Korean J Orthod.  2019 Mar;49(2):89-96. 10.4041/kjod.2019.49.2.89.

Long-term stability of maxillary and mandibular arch dimensions when using rapid palatal expansion and edgewise mechanotherapy in growing patients

• Kim KB
• Doyle RE
• Araújo EA
• Behrents R
• Oliver DR
• Thiesen G

• KMID: 2453972
• DOI: http://doi.org/10.4041/kjod.2019.49.2.89

Abstract

OBJECTIVE
The purpose of this study was to assess the long-term stability of rapid palatal expansion (RPE) followed by full fixed edgewise appliances.
METHODS
This study included 67 patients treated using Haas-type RPE and non-extraction edgewise appliance therapy at a single orthodontic practice. Serial dental casts were obtained at three different time points: pretreatment (T1), after expansion and fixed appliance therapy (T2), and at long-term recall (T3). The mean duration of the T1-T2 and T2-T3 periods was 4.8 ± 3.5 years and 11.0 ± 5.4 years, respectively. The dental casts were digitized, and the computed measurements were compared with untreated reference data.
RESULTS
The majority of treatment-related increases in the maxillary and mandibular arch measurements were statistically significant (p < 0.05) and greater than expected for the untreated controls. Although many measurements decreased postretention (T2-T3), the net gains persisted for all of the measurements evaluated.
CONCLUSIONS
The use of RPE therapy followed by full fixed edgewise appliances is an effective method for increasing maxillary and mandibular arch width dimensions in growing patients.

Keyword

Expansion; Stability; Digital models

MeSH Terms

Humans
Methods

Figure

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  Figure 1 Location of the digitized points (mesial, distal, lingual, and buccal) to determine the centroid landmark. Similar points and landmarks are located on the mandibular dental arch.

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  Figure 2 Location of the centroid is found first by determining the midpoint (A) of the line connecting the mesial and distal landmarks. A similar midpoint (B) is constructed midway between the buccal and lingual landmarks of the tooth. The centroid (C) is located between points A and B. Adapted from the article of Moyers et al. (Standards of human occlusal development, 1976).8

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  Figure 3 Computation of arch width (from the lingual point).

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  Figure 4 Treatment and posttreatment changes in the maxillary and mandibular arches. *p < 0.05.

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  Figure 5 Age- and sex-specific z scores based on established reference data reported by Moyers et al. (Standards of human occlusal development, 1976)8. *p < 0.05.

Reference

1. Timms DJ. The dawn of rapid maxillary expansion. Angle Orthod. 1999; 69:247–250.

2. Haas AJ. The treatment of maxillary deficiency by opening the midpalatal suture. Angle Orthod. 1965; 35:200–217.

3. Moussa R, O'Reilly MT, Close JM. Long-term stability of rapid palatal expander treatment and edgewise mechanotherapy. Am J Orthod Dentofacial Orthop. 1995; 108:478–488.

4. Wertz RA. Skeletal and dental changes accompanying rapid midpalatal suture opening. Am J Orthod. 1970; 58:41–66.

5. Asanza S, Cisneros GJ, Nieberg LG. Comparison of Hyrax and bonded expansion appliances. Angle Orthod. 1997; 67:15–22.

6. McNamara JA Jr, Baccetti T, Franchi L, Herberger TA. Rapid maxillary expansion followed by fixed appliances: a long-term evaluation of changes in arch dimensions. Angle Orthod. 2003; 73:344–353.

7. Barry M. In-office digital study models. J Clin Orthod. 2011; 45:385–389.

8. Moyers RE, vander Linden FP, Riolo ML, McNamara JA. Standards of human occlusal development. Monograph 5. Craniofacial growth series. Ann Arbor: Center for Human Growth and Development, University of Michigan;1976. p. 371.

9. Haahr M. True random number service [Internet]. Dublin: RANDOM.ORG;1998. cited 2014 May 4. Available from: www.random.org.2010.

10. Haas AJ. Palatal expansion: just the beginning of dentofacial orthopedics. Am J Orthod. 1970; 57:219–255.

11. Lima AC, Lima AL, Filho RM, Oyen OJ. Spontaneous mandibular arch response after rapid palatal expansion: a long-term study on Class I malocclusion. Am J Orthod Dentofacial Orthop. 2004; 126:576–582.

12. Pinheiro FH, Garib DG, Janson G, Bombonatti R, de Freitas MR. Longitudinal stability of rapid and slow maxillary expansion. Dental Press J Orthod. 2014; 19:70–77.

13. Mohan CN, Araujo EA, Oliver DR, Kim KB. Long-term stability of rapid palatal expansion in the mixed dentition vs the permanent dentition. Am J Orthod Dentofacial Orthop. 2016; 149:856–862.