS, Thomas WM, Berger DG (1988). Distalization of molars with repelling magnets. J Clin Orthod 20:40-44.
• Gianely AA, Vaitas AS, Thomas WM (1989). The use of magnets to move molars distally. Am J Orthod Dentofac Orthop 96:161-167.[CrossRef][Medline] [Order article via Infotrieve]
• Kalra V., Burstone CJ, Nanda R. (1989). Effects of a fixed magnetic appliance on the dento facial complex. Am J Orthod Dentofac Orthop 95:467-478.[CrossRef][Medline] [Order article via Infotrieve]
• Kiliaridis S., Egermark I., Thilander B. (1990). Anterior open bite treatment with magnets. Eur J Orthod 12:447-457.[Abstract/Free Full Text]
• Melsen B., McNamara JA Jr, Hoenie CD (1991). Effect of biteblocks and repelling magnets on root formation of unerupted premolars in Macaca monkeys. Proc Finn Dent Soc 87:109-114.[Medline] [Order article via Infotrieve]
• Muller GH (1962). Die Doppelplatte mit Oberkiefer-Spornführung. Fortschr Kieferorthop 23:243-250.
• Reitan K. (1974). Initial tissue behavior during apical root resorption. Angle Orthod 44:68-82.[Medline] [Order article via Infotrieve]
• Tsutsui H., Kinouchi Y., Sasaki H., Shiota M., Ushita T. (1979). Studies on the SmComagnet as a dental material. J Dent Res 58:1597-1606.
• Vardimon AD, Stutzmann JJ, Graber TM, Petrovic AM (1989). Functional orthopedic magnetic appliance (FOMA) II-modusoperandi. Am J Orthod Dentofac Orthop 95:371-387.[Medline] [Order article via Infotrieve]
• Vardimon AD, Graber TM, Voss LR, Muller TP (1990). Functional orthopedic magnetic appliance (FOMA) III-modusoperandi. Am J Orthod Dentofac Orthop 97:135-148.[Medline] [Order article via Infotrieve]
• Vardimon AD, Graber TM, Drescher D., Bourauel C. (1991). Rare earth magnets and impaction. Am J Orthod Dentofac Orthop 100:494-512.[CrossRef][Medline] [Order article via Infotrieve]
• Wood MG, Nanda RS (1988). Intrusion of posterior teeth with magnets: An experiment in growing baboons. Angle Orthod 58:136-150.[Medline] [Order article via Infotrieve]
• Wood MG, Nanda RS (1991). Intrusion of posterior teeth with magnets: An experiment in nongrowing baboons. Am J Orthod Dentofac Orthop 100:393-400.[Medline] [Order article via Infotrieve]

Journal of Dental Research, Vol. 73, No. 1, 67-74 (1994)
DOI: 10.1177/00220345940730010901


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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Vardimon, A.D. Articles by Schmuth, G.P.F. Search for Related Content PubMed PubMed Citation Articles by Vardimon, A.D. Articles by Schmuth, G.P.F. Social Bookmarking                         What's this?