Discrepancia negativa transversal del maxilar y diferencias cefalométricas laterales según el ancho de la arcada superior / Negative maxillary transverse discrepancy and cephalometric lateral differences according to the width of upper arch

Introduction: Negative maxillary transverse discrepancy is not exclusive to narrow upper arch. The transverse discrepancy due to maxillary deficiency is well described, but this is not the case when the maxilla displays adequate dimensions and the origin of the problem is an excess of mandibular width. Objective: To describe the cephalometric characteristics of negative maxillary transverse discrepancy present in narrow upper arches with those of normal or increased width. Methods: An observational and cross-sectional study was carried out in records of patients with negative maxillary transverse discrepancy. The cases referred to the maxillofacial surgery department at Hospital Clínico Quirúrgico "Hermanos Ameijeiras" between January 2016 and January 2020 were selected. The initial study models were measured and two groups were formed: those with a distance between central fossae of 16 to 26, less than 47 mm and the other with equal or greater values. Lateral cephalometric analysis of Ricketts, McNamara, Björk & Jarabak, Burstone and soft profile were performed on the initial teleradiographs. Using the Mann Whitney U test of independent samples, measurements with statistically significant differences between both groups were selected. (p <0.05). Results: Significant differences were found regarding the cranial-mandibular relationship, mandibular anatomy, maxillo-mandibular relationship and occlusal relationship. The most important differences observed in each group were respectively: S-Ar / Ar-Go ratio (p = 0.033), mandibular body length (p = 0.01), mandibular-maxillary difference (p = 0.003) and overjet (p = 0.043). Conclusions: In the studied patients, negative maxillary transverse discrepancy has the same probability of presenting a wide or in norm upper arch, as well as a narrow arch. In the first case, it is more likely to find jaws with increased body length, a skeletal class III pattern and a concave profile; in the second case, the tendency is to present small jaws with increased articular angle and dental overjet(AU)

Introducción: La discrepancia negativa transversal del maxilar no es exclusiva de una arcada superior angosta. La discrepancia transversal por deficiencia maxilar está bien descrita, pero no ocurre así cuando el maxilar se presenta con dimensiones adecuadas y el origen del problema es un exceso del ancho mandibular. Objetivo: Describir las diferencias cefalométricas de la discrepancia negativa transversal del maxilar que presentan arcadas superiores estrechas con aquellas de ancho normal o incrementado. Métodos: Se realizó un estudio observacional, de corte transversal, en expedientes de pacientes con discrepancia negativa transversal del maxilar. Se seleccionaron los casos que acudieron entre enero del 2016 y enero del 2020 a la consulta de cirugía maxilofacial del Hospital Clínico Quirúrgico "Hermanos Ameijeiras". Se midieron los modelos de estudio iniciales y se conformaron dos grupos: aquellos con distancia entre fosas centrales de 16-26, menor de 47 mm y el otro con valores iguales o superiores. Se realizaron análisis cefalométricos laterales en las telerradiografías iniciales de Ricketts, McNamara, Björk & Jarabak, Burstone y perfil blando. Por medio de la prueba U de Mann Whitney de muestras independientes, se seleccionaron las mediciones con diferencias estadísticas significativas entre ambos grupos (p < 0.05). Resultados: Se encontraron diferencias significativas concernientes a la relación cráneo mandibular, anatomía mandibular, relación máxilo mandibular y relación oclusal. Las diferencias observadas más importantes de cada grupo fueron respectivamente: relación S-Ar/Ar-Go (p = 0,033), longitud del cuerpo mandibular (p = 0,01), diferencia mandibular-maxilar (p = 0,003) y resalte (p = 0,043). Conclusiones: En los pacientes estudiados, las discrepancias negativas transversales tienen la misma probabilidad de presentarse con la arcada superior ancha o en norma, que angosta. En los primeros es más probable encontrar mandíbulas con longitud del cuerpo incrementada, patrón de clase III esquelética y perfil cóncavo; en los segundos, la tendencia es a presentar mandíbulas pequeñas con ángulo articular y resalte dentario aumentados(AU)

Osteotomía Le Fort III modificada en un paciente no sindrómico / Modified Le Fort III osteotomy in a non-syndromic patient

Las discrepancias dento-esqueletales severas presentan un reto para el cirujano maxilofacial, existe una versatilidad de osteotomías para las diferentes anomalías del crecimiento y desarrollo, sin embargo, son pocas las que permiten mejorar la proyección malar. La osteotomía Le Fort III modificada fue utilizada en un principio en pacientes con algún síndrome craneofacial, pero actualmente es una alternativa útil para discrepancias severas en pacientes no sindrómicos, ya que permite un avance cigomático-maxilar, favorece la proyección malar y disminuye la exposición escleral con un número limitado de complicaciones. Se presenta el caso de un paciente masculino de 33 años con antecedente de fractura orbitocigomática y piso orbitario izquierda con una discrepancia dento-esqueletal severa, la que fue tratada mediante osteotomía Le Fort III modificada, osteotomías sagitales mandibulares para un avance máxilo-malar y retroceso mandibular respectivamente y una genioplastia de avance; logrando un resultado funcional y estético adecuado.

The dento-skeletal severe discrepancies present a challenge for the maxillofacial surgeon, there is a versatility of osteotomies for the different growth and development anomalies, however, a few of them make possible to improve malar projection. The modified Le Fort III osteotomy was originally used in patients with some craniofacial syndrome, but now it is a useful alternative for severe discrepancies in non-syndromic patients, since it allows a zygomatic-maxillary advance, favors malar projection and reduces scleral exposure with a limited number of complications. The case of a 33-year-old male patient with a history of orbitozygomatic fracture and left orbital floor with a severe dento-skeletal discrepancy is presented, who was treated by modified Le Fort III osteotomy, mandibular sagittal osteotomies for maxillo-malar advancement and retrogression mandibular respectively and geniplasty for advance; achieving a suitable functional and aesthetic result.

Management of skeletal Class III with facial asymmetry using skeletal anchorage: 4-year follow-up

ABSTRACT Introduction: Skeletal Class III malocclusion with asymmetry is one of the most difficult problems to correct in orthodontics. A functional shift of the mandible in growing patients may occur accompanying a Class III, due to constricted maxillary arch and occlusal interferences. Studies have indicated that posterior unilateral crossbite develops early and has a low rate of spontaneous correction. It may further lead to development of mandibular and facial asymmetry by growth and displacement of mandible if left untreated in growing patients. Objective: This article reports the clinical case of a thirteen-year-old female patient in CVMI transition stage that had maxillary hypoplasia with a developing facial asymmetry. Results: The case was successfully managed with bone-anchored facemask therapy and with elimination of occlusal interferences with guided occlusion. Reverse twin block in the retention phase maintained the results achieved. Conclusion: A four-year follow-up evaluation revealed successful maintenance of the treatment results.

RESUMO Introdução: A má oclusão de Classe III esquelética com assimetria é um dos problemas mais difíceis de se corrigir na Ortodontia. O desvio funcional da mandíbula em pacientes em fase de crescimento pode ocorrer acompanhado da Classe III, devido à atresia maxilar e interferências oclusais. Estudos têm indicado que a mordida cruzada posterior unilateral se desenvolve precocemente e apresenta baixo índice de correção espontânea. Isso pode levar ao desenvolvimento de assimetria mandibular e facial, resultante do crescimento e deslocamento da mandíbula, caso os pacientes não sejam tratados na fase de crescimento. Objetivo: O presente artigo relata o caso clínico de uma paciente com treze anos de idade, com IMVC em estágio de transição e que apresentava hipoplasia maxilar com assimetria facial em desenvolvimento. Resultados: O caso foi tratado com sucesso por meio de terapia com máscara facial osseossuportada, eliminando as interferências oclusais por meio de uma oclusão guiada. O uso do aparelho Twin-block reverso como contenção preservou os resultados atingidos. Conclusão: O acompanhamento após quatro anos confirmou a manutenção dos resultados do tratamento.

Skeletal Class III malocclusion treatment using mandibular and maxillary skeletal anchorage and intermaxillary elastics: a case report

ABSTRACT Introduction: Skeletal Class III malocclusion is one of the most challenging malocclusions to treat. In around 40% of Class III patients, maxillary retrognathia is the main cause of the problem and in most patients, orthopedic/surgical treatments includes some type of maxillary protraction. Objective: The aim of this case report was to describe a treatment method for a patient with maxillary retrognathia and Class III skeletal discrepancy using mandibular and maxillary skeletal anchorage with intermaxillary elastics. Case report: A 13-year-old boy with maxillary retrognathia and mandibular prognathism was treated using bilateral miniplates. Two miniplates were inserted in the mandibular canine area and two other miniplates were placed in the infrazygomatic crests of the maxilla. Class III intermaxillary elastics were used between the miniplates. Results: After eight months of orthopedic therapy, ANB angle increased by 4.1 degrees and ideal overjet and overbite were achieved. Mandibular plane angle was increased by 2.1 degrees and the palatal plane was rotated counterclockwise by 4.8 degrees. Conclusion: This case showed that the skeletal anchorage treatment method may be a viable option for treating patients with Class III skeletal malocclusion.

RESUMO Introdução: a Classe III esquelética é considerada uma das más oclusões mais difíceis de se tratar. Em cerca de 40% dos pacientes afligidos por ela, a principal causa do problema é o retrognatismo maxilar e, na maioria desses pacientes, o tratamento ortopédico/cirúrgico inclui algum tipo de protração da maxila. Objetivo: o objetivo do presente relato de caso é descrever o método de tratamento de um paciente Classe III com discrepância esquelética e retrognatismo maxilar, usando elásticos intermaxilares e ancoragem esquelética superior e inferior. Relato de caso: paciente de 13 anos de idade, com retrognatismo maxilar e prognatismo mandibular, tratado com miniplacas inseridas bilateralmente. Duas miniplacas foram instaladas na região dos caninos inferiores, e outras duas miniplacas foram inseridas na região da crista infrazigomática maxilar. Elásticos intermaxilares de Classe III foram conectados às miniplacas. Resultados: após 8 meses de tratamento ortopédico, o ângulo ANB aumentou 4,1o e obteve-se sobressaliência e sobremordida ideais. O ângulo do plano mandibular aumentou 2,1o e o plano palatal girou 4,8o no sentido anti-horário. Conclusão: esse caso clínico demonstrou que o método de tratamento com ancoragem esquelética pode ser uma opção válida para pacientes com má oclusão de Classe III esquelética.