RESUMEN
OBJECTIVE: The aim of this study was to evaluate the stability of treatment with a Herbst appliance associated with Hyrax expander (Stage I), followed by fixed appliances (Stage II) and follow-up for an average of 4 years after Stage II, on dentoskeletal facial structures. METHODS: This study involved 50 adolescents with Angle Class II division 1 malocclusion associated with mandibular retrognathism: Treated Group (TG-25) and Control Group (CG-25). Lateral cephalometric radiographs were taken: T1, immediately before Stage I (TG) or at the beginning of the follow-up period (CG); T2, at the end of Stage I (TG) or the follow-up period (CG); T3, at the end of Stage II (TG); and T4, on average, 4 years after Stage II (TG). Enlow's counterpart analysis and some cephalometric measurements were evaluated. Parametric and non-parametric tests were used (P ≤ 0.05). RESULTS: The ramus alignment variables (P < 0.001), SNB (0.040), ANB (<0.001), 1.PP (P = 0.015), 1.MP (P < 0.001), ms/RLp (P < 0.001), mi/RLp (P < 0.001) and S-LS (P = 0.005) showed differences between TG and CG from T1 to T2. Longitudinally, there were differences in ramus alignment, P = 0.003, T1 > T2 < T3 = T4; SNB, P = 0.016, T1 < T2 = T3 = T4; ANB, P < 0.001, T1 > T2 = T3 = T4; 1.MP, P < 0.001, T1 < T2 = T3 = T4; ms/RLp, P = 0.002, T1 = T2 < T3 = T4; mi/RLp, P < 0.001, T1 < T2 = T3 = T4; S-LS, P < 0.001, T1 > T2 = T3 = T4 and S-LI, P = 0.003, T1 = T2 = T3 > T4. CONCLUSION: The nasomaxillary complex (MCF/PM alignment) tended to a retrusive effect to compensate the degree of mandibular retrusion. The protrusive effect of the lower facial third was evident after the Herbst stage and did not remain stable in the follow-up. The dentoalveolar compensation and improvement in facial profile remained stable.
Asunto(s)
Maloclusión Clase II de Angle , Aparatos Ortodóncicos Funcionales , Adolescente , Humanos , Cefalometría , Huesos Faciales/diagnóstico por imagen , Estudios de Seguimiento , Maloclusión Clase II de Angle/diagnóstico por imagen , Maloclusión Clase II de Angle/terapia , Mandíbula/diagnóstico por imagen , Aparatos Ortodóncicos Funcionales/normas , Estudios LongitudinalesRESUMEN
OBJECTIVE: To assess the dentoskeletal changes observed in treatment of Class II, division 1 malocclusion patients with mandibular retrognathism. Treatment was performed with the Herbst orthopedic appliance during 13 months (phase I) and pre-adjusted orthodontic fixed appliance (phase II). METHODS: Lateral cephalograms of 17 adolescents were taken in phase I onset (T1) and completion (T2); in the first thirteen months of phase II (T3) and in phase II completion (T4). Differences among the cephalometric variables were statistically analyzed (Bonferroni variance and multiple comparisons). RESULTS: From T1 to T4, 42% of overall maxillary growth was observed between T1 and T2 (P<0.01), 40.3% between T2 and T3 (P<0.05) and 17.7% between T3 and T4 (n.s.). As for overall mandibular movement, 48.2% was observed between T1 and T2 (P<0.001) and 51.8% between T2 and T4 (P<0.01) of which 15.1% was observed between T2 and T3 (n.s.) and 36.7% between T3 and T4 (P<0.01). Class II molar relationship and overjet were properly corrected. The occlusal plane which rotated clockwise between T1 and T2, returned to its initial position between T2 and T3, remaining stable until T4. The mandibular plane inclination did not change at any time during treatment. CONCLUSIONS: Mandibular growth was significantly greater in comparison to maxillary, allowing sagittal maxillomandibular adjustment. The dentoalveolar changes (upper molar) that overcorrected the malocclusion in phase I, partially recurred in phase II, but did not hinder correction of the malocclusion. Facial type was preserved.
Asunto(s)
Maloclusión Clase II de Angle/terapia , Aparatos Ortodóncicos Funcionales , Retrognatismo/terapia , Adolescente , Cefalometría/métodos , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Mandíbula/crecimiento & desarrollo , Mandíbula/patología , Avance Mandibular/instrumentación , Maxilar/crecimiento & desarrollo , Maxilar/patología , Diente Molar/patología , Diseño de Aparato Ortodóncico , Técnica de Expansión Palatina/instrumentación , Rotación , Técnicas de Movimiento Dental/instrumentación , Resultado del TratamientoRESUMEN
INTRODUCTION: The purpose of this prospective study was to evaluate qualitatively articular disc position and configuration of the temporomandibular joint (TMJ) with magnetic resonance imaging (MRI) in children with functional unilateral posterior crossbite (FUPXB) treated with Haas-type orthopedic appliances. METHODS: The sample included 30 Brazilian children (60 TMJs) of both sexes (8 boys, 22 girls), aged 6.8 to 14.2 years (mean, 10.5 years; SD, 2.1 years). The MRIs were acquired in closed-mouth (CM), maximum-intercuspal (MI), and open-mouth (OM) positions in 3 stages of treatment: initial (T1), at the beginning of treatment; intermediate (T2), immediately after the removal of the expander, and final (T3), 9 months later, at the end of the observation period. RESULTS: No changes were found in articular disc positions of 96.6% of the TMJs in the CM and MI positions, and in 95% in the OM position at T1, T2, and T3. For the articular disc configuration, no changes were observed in 96.66% of the TMJs in the CM and MI positions, and in all TMJs in the OM position, at T1, T2, and T3. CONCLUSIONS: On average, this treatment method did not change articular disc positions and configurations.