Avaliação da fixação dos avanços maxilares pela técnica de osteotomia Le Fort I / Evaluación de la fijación de avances maxilar mediante la técnica de osteotomía Le Fort I / Evaluation of the fixation of maxillary advancements by the Le Fort I osteotomy technique

Introdução: A osteotomia Le Fort I possibilita a correção de deformidades dentofaciais que envolvem o terço médio da face. Para sua fixação, convencionou-se o emprego de quatro mini-placas nos pilares zigomático-maxilar e nasomaxilar. Propôs-se então, a dispensa da fixação do segmento posterior, surgindo questionamentos relacionados à capacidade biomecânica do sistema. Objetivos: Comparar o estresse biomecânico gerado em três meios distintos de fixação da osteotomia Le Fort I frente ao movimento de avanço sagital linear maxilar de 7mm. Metodologia: Trata-se de uma pesquisa experimental laboratorial, utilizando-se da análise de elementos finitos como ferramenta analítica, a fim de constatar qual das técnicas sofrerá maior estresse biomecânico. Resultados: Constatou-se que o estresse biomecânico gerado é maior quando aplicado em 4 pontos do que quando aplicado em apenas 2 pontos. Conclusão: Os resultados obtidos fornecem informações aos cirurgiões sobre a real necessidade do uso de fixação adicional de acordo com o método de fixação planejado. No entanto, deve ser interpretado de forma cautelosa, considerando-se as limitações deste estudo. Sendo assim, uma análise incipiente, que tem como intuito o fornecimento de evidência científica de grande significância.

Introducción: La osteotomía Le Fort I permite la corrección de deformidades dentofaciales que involucran el tercio medio de la cara. Para su fijación se acordó utilizar cuatro miniplacas en los pilares cigomaticomaxilar y nasomaxilar. Entonces se propuso prescindir de la fijación del segmento posterior, planteando interrogantes relacionados con la capacidad biomecánica del sistema. Objetivos: Comparar el estrés biomecánico generado en tres medios diferentes de fijación de la osteotomía Le Fort I frente a un movimiento de avance sagital lineal maxilar de 7mm. Metodología: Se trata de una investigación experimental de laboratorio, utilizando como herramienta analítica el análisis de elementos finitos, con el fin de comprobar cuál de las técnicas sufrirá un mayor estrés biomecánico. Resultados: Se encontró que el estrés biomecánico generado es mayor cuando se aplica en 4 puntos que cuando se aplica solo en 2 puntos. Conclusión: Los resultados obtenidos brindan información a los cirujanos sobre la necesidad real de utilizar fijación adicional de acuerdo al método de fijación planificado. Sin embargo, debe interpretarse con cautela, considerando las limitaciones de este estudio. Por tanto, un análisis incipiente, que pretende aportar evidencias científicas de gran trascendencia.

Introduction: The Le Fort I osteotomy allows the correction of dentofacial deformities involving the middle third of the face. For its fixation, it was agreed to use four mini plates on the zygomaticomaxillary and nasomaxillary pillars. It was then proposed to dispense with the fixation of the posterior segment, raising questions related to the biomechanical capacity of the system. Objectives: To compare the biomechanical stress generated in three different means of fixation of the Le Fort I osteotomy against a 7mm maxillary linear sagittal advancement movement. Methodology: This is an experimental laboratory research, using finite element analysis as an analytical tool, in order to verify which of the techniques will suffer greater biomechanical stress. Results: It was found that the biomechanical stress generated is greater when applied to 4 points than when applied to only 2 points. Conclusion: The results obtained provide information to surgeons about the real need to use additional fixation according to the planned fixation method. However, it should be interpreted with caution, considering the limitations of this study. Therefore, an incipient analysis, which aims to provide scientific evidence of great significance.

Application and development of orthognathic surgery in treatment of syndromic craniosynostosis / 中国修复重建外科杂志

OBJECTIVE@#To summarize the application and recent development of orthognathic surgery in treating syndromic craniosynostosis.@*METHODS@#The related literature at home and abroad in recent years was extensively reviewed, and the indications, routine procedures, and protocols of orthognathic surgery in the treatment of syndromic craniosynostosis were summarized and analyzed.@*RESULTS@#Craniosynostosis is a common congenital craniofacial malformation. Syndromic craniosynostosis usually involves premature fusion of multiple cranial sutures and is associated with other deformities. Orthognathic surgery is the necessary and effective means to improve the midfacial hypoplasia and malocclusion. Le Fort I osteotomy combined with sagittal split ramus osteotomy are the common surgical options. Orthognathic surgery should combine with craniofacial surgery and neurosurgery, and a comprehensive long-term evaluation should be conducted to determine the best treatment plan.@*CONCLUSION@#Orthognathic surgery plays an important role in the comprehensive diagnosis and treatment of syndromic craniosynostosis. The development of digital technology will further promote the application and development of orthognathic surgery in the treatment of syndromic craniosynostosis.

Anatomical control of the lower nasal width in Le Fort I osteotomy / Control anatómico del ancho nasal inferior en osteotomía Le Fort I

SUMMARY: The aim of this research is to show a simple technique to obtain control in the alar base width in Le Fort I osteotomy. The technique was used in eighteen patients submitted to maxillary impaction and/or advancements (≥ 3 mm). Inter-alar width, alar base width and right/left nostril were studied before surgery and 6 months of follow-up. Data were reported as means and standard deviations; statistical analysis was realized by t test considering a p-value <0.05. Left nostril was modified 0.33 ± 1.03 mm, right nostril was modified 0.39 ± 0.98 mm after 6 months and inter-alar width show a decrease of 0.17 ± 1.15 mm. No statistical differences were observed between the preoperative and the postoperative measurements. Our results show this technique as effective in to obtain a stable position in nasal width.

RESUMEN: el objetivo de esta investigación es presentar una técnica simple para obtener el control en el ancho de la base alar en la ejecución de una osteotomía de Le Fort I. La técnica fue usada en 18 sujetos sometidos a cirugía maxilar de ascenso y/o avance maxilar mayor (≥ 3 mm). El ancho inter-alar, el ancho de la base alar y el orificio nasal derecho e izquierdo fueron estudiados antes de la cirugía y seis meses después de la misma. Los datos fueron presentados en promedios y desviación estándar; el análisis estadístico fue realizado utilizando el t test considerando un valor de p <0,05. El orificio izquierdo fue modificado en 0,33 ± 1,03 mm, el orificio izquierdo fue modificado en 0,39 ± 0,98 mm des- pués de 6 meses y el ancho inter alar mostro una reducción de 0,17 ± 1,15 mm. No se observaron diferencias estadísticas entre las mediciones obtenidas previo a la cirugía y después de la cirugía. Nuestros resultados muestran que la técnica es efectiva para obtener una posición estable del ancho nasal.

Prognostic factors for maxillary sinus mucosal thickening following Le Fort I osteotomy: a retrospective analysis / 대한악안면성형재건외과학회지

BACKGROUND: Le Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined. METHODS: Using MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery. RESULTS: The mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. CONCLUSIONS: Operative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.

An idiopathic delayed maxillary hemorrhage after orthognathic surgery with Le Fort I osteotomy: a case report

A Le Fort I osteotomy is a common procedure for correcting dental and facial deformities in orthognathic surgery. In rare cases, a delayed hemorrhage can occur as early as several hours or up to 12 weeks, postoperatively. The most frequently involved blood vessels in a delayed hemorrhage are the descending palatine artery, the internal maxillary artery, and the pterygoid venous plexus of veins. Intraoral bleeding accompanied by severe epistaxis in these cases makes it difficult to locate the precise bleeding focus. Eventual uncontrolled bleeding would require Merocel packing or surgical intervention. In general, a severe late postoperative hemorrhage is most effectively managed by angiography and embolization. Herein we describe a delayed hemorrhage case in which the cause was not evident on angiography. We were able to detect the bleeding point through an endoscopic nasal approach and treat it using direct cauterization.

Orthognathic surgery for patients with fibrous dysplasia involved with dentition / 대한악안면성형재건외과학회지

BACKGROUND: Fibrous dysplasia (FD) is characterized by the replacement of normal bone by abnormal fibro-osseous connective tissue and typically treated with surgical contouring of the dysplastic bone. When dysplastic lesions involve occlusion, not only is surgical debulking needed, orthognathic surgery for correction of dentofacial deformity is mandatory. However, the long-term stability of osteotomized, dysplastic bone segments is a major concern because of insufficient screw-to-bone engagement during surgery and the risk of FD lesion re-growth. CASE PRESENTATION: This case report reviewed two patients with non-syndromic FD that presented with maxillary occlusal canting and facial asymmetry. Le Fort I osteotomy with recontouring of the dysplastic zygomaticomaxillary region had been performed. The stability of osseous segments were favorable. However, dysplastic, newly formed bone covered the previous plate fixation site and mild bony expansion was observed, which did not influence the facial profile. Including the current cases, 15 cases of orthognathic surgery for FD with dentition have been reported in the literature. CONCLUSION: The results showed that osteotomy did not appear to significantly reduce the long-term stability of the initial fixation insufficiency of the screw to the dysplastic bone. However, based on our results and those of the others, long-term follow-up and monitoring are needed, even in cases where the osteotomized segment shows stable results.

Surgical Treatment for a Huge Maxillary Ameloblastoma via Le Fort I Osteotomy: A Case Report

Ameloblastomaa are odontogenic benign tumors with epithelial origin, which are characterized by slow, aggressive, and invasive growth. Most ameloblastomas occur in the mandible, and their prevalence in the maxilla is low. A 27-year-old male visited our clinic with a chief complaint of the left side nasal airway obstruction. Three-dimensional computed tomography showed left maxillary sinus filled with a mass. Except for the perforated maxillary left edentulous area, no invaded or destructed bone was noted. The tumor was excised via Le Fort I osteotomy. The main mass was then sent for biopsy and it revealed acanthomatous ameloblastoma. The lesion in the left maxillary sinus reached the ethmoidal sinus through the nasal cavity but did not invade the orbit and skull base. The tumor was accessed through a Le Fort I downfracture in consideration of the growth pattern and range of invasion. The operation site healed without aesthetic appearances and functional impairments. However, further long-term clinical observation is necessary in the future for the recurrence of ameloblastoma. Conservative surgical treatment could be the first choice considering fast recovery after surgery and the patient's life quality.

Surgical correction of septal deviation after Le Fort I osteotomy / 대한악안면성형재건외과학회지

BACKGROUND: The Le Fort I osteotomy is one of the most widely used and useful procedure to correct the dentofacial deformities of the midface. The changes of the maxilla position affect to overlying soft tissue including the nasal structure. Postoperative nasal septum deviation is a rare and unpredicted outcome after the surgery. There are only a few reports reporting the management of this complication. CASE PRESENTATION: In our department, three cases of the postoperative nasal septum deviation after the Le Fort I osteotomy had been experienced. Via limited intraoral circumvestibular incision, anterior maxilla, the nasal floor, and the anterior aspect of the septum were exposed. The cartilaginous part of the nasal septum was resected and repositioned to the midline and the anterior nasal spine was recontoured. Alar cinch suture performed again to prevent the sides of nostrils from flaring outwards. After the procedure, nasal septum deviation was corrected and the esthetic outcomes were favorable. CONCLUSION: Careful extubation, intraoperative management of nasal septum, and meticulous examination of pre-existing nasal septum deviation is important to avoid postoperative nasal septum deviation. If it existed after the maxillary osteotomy, septum repositioning technique of the current report can successfully correct the postoperative septal deviation.

A Case of Ancient Schwannoma in Retromaxillary Area Removed with Le Fort I Osteotomy Approach

Schwannoma, which manifests as a smooth and solitary, encapsulated lesion, originates from the nerve sheaths of Schwann cells. Ancient schwannoma, a rare histologic variant of schwannoma, characterized by its distinctive degenerative changes. Basically, treatment entails complete removal of the mass, with maximal safeguarding of the nerve. However, depending on tumor size and extent, complete removal can be problematic. Le Fort I osteotomy in orthognathic surgery is widely utilized and can be effective to remove the skull base tumors. A 25-year-old woman presented with stabbing pain of 1-2 seconds duration occurring every two hours in the interior of the right face, which condition had persisted for one year. Magnetic resonance imaging showed mass lesion in the right retromaxillary area. Mass in retromaxillary area was removed by Le Fort I osteotomy. Pathologic examination confirmed the diagnosis of ancient schwannoma. In the course of a six-month follow-up, neither recurrence nor malocclusion was observed.

Three Dimensional Study on the Postoperative Stability after Advancement of Maxilla Using Le Fort I Osteotomy

0.05). In transverse plane, the distance between S1-S0 of PNS was -3.87+/-2.37 mm, S2-S0 of PNS was -3.79+/-2.39 mm, and S1-S2 of PNS was -0.08+/-0.18 mm. There were significant differences between these data (P<0.05). In coronal plane, the distance between S1-S0 of A-point was 3.99+/-0.86 mm, S2-S0 was 3.57+/-1.09 mm, and S1-S2 was 0.42+/-0.42 mm. There were significant differences between these data (P<0.05). In coronal plane, the distance between S1-S0 of PNS was 3.82+/-0.96 mm, S2-S0 was 3.43+/-0.91 mm, and S1-S2 was 0.39+/-0.49 mm. There were significant differences between these data (P<0.05). In transverse plane, it was estimated that PNS has no statistical postoperative stability in the same direction. In coronal plane, it was estimated that both A-point and PNS had no statistical postoperative stability (P<0.05).CONCLUSION: Clinically, the operation plan needs to take into account of the maxillary relapse.

Evaluation of Maxillary Sinus Using Cone-beam Computed Tomography in Patients Who Underwent Le Fort I Osteotomy

or =2 mm and 6 mm but not complete), total opacification, and polypoidal mucosal thickening. The diameters of the maxillary sinus ostium on the coronal cross-sectional view were also calculated.RESULTS: Out of 166 maxillary sinuses in 83 patients, 42 (25.3%) maxillary sinuses before surgery and 37 (22.3%) maxillary sinuses after surgery showed abnormalities. A decrease in the diameters of maxillary ostium was observed after surgery (P<0.05). However, there was no significant difference in mucosal thickness both, preoperatively and postoperatively.CONCLUSION: The orthognathic surgery didn't deteriorate the maxillary sinus abnormaility. Despite the low prevalence of sinus complications in orthognathic surgery, all the patients should be informed of the possibility of sinusitis that could require the surgical intervention before surgery.

Estudo cefalométrico computadorizado da projeção maxilar e seus efeitos sobre os tecidos moles sobrejacentes após a cirurgia ortognática / Computadorized cephamometric study of the maxillary projection and its effects on the overlying soft tissues after orthognathic surgery

O objetivo do presente estudo consistiu em realizar a análise cefalométrica computadorizada retrospectiva da projeção maxilar e de seus efeitos sobre os tecidos moles da região anterior da maxila de 15 pacientes portadores de deformidade dentofacial esquelética caracterizada por prognatismo mandibular (Padrão III). Seis indivíduos eram do gênero masculino e 9 do gênero feminino, com idade média de 26,06 anos (desvio-padrão de 7,34). Esses pacientes foram submetidos à cirurgia ortognática para avanço de maxila, por meio da osteotomia Le Fort I, e recuo de mandíbula, por meio da osteotomia sagital bilateral da mandíbula. As radiografias cefalométricas pré e pós-operatórias, com intervalo médio de 30,13 meses (desvio-padrão de 15,76), foram analisadas com base na comparação de medidas lineares e angulares por meio da utilização do programa Dolphin Imaging® 10.0 (Dolphin/3M - EUA) e os dados obtidos foram submetidos à análise estatística pelo teste não paramétrico de Wilcoxon. Ocorreu redução significativa da projeção nasal e aumento não significativo da base nasal e do ângulo nasolabial. Os valores do SNA confirmam o avanço da maxila e os valores do SNB o recuo de mandíbula, enquanto que o ANB e o trespasse horizontal tornaram-se positivos. Pode-se concluir que o avanço maxilar produz efeitos na projeção maxilar e nos tecidos moles sobrejacentes. Tais efeitos, na maioria dos casos, mostram uma tendência ao aumento das medidas lineares e angulares envolvidas, porém essa tendência pode variar de acordo com o montante e direção do movimento, além de características relacionadas aos indivíduos e aos procedimentos.

Accuracy of simulation surgery of Le Fort I osteotomy using optoelectronic tracking navigation system

INTRODUCTION: The aim of this study was to demonstrate that the simulation surgery on rapid prototype (RP) model, which is based on the 3-dimensional computed tomography (3D CT) data taken before surgery, has the same accuracy as traditional orthograthic surgery with an intermediate splint, using an optoelectronic tracking navigation system. MATERIALS AND METHODS: Simulation surgery with the same treatment plan as the Le Fort I osteotomy on the patient was done on a RP model based on the 3D CT data of 12 patients who had undergone a Le Fort I osteotomy in the department of oral and maxillofacial surgery, Seoul National University Dental Hospital. The 12 distances between 4 points on the skull, such as both infraorbital foramen and both supraorbital foramen, and 3 points on maxilla, such as the contact point of both maxillary central incisors and mesiobuccal cuspal tip of both maxillary first molars, were tracked using an optoelectronic tracking navigation system. The distances before surgery were compared to evaluate the accuracy of the RP model and the distance changes of 3D CT image after surgery were compared with those of the RP model after simulation surgery. RESULTS: A paired t-test revealed a significant difference between the distances in the 3D CT image and RP model before surgery.(P<0.0001) On the other hand, Pearson's correlation coefficient, 0.995, revealed a significant positive correlation between the distances.(P<0.0001) There was a significant difference between the change in the distance of the 3D CT image and RP model in before and after surgery.(P<0.05) The Pearson's correlation coefficient was 0.13844, indicating positive correlation.(P<0.1) CONCLUSION: Theses results suggest that the simulation surgery of a Le Fort I osteotomy using an optoelectronic tracking navigation system is relatively accurate in comparing the pre-, and post-operative 3D CT data. Furthermore, the application of an optoelectronic tracking navigation system may be a predictable and efficient method in Le Fort I orthognathic surgery.

An Evaluation of Initial Stability after Maxillary Posterior Impaction

Evaluation of Stability Following Two-Jaw Surgery

Tratamento ortocirúrgico da classe III e mordida aberta severa / Ortho-surgical treatment of class III with severe open-bite

Relato de caso ortocirúrgico de uma paciente classe III com mordida aberta total. A cirurgia consistiu em recuo de 6 mm da mandíbula, avanço e elevação posterior de 4 mm da maxila, pelas técnicas de osteotomia sagital do ramo mandibular e Le Fort I, associadas à fixação interna rígida. Após a obtenção da harmonia facial e dentoesquelética observou-se leve recidiva dentária, com diastema na distal dos caninos inferiores, na fase de contenção. Esse caso demonstra que a cirurgia ortognática é um valioso recurso no tratamento das má-oclusões esqueléticas, em especial, a Classe III.

A case report of a Class III ortho-surgical treatment with a full open bite. The surgery of choice was 6 mm mandibular setback, and anterior displacement and posterior elevation of the maxilla in 4 millimeters, by the sagital split technique for the mandibular ramus and Le Fort I, associated to internal rigid fixation. After facial, skeletal and tooth harmonies were acquired, slight dental relapse in orthodontic treatment long-term was observed. This case report elucidates that orthognatic surgery is a valuable resource in treatment of skeletal malocclusions, especially in Class III cases.

Soft tissue changes associated with ASO/BSSRO and Le Fort I/BSSRO in skeletal Class III malocclusion with upper lip protrusion / 대한치과교정학회지

OBJECTIVE: The objective of this study was to compare maxillary soft tissue changes and their relative ratios to hard tissue changes after anterior segmental osteotomy (ASO)/bilateral sagittal split ramus osteotomy (BSSRO) and Le Fort I/BSSRO in skeletal Class III malocclusion with upper lip protrusion. METHODS: The study sample comprised the ASO/BSSRO group (n = 14) and the Le Fort I/BSSRO group (n = 15). The Le Fort I/BSSRO group included cases of maxillary posterior impaction only. Lateral cephalograms were taken 2 months before and 6 months after surgery. Linear and angular measurements were performed. RESULTS: The anterior maxilla moved backward in both groups after surgery, however the amount of change was significantly larger in the ASO/BSSRO group (p < 0.01). The ratios of hard to soft tissue change were 79% (SLS to A point), 80% (LS to A point) in the ASO/BSSRO group, and 15% (SLS to A point), 68% (LS to A point) in the Le fort I/BSSRO group. In addition, there was a 3.23degrees increase of the occlusal plane in the Le Fort I/BSSRO group. CONCLUSIONS: When two-jaw surgery is indicated in skeletal Class III patients with protrusive lips, ASO may be a treatment of choice for cases with more severe upper lip protrusion, while Le Fort I with posterior impaction may be considered if an increase of occlusal plane angle is required.

THE SKELETAL STABILITY OF LE FORT I MAXILLARY ADVANCEMENT

QUANTITATIVE ASSESSMENT OF NASAL AND UPPER LIP CHANGES AFTER LE FORT I OSTEOTOMY SURGERY USING A 3-DIMENSIONAL COMPUTED TOMOGRAPHY

Complicaciones asociadas con osteotomía Le Fort I / Complications associated with Le Fort I osteotomy

La osteotomía Le Fort I es un procedimiento rutinario en cirugía ortognática. Los autores reportan la ocurrencia de complicaciones intra y posquirúrgicas. La osteotomía Le Fort I está relacionada con gran variedad de complicaciones. Un conocimiento preciso de las complicaciones debería ayudar al cirujano, al ortodoncista y al paciente para estimar los beneficios de una cirugía electiva versus los riesgos. El conocer las complicaciones también debería ayudar a prevenir su ocurrencia y facilitar el tratamiento. El propósito de esta revisión fue reportar las complicaciones quirúrgicas y posquirúrgicas que están relacionadas con la osteotomía Le Fort I. Se presentan las complicaciones en el siguiente orden: oftalmológicas, vasculares, del seno cavernoso, necrosis avascular, edema, infecciosas, neurológicas, resultados estéticos desfavorables, cambios pulpares y otras complicaciones de rara ocurrencia.

Le Fort I osteotomy has become a routine procedure in elective orthognathic surgery. The authors report the occurrence of intra and post operative complications in Le Fort I osteotomy. The Le Fort I osteotomy is related to a variety of complications. A precise assessment of complications might be helpful for the patient, the orthodontist, and the surgeon in order to estimate the benefit of an elective operation versus its immanent risks. Knowledge of complications also might help to prevent their occurrence and facilitate their management. The aim of this review was to report the types and frequencies of intra and post operative complications related to Le Fort I osteotomy. This review presents surgical complications in the following order: Ophthalmic complications, Vascular complications, Cavernous sinus fistula, Ischemic complications including aseptic necrosis, swelling, significant infections such as abscesses or maxillary sinusitis, Nerve injures, unfavorable esthetic results, unfavorable pulpal reactions and other unusual complications.