Background: Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots. Results: A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery. Conclusions This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.

Background: Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots. Results: A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery. Conclusions This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.

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.
Chin ; Congenital Abnormalities ; Equidae ; Glenoid Cavity ; Humans ; Jaw ; Joints ; Mandible ; Mandibular Condyle ; Mandibular Osteotomy ; Maxilla ; Methods ; Oral and Maxillofacial Surgeons ; Orbit ; Orthognathic Surgery ; Osteotomy, Sagittal Split Ramus ; Surgery, Oral ; Temporomandibular Joint

Background: Excessive bleeding is a major intraoperative risk associated with orthognathic surgery. This study aimed to investigate the factors involved in massive bleeding during orthognathic surgeries so that safe surgeries can be performed. Patients (n=213) diagnosed with jaw deformities and treated with bimaxillary orthognathic surgery (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) in the Department of Oral and Maxillofacial Surgery at the Suidobashi Hospital, Tokyo Dental College between January 2014 and December 2016 were included. Using the patients’ medical and operative records, the number of cases according to sex, age at the time of surgery, body mass index (BMI), circulating blood volume, diagnosis of maxillary deformity, direction of maxillary movement, operative duration, incidence of bad split, injury of nasal mucosa, and blood type were analyzed. Results: The results revealed that BMI, circulating blood volume, nasal mucosal injury, and operative time were associated with the risk of intraoperative massive bleeding in orthognathic surgeries. Chi-square tests and binomial logistic regression analyses showed significant differences in BMI, circulating blood volume, direction of maxillary movement, operative duration, and injury to the nasal mucosa. Operative duration emerged as the most important risk factor. Furthermore, a >4-mm upward migration of the posterior nasal spine predicted the risk of massive bleeding in orthognathic surgery. Conclusions The upward movement of the maxilla should be recognized during the preoperative planning stage as a risk factor for intraoperative bleeding, and avoiding damage to the nasal mucosa should be considered a requirement for surgeons to prevent massive bleeding during surgery.

Background: Mesiodentes are the most common supernumerary teeth. The cause is not fully understood, although proliferations of genetic factors and the dental lamina have been implicated. Mesiodentes can cause delayed or ectopic eruption of permanent incisors, which can further alter occlusion and appearance. Careful attention should be paid to the position and direction of the mesiodentes because of possible damage to adjacent roots in the permanent dentition period, errant extraction in the deciduous and mixed dentition periods, and damage to the permanent tooth embryo. To avoid these complications, we applied mixed reality (MR) technology using the HoloLens® (Microsoft, California). In this study, we report on three cases of mesiodentes extraction under general anesthesia using MR technology. Results: The patients ranged in age from 6 to 11 years, all three were boys, and the direction of eruption was inverted in all cases. The extraction approach was palatal in two cases and labial in one case. The average operative time was 32 min, and bleeding was minimal in all cases. No intraoperative or postoperative complications occurred. An image was shared preoperatively with all the surgeons using an actual situation model. Three surgeons used Microsoft HoloLens® during surgery, shared MR, and operated while superimposing the application image in the surgical field. Conclusions The procedure was performed safely; further development of MR surgery support systems in the future is suggested.

A 55-year-old man was brought to our hospital with a knife penetrating his left anterior chest wall following a suicide attempt. Massive left hemothorax was identified on echocardiography ; however, there was no evidence of cardiac tamponade. After draining blood from the left thorax, computed tomography (CT) revealed that the tip of the knife had penetrated the left lung and reached the left pulmonary vein. In preparation for cardiopulmonary bypass, an emergency thoracotomy was scheduled with a plan to access the left lung and left pulmonary vein. The patient was transferred to the operating room, and the procedure was started with the patient in the supine position. During dissection of the femoral vessels, the patient suddenly developed hypotension. After surgical access to the heart was achieved via median sternotomy, a pericardiotomy was performed and cardiopulmonary bypass was established. A 50-mm stab wound was identified at the lateral wall of the left ventricle. The knife was removed, and the left ventricular wound was repaired. The lingular segment of the left lung was partially resected. The patient had no postoperative complications and was transferred to the referral hospital on postoperative day 25. This case report emphasizes the importance of taking appropriate measures for thoracotomy and cardiopulmonary bypass in patients with penetrating thoracic trauma with massive hemothorax, even in the absence of cardiac tamponade on imaging. We were able to successfully manage a life-threatening condition by taking appropriate measures.

A 92 year-old-female with melena was admitted to our hospital. She underwent Y-graft replacement of the abdominal aorta at the age of 65. Gastroduodenal fiberscopic examination and computed tomography (CT) confirmed the diagnosis of aortoduodenal fistula. The fistula in the proximal anastomotic site was occluded with a suture ligature and omentopexy was performed. On the 15th post-operative day she developed high-grade fever. CT revealed a pseudoaneurysm formation at the proximal anastomosis site. She underwent emergency endovascular aneurysmal repair (EVAR). Her postoperative course was uneventful. She is doing well without symptoms of recurrent infection.

A 57-year-old man presented with a one-month history of dyspnea. Computed tomography revealed a pulmonary embolism, and echocardiography revealed multiple linear floating thrombi in the right atrium. An urgent surgical thrombectomy was performed, and most of the thrombi in the right atrium and bilateral pulmonary arteries were removed under cardiopulmonary bypass. The thrombi in the right atrium adhered to the linear Chiari networks. The patient was treated with rivaroxaban uneventfully and subsequently discharged on postoperative day 26. Herein, we report a case of right atrial thrombi and pulmonary embolism likely augmented by the Chiari network, which was successfully treated with surgical thrombectomy.

Neonatal Marfan syndrome is the most severe form of Marfan syndrome usually showing critical cardio-respiratory symptoms from the neonatal period or early infancy. We report a boy with this syndrome who presented with heart failure at 3 months of age and was referred to our department at 6 months old after intense medical treatment. He had enophthalmos, funnel chest, arachnodactyly, and Steinberg's thumb sign, but had no family history of Marfan syndrome or other cardiac diseases. Left ventricular dilatation, severe mitral regurgitation and moderate tricuspid regurgitation were noted on echocardiography. Mitral valvuloplasty and tricuspid annuloplasty were performed, and the regurgitation improved to trivial and mild level, respectively. However, rapid exacerbation of mitral regurgitation occurred, and the patient fell into circulatory collapse which needed circulatory support with extracorporeal membrane oxygenator (ECMO) on 18th postoperative day. In the emergency operation, the previous surgical procedures on the mitral valve were intact and we thought that rapid progression of the mitral annular dilatation and valve expansion to be the cause of exacerbation. Mitral valve replacement (Regent® 21 mm aortic) was performed, and the cardiac function improved, but ECMO was still needed because of the depressed respiratory function. Furthermore, tricuspid regurgitation due to annular dilatation and valve expansion was aggravated rapidly which needed tricuspid valve replacement (ATS® 20 mm mitral) 9 days after the mitral valve replacement. ECMO was ceased on the 37th day and the patient was extubated on 71st day. He was discharged from the hospital 5 months after the first operation. One year has passed after discharge, and he is doing well with anticoagulation. In the treatment of neonatal Marfan syndrome, surgical procedure for valve repair is still controversial and it should be remembered that rapid exacerbation of the atrioventricular valve can occur even after satisfactory valve repair and there should be no hesitation regarding surgical intervention when needed.

Introduction: Recently, community-based medical education has become widespread in Japanese medical schools, but the current status is not clear on a national level. A second survey of community-based medical education at all Japanese medical schools was conducted. The first survey was done in 2011. Methods: Members of the Council made and distributed a questionnaire to medical schools in order to assess the situation of community-based medical education as of April 2014. Results: A total of eighty schools responded. The number of schools which had community medicine programs was seventy-eight. In the first survey, the number was seventy-three. Seventy-seven schools gave community-based clinical clerkships. Discussion: The number of medical schools that had curriculum about community medicine was more than indicated in the first survey. Further research about the contents or implementation system of community-based clerkships is needed.