Comparison of the tooth alignment stability using canine-to-canine retainers bonded in two different forms

• Ano de defesa: 2021
• Autor(a) principal: Freitas, Jessica Quereza de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Apinhamento; Contenção ortodôntica; Crowding; Estabilidade em longo prazo; Long-term stability; Orthodontic retainer; Recidiva; Relapse
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/25/25144/tde-26112021-160544/

Objective: The purpose is to evaluate the stability of the mandibular anterior teeth alignment by comparing two forms of bonding of the fixed canine-to-canine retainer, bonded only to the canines and bonded to each of the mandibular incisors and canines, with 5 years follow-up. Material and Methods: 43 patients (22 female, 21 male) with Class I and Class II malocclusion, were divided into 2 groups: Group 1: 25 patients (13 females, 12 males) with retainer bonded only to the canines. Mean initial age, treatment time, long-term posttreatment time were 13.42 (SD, 1.51), 3.06 (1.56) and 5.60 (SD, 1.36) years, respectively. Group 2: 18 patients (9 females, 9 males) with retainer bonded to the all mandibular anterior teeth. Mean initial age, treatment time, long-term posttreatment time were 13.01 (SD, 2.94), 3.62 (SD, 1.84), 5.31 (SD, 0.77) years, respectively. Dental casts were obtained and digitized at pretreatment (T1), posttreatment (T2) and at a mean of 5 years long-term posttreatment (T3). The following measurements were obtained: Little irregularity Index, intercanine, interpremolar and intermolar widths. The intergroup comparisons of the variables at pretreatment, posttreatment and long-term posttreatment stages and the treatment and long-term posttreatment changes were performed with independent t tests. Results: The mandibular irregularity index showed a statistically significant decrease with treatment and remained stable in the long-term posttreatment follow-up. In the group 1, there was a significantly increase in the mandibular inter first premolars width with treatment and it was stable in the long-term posttreatment. In the group 2, the mandibular inter second premolars width showed a significantly increase with treatment and it remained stable in the long-term. The intergroup comparison at all stages (T1, T2 and T3) showed no statistically significant differences between the groups. Group 2 showed a greater decrease in the mandibular intercanine width than the all teeth group in the long-term posttreatment phase. Conclusions: There was no difference in the amount of relapse of mandibular anterior crowding with fixed canine-to-canine retainers bonded only to the canines and bonded all the six anterior teeth. Thus, both retainers can be recommended. However, the canine group showed a decrease in the mandibular intercanine width in long term posttreatment.