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Introduction:The length of time that it takes an orthodontist to treat adult patients varies widely. Objective: The aim of this study was to investigate how different variables influence treatment time. Methods: Seventy clinical case reports of successfully treated adult patients were examined. The patients were selected from 4,723 records held by three experienced orthodontists. The influence exerted by the following variables on treatment time was assessed: age, sex, facial pattern, severity of malocclusion (measured by the PAR index), sagittal relationship of canines, type of brackets (ceramic or metal), tooth extractions, missed appointments and orthodontic appliance issues/breakages, the latter being the dependent variable. Assessment was performed by multiple linear regression analysis, followed by the stepwise method with P < 0.05. Results: The number of times a patient missed their appointment (no-show) (R 2 = 14.4%, p < 0.0001) and the number of appliance issues/breakages (R 2 = 29.71%, p = 0.0037) significantly affected variability in treatment time, and these two variables together can predict 43.75% (R 2 total) of the overall variability in treatment time. Other factors, such as canine relationship at the beginning of treatment, bracket type (metal or ceramic), tooth extractions, age at start of treatment, severity of the initial malocclusion, sex and facial pattern had no significant bearing on treatment time. Conclusions:The duration of orthodontic treatment in adults, when performed by experienced orthodontists, is mainly influenced by factors related to patient compliance. However, several factors which were not included in this study may contribute to variability in orthodontic treatment time.Keywords: Adult. Time factors. Orthodontics.Introdução: o tratamento ortodôntico de pacientes adultos apresenta grande variabilidade no tempo necessário para sua realização. Objetivo: o objetivo desse trabalho foi investigar a influência de diversas variáveis sobre o tempo de tratamento. Métodos: foram examinados 70 casos clínicos, de pacientes adultos, com bom resultado final, coletados em clínicas de três ortodontistas experientes, cujo acervo total inicial era de 4.723 prontuários. A influência das variáveis idade, sexo, padrão facial, severidade inicial da má oclusão (medida por meio do índice PAR), relação sagital de caninos, tipo de braquetes (estético ou metálico), exodontias, faltas às consultas e "quebras" de aparelho, sobre o tempo de tratamento (variável dependente), foram avaliadas por meio da análise de regressão linear múltipla, seguida do método Stepwise, com p < 0,05. Resultados: a quantidade de faltas (R 2 = 14,04%, p < 0,0001) e o número de "quebras" do aparelho (R 2 = 29,71%, p = 0,0037) tiveram influência significativa na variação do tempo de tratamento, sendo essas duas variáveis juntas capazes de prever 43,75% (R 2 total) da variação no tempo de tratamento. Outros fatores, como a relação de caninos ao início do tratamento, o tipo de braquete usado (metálico ou cerâmico), exodontias, a ...

The aim of this study was to evaluate the effects of the mandibular protraction appliance (MPA) for treating mild to moderate Class II malocclusion at different stages of dentofacial development. Lateral radiographs were evaluated before (T0) and at the end (T1) of orthodontic treatment with fixed appliance associated with MPA. Sixty-five consecutively treated patients were divided according to the stage of dentofacial development: 21 children in late mixed dentition, 22 adolescents and 22 young adults with full permanent dentition. The differences between and within groups were analyzed by MANOVA at p<0.05. The correction of anteroposterior discrepancy (Wits) was significantly reduced in all development stages (p<0.01), with no difference between groups. Class II was corrected predominantly by dental changes in the mandibular arch, with accentuated proclination of the mandibular incisors and mesial displacement of mandibular molars. The MPA had no skeletal effects in any of the groups, except for a mild reduction of SNA (p=0.018) and ANB angles (p<0.0001) among the mixed dentition children. With regard to soft-tissue profile, facial convexity decreased significantly in all groups (p<0.01). In conclusion, the MPA associated with fixed appliance corrected the Class II occlusion, basically by a mandibular arch protrusion. A mild skeletal maxillary change was significant only when this treatment protocol began during mixed dentition.

Bracket prescriptions with greater angulation led to an increased use of space within the dental arch, mainly in the radicular region. The consequence of this radicular angular displacement will need to be further investigated.

OBJECTIVE: The aim of this longitudinal study, comprising young adults without orthodontic treatment, was to assess spontaneous changes in lower dental arch alignment and dimensions. METHODS: Twenty pairs of dental casts of the lower arch, obtained at different time intervals, were compared. Dental casts obtained at T1 (mean age = 20.25) and T2 (mean age = 31.2) were compared by means of paired t-test (p < 0.05). RESULTS: There was significant reduction in arch dimensions: 0.43 mm for intercanine (p = 0.0089) and intermolar (p = 0.022) widths, and 1.28 mm for diagonal arch length (p < 0.001). There was a mild increase of approximately 1 mm in the irregularity index used to assess anterior alignment (p < 0.001). However, regression analysis showed that changes in the irregularity index revealed no statistically significant association with changes in the dental arch dimensions (p > 0.05). Furthermore, incisors irregularity at T2 could not be predicted due to the severity of this variable at T1 (p = 0.5051). CONCLUSION: Findings suggest that post-growth maturation of the lower dental arch leads to a reduction of dental arch dimensions as well as to a mild, yet significant, increase in dental crowding, even in individuals without orthodontic treatment. Furthermore, dental alignment in the third decade of life cannot be predicted based on the severity of dental crowding at the end of the second decade of life.