Study on soft tissue changes of angle class Ⅱ division Ⅰ mandibular retraction patients during mixed dental period with MRC functional correction / 口腔疾病防治

Objective @#To observe the changes of soft tissue in patients with Angle class Ⅱ division Ⅰ malocclusion during mixed dentition treated with MRC functional appliance.@* Methods @# Twenty patients with Class Ⅱ division Ⅰ malocclusion of Angle were treated with functional MRC. The facial features before and after treatment were measured by software and the results were analyzed statistically. @*Results@#The patients′soft tissue profiles were improved significantly before and after treatment, The OE-Prn-Pos angle, OE-N′-B′ angle, OE-N′-Pos angle, OE-Prn-N′angle, Cm-Sn-UL angle, and N′-Sn-Pos angle increased significantly (P < 0.05). The OE-Sn-UL angle, and Sn-N′-B′ angle decreased significantly (P < 0.05); the distance between the lateral soft tissue line and the middle Sn-H line, UL-E line and LL-E line were significantly different (P < 0.05). The distances were all reduced, and the difference was statistically significant (P < 0.05).@* Conclusion @#The application of an MRC functional appliance can improve the relationship among nasolabial soft tissue, upper and lower lip soft tissue, and chin-lip soft tissue, thus improving the protrusion profile of patients.

Effect of Clark's twin-block appliance (CTB) and non-extraction fixed mechano-therapy on the pharyngeal dimensions of growing children

Abstract Introduction: Narrow airway dimensions due to mandibular deficiency can predispose an individual to severe respiratory distress. Hence, treatment with mandibular advancement devices at an early age might help improving the pharyngeal passage and reduce the risk of respiratory difficulties. Therefore, the aim of the current study was to evaluate the mean changes in the pharyngeal dimensions of children with mandibular deficiency treated with Clark's twin-block appliance (CTB) followed by fixed orthodontic treatment. Methods: Orthodontic records of 42 children with mandibular deficiency were selected. Records comprised three lateral cephalograms taken at the start of CTB treatment, after CTB removal and at the end of fixed appliance treatment, and were compared with 32 controls from the Bolton-Brush study. Friedman test was used to compare pre-treatment, mid-treatment and post-treatment pharyngeal dimensions. Wilcoxon signed rank test was used to compare the airway between pre-treatment and post follow-up controls. Mann-Whitney U test was applied to compare the mean changes in pharyngeal dimensions between treatment group and controls from T2 to T0. Post-hoc Dunnet T3 test was used for multiple comparisons of treatment outcomes after CTB and fixed appliances, taking a p-value of ≤ 0.05 as statistically significant. Results: Superior pharyngeal space (p < 0.001) and upper airway thickness (p = 0.035) were significantly increased after CTB, and the change in superior pharyngeal space remained stable after fixed mechano-therapy. Conclusion: CTB can have a positive effect in improving pharyngeal space and the resultant increase in airway remains stable on an average of two and a half years.

Resumo Introdução: a redução nas dimensões das vias aéreas causada pela deficiência mandibular pode predispor um indivíduo a dificuldades respiratórias severas. Assim, o tratamento com aparelhos de avanço mandibular na infância pode contribuir para melhorar a via aérea faríngea e reduzir o risco de problemas respiratórios. Objetivo: o objetivo do presente estudo foi avaliar as alterações médias nas dimensões da faringe de crianças com deficiência mandibular tratada com o aparelho Twin Block (TBC) seguido pelo tratamento ortodôntico fixo. Métodos: a documentação ortodôntica de 42 crianças com deficiência mandibular, consistindo de três telerradiografias de perfil - tiradas ao início do tratamento com TBC (T0), após a remoção do aparelho (T1) e ao final do tratamento ortodôntico fixo (T2) - foi selecionada e comparada à de 32 crianças controle do estudo Bolton-Brush. O teste de Friedman foi utilizado para comparar as dimensões da faringe antes, durante e após o tratamento. O teste de postos de Wilcoxon foi utilizado para comparar as vias aéreas antes do tratamento e depois do acompanhamento das crianças controle. O teste U de Mann-Whitney foi empregado para comparar as alterações médias nas dimensões da faringe entre o grupo tratado e as crianças controle, de T0 a T2. O teste T3 de Dunnett foi utilizado como post-hocpara realizar comparações múltiplas dos resultados do tratamento após o uso do TBC e dos aparelhos fixos, considerando-se como estatisticamente significativo um valor de p ≤ 0,05. Resultados: o espaço faríngeo superior (p < 0,001) e a espessura das vias aéreas superiores (p = 0,035) aumentaram significativamente após o uso do TBC, e a alteração no espaço faríngeo superior permaneceu estável após a mecanoterapia fixa. Conclusão: o TBC pode produzir um efeito positivo no espaço faríngeo, e aumento resultante nas vias aéreas permanece estável, em média, por dois anos e meio.

Mentoplastia para avanço do músculo genioglosso em pacientes com síndrome da apnéia-hipopnéia do sono obstrutiva e retrognatismo mandibular / Genioplasty for genioglossus muscle advancement in patients with obstructive sleep apnea-hypopnea syndrome and mandibular retrognathia

A Síndrome da Apnéia-Hipopnéia do Sono Obstrutiva (SAHSO) é um doença de fisiopatologia complexa, e sua etiologia é multifatorial e não entendida completamente. Cirurgia com avanço do músculo genioglosso é indicado em obstrução na região de hipofaringe. OBJETIVO: Avaliar a eficácia e complicações da técnica de mentoplastia para avanço do músculo genioglosso em pacientes com síndrome da apnéia-hipopnéia do sono obstrutiva (SAHSO). MÉTODOS: Polissonografia, exame físico e análise cefalométrica foram realizados em 10 pacientes não-obesos, que apresentavam SAHSO leve ou moderada, índice de apnéia-hipopnéia (IAH) entre 5 e 30, obstrução de hipofaringe e retrognatismo mandibular. RESULTADOS: IAH pré-operatório médio foi de 12,4±4,6 diminuindo a média pós-operatória para 4,4±5,7 (p < 0,001). Quando 50 por cento de redução do IAH pré-operatório foram escolhidos como parâmetro, o índice de sucesso foi de 70 por cento. A análise cefalométrica revelou um aumento do espaço aéreo posterior (EAP) em todos os pacientes, a média pré-operatória foi de 7,9±2,3mm para uma média pós-operatória de 10,8±2,5mm (p < 0,001). CONCLUSÃO: Mentoplastia para avanço do músculo genioglosso parece reduzir os sinais da SAHSO, podendo ser considerada uma opção com tratamento cirúrgico em pacientes com obstrução na hipofaringe. Os dados coletados indicam esse procedimento como opção em pacientes com SAHSO e retrognatismo mandibular.

Obstructive sleep apnea syndrome is a complex disease, which the etiology is multifactorial and incompletely understood. Surgery with genioglossus advancement is indicated in hypopharynx obstruction. AIM: evaluate the efficacy and complications of genioplasty technique for genioglossus muscle advancement in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: polysomnography, physical examination and cephalometric analysis were performed in 10 non-obese patients, who presented mild or moderate OSAHS, an apnea-hypopnea index (AHI) between 5 and 30, with hypopharynx obstruction and mandibular retrognathia. RESULTS: the AHI preoperative mean of 12.4±4.6 decreased to a postoperative mean of 4.4±5.7 (p < 0,001). When 50 percent reduction of preoperative AHI was chosen as a parameter, its rate was 70 percent (7/10). Cephalometric analysis revealed an increase in the posterior airway space (PAS) in all patients, from a preoperative mean value of 7.9±2.3mm to a postoperative mean value of 10.8±2.5mm (p < 0,001). CONCLUSION: genioplasty for genioglossus advancement seemed to reduce OSAHS signs, thus, it can be considered as an option for the surgical treatment of patients with hypopharynx obstruction. Data collected supports this surgical procedure as an option in patients with OSAHS and mandibular retrognathia.

Preparation and clinical application of mandibular protraction appliance / 中华医学美学美容杂志

Objective To design a mandibular protraction appliance and to observe its effect in the treatment of mandibular retrognathia with malocclusion of Angle class II and division I. Methods 30 cases of mandibular retrognathia with Angle class II and division I malocclusion were treated with the mandibular protraction and edgewise appliance. Cephalometric radiograph and measurement were taken before and after treatment. Statistical analysis were performed. Results After treatment, maxillary and mandibular anterior teeth were arranged in dental arch neatly. Molar relationship and overjet and overbite were returned normal. SNB, ANB angle and Co-Po, Iis-SP, Mis-SP were remarkably changed. Conclusion The mandibular protraction appliance is an orthopedic force applicance. It can effectively induce forward movement of mandible and in the meantime restrain maxillary growth. It is feasible for the treatment of mandibular retrognathia.