Objective The aim of this study was to assess the frequency of mandibular second premolar (MnP2) distoangulation among orthodontic patients and the angular changes after a longitudinal follow-up. Methods The sample was collected from the orthodontic records of 865 patients. The distoangulation group was composed of 42 patients (mean age 9.29 ± 1.24 years, 16 male, 26 female) with distoangulation of MnP2. The control group was composed of 32 patients (mean age 9.38 ± 1.10 years, 15 male, and 17 female) without distoangulation of MnP2. Panoramic radiographs taken in the mixed (T1) and the early permanent dentition (T2) were analyzed in both groups. Longitudinal angular changes (distal angle θ and premolar-molar angle γ), degree of root formation, second premolar depth, and prevalence of associated dental anomalies were analyzed. Intergroup comparison was performed with Mann–Whitney, t-tests, and chi-square tests (P < 0.05). Results The prevalence of MnP2 distoangulation in the mixed dentition was 4.85%. The distoangulation group showed a smaller initial distal angle (59.34o ± 8.41) when compared to control group (79.88o ± 7.60). The spontaneous eruption of the MnP2 with distoangulation was observed in 76.57% of the sample. MnP2 distoangulation was significantly associated with agenesis of its antimere, small maxillary lateral incisors, and deciduous molar infraocclusion. Limitations Severe cases of MnP2 distoangulation were absent in this study. Conclusions The frequency of MnP2 distoangulation among orthodontic patients was 4.85%. Mild to moderate distoangulated Mnp2 spontaneously uprighted from the mixed to the permanent dentition. Small lateral incisors, second premolar agenesis, and infraocclusion of deciduous molar were frequently found in cases with MnP2 distoangulation.
Objectives To compare the perception of pain and discomfort of patients and guardians during treatment between miniscrew-anchored maxillary protraction (MAMP) therapy using Hybrid (HH) and Conventional Hyrax (CH) expanders. Materials and Methods Group HH was composed of 18 subjects (8 female, 10 male; initial age: 10.80 years) with Class III malocclusion treated with a hybrid expander in the maxilla and two miniscrews in the anterior region of the mandible. Class III elastics were used from maxillary first molar to mandibular miniscrews. Group CH was composed of 14 subjects (6 female, 8 male; initial age: 11.44 years) treated with a similar protocol except for conventional Hyrax expander. Pain and discomfort of patients and guardians were assessed using a visual analog scale immediately after placement (T1), after 24 hours (T2), and 1 month after appliance installation (T3). Mean differences (MD) were obtained. Intergroup and intragroup timepoint comparisons were performed using independent t-tests, analysis of variance for repeated measures and Friedman test (P < 5%). Results Both groups demonstrated similar levels of pain and discomfort with a significant decrease after 1 month of appliance placement (MD: 4.21; P = .608). Compared to patient perceptions, guardians reported a higher level of pain and discomfort at all timepoints (MD, T1: 13.91, P < .001; T2: 23.15, P < .001; T3: 9.35, P = .008). Conclusions MAMP therapy with HH and CH produced similar levels of pain and discomfort after appliance installation until 1 month after treatment. Pain and discomfort may not influence the choice between HH and CH expanders.
Os apinhamentos suaves a moderados na dentição mista podem ser tratados com expansão rápida da maxila (ERM) associada à expansão lenta do arco dentário inferior. A expansão lenta no arco inferior pode ser conduzida com uma alternativa de aparelho fixo e com parafuso. O objetivo deste artigo consiste em apresentar o protocolo laboratorial e clínico do expansor de Williams. Apresentou-se um caso clínico de uma paciente do sexo feminino, 9 anos de idade, com a face simétrica do Padrão I na dentadura mista, com apinhamento moderado dos incisivos inferiores e apinhamento suave no arco superior. O tratamento foi realizado com expansão superior e inferior. No arco superior, a ERM mediante o aparelho Hyrax foi realizada. No arco inferior, procedeu-se à expansão lenta com expansor de Williams. Obteve-se uma adequada oclusão com o alinhamento dos incisivos permanentes e uma melhora do corredor bucal no sorriso. O expansor de Williams representa uma alternativa para os casos que necessitam expansão lenta do arco dentário inferior, independendo da colaboração do paciente. Quando adequadamente construído, o expansor mostra-se confortável e efetivo.
Objective:The aim of this study was to assess the angular changes of mandibular second premolars (MnP2) with distoangulation and to evaluate the different clinical outcomes after a longitudinal follow-up. Methods: The sample was collected from the orthodontic records of 865 patients who sought phase I treatment at one single center. Distoangulation group was composed by 42 patients (mean age 9.29±1.24 years, 16 male, 26 female) with distoangulation of MnP2. The control group was composed by 32 patients (mean age 9.38±1.10 years, 15 male, 17 female) without distoangulation of MnP2. Panoramic radiographs taken in the mixed (T1) and the early permanent dentition (T2) were analyzed in both groups. Longitudinal angular changes, the degree of root formation, second premolar depth and the prevalence of associated dental anomalies were analyzed. Intergroup comparison was performed with Mann-Whitney and t tests. Intergroup comparison of dental anomaly frequency was performed using Chi-square tests (p<0.05). Results: The prevalence of MnP2 distoangulation in the mixed dentition was 4.85%. The distoangulation group showed a greater initial θ angle (59.34 o ±8.41) when compared to the control group (79.88 o ±7.60). The spontaneous eruption of the MnP2 with distoangulation was observed in 76.57% of the sample. The extraction of the predecessor second deciduous molar followed by the spontaneous eruption was found in 23.43%. MnP2 distoangulation was significantly associated with agenesis of its antimere, small maxillary lateral incisors and deciduous molar infraocclusion. Conclusions: Conservative approaches may be preferred in cases of mandibular second premolar distoangulation. Severe cases of MnP2 distoangulation were rare.
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