A Case of Redo-Mitral Valve Replacement for a Björk-Shiley Delrin Valve Implanted 47 Years Previously / 日本心臓血管外科学会雑誌

We report a case of redo mitral valve replacement (MVR) for a Björk-Shiley Delrin valve implanted 47 years previously. A 71-year-old man initially underwent MVR for mitral regurgitation at our hospital at the age of 16 years. Following the operation, follow-up examinations were performed at the outpatient clinic and annual transthoracic echocardiogram findings showed only mild mitral regurgitation, with no adverse events noted. However, a transthoracic echocardiogram examination performed 45 years after the operation revealed mild to moderate mitral regurgitation, while dyspnea with exertion was also noted at that time. As part of a more detailed examination, transesophageal echocardiogram results showed moderate transvalvular leakage. Redo MVR was subsequently performed under the diagnosis of prosthetic valve dysfunction. Analysis of the explanted prosthetic valve revealed wear of the Delrin disk, and widening of the gap between the disk and strut, which were presumed to be the cause of transvalvular leakage. A half century has passed since introduction of the Björk-Shiley valve and the present is a rare case of valve malfunction. Presented here are related details, along with a review of existing literature and results of Björk-Shiley valve use at our hospital.

Research progress on the design of fixed implant-supported prostheses in edentulous jaws / 口腔疾病防治

@#With the aging of the population and the increase in the number of edentulous patients, implant-supported fixed restorations have become more prevalent in clinical treatment. It is necessary to assess the patient's remaining bone and occlusal situation correctly; the upper jaw usually needs 6 to 8 implants, whereas the lower jaw needs 4 to 6 implants. Patients with severe alveolar bone atrophy can adopt the "all-on-4/6" treatment plan, short implants, and zygomatic and pterygomaxillary implants to avoid complex bone grafting and remain cautious when the surgical procedures require more surgical experience. According to the repair methods, the superstructure can be divided into one-piece repair and segmental repair. One-piece repair has a lower implant number, flexible location, and reasonable stress distribution but a high maintenance cost. Sectional repair easily achieves passive placement, convenient cleaning, and maintenance in the late stages, but implants need quantity and high requirements for alveolar bone. However, the requirements for alveolar bone and implant number are high. Mutually protected occlusion with minimal or no cantilever on provisional prosthesis is recommended.

Tilted implantation technique for edentulous patients / 华西口腔医学杂志

The tilted implantation technique is characterized by placing the implant at an angle of more than 15° and less than 45° from the horizontal plane. This technique can avoid damaging the maxillary sinus, inferior alveolar nerve, nasal base, and other anatomical structures when the height of the upper and lower jaw available bone is insufficient, to maximize the use of available bone and avoid a large range of bone increment. The tilted implantation technique can reduce the trauma of the surgery, increase the possibility of immediate restoration and shorten the treatment cycle, which has been widely used clinically. In this review, the scope of application, design elements, design scheme and complications of the tilted implantation technique for edentulous patients will be described.

A Case of Redo-Aortic Valve Replacement for a Lillehei-Kaster Valve Implanted 42 Years Ago / 日本心臓血管外科学会雑誌

We present a case of redo aortic valve replacement (AVR) in a 71-year-old man with a Lillehei-Kaster valve implanted 42 years prior. The patient initially underwent AVR and open mitral commissurotomy procedures for aortic regurgitation complicated with mitral stenosis in 1978 at the age of 29. Thereafter, he was followed at our outpatient clinic and treated without anticoagulant therapy for the initial two decades of the postoperative period. During the long-term follow-up, the mean pressure gradient remained between 40 and 60 mmHg and there were no adverse events noted before occurrence of heart failure triggered by tachycardia and pneumonia. Following improvement of heart failure, redo AVR was performed. There was no structural damage, thrombosis, or Lillehei-Kaster valve opening restrictions, though severe pannus growth on the left ventricle side was observed, which was thought to be the cause of the increased pressure gradient. This is the first known report of redo AVR after many years in a patient who underwent Lillehei-Kaster valve implantation. Furthermore, no other study has noted findings regarding pressure gradient change during the long-term follow-up period in such cases.

Development of tilted implant for free end of maxillary posterior teeth / 华西口腔医学杂志

Vertical bone insufficiency in the maxillary posterior teeth is a common clinical situation. At present, the bone insufficiency in the maxillary posterior teeth is mainly overcome by bone grafting through maxillary sinus floor elevation. Compared with traditional axial implantation, tilted implantation can better avoid bone grafting, reduce complications, shorten the treatment cycle, reduce the treatment cost for patients, and gradually be promoted in clinical settings. This article reviews the concept, biomechanics, clinical evaluation, and digital trend of tilted implants of maxillary posterior teeth.

Outcomes of Anti-vascular Endothelial Growth Factor Treatment for Foveal Serous Retinal Detachment Associated with Inferior Staphyloma

PURPOSE: To evaluate the efficacy of anti-vascular endothelial growth factor (VEGF) treatment of eyes with foveal serous retinal detachment (SRD) associated with inferior staphyloma and to investigate choroidal thickness changes following anti-VEGF therapy. METHODS: In this observational case series, eyes with inferior staphyloma accompanied by foveal SRD were treated with a single intravitreal anti-VEGF injection, followed by further injections as needed. Changes in height and width of subretinal fluid (SRF) and visual acuity after treatment were assessed. Choroidal thickness was measured at the subfovea, 1.5 mm superior and inferior to the fovea using enhanced depth imaging optical coherence tomography at baseline and 1 month after initial anti-VEGF therapy. RESULTS: Six eyes from six patients were included. One month after the initial injection, the mean SRF height and width had decreased significantly from 112.5 ± 40.1 to 44.5 ± 48.7 µm (p = 0.046) and from 1,401.8 ± 627.3 to 690.7 ± 634.7 µm (p = 0.028), respectively. Mean choroidal thickness at the superior point decreased from 218.7 ± 59.3 to 200.5 ± 61.0 µm (p = 0.046). SRF resolved completely in three of the six eyes (50%) with a mean of 6.8 ± 5.9 injections (range, 1 to 15). All eyes experienced at least one recurrence of exudation, at a mean interval of 4.8 months. Mean visual acuity improvement was 0.17 logarithm of the minimum angle of resolution units at a mean of 28.7 months follow-up. CONCLUSIONS: Anti-VEGF therapy resulted in an SRF decrease and modest visual improvement in eyes with foveal SRD associated with inferior staphyloma. Reduction in superior choroidal thickness appeared to contribute to the clinical improvements that were observed.

Maxillary complete denture and mandibular All-on-4 implant restoration considering maintenance: a case report

In the case of edentulous patients, the total amount of occlusal force is dispersed by the keratinized gingiva during mastication, in result, causing lower masticatory and chewing efficiency. In particular, the mandibular area has more side effects such as pain than the maxilla has. It gets worse when the patient has more absorption of alveolar bone, but the implant treatment is often interrupted due to the existence of the inferior alveolar nerve. In this case, a patient treated with the all-on-4 method by placing the implant in the anterior part of mandible and with the conventional complete denture for the maxilla has maintained without complications and was satisfied with the restoration both functionally and esthetically.

Dynamic simulation and experimental verification of human body turning over in supine position / 生物医学工程学杂志

The tilted supine position has been evaluated to be one of the significantly effective approaches to prevent bedsore of the patients in the bedridden state. Thus, it has deeply positive influences that in view of dynamics this study explores how the position works. Based on the anatomical theories, this study formulates the human dynamic model. Furthermore, the dynamic simulation of three usual postures in tilted supine position including lying on back, lying with one knee bent and lying with the upper and lower limb on one side lifted is carried out. Therefore, the changes of the three driving forces named as chest force, waist force and thigh force in the tilted supine position can be observed. In order to verify the validity of this simulation, this study obtains the electromyogram measurements of ectopectoralis, external obliques and thigh muscles which are respectively close to the chest, waist and thigh by conducting the human force measurements experiment. The result revealed that in terms of range and trend, the experimental data and simulation's data were consistent. In conclusion, the changes of these muscles in the supine position movements are researched efficiently by both this experiment and the dynamic simulation. Besides, the result is crucially key to find the mechanism of human's tilted supine position movements.

A Case of Polypoidal Choroidal Vasculopathy and Serous Retinal Detachment in a Bilateral Dome-shaped Macula

PURPOSE: To report a case of polypoidal choroidal vasculopathy in the right eye which improved after intravitreal injection of anti-vascular endothelial growth factor, and serous retinal detachment (SRD) in the left eye which improved spontaneously in a patient with a bilateral dome-shaped macula (DSM) with a tilted optic disc and inferonasal posterior staphyloma. CASE SUMMARY: A 50-year-old female visited our clinic with visual disturbance of the right eye for 5 days. A tilted optic disc with inferonasal posterior staphyloma and DSM were observed in both eyes by fundus examination and spectral domain optical coherence tomography (SD-OCT), and there was no specific finding in the left eye, but pigment epithelial detachment (PED) with subretinal hemorrhage was observed in the right eye. Polyps and branching vascular networks were found using indocyanine green angiography. We performed intravitreal C3F8 gas and aflibercept injection. After 3 months, SD-OCT of the right eye showed no subretinal hemorrhage and diminished PED. SD-OCT of the left eye showed SRD but the SRD disappeared after 1 month. SD-OCT of the left eye showed no recurrence of the SRD. CONCLUSIONS: In a patient with a tilted optic disc and dome-shaped macula, polypoidal choroidal vasculopathy and SRD may occur, so appropriate treatment will be necessary.

Application of digital implant system on implant treatment with “all-on-4” concept / 대한치과보철학회지

Recently, digital implant systems are expanding its influence in dental area. Due to technical improvement, they jumped over their limits nowadays. We can use these newest systems to treat edentulous patient, from implant surgery to fabrication of prosthesis. In this case, The patient was a fifty years old female. She had a full edentulous ridge on mandible and wanted to reconstruct occlusion with using implants. We planned to use digital implant system with “all-on-4” concept on mandible and produced surgical guide for flapless implant surgery. After the surgery, we tried to fabricate full arch prosthesis just using a digital devices and confirmed satisfying result.

Tilted implants and final fixed prostheses treatment in edentulous mandible with severely resorbed / 实用医学杂志

Objective To evaluate the clinical outcomes of severely resorbed edentulous mandibles with tilted implants and fixed prostheses. Methods Ten patients with severely resorbed edentulous mandibles were en-rolled. Each patient received 4 implants,two posteriors placed tilted implants. Immediate loading of tilted implants were applied in all cases using a fixed provisional prosthesis. All patients were finalized 3-4 months with fixed pros-theses. Results 40/40 implants with initial torque(>35N.cm)were followed 1-1.5 years presenting 100%surviv-al. Conclusion The method of using tilted implants and fixed prostheses in the cases of severely resorbed edentu-lous mandibles can achieve an ideal short-term and medium-term effects.

Clinical application and research progress of All-on-Four / 口腔疾病防治

@#To seek convenient and effective method for reconstruction of edentulous jaw, Maló and his colleagues developed All-on-Four implant immediate-function concept. The principle of All-on-Four is to support the full-arch prosthesis by 4 implants and to achieve immediate loading after surgery. Its advantages include avoiding additional bone grafting, evading critical anatomical structures and immediate prosthesis. In recent years, All-on-Four technique has been widely utilized in clinical practice as a viable approach for edentulous patients. With the auxiliary of guided surgery and biomechanical researches, All-on-Four has achieved predictable clinical results. In this paper, the development, investigation of biomechanics and main points of surgery and prosthesis of All-on-Four were briefly reviewed.

Zirconia ceramic fixed dental prosthesis with all-on-4 concept implants for irradiated maxilla: A case report / 대한치과보철학회지

The implant-supported fixed dental prosthesis in irradiated maxilla needs meticulous treatment planning due to low bone healing capacity. All-on-4 concept implantation can reduce the number of implants to be placed avoiding bone grafting procedure. Conventionally, prefabricated angled abutments for tilted implants have been used. However, in this case, it was replaced with computer-aided design and computer-aided manufacturing (CAD/CAM) abutment. This case report described all-on-4 concept implantation and fabrication of CAD/CAM zirconia fixed dental prostheses using CAD/CAM titanium abutments.

Fracture load and fracture modes of prefabricated fiber post restoration in different tilted mandible premolars:A pilot study / 实用口腔医学杂志

80 extracted human mandible premolars were divided into 10 groups(n =8)based on the post with different tilted angles(0°, buccal 15°and 30°,ligual 15°and 30°).The samples in experiment group were restored with fiber post while in the control group with cast post.Then all the teeth were restored with cast crown and bonded by glass ionomer.Compressive load with the speed of 1.0 mm/min was ap-plied to the restored teeth with a universal material testing machine until failure and the fracture modes were observed.The fracture load of fi-ber post and cast post restoration with the same tilted angles was similar(P >0.05).The main fracture mode of the teeth in all groups was unfavorable tooth fracture.No significant interaction was observed(P =0.217)between the 2 kinds of post and angulation of tilted teeth.

Changes in occlusal force depending on the movement of the adjacent and opposing teeth after loss of lower first molar: comparative study by using a strain gauge

PURPOSE: The aim of this study was to investigate the changes in occlusal force after loss of the lower first molar depending on the inclination and extrusion of the adjacent and opposing teeth by using a strain gauge. MATERIALS AND METHODS: Anatomic teeth were used to reconstruct the normal dental arch with loss of the lower right first molar. A uniformly thick layer of silicone was applied to the root to mimic the periodontal ligament. Four stages of dies with varying degrees of inclination and extrusion of the adjacent and opposing teeth were constructed and attached to master model interchangeably by using a CAD/CAM fabricated customized die system. The strain gauges were attached to teeth and a universal testing machine was used to determine the changes in occlusal force. An independent t-test and one-way ANOVA were performed (α = .05). RESULTS: While simulating chewing food, the upper first, second premolar and lower second molar showed greater occlusal force than before extraction. When the change of adjacent teeth's occlusal force with their progressive movement after molar loss was evaluated, the difference among four die models was significant and was in the decreasing aspect (P < 0.05). CONCLUSION: When the lower first molar was lost and the adjacent teeth did not move yet, the occlusal force in adjacent teeth was higher than that when the lower first molar still existed. In addition, the occlusal force in the upper premolars and lower second molar decreased significantly with the progressive movement of adjacent teeth.

Stress analysis in maxillary all-on-four model / Análisis del estrés en un modelo maxilar del concepto all-on-four

The aim of this research was to evaluate the load distribution in tilted distal implants used in the all-on-four system. Two implant schemes were used. In both, two vertical anterior implants and tilted posterior implants were installed, one group with an angulation of 15 and another with an angulation of 35. The implants were installed together with a bar binding them all in a photoelastic model obtained from a replica of an edentulous maxilla. In this model, loads were produced in the sector of the bar cantilever, the abutment of the tilted implants and over the four implants using devices specially designed for this purpose. The bands were recorded with a digital camera, and the qualitative and quantitative analyses were carried out by means of student's t-test and the Mann-Whitney test in Biostat v. 5.0, considering a level of p<0.05 to establish a statistically significant relation. In the qualitative analysis, the implant with 35 presented the greatest amount of stress on the cantilever forces at cervical level. The quantitative studies showed fewer differences in all aspects assessed, although significant differences were observed between the two systems when loads were applied at cantilever level. It can be concluded that there are minimal differences in the stress distribution when comparing implants with angulations of 15 or 35. However, there is a greater concentration of stress at the cervical level in implants tilted to 35.

El objetivo de esta investigación fue evaluar la distribución de cargas en implantes angulados distales utilizados en el sistema "All-On-Four". Dos esquemas de implantes fueron empleados. En ambos, dos implantes verticales en el área anterior y dos implantes angulados en el sector posterior fueron instalados, utilizando angulaciones de 15 y 35 o en estos últimos. Los implantes fueron instalados de forma conjunta mediante una barra unida al sistema de resina fotoelástica obtenida de una replica de una maxila edéntula. En este modelo, las cargas fueron producidas en el sector del cantiléver de la barra, el pilar del implante angulado y, mediante un sistema genérico, sobre la totalidad de los implantes. Las bandas de estrés fueron reconocidas en una cámara digital donde los análisis cualitativos y cuantitativos fueron realizados utilizando las pruebas t de Student y Mann-Whitney en el programa computacional Biostat v. 5.0, considerando un valor de p<0,05 para establecer diferencias significativas. En el análisis cualitativo, los implantes con 35 presentaron una gran cantidad de estrés en el área de cantiléver, principalmente a nivel cervical. Los estudios cuantitativos mostraron limitadas diferencias en todos los aspectos, aunque diferencias significativas fueron alcanzadas cuando se compararon ambos sistemas después de la carga a nivel del cantiléver. Se puede concluir que hay diferencias menores en la distribución de estrés cuando se comparan implantes dentales con angulación de 15 y 35. Sin embargo, existe una mayor cantidad de concentraciones de estrés a nivel cervical en los implantes con 35 de angulación.

Examining incisor root resorption using CBCT after orthodontic treatment for adults with skeletal classⅢmalocclusion / 天津医药

Objective To evaluate incisor root resorption of adults with skeletal classⅢmalocclusion through three-dimensional reconstruction of cone beam computed tomography (CBCT) image using interacting medical imaging control sys?tem (Mimics) and then offer guidance for labially tilted angle control in orthodontic treatment and distance of bone moving in surgery. Methods Adults of skeletal class Ⅲ malocclusion (n=30) who underwent orthodontic-orthognathic combination treatment were included in this study. CBCT images were then reconstructed three-dimensionally using Mimics 10.01. Each incisor were separated at cementum-enamel junction as crown and root. Labially tilted angle and root volumes of each inci?sor were measured before and after operations. At last, the correlativity between root resorption and labially tilted angle was calculated through statistic analysis. Results The decrement of upper, lower and front incisors’root volumes upon treat?ment is statistically significant. However, there is no statistically significant difference of incisor ’s root volumes among eight incisors nor between different gender. There is linear correlation between root volumes and labially tilted angle when the lat?ter changes 7° or more when they followed the fomular =-21.416+5.618X. Conclusion For adults with skeletal classⅢmalocclusion, orthodontic treatment before orthognathic surgery decrease incisor root volumes when labially tilted angle changes 7° or more.

Use of Tilted Implants in Prosthetic Rehabilitation / Uso de Implantes Inclinados en la Rehabilitación Protésica

Biomechanical measurements show that tilted implants, when part of a prosthetic support, avoid the use of distal cantilever units. This study included 20 women (78%) and 12 men (22%), aged over 50 years old (89%), with a total of 156 implants. A delayed occlusal loading protocol was used and the average distal implant length and diameter were 10 mm and 4 mm respectively. Patients were followed up for 2 to 5 years after prosthesis connection. The aims of this study are to analyze the use of tilted implants in prosthetic rehabilitation of maxillae to reduce cantilevers length, and to study the biomechanical implications of implant-bone interface.

Mediciones biomecánicas demuestran que los implantes inclinados, cuando son parte de un soporte de prótesis, evitan el uso de unidades distales en voladizo. Se incluyeron 20 mujeres (78%) y 12 hombres (22%), mayores de 50 años (89%), con un total de 156 implantes. Se utilizó un protocolo de carga oclusal retardada, y la longitud y el diámetro promedios del implante a nivel distal distal, fue de 10 mm y 4 mm, respectivamente. Los pacientes fueron seguidos durante 2 a 5 años después de la conexión de la prótesis. El objetivo de este estudio consiste en analizar el uso de los implantes inclinados en la rehabilitación protésica de maxilares para reducir la longitud de los voladizos, y estudiar las implicaciones biomecánicas de la interfase hueso-implante.

Función protésica inmediata con técnica all on-4 mandibular: primer reporte al 1er año de carga inmediata / Immediate prosthetic function with all on-4 mandibular technique: first report after 1 year of immediate loading

Propósito: El objetivo del presente estudio prospectivo es la observación del comportamiento de la función protésica inmediata sobre implantes axiales en combinación con implante inclinados posteriores distribuidos poligonalmente en mandíbulas edéntulas. Material y Métodos: De un grupo de 28 individuos desdentados completos mandibulares se observaron 25 individuos distribuidos en 13 hombres y 12 mujeres con un promedio de edad de 57.8 años, bajo la modalidad de rehabilitación protésica implanto asistida en distribución poligonal de arco completo híbrida con una barra de titanio soldada de sección circular de 2mm de grosor instalada a las 48 hrs. de realizada la inserción de los implantes, la cual a los 3 meses fue cambiado por una estructura colada en titanio como prótesis definitiva. Durante el periodo de observación se evaluó la tasa de éxito implantario, las complicaciones biológicas y mecánicas por un periodo inicial de 1 año. El protocolo se inicia con la valoración y confección de un enfilado dentario de prótesis completa convencional, el que, una vez aceptado por el paciente, es duplicado para la confección de una guía tomográfica, con la cual se procederá a la toma de un scanner dental, relacionado las necesidades protésicas y la distribución implantaria en relación a la emergencia y prolongación del nervio mentoniano, altura del foramen mentoniano y forma de la mandíbula. Todos los pacientes fueron operados elevando un colgajo de espesor total y utilizando la guía quirúrgica All on-4 (Nobel Biocare) bajo sedación endovenosa y utilizando una cubeta multifuncional para la toma de registros maxilomandibulares e implantarios en el proceso de carga imediata...

Purpose: The purpose of this prospective study is the observation of the behaviour of immediate occlusal loading with axial implants in combination with posterior tilted implants in edentulous mandibles polygonally distributed. Methods: From a group of 28 individuals with complete edentulous mandible, 25 individuals distributed in 13 men and 12 women were observed with an average age of 57.8 years, under the implant-assisted prosthetic rehabilitation modality in full arch polygonal hybrid distribution with a welded 2mm-thick titanium bar of circular section installed 48 hrs after insertion of the implant, which was changed after 3 months to a titanium casting structure as definitive prosthesis. During the observation period, the implant success rate, biological and mechanical complications were assessed for an initial period of 1 year. The protocol begins with the assessment and preparation of the lining of a conventional complete denture. Once accepted by the patient, it is doubled to make a tomographic guidance, used to take a dental scanner, The prosthetic needs and implant distribution are related to the emergence and continuation of the mental nerve, mental foramen and height and shape of the jaw. All patients were operated lifting a full-thickness flap and using the All on-4 (Nobel Biocare) surgical guide under intravenous sedation, and a flexible bucket for the maxillomandibular and implant records in the immediate loading...

Three-dimensional finite element analysis of tilted implants in the maxillary posterior region / 中国组织工程研究

BACKGROUND:Bone mass deficiency is common during implantation in the maxil ary posterior region. Some patients do not want to accept extra surgery for increasing bone because of surgical trauma or medical expenses. Technology of the tilted implant has been proposed, but it has not been recognized and has a lack of relevant evidence. OBJECTIVE:To investigate the stress distribution of per-implant bone which is subjected to different loading conditions when the different abutment angulations are applied, and to analyze the safety factor of different implants to verify the feasibility of the tilted implant in the maxil ary posterior region. METHODS:The finite element models of the different angulate abutments were established in commercial software packages. The safety factor of implant in the same power load was observed, and stress and strain condition of the implant and the surrounding bone was also observed. RESULTS AND CONCLUSION:With the increased abutment angulation, the maximum strain of pre-implant bone was significantly increased, and the safety factor of implant decreased gradual y. Thus, the tilted implant is not recommended in the maxil ary posterior region.