**1. Introduction**

The presence of diastemas in the anterosuperior region used to be considered unpleasant, being one of the main reasons why patients seek orthodontic treatment. However, some studies report that the stability of the orthodontic closure of the diastemas, particularly of the median diastema in the permanent denture phase, is low. Long-term stability is one of the main objectives in orthodontic treatment; however, it is one of the most difficult to reach.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

In the anterosuperior region, this stability is especially desired and verified by patients. Most of the publications on anterosuperior diastemas consist of clinical cases and reviews of the literature on the etiology of the problem and its possible treatments. But, there is a shortage in the literature of studies on the stability of the treatment of the upper interincisal subjects. The present chapter seeks to evaluate the recurrence of the upper interincisal diastemas, the factors associated to the relapse and stability, some treatment proposals, and considerations for retention.

found that the number of diastemas per individual decreased with age, but 79% of the preexisting spaces remained, resulting in a percentage of 38% of young adults with spacing

Stability of Diastemas Closure after Orthodontic Treatment

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Richardson et al. [6] observed a higher percentage of 6-year-old girls with median diastemas; however, at age 14, the opposite occurred. The authors believe that this is due to an earlier

The findings of Steigman and Weissberg [8] corroborate those of the other authors, since they found dimorphism only in the subgroup between 14 and 16 years. There was no difference between genders in the 12- to 14-year-old and 16- to 18-year-old groups. Another study published by Steigman et al. [9] supported this finding, demonstrating that there was no difference between genders regarding the number of spaces in the arches in a sample of patients aged 16–22 years. It was also found that the number of diastemas decreased with age in both

In an epidemiological study on the prevalence of diastemas in white and black ethnic groups, Richardson et al. [6] observed, in a sample of children between 6 and 14 years of age, a higher frequency of diastemas in blacks at almost all ages. A prevalence of 23% of blacks at 14 years of age with diastema was found, differing from 14% of whites of this age with central interincisive spaces. Similarly, Lavelle [4] found a higher incidence of central interincisive diastemas in melanodermas (5.5%) than in leucodermas (3.4%) and a lower incidence in xanthomas (1.7%). Likewise, McVay and Latta [5] found a very significant difference between the prevalence of blacks (29%) compared to the percentage of 20% of adults presenting this space in both the white and yellow race.

It is a consensus in the literature that, during the development of occlusion, in the deciduous and mixed dentition stages, the presence of diastemas is a characteristic of normality [2, 10–14]. Nevertheless, Richardson et al. [6] suggested that median diastemas are more than a phase of development eliminated over time, due to the high prevalence found in 18% of adolescents with medium diastemas. Edwards [15] stated that if the median space is greater than 2 mm, it is unlikely to close spontaneously. It was observed in a longitudinal study in adolescents that there was stability in most of the existing diastema, although some were

Authors have suggested that these spaces in the primary dentition are normal and would have the function of assisting in the eruption of permanent teeth [10, 16]. In describing the

between the teeth.

**2.3. Prevalence according to gender**

**2.4. Prevalence according to race**

**3.1. Primary dentition**

maturation of the girls in relation to the boys.

genders, but this occurred earlier in females than in males.

**3. Diastemas and occlusion development**

eliminated even after the eruption of permanent canines [9].
