Mechanical Evaluation of Different Stable Internal Fixation Techniques of Sagittal Osteotomy in Mandibular Advance / Evaluación Mecánica de Diferentes Técnicas de Fijación Interna Estable de Osteotomía Sagital en Avance Mandibular

The mandibular advancements performed in orthognathic surgeries can be stabilized with several techniques when using stable internal fixation. This study aims to comparatively evaluate, in vitro, the mechanical strength in a polyurethane mandibular model for four fixation techniques for sagittal split ramus osteotomy mandibular. 60 samples were divided into 4 groups, with 15 units for each group: group A, group B, group C and group D. Advances of 5 mm were made for each subgroup and fixed with 2.0 mm system plates and monocortical screws in the replicas of human hemimandibles in polyurethane resin. The samples were submitted to mechanical tests of linear loading, being evaluated the peak load and peak deformation. Technique B presented higher peak load (Kgf) and techniques A and B presented higher peak strain (p<0.05). Technique D presented lower peak load and lower peak strain (p<0.05). It is concluded that the study based on the development of new techniques for fixation for sagittal osteotomy of the mandibular ramus is of great importance for the advancement of orthognathic surgery, provided by the technical innovation of more favorable plate models.

Los avances mandibulares realizados en cirugías ortognáticas pueden estabilizarse con varias técnicas cuando se utiliza fijación interna estable. Este estudio tuvo como objetivo evaluar comparativamente, in vitro, la resistencia mecánica en un modelo mandibular de poliuretano para cuatro técnicas de fijación para la osteotomía sagital de la rama mandibular. Se dividieron 60 muestras en 4 grupos, con 15 unidades para cada grupo: grupo A, grupo B, grupo C y grupo D. Se realizaron avances de 5 mm para cada subgrupo y se fijaron con placas de sistema de 2,0 mm y tornillos monocorticales en las réplicas de hemimandíbulas humanas en resina de poliuretano. Las muestras fueron sometidas a pruebas mecánicas de carga lineal, siendo evaluadas la carga máxima y la deformación máxima. La técnica B presentó mayor pico de carga (Kgf) y las técnicas A y B presentaron mayor pico de deformación (p<0,05). La técnica D presentó menor carga máxima y menor tensión máxima (p<0,05). Se concluye que el estudio basado en el desarrollo de nuevas técnicas de fijación para la osteotomía sagital de la rama mandibular es de gran importancia para el avance de la cirugía ortognática, proporcionada por la innovación técnica de modelos de placas más favorables.

Mid-term follow-up of superior pubic ramus osteotomy in locked symphysis pubis with urethral injury: A case report / 中华创伤杂志(英文版)

A locked pubic ramus body is an unusual variant of lateral compression injury. Till date, there have been only 25 cases reported in the published literature. We herein described a case where the right pubic ramus was entrapped within the opposite obturator foramen with an overlap of greater than 4 cm, with associated urethral injury. When all maneuvers of closed and instrumented reduction failed, we performed a superior pubic ramus osteotomy on the left side and unlocked the incarcerated right pubic ramus. The osteotomy site was stabilized with a 6-hole recon plate. The patient underwent delayed urethral repair 10 weeks after the index surgery. At 3-year follow-up, the patient has sexual dysfunction especially difficulty in maintaining erection, secondary urethral stricture, heterotopic ossification, and breakage of implants.

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.

Estabilidad del tratamiento ortodóncico-quirúrgico de avance mandibular mediante osteotomía sagital bilateral de rama mandibular en pacientes clase II. Revisión narrativa / Stability of the orthodontic-surgical treatment of mandibular advancement through bilateral sagittal split osteotomy in class II patients. Narrative review

RESUMEN: Introducción: La anomalía esqueletal clase II posee un 16 a 22,5% de prevalencia mundial. Cuando estos pacientes se someten al avance mandibular mediante osteotomía sagital de rama mandibular pueden presentar un grado de inestabilidad postoperatoria evidenciándose como recidiva de éste. Objetivo: Describir la estabilidad del avance mandibular mediante osteotomía sagital bilateral de rama mandibular en pacientes clase II esqueletal. Material y método: Se realizó una búsqueda electrónica en las bases de datos PubMed, EBSCO, The Cochrane Library, Tripdatabase y Scopus mediante las palabras clave "mandibular stability", "skeletal stability", "mandibular advancement", "sagittal split osteotomy", "sagittal split ramus osteotomy", "class II", "class III" y "distraction osteogenesis", relacionadas entre sí con los términos booleanos AND, OR y NOT. También se incluyeron los términos MeSH "mandibular advancement" y "Sagittal Split Ramus Osteotomy". Paralelamente se realizó una búsqueda manual en las revistas AJODO, BJOMS, JOMS y EJO. Resultados y discusión: Se seleccionaron 29 artículos: 24 estudios observacionales analíticos, 2 revisiones sistemáticas y 3 ensayos clínicos aleatorizados. El avance mandibular mediante osteotomía sagital de rama mandibular es estable. No obstante, se debe tener en cuenta la existencia de múltiples factores pre e intraquirúrgicos que podrían generar recidiva del tratamiento.

ABSTRACT: Introduction: The class II skeletal anomaly has a 16-22,5% prevalence worldwide. When class II patients undergo mandibular advancement through Bilateral Sagittal Split Osteotomy (BSSO), they can present a postoperative instability, evidenced as a relapse. Objective: To describe the stability of mandibular advancement through BSSO in skeletal class II patients. Materials and method: An electronic search was performed in the databases PubMed, EBSCO, The Cochrane Library, Tripdatabase and Scopus using the keywords "mandibular stability", "skeletal stability", "mandibular advancement", "sagittal split osteotomy", "sagittal split ramus osteotomy", "class II", "class III" and "distraction osteogenesis", related to each other with the Boolean terms AND, OR and NOT. Also "mandibular advancement" and "Sagittal Split Ramus Osteotomy" MeSH terms were included. In parallel, a manual search in the journals AJODO, BJOMS, JOMS and EJO was performed. Results and discussion: 29 articles were selected: 24 analytic observational studies, 2 systematic reviews and 3 randomized clinical trials. Mandibular advancement through BSSO is stable. However, multiple pre and intraoperative factors that could cause a treatment relapse must be taken into account.

Preoperative imaging of the inferior alveolar nerve canal by cone-beam computed tomography and 1-year neurosensory recovery following mandibular setback through bilateral sagittal split ramus osteotomy: a randomized clinical trial

OBJECTIVES: One of the most common complications of bilateral sagittal split ramus osteotomy (BSSRO) is neurosensory impairment of the inferior alveolar nerve (IAN). Accurate preoperative determination of the position of the IAN canal within the mandible using cone-beam computed tomography (CBCT) is recommended to prevent IAN dysfunction during BSSRO and facilitate neurosensory improvement after BSSRO.MATERIALS AND METHODS: This randomized clinical trial consisted of 86 surgical sites in 43 patients (30 females and 13 males), including 21 cases (42 sides) and 22 controls (44 sides). Panoramic and lateral cephalographs were obtained from all patients. In the experimental group, CBCT was also performed from both sides of the ramus and mandibular body. Neurosensory function of the IAN was subjectively assessed using a 5-point scale preoperatively and 7 days, 1 month, 3 months, 6 months, and 12 months post-surgery. Data were analyzed using Fisher's test, Spearman's test, t-test, linear mixed-model regression, and repeated-measures ANCOVA (α=0.05, 0.01).RESULTS: Mean sensory scores in the control group were 1.57, 2.61, 3.34, 3.73, and 4.20 over one year and were 1.69, 3.00, 3.60, 4.19, and 4.48 in the CBCT group. Significant effects were detected for CBCT intervention (P=0.002) and jaw side (P=0.003) but not for age (P=0.617) or displacement extent (P=0.122).CONCLUSION: Preoperative use of CBCT may help surgeons to practice more conservative surgery. Neurosensory deficits might heal faster on the right side.

Long-term stability after multidisciplinary treatment involving maxillary distraction osteogenesis, and sagittal split ramus osteotomy for unilateral cleft lip and palate with severe occlusal collapse and gingival recession: A case report / 대한치과교정학회지

In this report, we describe a case involving a 34-year-old woman who showed good treatment outcomes with long-term stability after multidisciplinary treatment for unilateral cleft lip and palate (CLP), maxillary hypoplasia, severe maxillary arch constriction, severe occlusal collapse, and gingival recession. A comprehensive treatment approach was developed with maximum consideration of strong scar constriction and gingival recession; it included minimum maxillary arch expansion, maxillary advancement by distraction osteogenesis using an internal distraction device, and mandibular setback using sagittal split ramus osteotomy. Her post-treatment records demonstrated a balanced facial profile and occlusion with improved facial symmetry. The patient's profile was dramatically improved, with reduced upper lip retrusion and lower lip protrusion as a result of the maxillary advancement and mandibular setback, respectively. Although gingival recession showed a slight increase, tooth mobility was within the normal physiological range. No tooth hyperesthesia was observed after treatment. There was negligible osseous relapse, and the occlusion remained stable after 5 years of post-treatment retention. Our findings suggest that such multidisciplinary approaches for the treatment of CLP with gingival recession and occlusal collapse help in improving occlusion and facial esthetics without the need for prostheses such as dental implants or bridges; in addition, the results show long-term post-treatment stability.

Estudo comparativo entre dois programas de computador (Dolphin Imaging® e Nemotec®) e método manual para análises cefalométricas de pacientes com deformidade dentofacial Padrão II / Comparative study of two computer software programs (Dolphin Imaging® and Nemotec®) and a manual method of cephalometric analysis for patients with dentofacial deformity Class II

Este estudo analisou traçados digitais obtidos por dois programas de computador (Dolphin Imaging® e Nemotec®) em comparação aos obtidos pelo método manual nas análises cefalométricas SNA, SNB, Co-A, Co-Gn, altura facial anterior, A-Nperp, Pg-Nperp e plano mandibular. 30 pacientes leucodermas, portadores de retrognatismo mandibular, foram avaliados e submetidos à cirurgia ortognática para correção da deformidade por meio da osteotomia sagital do ramo mandibular. Os traçados cefalométricos foram realizados em telerradiografias laterais obtidas uma semana antes da cirurgia. O método Manual e o Nemotec® apresentaram excelente confiabilidade em todas as medidas. Por outro lado, o método Dolphin Imaging® apontou baixa confiabilidade nas medidas altura facial anterior, Co-A e Co-Gn. Nas medidas A-Nperp, Pg-Nperp, Plano md, SNA e SNB, não houve diferença entre três métodos estudados. Na medida altura facial anterior, houve diferença entre os métodos Dolphin Imaging® e Nemotec®, mas não foram observadas diferenças em relação ao método manual. Nas medidas Co-A e Co-Gn, foi observado que o método Dolphin Imaging® apresentou média significativamente inferior aos demais métodos estudados. No método manual, somente as medidas Co-Gn, Pg-Nperp e SNB confirmaram o diagnóstico de retrognatismo mandibular, tendo o programa Nemotec® apresentado resultados melhores que o programa Dolphin Imaging®... (AU)

This study analyzed digital tracings obtained by two different computer software programs (Dolphin Imaging® and Nemotec®) and compare them to the manual method using cephalometric measurements SNA, SNB, Co-A, Co-Gn, anterior facial height, A-Nperp, Pg-Nperp and mandibular plane. Thirty Caucasian patients exhibiting mandibular retrognathia were analyzed and were submitted to orthognathic surgery to correct the deformity by bilateral sagittal split osteotomy. The cephalometric tracings were performed with lateral radiographs that were obtained a week prior to the surgery. The manual method and the Nemotec® software exhibited an excellent reliability in all measurements. However, the Dolphin Imaging® method exhibited low reliability in the anterior facial height, Co-A and Co-Gn measurements. For the measurements of A-Nperp, Pg-Nperp, Mandibular plan, SNA and SNB, there were no significant differences between the three methods studied. For the anterior facial height measurement, a statistically significant difference was found between the Dolphin Imaging® and Nemotec® methods, although not in relation to the manual method. For the Co-A and Co-Gn measurements, the Dolphin Imaging® method exhibited a significantly lower mean than the other methods studied. In manual method, only the Co-Gn, Pg-Nperp and SNB measurements confirmed the diagnosis of mandibular retrognathia and Nemotec® software provided better results than Dolphin Imaging®... (AU)

Successful application of high-flow nasal cannula in a patient with postoperative respiratory disturbance after bilateral sagittal split ramus osteotomy surgery: A case report

Bilateral sagittal split ramus osteotomy (BSSRO) is generally indicated for mandibular setback, to improve occlusion, masticatory function, and aesthetics by altering the mandibular position. However, BSSRO narrows the pharyngeal airway and increases airway resistance, resulting in postoperative respiratory disturbances during emergence from anesthesia. Oxygen delivery system via high-flow nasal cannula (HFNC) has been known to improve airway patency and oxygenation via low-level positive pressure as well as reduce the respiratory load. We report a case of postoperative respiratory disturbance, following a large mandibular setback, despite nasotracheal extubation in the fully awake patient. Respiratory disturbance was successfully controlled after oxygen delivery via HFNC until self-respiration was completely restored. Therefore, the use of HFNC may facilitate the control of postoperative respiratory disturbances induced by anatomical changes in upper airway after BSSRO surgery.

Novel condylar repositioning method for 3D-printed models / 대한악안면성형재건외과학회지

BACKGROUND: Along with the advances in technology of three-dimensional (3D) printer, it became a possible to make more precise patient-specific 3D model in the various fields including oral and maxillofacial surgery. When creating 3D models of the mandible and maxilla, it is easier to make a single unit with a fused temporomandibular joint, though this results in poor operability of the model. However, while models created with a separate mandible and maxilla have operability, it can be difficult to fully restore the position of the condylar after simulation. The purpose of this study is to introduce and asses the novel condylar repositioning method in 3D model preoperational simulation. METHODS: Our novel condylar repositioning method is simple to apply two irregularities in 3D models. Three oral surgeons measured and evaluated one linear distance and two angles in 3D models. RESULTS: This study included two patients who underwent sagittal split ramus osteotomy (SSRO) and two benign tumor patients who underwent segmental mandibulectomy and immediate reconstruction. For each SSRO case, the mandibular condyles were designed to be convex and the glenoid cavities were designed to be concave. For the benign tumor cases, the margins on the resection side, including the joint portions, were designed to be convex, and the resection margin was designed to be concave. The distance from the mandibular ramus to the tip of the maxillary canine, the angle created by joining the inferior edge of the orbit to the tip of the maxillary canine and the ramus, the angle created by the lines from the base of the mentum to the endpoint of the condyle, and the angle between the most lateral point of the condyle and the most medial point of the condyle were measured before and after simulations. Near-complete matches were observed for all items measured before and after model simulations of surgery in all jaw deformity and reconstruction cases. CONCLUSIONS: We demonstrated that 3D models manufactured using our method can be applied to simulations and fully restore the position of the condyle without the need for special devices.

Positional change in mandibular condyle in facial asymmetric patients after orthognathic surgery: cone-beam computed tomography study / 대한악안면성형재건외과학회지

BACKGROUND: We evaluated change in the mandibular condyle after orthognathic surgery using cone-beam computed tomography (CBCT) in patients with facial asymmetry. METHODS: Thirty patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry were classified into two groups according to the amount of menton deviation (MD) from the facial midline on anteroposterior (AP) cephalogram: group A (asymmetry, MD ≥ 4 mm; n = 15) and group B (symmetry, MD < 4 mm; n = 15). Position and angle of condylar heads on the axial, sagittal, and coronal views were measured within 1 month preoperatively (T0) and postoperatively (T1) and 6 months (T2) postoperatively. RESULTS: On axial view, both groups showed inward rotation of condylar heads at T1, but at T2, the change was gradually removed and the condylar head returned to its original position. At T1, both groups showed no AP condylar head changes on sagittal view, although downward movement of the condylar heads occurred. Then, at T2, the condylar heads tended to return to their original position. The change in distance between the two condylar heads showed that they had moved outward in both groups, causing an increase in the width between the two heads postoperatively. Analysis of all three-dimensional changes of the condylar head positions demonstrated statistically significant changes in the three different CBCT views in group B and no statistically significant changes in group A. CONCLUSIONS: There was no significant difference between the two groups in condylar head position. Because sagittal split ramus osteotomy can be performed without significant change in symmetrical and asymmetrical cases, it can be regarded as an effective method to stabilize the condylar head position in patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry.

The effect of botulinum toxin-A injection into the masseter muscles on prevention of plate fracture and post-operative relapse in patients receiving orthognathic surgery / 대한악안면성형재건외과학회지

BACKGROUND: Botulinum toxin-A (BTX-A) injection into muscle reduces muscular power and may prevent post-operative complication after orthognathic surgery. The purpose of this study was (1) to evaluate BTX-A injection into the masseter muscle on the prevention of plate fracture and (2) to compare post-operative relapse between the BTX-A injection group and the no injection group. METHODS: Sixteen patients were included in this study. Eight patients received BTX-A injection bilaterally, and eight patients served as control. All patients received bilateral sagittal split ramus osteotomy for the mandibular setback and additional surgery, such as LeFort I osteotomy or genioplasty. Post-operative plate fracture was recorded. SNB angle, mandibular plane angle, and gonial angle were used for post-operative relapse. RESULTS: Total number of fractured plates in patients was 2 out of 16 plates in the BTX-A injection group and that was 8 out of 16 plates in the no treatment group (P = 0.031). However, there were no significant differences in post-operative changes in SNB angle, mandibular plane angle, and gonial angle between groups (P > 0.05). CONCLUSIONS: BTX-A injection into the masseter muscle could reduce the incidence of plate fracture.

Odontoma Compuesto: Diagnóstico y Tratamiente Reporte de Casos & Revisión de la Literatura / Compound Odontoma: Diagnosis and Treatment Therapeutic Measures. Case Reports & Literature Review

RESUMEN: Los odontomas son los tumores odontogénicos benignos más prevalentes. Estos están conformados por tejido dentario, epitelio odontogénico y tejido mesenquimático. Se dividen en dos subtipos: odontomas compuestos, que presentan tejidos dentarios normales, pero con una alteración en su conformación y tamaño, y odontomas complejos, que presentan tejidos dentarios bien formados, pero rodeados de tejido desorganizado. Se presentan tres casos de pacientes sexo femenino, quienes acuden para evaluación y tratamiento debido al hallazgo radiográfico de odontoma compuesto. En el caso nº 1 se realizó la desinclusión del diente impactado, la exodoncia del diente remanente, la exéresis del odontoma compuesto, la instalación de un implante dental en el alveolo de la zona intervenida y, finalmente, el posicionamiento de injerto óseo. En el caso nº 2 se realizó la exodoncia del diente temporal remanente y la exéreis del odontoma compuesto. Ambos casos evolucionaron de manera favorable sin complicaciones post operatorias. En el caso nº 3 se realizó la fenestración del diente 18 y la exéreis del odontoma compuesto que retenía su erupción. Todos los casos evolucionaron de manera favorable sin complicaciones post operatorias. Dada la prevalencia de esta patología, es necesario un adecuado conocimiento sobre ella y sus características, para realizar un adecuado diagnóstico y tratamiento. Existen distintas medidas terapéuticas respecto a la rehabilitación de una zona edéntula como resultado de la exéresis de estos tumores. Esto depende principalmente de la edad del paciente. Al ser requeridas medidas rehabilitadoras, un punto importante a considerar es la posibilidad de realizar todos los procedimientos quirúrgicos en un solo tiempo operatorio.

ABSTRACT: Odontomas are the most common benign odontogenic tumors and are composed of dental tissue, odontogenic epithelium and mesenchymal tissue. They are divided into two subtypes: Compound odontomas, which present normal tooth tissue, but an alteration in their conformation and size, and complex odontomas, which present well-formed tooth tissue, but are surrounded by disorganized tissue. A bibliographic review was performed by one operator in Pubmed and Epistemonikos. After filtering by title and abstract, only one systematic review was selected. We present two clinical cases of compound odontoma in female patients at the Military Hospital in Santiago. Patients were referred for evaluation and treatment due to the radiographic finding of compound odontoma. In case # 1, the impacted tooth was disincluded, the remaining temporal tooth was extracted, and excision of the compound odontoma carried out; subsequently a bone graft implant was placed in the remaining socket. In case # 2, the remaining temporal tooth was extracted and compound odontoma excised. After that, natural eruption of the corresponding permanent tooth is expected. In case # 3, tooth 1.8 fenestration and excision of compound odontoma was performed. In this case also, natural eruption of the corresponding permanent tooth is expected. Given the prevalence of this pathology, adequate knowledge of compound odontomas and their characteristics is necessary for proper diagnosis and treatment. There are different therapeutic measures for the rehabilitation of an edentulous area following excision of compound odontoma. This depends mainly on the age of the patient. When rehabilitation measures are required, an important aspect to consider for the patient, is the possibility of a single surgical event, as was done in case # 1.

Osteotomia sagital do ramo mandibular na remoção de dentes impactados: relato de caso / Sagittal split ramus osteotomy for removal of impacted teeth: a case report

A osteotomia sagital do ramo mandibular é uma técnica cirúrgica, utilizada desde a década de 50, no tratamento de deformidades dentoesqueléticas da mandíbula. Consiste numa técnica consagrada, segura, com riscos previsíveis e prognóstico extremamente favorável, que pode ser utilizada, também, para remoção de dentes com impactação severa na região de ramo/ângulo/corpo da mandíbula. Este artigo tem como objetivo descrever um caso de uma paciente com impactação do segundo e terceiro molar inferior, a qual foi submetida à remoção pela técnica de osteotomia sagital do ramo da mandíbula. O sucesso do caso demonstra que essa é uma técnica viável como alternativa na cirurgia de dentes severamente impactados, que apresentem, por exemplo, risco de lesão do nervo alveolar inferior e fratura mandibular... (AU)

The sagittal ramus split osteotomy of the mandibular is a surgical technique used since the 50s in the treatment of deformities dentalskeletal jaw. Is a dedicated, safe technique with predictable risks and extremely favorable prognosis, which can also be used for removal of teeth with severe impaction in the ramus/angle/body of the mandible. This article aims to describe a case of a patient with impaction of the second and third molar, which was subjected to removal by sagittal ramus split osteotomy technique of the jaw. The success of the case shows that this is a viable technique as an alternative to severely impacted teeth surgery that have, for example, risk of inferior alveolar nerve injury and mandibular fracture... (AU)

Inusual complicación en procedimiento de cirugía ortognática / Unusual complication in an orthognathicsurgery procedure

Objetivo: presentar un caso de pseudoaneurisma de la arteria maxilar interna, complicación hemorrágica infrecuente mediata al procedimiento de osteotomía sagital mandibular. Caso clínico: El tratamiento consistió en la embolización selectiva del vaso afectado, un procedimiento menos cruento que las maniobras hemostáticas tradicionales, como la ligadura arterial a través de un abordaje cervical. Conclusión: Es posible resolver la hemorragia con un método alternativo pero seguro, que conlleva menos morbilidades asociadas a las maniobras hemostáticas clásicas.

Aim: to report a mediate rare bleeding complication tothe procedure of mandibular sagittal split osteotomy as is thepseudoaneurysm of the internal maxillary artery is.Case report: The treatment consisted of selective embolizationof the affected vessel, which turns out to be a lessinvasive procedure than traditional hemostatic maneuverssuch as arterial ligation through a cervical approach.Conclusion: It is possible to resolve the bleeding withan alternative safe method with lower morbidity than the oneassociated with classical hemostatic maneuvers.

New Treatment in Facial Nerve Palsy Caused by Sagittal Split Ramus Osteotomy of Mandible

A 25-years-old woman with mandibular prognathism underwent a mandibular setback by way of mandibular sagittal split ramus osteotomy (MSSRO). After 2 days of operation, she developed difficulty of closing her right eye. The blink reflex test and motor nerve conduction study of the right orbicularis oris muscle were revealed right facial neuropathy of unknown origin and House-Brackmann facial nerve grading system (HBFNGS) grade V. For treatment, we initially prescribed oral prednisolone and nimodipine including physical therapy. The samples consisted of 11 facial nerve palsy patients caused by MSSRO and were analysed about onset of facial nerve palsy, postoperative HBFNGS, final HBFNGS, treatment method and recovery time. At 10 weeks of treatment of nimodipine, she had completely regained normal function (HBFNGS grade I) of the right facial nerve. The clinical results lead to assume a fast recovery of facial nerve function by the nimodipine medication, whereas average time of recovery is 16.32 weeks in references. Despite of the limited one patient treated, the result was very promising with respect to a faster recovery of the facial nerve function. Considering the use of nimodipine treatment for peripheral facial nerve palsy following a surgical approach with an anatomically preserved nerve can be recommended.

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.

Mechanical evaluation of the use of conventional and locking miniplate/screw systems used in sagittal split ramus osteotomy

OBJECTIVES: The aim of this study was to compare the mechanical resistance of four different osteosyntheses modeled in two different sagittal split ramus osteotomy (SSRO) designs and to determine the linear loading in a universal testing machine. MATERIALS AND METHODS: An in vitro experiment was conducted with 40 polyurethane hemimandibles. The samples were divided into two groups based on osteotomy design; Group I, right angles between osteotomies and Group II, no right angles between osteotomies. In each group, the hemimandibles were distributed into four subgroups according to the osteosynthesis method, using one 4-hole 2.0 mm conventional or locking plate, with or without one bicortical screw with a length of 12.0 mm (hybrid technique). Each subgroup contained five samples and was subjected to a linear loading test in a universal testing machine. RESULTS: The peak load and peak displacement were compared for statistical significance using PASW Statistics 18.0 (IBM Co., USA). In general, there was no difference between the peak load and peak displacement related to osteotomy design. However, when the subgroups were compared, the osteotomy without right angles offered higher mechanical resistance when one conventional or locking 2.0 mm plate was used. One locking plate with one bicortical screw showed higher mechanical resistance (162.72±42.55 N), and these results were statistically significantly compared to one conventional plate with monocortical screws (P=0.016) and one locking plate with monocortical screws (P=0.012). The difference in peak displacement was not statistically significant based on osteotomy design or internal fixation system configuration. CONCLUSION: The placement of one bicortical screw in the distal region promoted better stabilization of SSRO. The osteotomy design did not influence the mechanical behavior of SSRO when the hybrid technique was applied.

Comparative study of postoperative stability between conventional orthognathic surgery and a surgery-first orthognathic approach after bilateral sagittal split ramus osteotomy for skeletal class III correction

OBJECTIVES: The purpose of this study is to compare the postoperative stability of conventional orthognathic surgery to a surgery-first orthognathic approach after bilateral sagittal split ramus osteotomy (BSSRO). MATERIALS AND METHODS: The study included 20 patients who underwent BSSRO for skeletal class III conventional orthognathic surgery and 20 patients who underwent a surgery-first orthognathic approach. Serial lateral cephalograms were analyzed to identify skeletal changes before surgery (T0), immediately after surgery (T1), and after surgery (T2, after 1 year or at debonding). RESULTS: The amount of relapse of the mandible in the conventional orthognathic surgery group from T1 to T2 was 2.23±0.92 mm (P<0.01) forward movement and −0.87±0.57 mm (non-significant, NS) upward movement on the basis of point B and 2.54±1.37 mm (P<0.01) forward movement and −1.18±0.79 mm (NS) upward movement on the basis of the pogonion (Pog) point. The relapse amount of the mandible in the surgery-first orthognathic approach group from T1 to T2 was 3.49±1.71 mm (P<0.01) forward movement and −1.78±0.81 mm (P<0.01) upward movement on the basis of the point B and 4.11±1.93 mm (P<0.01) forward movement and −2.40±0.98 mm (P<0.01) upward movement on the basis of the Pog. CONCLUSION: The greater horizontal and vertical relapse may appear because of counter-clockwise rotation of the mandible in surgery-first orthognathic approach. Therefore, careful planning and skeletal stability should be considered in orthognathic surgery.

Signs and symptoms of temporomandibular disorder and patients' satisfaction before and after orthognathic surgery

Aim: To evaluate signs and symptoms of temporomandibular joint disorder and satisfaction in patients before and after orthognathic surgery. Methods: The sample consisted of 15 patients aged between 19 and 47 years old, indicated for orthodontic-surgical treatment. All patients answered na anamnesis questionnaire based on Helkimo Anamnestic Index to evaluate subjective symptoms and underwent a clinical evaluation based on Helkimo Disfunction Index, applied at three time points: before (T0), three (T1) and six months (T2) after surgery. Statistical models used were χ2 test (Chi-square), Tukey test, confidence interval and analysis of variance (ANOVA). Results: Statistical analysis revealed no significant difference in the incidence of joint sounds, maximum mouth opening, deviation of mouth opening and pain in the TMJ region (p>0.05). No patient presented worsening of the symptomatology. As regards muscular pain, there was a statistically significant improvement with time (p<0.05) and 86.7% of patients reported that they were satisfied with the obtained results. Conclusions: Improvement of TMD after orthognathic surgery may not be the result of correcting malocclusion and satisfaction with the results can be a factor of TMD improvement (Au)

Changes of lip morphology following mandibular setback surgery using 3D cone-beam computed tomography images / 대한악안면성형재건외과학회지

BACKGROUND: The aims of this study are to evaluate the lip morphology and change of lip commissure after mandibular setback surgery (MSS) for class III patients and analyze association between the amount of mandibular setback and change of lip morphology. METHODS: The samples consisted of 14 class III patients treated with MSS using bilateral sagittal split ramus osteotomy. Lateral cephalogram and cone-beam CT were taken before and about 6 months after MSS. Changes in landmarks and variables were measured with 3D software program Ondemand™. Paired and independent t tests were performed for statistical analysis. RESULTS: Landmarks in the mouth corner (cheilion, Ch) moved backward and downward (p .05, p < .005). On lateral view, upper lip prominent point (UP) moved downward and stomion moved backward and upward and the angle of Ls-UP-Stm (°) was decreased. Lower lip prominent point (LP) moved backward and downward, and the angle of Stm-LP-Li (°) was increased. Li moved backward. Finally, landmarks in the lower incisor tip (L1) moved backward and upward, but stomion moved downward. After surgery, lower incisor tip (L1) was positioned more superiorly than stomion (p < .05). There were significant associations between horizontal soft tissue and corresponding hard tissue. The posterior movement of L1 was related to statistically significantly about backward and downward movement of cheilion. CONCLUSIONS: The lip morphology of patients with dento-skeletal class III malocclusion shows a significant improvement after orthognathic surgery. Three-dimensional lip morphology changes in class III patients after MSS exhibited that cheilion moved backward and downward, upper lip projection angle became acute, lower lip projection angle became obtuse, change of upper lip area on lateral view was increased, change of lower lip area decreased, and morphology of lower lip was protruding. L1 was concerned with the lip tissue change in statistically significant way.