Avaliação mecânica de diferentes tipos de fixação para osteotomia Le Fort I após grande avanço maxilar / Evaluation biomechanical of different types of fixation for Le Fort I osteotomy after major maxillary advancement

Objetivo: Avaliar a estabilidade mecânica de quatro métodos de osteossíntese na maxila após um avanço linear de 11mm. Materiais e Métodos: Foram realizadas osteotomias Le Fort I em 20 modelos de resinas da região do terço médio da face e divididos em quatro grupos que receberam diferentes tipos de osteossíntese na região anterior, pois todos os grupos receberam uma placa "L" (PL) do sistema 2.0 de quatro furos na região posterior, sendo eles: grupo I, placas Lindorf (PLf), grupo II: placas Lindorf modificada (PLfM), grupo III placas em "T" invertido (PTi) e grupo IV: placas PL. Uma máquina universal de testes mecânicos (EMIC ­ Linha DL) foi usada para o ensaio mecânico. As amostras foram acopladas a um suporte metálico, especialmente desenvolvido para o teste, e foram posicionadas na máquina EMIC e submetidas a uma carga linear axial na linha média entre os incisivos centrais com velocidade de 1 mm/min, até o deslocamento em 5mm. Os dados obtidos em newtons (N), tempo de aplicação da força e quantidade de deformação foram computados pelo software Bluehill 2 (2004) interligado à EMIC e então, foram calculados os dados de energia exigida para deslocamento e rigidez de cada material que foram submetidos à análise estatística pelo software SPSS/PC 20.0 (Chicago, USA) e foi realizado o teste t para amostra independentes (ANOVA) e o limite de significância estatística foi P<0,05. Resultados: O grupo I e II apresentaram maior resistência ao deslocamento (P< 0,05) quando comparado aos demais grupos. Sendo assim, o sistema de fixação dos grupos I e II promoveu uma melhor estabilidade dos segmentos em comparação com os demais sistemas de fixação no avanço maxilar de 11mm, quando submetido a uma carga axial linear na linha média dos incisivos centrais. Conclusão: Para grandes avanços lineares da maxila o sistema de fixação com maior resistência à deformação é com a utilização de placas do tipo PLfM seguido PLf na região anterior e do tipo PL na região posterior bilateralmente(AU)

Objective: The aim of the study was evaluate the mechanical stability of four methods of osteosynthesis in the maxilla after a linear advance of 11mm. Materials and Methods: Le Fort I osteotomies were performed on 20 resin models in the middle third of the face and divided into four groups that received different types of osteosynthesis in the anterior region, as all groups received an "L" (PL) plate of the 2.0 system with four holes in the posterior region, which are: group I, Lindorf plates (PLf), group II: modified Lindorf plates (PLfM), group III inverted "T" plates (PTi) and group IV: PL plates. A universal mechanical testing machine (EMIC - DL Line) was used for the mechanical test. The samples were attached to a metallic support, specially developed for the test, and were positioned on the EMIC machine and subjected to an axial linear load in the midline between the central incisors at a speed of 1 mm / min, until the displacement at 5 mm. The data obtained in newtons (N), force application time and amount of deformation were computed by the software Bluehill 2 (2004) connected to EMIC and then, the data of energy required for displacement and stiffness of each material that were submitted were calculated. statistical analysis using SPSS / PC 20.0 software (Chicago, USA) and the t test for independent samples (ANOVA) was performed and the limit of statistical significance was p<0.05. Results: Group I and II showed greater resistance to displacement (p<0.05) when compared to the other groups. Thus, the fixation system of groups I and II promoted a better stability of the segments in comparison with the other fixation systems in the maxillary advance of 11mm, when subjected to a linear axial load in the midline of the central incisors. Conclusion: For large linear advances of the maxilla, the fixation system with greater resistance to deformation is with the use of PLfM plates followed by PLf in the anterior region and PL type in the posterior region bilaterally(AU)

Cambios Faciales y su Estabilidad en el Tiempo en Pacientes con Fisura Labiopalatina no Sindrómica Sometidos a Distracción Osteogénica Maxilar con Distractor Externo Rígido. Revisión Narrativa / Facial Changes and their Stability over Time in Non-Syndromic Cleft Lip and Palate Patients Undergoing Maxillary Distraction Osteogenesis Through Rigid External Distractor. Narrative Review

RESUMEN: Las fisuras labiopalatinas corresponden a las malformaciones de cabeza y cuello de mayor prevalencia a nivel mundial; dentro de las cuales, aquellas que no están asociadas a síndrome son las más frecuentes. Los pacientes que sufren estas malformaciones presentan en muchos casos hipoplasia maxilar. La distracción osteogénica maxilar mediante distractor externo rígido constituye una alternativa de tratamiento para la corrección de esta deficiencia esqueletal. Describir los cambios faciales y su estabilidad en el tiempo, en pacientes con fisura labio palatina no sindrómica sometidos a distracción osteogénica maxilar con distractor externo rígido. Se realizó una búsqueda estratégica en las bases de datos PubMed, Epistemonikos, EBSCO, BEIC y The Cochrane Library a través de las palabras clave cleft palate; cleft lip and palate; distraction osteogenesis; osteodistraction; callotasis; callotases; callus distraction, maxillary hypoplasia; midface hypoplasia; hypoplastic maxilla; maxillary deficiency; retromaxilla y maxillary retrognatism; con los términos booleanos AND y OR. Se seleccionaron 20 artículos: 2 revisiones sistemáticas, 3 ensayos clínicos, 14 estudios observacionales descriptivos y 1 estudio observacional analítico. La distracción osteogénica maxilar con distractor externo rígido corresponde a una alternativa efectiva en el tratamiento de la retrusión del tercio medio en pacientes con fisura labiopalatina no sindrómica. Esta técnica, sin embargo, no consigue cambios completamente estables, existiendo múltiples factores relacionados con su recidiva.

ABSTRACT: Cleft lip and palate is the world's most prevalent head and neck malformation, within which, nonsyndromic is the most frequent. Patients with this malformation in many cases present maxillary hypoplasia. Maxillary distraction osteogenesis through a rigid external distractor constitutes an alternative to correct this skeletal deficiency. The objective of this study was to describe facial changes and their stability over time in non-syndromic cleft lip and palate patients undergoing distraction osteogenesis through rigid external distractor. An electronic search was carried out in PubMed database, Epistemonikos, EBSCO, BEIC and The Cochrane Library through the keywords cleft palate; cleft lip and palate; distraction osteogenesis; osteodistraction; callotasis; callotases; callus distraction, maxillary hypoplasia; midface hypoplasia; hypoplastic maxilla; maxillary deficiency; retromaxilla and maxillary retrognatism, related to each other with the Boolean terms AND and OR. For this analysis 20 articles were selected: 2 systematic reviews, 3 clinical trials, 14 descriptive observational studies and 1 analytic observational study. Maxillary distraction osteogenesis through rigid external distractor is an effective alternative in the treatment of midface retrusion in non-syndromic cleft lip and palate patients. However, this technique does not completely achieve stable changes, due to multiple factors related to its recurrence.

Le Fort I osteotomy as treatment for traumatic class III malocclusion caused by Le Fort III fracture: A case report

Trauma in the modern society is characterized by multiple injuries, and the several comorbidities are often accompanied by facial bone fracture. The types of multiple facial bone fractures vary from Le Fort to panfacial fracture. Le Fort fracture, which can cause problems, such as facial disfigurement, functional impairment of mastication, malocclusion and speech abnormalities, is a challenging case for plastic surgeons. The purpose of treatment for patients with malocclusion due to Le Fort fracture is to maintain and restore both function and aesthetics. The author reports a case of Le Fort I osteotomy as a surgical correction of traumatic class III malocclusion due to Le Fort III fracture.

Concepts, protocol, variations and current trends in surgery first orthognathic approach: a literature review

ABSTRACT In the current era of expedited orthodontics, among many clinicians, tertiary care hospitals and patients, surgery first orthognathic approach (SFOA) has gained popularity. The advantages of SFOA (face first approach) are the reduced overall treatment duration and the early improvement in facial esthetics. In SFOA, the absence of a presurgical phase allows surgery to be performed first, followed by comprehensive orthodontic treatment to achieve the desired occlusion. The basic concepts of surgery early, surgery last, SFOA and Sendai SFOA technique along with its variations are reviewed in the present article. The recent advancement in SFOA in the context of preoperative preparation, surgical procedures and post-surgical orthodontics with pertinent literature survey are also discussed.

RESUMO Na presente era da Ortodontia de resultados acelerados, a cirurgia ortognática com benefício antecipado (COBA) ganhou popularidade entre muitos clínicos, hospitais terciários e pacientes. A vantagem da COBA é a redução da duração total do tratamento, juntamente com a melhora precoce da estética facial. Na COBA, a ausência de uma fase pré-cirúrgica permite que a cirurgia seja realizada antes e, só então, venha o tratamento ortodôntico abrangente para se alcançar a oclusão desejada. Os conceitos básicos de cirurgia primeiro, cirurgia por último, COBA e a técnica COBA de Sendai, bem como suas variações, são aqui revistos. Também são discutidos no presente artigo, junto com a revisão da literatura pertinente, os recentes avanços da COBA no contexto do preparo pré-cirúrgico, dos procedimentos cirúrgicos e da Ortodontia pós-cirúrgica.

The Effect of a Condylar Repositioning Plate on Condylar Position and Relapse in Two-Jaw Surgery

BACKGROUND: Numerous condylar repositioning methods have been reported. However, most of them are 2-dimensional or are complex procedures that require a longer operation time and a highly trained surgeon. This study aims to introduce a new technique using a condylar repositioning plate and a centric relation splint to achieve a centric relationship. METHODS: We evaluated 387 patients who had undergone surgery for skeletal jaw deformities. During the operation, a centric relation splint, intermediate splint, final centric occlusion splint, and condylar repositioning plate along with an L-type mini-plate for LeFort I osteotomy or a bicortical screw for bilateral sagittal split ramus osteotomy were utilized for rigid fixation. The evaluation included: a physical examination to detect preoperative and postoperative temporomandibular joint dysfunction, 3-dimensional computed tomography and oblique transcranial temporomandibular joint radiography to measure 3-dimensional condylar head movement, and posteroanterior and lateral cephalometric radiography to measure the preoperative and postoperative movement of the bony segment and relapse rate. RESULTS: A 0.3% relapse rate was observed in the coronal plane, and a 2.8% relapse rate in the sagittal plane, which is indistinguishable from the dental relapse rate in orthodontic treatment. The condylar repositioning plate could not fully prevent movement of the condylar head, but the relapse rate was minimal, implying that the movement of the condylar head was within tolerable limits. CONCLUSIONS: Our condylar repositioning method using a centric relation splint and mini-plate in orthognathic surgery was found to be simple and effective for patients suffering from skeletal jaw deformities.

Retiform hemangioendothelioma in the infratemporal fossa and buccal area: a case report and literature review

We report a case of retiform hemangioendothelioma (RH) located in the infratemporal fossa and buccal area in a 13-year-old Korean boy. The tumor originated from the sphenoid bone of the infratemporal fossa area and spread into the cavernous sinus, orbital apex, and retro-nasal area with bone destruction of the pterygoid process. Tumor resection was conducted via Le Fort I osteotomy and partial maxillectomy to approach the infratemporal fossa and retro-nasal area. The diagnosis of RH was confirmed after surgery. In the presented patient, surgical excision was incomplete, and close follow-up was performed. There was no evidence of expansion or metastasis of the residual tumor in the 8 years after surgery. In cases of residual RH with low likelihood of expansion and metastasis, even though RH is an intermediate malignancy, close follow-up can be the appropriate treatment choice over additional aggressive therapy. To date, 29 papers and 48 RH cases have been reported, including this case. This case is the second reported RH case presenting as primary bone tumor and the first case originating in the oromaxillofacial area.

Salvage rapid maxillary expansion for the relapse of maxillary transverse expansion after Le Fort I with parasagittal osteotomy

Maxillary transverse deficiency is one of the most common deformities among occlusal discrepancies. Typical surgical methods are segmental Le Fort I osteotomy and surgically-assisted rapid maxillary expansion (SARME). This patient underwent a parasagittal split with a Le Fort I osteotomy to correct transverse maxillary deficiency. During follow-up, early transverse relapse occurred and rapid maxillary expansion (RME) application with removal of the fixative plate on the constricted side was able to regain the dimension again. RME application may be appropriate salvage therapy for such a case.

Two Cases of Epiphora Following Le Fort I Osteotomy / 대한이비인후과학회지

The lacrimal drainage system begins at the puncta and empties through the valve of Hasner into the inferior meatus. The varieties of the anatomic location, size and morphology of this valve can predispose susceptible individuals to an increased incidence of iatrogenic injury during nasal surgical procedures, thus necessitating a comprehensive understanding of the system. We report two cases of epiphora following two-jaw surgeries for cosmetic purposes. Nasolacrimal duct obstructions were diagnosed, and the symptoms were improved with dacryocystorhinostomies.

Stability of bimaxillary surgery on Class III malocclusion treatment

OBJECTIVE: To evaluate the stability of bimaxillary surgery in patients with skeletal malocclusion, with the use of rigid internal fixation. METHODS: Lateral cephalograms from 20 patients, 11 males and 9 females, mean age of 26 years and 1 month, were evaluated before surgery, immediately post-operative and at least 6 months after surgery. Nineteen cephalometric measurements were evaluated, and the results were statistically analyzed by means of the Student's t test and the Kruskal-Wallis test. RESULTS: The Le Fort I maxillary advancement surgery showed almost no relapse. There was lack of stability of mandibular setback, with relapse of 37.33% on point B, due to counterclockwise rotation of the mandible between post-operative periods, occurred by better intercuspation after surgery and muscle adaptation. The results showed the same tendencies for both genders. CONCLUSION: It was concluded that on the bimaxillary surgery treatment of Class III malocclusion, the maxillary surgery was very stable, but the mandibular setback recurred. No statistical differences were found in surgical stability between genders.

OBJETIVO: avaliar a estabilidade da cirurgia combinada de maxila e mandíbula em pacientes com má oclusão esquelética de Classe III com a utilização de fixação interna rígida. MÉTODOS: utilizaram-se telerradiografias obtidas em norma lateral de 20 pacientes, sendo 11 do sexo masculino e 9 do feminino, com média de idade de 26 anos e 1 mês, avaliados antes da cirurgia, no pós-operatório imediato e no mínimo 6 meses após a cirurgia. Avaliaram-se dezenove grandezas cefalométricas e os resultados foram analisados estatisticamente por meio do teste t de Student e da análise de Kruskal-Wallis. RESULTADOS: a cirurgia de avanço maxilar praticamente não apresentou recidiva. Ocorreu perda de estabilidade do recuo mandibular, com recidiva de 37,33% no ponto B, devido ao giro anti-horário da mandíbula entre os períodos pós-operatórios, ocorrido pela melhor intercuspidação pós-cirúrgica e adaptação muscular. Os resultados apresentaram as mesmas tendências para ambos os sexos. CONCLUSÃO: concluiu-se que no tratamento cirúrgico combinado da má oclusão de Classe III, o procedimento realizado na maxila mostrou-se muito estável, já o recuo mandibular apresentou recidiva. Não evidenciou-se diferenças estatísticas na estabilidade cirúrgica entre os sexos.

Stability and Considerations of Total Maxillary Setback Le Fort I Osteotomy for the Correction of Maxillary Protrusion

Perceptual Speech Assessment after Maxillary Advancement Osteotomy in Patients with a Repaired Cleft Lip and Palate

BACKGROUND: Maxillary hypoplasia refers to a deficiency in the growth of the maxilla commonly seen in patients with a repaired cleft palate. Those who develop maxillary hypoplasia can be offered a repositioning of the maxilla to a functional and esthetic position. Velopharyngeal dysfunction is one of the important problems affecting speech after maxillary advancement surgery. The aim of this study was to investigate the impact of maxillary advancement on repaired cleft palate patients without preoperative deterioration in speech compared with non-cleft palate patients. METHODS: Eighteen patients underwent Le Fort I osteotomy between 2005 and 2011. One patient was excluded due to preoperative deterioration in speech. Eight repaired cleft palate patients belonged to group A, and 9 non-cleft palate patients belonged to group B. Speech assessments were performed preoperatively and postoperatively by using a speech screening protocol that consisted of a list of single words designed by Ok-Ran Jung. Wilcoxon signed rank test was used to determine if there were significant differences between the preoperative and postoperative outcomes in each group A and B. And Mann-Whitney U test was used to determine if there were significant differences in the change of score between groups A and B. RESULTS: No patients had any noticeable change in speech production on perceptual assessment after maxillary advancement in our study. Furthermore, there were no significant differences between groups A and B. CONCLUSIONS: Repaired cleft palate patients without preoperative velopharyngeal dysfunction would not have greater risk of deterioration of velopharyngeal function after maxillary advancement compared to non-cleft palate patients.

Osteotomia le fort i: aspectos de interesse no tratamento de nasoangiofibroma juvenil / Le fort i osteotomy: interest aspects in juvenile nasoangiobibroma management

O angiofibroma nasofaríngeo é um tumor benigno, de caráter fibrovascular e de ocorrência rara. Apresenta característica localmente agressiva e destrutiva e acomete, quase que exclusivamente, homens, com predileção pela fase da adolescência. O diagnóstico é feito por meio de exame clínico e de imagens, sendo contraindicada a biópsia incisional devido ao risco elevado de sangramento de difícil controle. O tratamento é a completa excisão cirúrgica, sendo a radioterapia reservado para os casos de recidivas e tumores extensos com vascularização incomum ou extensão intracraniana. Os acessos cirúrgicos utilizados para ressecção desse tumor incluem a abordagem transmaxilar (le fort I), transantral, transpalatal, combinada, endoscópica e outras. O trabalho aborda um relato de caso, relacionando os aspectos de interessa da osteotomia Le For I, suas vantagens e desvantagens no tratamento do Angiofibroma Juvenil Nasofaríngeo.

Nasopharyngeal angiofibroma is a rare and benign tumor that has a fibrovascular feature. It has been locally aggressive and destructive that affects almost exclusively male, especially on teens.The diagnosis has done by clinical examination and radiography, but incisional biopsy is contraindicated due to risk of bleeding with difficult control. The recommended approach has been a wide surgical excision with radiotherapy being reserved for cases of recurrence and tumor vasculature with unusual or extensive intracranial extension. The surgical approaches used for resection of these tumors include the approach transmaxillary (le fort I), transnasal, transpalatal, combined endoscopic and others. The paper addresses a case report, listing the aspects of the interest of Le Fort I osteotomy, advantages and disadvantages in the treatment of Juvenile Nasopharyngeal Angiofibroma.

Positional Changes of the Internal Reference Points Followed by Reposition of the Maxilla: A Study of a 3D Virtual Surgery Program

Soft tissue changes of upper lip and nose following posterosuperior rotation of the maxilla by Le Fort I osteotomy

INTRODUCTION: This study evaluate the soft tissue changes to the upper lip and nose after Le Fort I maxillary posterosuperior rotational movement. MATERIALS AND METHODS: Twenty Skeletal class III patients, who had undergone bimaxillary surgery with a maxillary Le Fort I osteotomy and bilateral sagittal split ramus osteotomy, were included in the study. The surgical plan for maxilla was posterosuperior rotational movement, with the rotation center in the anterior nasal spine (ANS) of maxilla. Soft and hard tissue changes were measured by evaluating the lateral cephalograms obtained prior to surgery and at least 6 months after surgery. For cephalometric analysis, four hard tissue landmarks ANS, posterior nasal spine [PNS], A point, U1 tip), and five soft tissue landmarks (pronasale [Pn], subnasale [Sn], A' Point, upper lip [UL], stomion superius [StmS]) were marked. A paired t test, Pearson's correlation analysis and linear regression analysis were used to evaluate the soft and hard tissue changes and assess the correlation. A P value <0.05 was considered significant. RESULTS: The U1 tip moved 2.52+/-1.54 mm posteriorly in the horizontal plane (P<0.05). Among the soft tissue landmarks, Pn moved 0.97+/-1.1 mm downward (P<0.05), UL moved 1.98+/-1.58 mm posteriorly (P<0.05) and 1.18+/-1.85 mm inferiorly (P<0.05), and StmS moved 1.68+/-1.48 mm posteriorly (P<0.05) and 1.06+/-1.29 mm inferiorly (P<0.05). The ratios of horizontal soft tissue movement to the hard tissue were 1:0.47 for the A point and A' point, and 1:0.74 for the U1 tip and UL. Vertically, the movement ratio between the A point and A' point was 1:0.38, between U1 tip and UL was 1:0.83, and between U1 tip and StmS was 1:0.79. CONCLUSION: Posterosuperior rotational movement of the maxilla in Le Fort I osteotomy results in posterior and inferior movement of UL. In addition, nasolabial angle was increased. Nasal tip and base of the nose showed a tendency to move downward and showed significant horizontal movement. The soft tissue changes in the upper lip and nasal area are believed to be induced by posterior movement at the UL area.

Study about the relationship between the amount of posterior impaction and the change of occlusal plane angle and incisor inclination in Le Fort I osteotomy

INTRODUCTION: In the management of dentofacial deformities, variable movement of the maxilla can be made possible by a Le Fort I osteotomy. Posterior impaction of the maxilla necessary for rotation of the maxillomandibular complex enhances the functions and esthetic results. In cases of posterior impaction of the maxilla, an increase in the figure of the occlusal plane angle and incisor inclination can occur. This study reports the relationship between the amount of posterior impaction and the change in the occlusal plane angle and incisor inclination in a Le Fort I osteotomy by preoperative and postoperative lateral cephalograms. MATERIALS AND METHODS: Twenty patients who had undergone orthognathic surgery in Dong-A University Medical Center participated in this study. Lateral cephalometrics, within 3 weeks prior to surgery and 3 days after surgery, were used for analysis. Pre and postoperative measurements of the occlusal plane angle and incisal inclination based on the Frankfort horizontal (FH) plane were performed. X and Y were defined as the amount of vertical change in the upper incisor tip and the amount of vertical change in the upper first molar mesial cup tip through the operation. The amount of final posterior maxillary impaction was determined by subtracting Y from X, which is the difference in vertical height. According to the amount of posterior maxillary impaction, the change in the occlusal plane angle and incisal inclination was measured. RESULTS: The average posterior maxillary impaction was 2.91 mm and the average change in the occlusal plane angle and incisal inclination was 6.54degrees after surgery. As a result, each mm of posterior maxillary impaction changed the occlusal plane angle and incisal inclination by 2.25degrees. Statistically, there was high significance. Two cases were observed: one with the same amount of posterior maxillary impaction performed on both the right and left showing 2.20degrees, and the other with a different amount of posterior maxillary impaction performed showing 2.35degrees. In this case, there was no significance difference between the two cases. CONCLUSION: Each mm of posterior maxillary impaction changes the occlusal plane angle and incisal inclination by an average of 2.25degrees. In posterior maxillary impaction, there was no significant difference in the amount of change in the occlusal plane angle and incisal inclination regardless of whether there was an equal amount of posterior maxillary impaction on both sides. This study is expected to help in the presurgical orthodontic preparation and presurgical treatment planning.