Silicon(Si)diffraction microlens arrays are usually used to integrating with infrared focal plane arrays(IRFPAs)to improve their performance.The errors of lithography are unavoidable in the process of the Si diffrac-t...Silicon(Si)diffraction microlens arrays are usually used to integrating with infrared focal plane arrays(IRFPAs)to improve their performance.The errors of lithography are unavoidable in the process of the Si diffrac-tion microlens arrays preparation in the conventional engraving method.It has a serious impact on its performance and subsequent applications.In response to the problem of errors of Si diffraction microlens arrays in the conven-tional method,a novel self-alignment method for high precision Si diffraction microlens arrays preparation is pro-posed.The accuracy of the Si diffractive microlens arrays preparation is determined by the accuracy of the first li-thography mask in the novel self-alignment method.In the subsequent etching,the etched area will be protected by the mask layer and the sacrifice layer or the protective layer.The unprotection area is carved to effectively block the non-etching areas,accurately etch the etching area required,and solve the problem of errors.The high precision Si diffraction microlens arrays are obtained by the novel self-alignment method and the diffraction effi-ciency could reach 92.6%.After integrating with IRFPAs,the average blackbody responsity increased by 8.3%,and the average blackbody detectivity increased by 10.3%.It indicates that the Si diffraction microlens arrays can improve the filling factor and reduce crosstalk of IRFPAs through convergence,thereby improving the perfor-mance of the IRFPAs.The results are of great reference significance for improving their performance through opti-mizing the preparation level of micro nano devices.展开更多
Objective: To study the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to determine the risk factors associated with the occurrence of this pathology. Method: An observational retrospective ...Objective: To study the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to determine the risk factors associated with the occurrence of this pathology. Method: An observational retrospective study was conducted in the Department of Oncology, Rheumatology, and Maxillofacial Surgery of Ibn Rochd University Hospital, Casablanca. The study utilized complete medical records from 2014 to 2022 and included consultations of patients receiving bisphosphonates (BPs) in July and September 2022. Statistical analysis was performed using SPSS version 16.0. Results: Our study population comprised 104 patients, of whom 91% were women and 49% were over 65 years old. Seventy-two percent of patients had a general pathology. Among them, 64 patients were treated with zoledronate, 43 with alendronate, and the remainder with risedronate, ibandronate, and pamidronate. The most common indications for treatment were bone metastasis following breast cancer (29.8%) and osteoporotic fractures (19.2%). Sixty-seven patients received intravenous (IV) treatment;only 10.5% exhibited good oral health. Fifty percent of patients underwent dental treatment, primarily tooth extractions. Osteonecrosis of the jaw (ONJ) was diagnosed in 1.9% of patients, predominantly in stages 1 and 2. Conclusion: Second and third-generation bisphosphonates are more strongly associated with the development of ONJ. Risk factors include monthly IV administration, poor oral health, comorbidities such as diabetes, medications like corticosteroids, invasive dental procedures, and not only oncological conditions but also rare indications such as bone algodystrophy. Nevertheless, our observed prevalence of 1.9% aligns with international rates ranging from 0.8% to 12%. However, most of the studies that have been carried out have been retrospective studies with insufficient numbers of patients. Further prospective epidemiological studies based on standardized protocols with rigorous and appropriate follow-up over several years are essential to determine the exact prevalence of ONJ.展开更多
The current parallel ankle rehabilitation robot(ARR)suffers from the problem of difficult real-time alignment of the human-robot joint center of rotation,which may lead to secondary injuries to the patient.This study ...The current parallel ankle rehabilitation robot(ARR)suffers from the problem of difficult real-time alignment of the human-robot joint center of rotation,which may lead to secondary injuries to the patient.This study investigates type synthesis of a parallel self-alignment ankle rehabilitation robot(PSAARR)based on the kinematic characteristics of ankle joint rotation center drift from the perspective of introducing"suitable passive degrees of freedom(DOF)"with a suitable number and form.First,the self-alignment principle of parallel ARR was proposed by deriving conditions for transforming a human-robot closed chain(HRCC)formed by an ARR and human body into a kinematic suitable constrained system and introducing conditions of"decoupled"and"less limb".Second,the relationship between the self-alignment principle and actuation wrenches(twists)of PSAARR was analyzed with the velocity Jacobian matrix as a"bridge".Subsequently,the type synthesis conditions of PSAARR were proposed.Third,a PSAARR synthesis method was proposed based on the screw theory and type of PSAARR synthesis conducted.Finally,an HRCC kinematic model was established to verify the self-alignment capability of the PSAARR.In this study,93 types of PSAARR limb structures were synthesized and the self-alignment capability of a human-robot joint axis was verified through kinematic analysis,which provides a theoretical basis for the design of such an ARR.展开更多
Mandibular advancement devices(MADs)are widely used treatments for obstructive sleep apnea.MADs function by advancing the lower jaw to open the upper airway.To increase patient comfort,most patients allow the mouth to...Mandibular advancement devices(MADs)are widely used treatments for obstructive sleep apnea.MADs function by advancing the lower jaw to open the upper airway.To increase patient comfort,most patients allow the mouth to be opened.However,not all systems maintain the lower jaw in a forward position during mouth opening,which results in the production of a retrusion that favors the collapse of the upper airway.Furthermore,the kinematic behavior of the mechanism formed by the mandible-device assembly depends on jaw morphology.This means that,during mouth opening,some devices cause lower jaw protrusion in some patients,but cause its retraction in others.In this study,we report the behavior of well-known devices currently on themarket.To do so,we developed a kinematic model of the lower jawdevice assembly.Thismodelwas validated for all devices analyzed using a high-resolution camera system.Our results show that some of the devices analyzed here did not produce the correct behavior during patient mouth opening.展开更多
Jaw and maxillofacial bone lesions encompass a wide variety of both neoplastic and non-neoplastic pathologies.These lesions can arise from various tissues,including bone,cartilage,and soft tissue,each presenting disti...Jaw and maxillofacial bone lesions encompass a wide variety of both neoplastic and non-neoplastic pathologies.These lesions can arise from various tissues,including bone,cartilage,and soft tissue,each presenting distinct challenges in diagnosis and treatment.While some pathologies exhibit characteristic imaging features that aid in diagnosis,many others are nonspecific.This overlap often necessitates a multimodal imaging approach,combining techniques such as radiographs,computed tomography,and magnetic resonance imaging to achieve a diagnosis or narrow the diagnostic considerations.This article provides a comprehensive review of the imaging approach to jaw and maxillofacial bone tumors,including updates on the 2022 World Health Organization classification of these tumors.The relevant anatomy of the jaw and dental structures that is important for accurate imaging interpretation is discussed.展开更多
BACKGROUND Currently,the differentiation of jaw tumors is mainly based on the lesion’s morphology rather than the enhancement characteristics,which are important in the differentiation of neoplasms across the body.Th...BACKGROUND Currently,the differentiation of jaw tumors is mainly based on the lesion’s morphology rather than the enhancement characteristics,which are important in the differentiation of neoplasms across the body.There is a paucity of literature on the enhancement characteristics of jaw tumors.This is mainly because,even though computed tomography(CT)is used to evaluate these lesions,they are often imaged without intravenous contrast.This study hypothesised that the enhancement characteristics of the solid component of jaw tumors can aid in the differentiation of these lesions in addition to their morphology by dual-energy CT,therefore improving the ability to differentiate between various pathologies.AIM To evaluate the role of contrast enhancement and dual-energy quantitative parameters in CT in the differentiation of jaw tumors.METHODS Fifty-seven patients with jaw tumors underwent contrast-enhanced dual-energy CT.Morphological analysis of the tumor,including the enhancing solid component,was done,followed by quantitative analysis of iodine concentration(IC),water concentration(WC),HU,and normalized IC.The study population was divided into four subgroups based on histopathological analysis-central giant cell granuloma(CGCG),ameloblastoma,odontogenic keratocyst(OKC),and other jaw tumors.A one-way ANOVA test for parametric variables and the Kruskal-Wallis test for nonparametric variables were used.If significant differences were found,a series of independent t-tests or Mann-Whitney U tests were used.RESULTS Ameloblastoma was the most common pathology(n=20),followed by CGCG(n=11)and OKC.CGCG showed a higher mean concentration of all quantitative parameters than ameloblastomas(P<0.05).An IC threshold of 31.35×100μg/cm^(3) had the maximum sensitivity(81.8%)and specificity(65%).Between ameloblastomas and OKC,the former showed a higher mean concentration of all quantitative parameters(P<0.001),however when comparing unilocular ameloblastomas with OKCs,the latter showed significantly higher WC.Also,ameloblastoma had a higher IC and lower WC compared to“other jaw tumors”group.CONCLUSION Enhancement characteristics of solid components combined with dual-energy parameters offer a more precise way to differentiate between jaw tumors.展开更多
Objective:To analyze the effectiveness of personalized 3D-printed rehabilitation orthotics in the postoperative recovery of jaw fractures.Methods:Relevant data were collected from 42 patients with jaw fractures treate...Objective:To analyze the effectiveness of personalized 3D-printed rehabilitation orthotics in the postoperative recovery of jaw fractures.Methods:Relevant data were collected from 42 patients with jaw fractures treated at our hospital between October 2017 and May 2020.Patients were randomly divided into a traditional group(n=17)and a modified group(n=25).The traditional group received standard rehabilitation methods,while the modified group used personalized 3D-printed rehabilitation orthotics combined with improved rehabilitation methods.The temporomandibular disability index(TDI),quality of life scores,postoperative recovery excellence rate,and mouth opening were compared between the two groups at different follow-up times(before rehabilitation,and at 1 week,3 months,and 6 months post-surgery).Results:At 1 week,3 months,and 6 months post-surgery,the TDI in both the traditional and modified groups was significantly lower than before rehabilitation,with statistically significant differences(P<0.05).At 3 and 6 months post-surgery,the TDI in the modified group was lower than in the traditional group,with statistically significant differences(P<0.05).At 3 and 6 months post-surgery,pain,appearance,activity,recreation,work,chewing,swallowing,speech,shoulder function,and total quality of life scores in both groups were higher than before rehabilitation,with the modified group showing significantly higher scores in pain,appearance,chewing,swallowing,and total quality of life(P<0.05).Compared to before rehabilitation,mouth opening significantly improved in both groups at 3 and 6 months post-surgery,with the modified group showing significantly greater improvement(P<0.05).Conclusion:Personalized 3D-printed rehabilitation orthotics are highly effective in the postoperative recovery of jaw fractures.They can improve patients’quality of life after surgery,enhance the excellent rate of postoperative recovery,and increase mouth opening.展开更多
A dynamics model of the self-aligning ball bearing is proposed based on the Jones-Harris method (JHM), and a computer program is developed to solve the equations by using the Newton-Raphson method. A parametric anal...A dynamics model of the self-aligning ball bearing is proposed based on the Jones-Harris method (JHM), and a computer program is developed to solve the equations by using the Newton-Raphson method. A parametric analysis of the centrifugal force and the gyroscopic moment, the contact loads, the contact angles, the radial deformation and the radial stiffness is carried out. The analytical results show that the applied loads and the rotational speed are two main factors that can influence the distributions of the contact loads and values of the contact angles. The centrifugal force and the gyroscopic moment increase with the increase in the rotational speed, resulting in the decrease of the inner raceway contact load and the increase of the outer raceway contact load. The outer raceway contact angle increases under the centrifugal force; on the contrary, the inner raceway contact angle decreases. Furthermore, the differences between the inner and the outer contact angles increase with the increase in the rotational speed. The higher rotational speed results in the decrease in radial stiffness for the self-aligning ball bearing, and the raceway curvature coefficient, to some extent, also influences the radial stiffness.展开更多
AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1...AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations(bone quantity and density), radiographic techniques, implant selection(number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.展开更多
Objective: To characterize the diagnostic features of ossifying fibroma (OF) and fibrous dysplasia (FD) of the jaw bones. Study Design: A histopathological and radiological analysis with full clinical documentation. S...Objective: To characterize the diagnostic features of ossifying fibroma (OF) and fibrous dysplasia (FD) of the jaw bones. Study Design: A histopathological and radiological analysis with full clinical documentation. Setting: University of Nairobi Dental Teaching Hospital (UNDH). Study Population: All archival cases diagnosed as FD and OF from 1992-2006 were retrieved from the UNDH Oral Pathology Laboratory records. New cases were included as they pre-sented over a 6-month period from January to June 2007. Methodology: Information regarding the histological type of a fibro-osseous lesion (FOL) including the clinical features, demographic and radiographic data was documented for analysis;and comparison between pathological parameters and the final diagnosis was evaluated with the chi-square test. Results: FD lesions constituted 40 (27.2%) cases while 107 (72.8%) were OF. The age ranged from 1 - 72 years (mean = 24.19 ± SD 13 years). The differences in the gender distribution were not statistically significant. Radiographic analyses showed statistically significant differences between the appearances of the body (p = 0.012) and the margins (p = 0.003) of FD and OF. The microscopic differences between the two lesions were not statistically significant. Conclusion: Differentiation between FD and OF is only possible after critically analyzing the clinical, radiological and histological criteria.展开更多
Aim: To report a series of thirty cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Material and Methods: For 30 patients with BRONJ, gender, age, underlying diagnosis, type of bisphosphonate (BP), adm...Aim: To report a series of thirty cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Material and Methods: For 30 patients with BRONJ, gender, age, underlying diagnosis, type of bisphosphonate (BP), administration route and duration, location and stage of osteonecrosis, symptoms and oral health status, radiological findings of the jaws, treatment and outcome, were recorded. Results: Underlying diagnoses in the series (12 male;18 female;mean age 70.50 ± 9.62) were: 12 multiple myeloma, 7 breast cancer, 3 prostate carcinoma, 1 kidney/lung/ bladder/mediastinal cancer, 1 chronic lymphocytic leukemia, 1 osteoporosis, 1 palatal osteosarcoma + osteoporosis, 1 non-Hodgkin’s lymphoma. Forty-seven osteonecrotic lesions were detected;30 localized in the mandible,17 inthe maxilla;trigger events were tooth extraction in 31 cases (66%), periodontal disease in 4 (8.50%), incongruous dentures in 3 (6.40%), perimplantitis in 1 (2.10%), unknown in 8 (17%). Twenty-nine patients had received treatment using amino bisphosphonates (25 zoledronate, 2 pamidronate, 2 alendronate) and 1 clodronate;the administration route was intravenous in 27 patients, oral in 2 and intramuscular in 1. Mean number of doses to bone exposure for patients was 34.11 for zoledronate, 50.50 for pamidronate, 146 for alendronate, and 500 for clodronate. Among statistical data the only significant finding was that panoramic dental radiography gave no concrete support for diagnosis of ONJ lesions (p ≤ 0.04). Conclusions: Our case series reflects literature data. We emphasize the insufficient role of panoramic radiography to study osteonecrotic lesions and the role of poor oral hygiene.展开更多
Central mucoepidermoid carcinoma of the jaws (CMCJ) is an extremely rare neoplasm. The clinical manifestation of CMCJ is nonspecific, which includes swelling, pain, mobile teeth and bleeding, etc. To develop the diagn...Central mucoepidermoid carcinoma of the jaws (CMCJ) is an extremely rare neoplasm. The clinical manifestation of CMCJ is nonspecific, which includes swelling, pain, mobile teeth and bleeding, etc. To develop the diagnosis and treatment of CMCJ. this article presents 2 cases of CMCJ treated in our hospital. Their clinical data, treatment and prognosis were analyzed retrospectively.展开更多
Medication-related osteonecrosis of the jaws (MRONJ) is a relatively new disease. MARX reported first cases in 2003. MRONJ relates to oral and parenteral bisphosphonates as well as to the so-called target cancer thera...Medication-related osteonecrosis of the jaws (MRONJ) is a relatively new disease. MARX reported first cases in 2003. MRONJ relates to oral and parenteral bisphosphonates as well as to the so-called target cancer therapies but the list of medications only grows. Although MRONJ is a relatively rare condition, it can be associated to significant morbidity with feeding limitations and intense pain. More severe cases can lead to potentially life-threatening infections. Every patient initiating bisphosphonate and/or target cancer therapy must visit a dentist before starting medication because preventive measures for MRONJ are much more effective compared to surgical management of the lesions. Surgical resolution can be especially difficult to obtain in the coexistence of certain complication factors like wider bone exposures, history of nitrogen containing bisphosphonates use (mainly zolendronate) and immunodeficiency. Recently, researchers have given attention to laser therapy associated to photosensitive agents as a possible option to management of some MRONJ lesions. Our case report demonstrates the use of photodynamic therapy in a denosumab related lesion in the mandible. It seems that denosumab related lesions are more amenable to treatment and total resolution because of the marked differences between its chemical and metabolic characteristics when compared to bisphosphonates.展开更多
Inflammatory jaw bone diseases are common in stomatology,including periodontitis,peri-implantitis,medication-related osteonecrosis of the jaw,radiation osteomyelitis of the jaw,age-related osteoporosis,and other speci...Inflammatory jaw bone diseases are common in stomatology,including periodontitis,peri-implantitis,medication-related osteonecrosis of the jaw,radiation osteomyelitis of the jaw,age-related osteoporosis,and other specific infections.These diseases may lead to tooth loss and maxillofacial deformities,severely affecting patients'quality of life.Over the years,the reconstruction of jaw bone deficiency caused by inflammatory diseases has emerged as a medical and socioeconomic challenge.Therefore,exploring the pathogenesis of inflammatory diseases associated with jaw bones is crucial for improving prognosis and developing new targeted therapies.Accumulating evidence indicates that the integrated bone formation and dysfunction arise from complex interactions among a network of multiple cell types,including osteoblast-associated cells,immune cells,blood vessels,and lymphatic vessels.However,the role of these different cells in the inflammatory process and the'rules'with which they interact are still not fully understood.Although many investigations have focused on specific pathological processes and molecular events in inflammatory jaw diseases,few articles offer a perspective of integration.Here,we review the changes and mechanisms of various cell types in inflammatory jaw diseases,with the hope of providing insights to drive future research in this field.展开更多
目的系统评价使用双膦酸盐药物(bisphosphonates,BPs)患者种植体早期失败率及种植术后药物相关性颌骨坏死(medication-related osteonecrosis of the jaw,MRONJ)发生率,为临床评估相关风险提供依据。方法计算机检索Cochrane Library、Wi...目的系统评价使用双膦酸盐药物(bisphosphonates,BPs)患者种植体早期失败率及种植术后药物相关性颌骨坏死(medication-related osteonecrosis of the jaw,MRONJ)发生率,为临床评估相关风险提供依据。方法计算机检索Cochrane Library、Wiley Online Library、PubMed、中国知网、万方数据知识服务平台,收集纳入各数据库建库至2022年5月发表的关于使用BPs患者种植体早期失败或种植术后发生MRONJ的临床研究。采用Stata 15.0软件对种植体早期失败率进行单组率Meta分析。结果共纳入13篇文献,其中口服BPs患者植入1182颗种植体,静脉注射BPs患者植入79颗,共计1261颗种植体。口服BPs患者合并种植体早期失败率为1.7%(95%CI:0.3%~3.9%),MRONJ发生率为0。静脉注射BPs患者种植体早期失败率为0,MRONJ发生率为5.6%。结论口服BPs患者种植体早期失败率及术后MRONJ发生率低,与健康人群基本相当。静脉使用BPs患者种植术后发生MRONJ风险较高,临床适应证选择应慎重。展开更多
基金Supported by the National Natural Science Foundation of China(NSFC 62105100)the National Key research and development program in the 14th five year plan(2021YFA1200700)。
文摘Silicon(Si)diffraction microlens arrays are usually used to integrating with infrared focal plane arrays(IRFPAs)to improve their performance.The errors of lithography are unavoidable in the process of the Si diffrac-tion microlens arrays preparation in the conventional engraving method.It has a serious impact on its performance and subsequent applications.In response to the problem of errors of Si diffraction microlens arrays in the conven-tional method,a novel self-alignment method for high precision Si diffraction microlens arrays preparation is pro-posed.The accuracy of the Si diffractive microlens arrays preparation is determined by the accuracy of the first li-thography mask in the novel self-alignment method.In the subsequent etching,the etched area will be protected by the mask layer and the sacrifice layer or the protective layer.The unprotection area is carved to effectively block the non-etching areas,accurately etch the etching area required,and solve the problem of errors.The high precision Si diffraction microlens arrays are obtained by the novel self-alignment method and the diffraction effi-ciency could reach 92.6%.After integrating with IRFPAs,the average blackbody responsity increased by 8.3%,and the average blackbody detectivity increased by 10.3%.It indicates that the Si diffraction microlens arrays can improve the filling factor and reduce crosstalk of IRFPAs through convergence,thereby improving the perfor-mance of the IRFPAs.The results are of great reference significance for improving their performance through opti-mizing the preparation level of micro nano devices.
文摘Objective: To study the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to determine the risk factors associated with the occurrence of this pathology. Method: An observational retrospective study was conducted in the Department of Oncology, Rheumatology, and Maxillofacial Surgery of Ibn Rochd University Hospital, Casablanca. The study utilized complete medical records from 2014 to 2022 and included consultations of patients receiving bisphosphonates (BPs) in July and September 2022. Statistical analysis was performed using SPSS version 16.0. Results: Our study population comprised 104 patients, of whom 91% were women and 49% were over 65 years old. Seventy-two percent of patients had a general pathology. Among them, 64 patients were treated with zoledronate, 43 with alendronate, and the remainder with risedronate, ibandronate, and pamidronate. The most common indications for treatment were bone metastasis following breast cancer (29.8%) and osteoporotic fractures (19.2%). Sixty-seven patients received intravenous (IV) treatment;only 10.5% exhibited good oral health. Fifty percent of patients underwent dental treatment, primarily tooth extractions. Osteonecrosis of the jaw (ONJ) was diagnosed in 1.9% of patients, predominantly in stages 1 and 2. Conclusion: Second and third-generation bisphosphonates are more strongly associated with the development of ONJ. Risk factors include monthly IV administration, poor oral health, comorbidities such as diabetes, medications like corticosteroids, invasive dental procedures, and not only oncological conditions but also rare indications such as bone algodystrophy. Nevertheless, our observed prevalence of 1.9% aligns with international rates ranging from 0.8% to 12%. However, most of the studies that have been carried out have been retrospective studies with insufficient numbers of patients. Further prospective epidemiological studies based on standardized protocols with rigorous and appropriate follow-up over several years are essential to determine the exact prevalence of ONJ.
基金Supported by Key Scientific Research Platforms and Projects of Guangdong Regular Institutions of Higher Education of China(Grant No.2022KCXTD033)Guangdong Provincial Natural Science Foundation of China(Grant No.2023A1515012103)+1 种基金Guangdong Provincial Scientific Research Capacity Improvement Project of Key Developing Disciplines of China(Grant No.2021ZDJS084)National Natural Science Foundation of China(Grant No.52105009).
文摘The current parallel ankle rehabilitation robot(ARR)suffers from the problem of difficult real-time alignment of the human-robot joint center of rotation,which may lead to secondary injuries to the patient.This study investigates type synthesis of a parallel self-alignment ankle rehabilitation robot(PSAARR)based on the kinematic characteristics of ankle joint rotation center drift from the perspective of introducing"suitable passive degrees of freedom(DOF)"with a suitable number and form.First,the self-alignment principle of parallel ARR was proposed by deriving conditions for transforming a human-robot closed chain(HRCC)formed by an ARR and human body into a kinematic suitable constrained system and introducing conditions of"decoupled"and"less limb".Second,the relationship between the self-alignment principle and actuation wrenches(twists)of PSAARR was analyzed with the velocity Jacobian matrix as a"bridge".Subsequently,the type synthesis conditions of PSAARR were proposed.Third,a PSAARR synthesis method was proposed based on the screw theory and type of PSAARR synthesis conducted.Finally,an HRCC kinematic model was established to verify the self-alignment capability of the PSAARR.In this study,93 types of PSAARR limb structures were synthesized and the self-alignment capability of a human-robot joint axis was verified through kinematic analysis,which provides a theoretical basis for the design of such an ARR.
基金supported by the research contracts 806/31.4830 and 806/31.5511 between the private company Laboratorio Ortoplus S.L.and the University of Malaga.
文摘Mandibular advancement devices(MADs)are widely used treatments for obstructive sleep apnea.MADs function by advancing the lower jaw to open the upper airway.To increase patient comfort,most patients allow the mouth to be opened.However,not all systems maintain the lower jaw in a forward position during mouth opening,which results in the production of a retrusion that favors the collapse of the upper airway.Furthermore,the kinematic behavior of the mechanism formed by the mandible-device assembly depends on jaw morphology.This means that,during mouth opening,some devices cause lower jaw protrusion in some patients,but cause its retraction in others.In this study,we report the behavior of well-known devices currently on themarket.To do so,we developed a kinematic model of the lower jawdevice assembly.Thismodelwas validated for all devices analyzed using a high-resolution camera system.Our results show that some of the devices analyzed here did not produce the correct behavior during patient mouth opening.
文摘Jaw and maxillofacial bone lesions encompass a wide variety of both neoplastic and non-neoplastic pathologies.These lesions can arise from various tissues,including bone,cartilage,and soft tissue,each presenting distinct challenges in diagnosis and treatment.While some pathologies exhibit characteristic imaging features that aid in diagnosis,many others are nonspecific.This overlap often necessitates a multimodal imaging approach,combining techniques such as radiographs,computed tomography,and magnetic resonance imaging to achieve a diagnosis or narrow the diagnostic considerations.This article provides a comprehensive review of the imaging approach to jaw and maxillofacial bone tumors,including updates on the 2022 World Health Organization classification of these tumors.The relevant anatomy of the jaw and dental structures that is important for accurate imaging interpretation is discussed.
文摘BACKGROUND Currently,the differentiation of jaw tumors is mainly based on the lesion’s morphology rather than the enhancement characteristics,which are important in the differentiation of neoplasms across the body.There is a paucity of literature on the enhancement characteristics of jaw tumors.This is mainly because,even though computed tomography(CT)is used to evaluate these lesions,they are often imaged without intravenous contrast.This study hypothesised that the enhancement characteristics of the solid component of jaw tumors can aid in the differentiation of these lesions in addition to their morphology by dual-energy CT,therefore improving the ability to differentiate between various pathologies.AIM To evaluate the role of contrast enhancement and dual-energy quantitative parameters in CT in the differentiation of jaw tumors.METHODS Fifty-seven patients with jaw tumors underwent contrast-enhanced dual-energy CT.Morphological analysis of the tumor,including the enhancing solid component,was done,followed by quantitative analysis of iodine concentration(IC),water concentration(WC),HU,and normalized IC.The study population was divided into four subgroups based on histopathological analysis-central giant cell granuloma(CGCG),ameloblastoma,odontogenic keratocyst(OKC),and other jaw tumors.A one-way ANOVA test for parametric variables and the Kruskal-Wallis test for nonparametric variables were used.If significant differences were found,a series of independent t-tests or Mann-Whitney U tests were used.RESULTS Ameloblastoma was the most common pathology(n=20),followed by CGCG(n=11)and OKC.CGCG showed a higher mean concentration of all quantitative parameters than ameloblastomas(P<0.05).An IC threshold of 31.35×100μg/cm^(3) had the maximum sensitivity(81.8%)and specificity(65%).Between ameloblastomas and OKC,the former showed a higher mean concentration of all quantitative parameters(P<0.001),however when comparing unilocular ameloblastomas with OKCs,the latter showed significantly higher WC.Also,ameloblastoma had a higher IC and lower WC compared to“other jaw tumors”group.CONCLUSION Enhancement characteristics of solid components combined with dual-energy parameters offer a more precise way to differentiate between jaw tumors.
基金Open Subject of Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases,College of Stomatology,Xi’an Jiaotong University(Project No.2011YHJB08)。
文摘Objective:To analyze the effectiveness of personalized 3D-printed rehabilitation orthotics in the postoperative recovery of jaw fractures.Methods:Relevant data were collected from 42 patients with jaw fractures treated at our hospital between October 2017 and May 2020.Patients were randomly divided into a traditional group(n=17)and a modified group(n=25).The traditional group received standard rehabilitation methods,while the modified group used personalized 3D-printed rehabilitation orthotics combined with improved rehabilitation methods.The temporomandibular disability index(TDI),quality of life scores,postoperative recovery excellence rate,and mouth opening were compared between the two groups at different follow-up times(before rehabilitation,and at 1 week,3 months,and 6 months post-surgery).Results:At 1 week,3 months,and 6 months post-surgery,the TDI in both the traditional and modified groups was significantly lower than before rehabilitation,with statistically significant differences(P<0.05).At 3 and 6 months post-surgery,the TDI in the modified group was lower than in the traditional group,with statistically significant differences(P<0.05).At 3 and 6 months post-surgery,pain,appearance,activity,recreation,work,chewing,swallowing,speech,shoulder function,and total quality of life scores in both groups were higher than before rehabilitation,with the modified group showing significantly higher scores in pain,appearance,chewing,swallowing,and total quality of life(P<0.05).Compared to before rehabilitation,mouth opening significantly improved in both groups at 3 and 6 months post-surgery,with the modified group showing significantly greater improvement(P<0.05).Conclusion:Personalized 3D-printed rehabilitation orthotics are highly effective in the postoperative recovery of jaw fractures.They can improve patients’quality of life after surgery,enhance the excellent rate of postoperative recovery,and increase mouth opening.
基金The National Natural Science Foundation of China (No.5047507, 50775036)the High Technology Research Program of Jiangsu Province (No.BG2006035)the Natural Science Foundation of JiangsuProvince (No.BK2009612)
文摘A dynamics model of the self-aligning ball bearing is proposed based on the Jones-Harris method (JHM), and a computer program is developed to solve the equations by using the Newton-Raphson method. A parametric analysis of the centrifugal force and the gyroscopic moment, the contact loads, the contact angles, the radial deformation and the radial stiffness is carried out. The analytical results show that the applied loads and the rotational speed are two main factors that can influence the distributions of the contact loads and values of the contact angles. The centrifugal force and the gyroscopic moment increase with the increase in the rotational speed, resulting in the decrease of the inner raceway contact load and the increase of the outer raceway contact load. The outer raceway contact angle increases under the centrifugal force; on the contrary, the inner raceway contact angle decreases. Furthermore, the differences between the inner and the outer contact angles increase with the increase in the rotational speed. The higher rotational speed results in the decrease in radial stiffness for the self-aligning ball bearing, and the raceway curvature coefficient, to some extent, also influences the radial stiffness.
文摘AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations(bone quantity and density), radiographic techniques, implant selection(number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.
文摘Objective: To characterize the diagnostic features of ossifying fibroma (OF) and fibrous dysplasia (FD) of the jaw bones. Study Design: A histopathological and radiological analysis with full clinical documentation. Setting: University of Nairobi Dental Teaching Hospital (UNDH). Study Population: All archival cases diagnosed as FD and OF from 1992-2006 were retrieved from the UNDH Oral Pathology Laboratory records. New cases were included as they pre-sented over a 6-month period from January to June 2007. Methodology: Information regarding the histological type of a fibro-osseous lesion (FOL) including the clinical features, demographic and radiographic data was documented for analysis;and comparison between pathological parameters and the final diagnosis was evaluated with the chi-square test. Results: FD lesions constituted 40 (27.2%) cases while 107 (72.8%) were OF. The age ranged from 1 - 72 years (mean = 24.19 ± SD 13 years). The differences in the gender distribution were not statistically significant. Radiographic analyses showed statistically significant differences between the appearances of the body (p = 0.012) and the margins (p = 0.003) of FD and OF. The microscopic differences between the two lesions were not statistically significant. Conclusion: Differentiation between FD and OF is only possible after critically analyzing the clinical, radiological and histological criteria.
文摘Aim: To report a series of thirty cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Material and Methods: For 30 patients with BRONJ, gender, age, underlying diagnosis, type of bisphosphonate (BP), administration route and duration, location and stage of osteonecrosis, symptoms and oral health status, radiological findings of the jaws, treatment and outcome, were recorded. Results: Underlying diagnoses in the series (12 male;18 female;mean age 70.50 ± 9.62) were: 12 multiple myeloma, 7 breast cancer, 3 prostate carcinoma, 1 kidney/lung/ bladder/mediastinal cancer, 1 chronic lymphocytic leukemia, 1 osteoporosis, 1 palatal osteosarcoma + osteoporosis, 1 non-Hodgkin’s lymphoma. Forty-seven osteonecrotic lesions were detected;30 localized in the mandible,17 inthe maxilla;trigger events were tooth extraction in 31 cases (66%), periodontal disease in 4 (8.50%), incongruous dentures in 3 (6.40%), perimplantitis in 1 (2.10%), unknown in 8 (17%). Twenty-nine patients had received treatment using amino bisphosphonates (25 zoledronate, 2 pamidronate, 2 alendronate) and 1 clodronate;the administration route was intravenous in 27 patients, oral in 2 and intramuscular in 1. Mean number of doses to bone exposure for patients was 34.11 for zoledronate, 50.50 for pamidronate, 146 for alendronate, and 500 for clodronate. Among statistical data the only significant finding was that panoramic dental radiography gave no concrete support for diagnosis of ONJ lesions (p ≤ 0.04). Conclusions: Our case series reflects literature data. We emphasize the insufficient role of panoramic radiography to study osteonecrotic lesions and the role of poor oral hygiene.
文摘Central mucoepidermoid carcinoma of the jaws (CMCJ) is an extremely rare neoplasm. The clinical manifestation of CMCJ is nonspecific, which includes swelling, pain, mobile teeth and bleeding, etc. To develop the diagnosis and treatment of CMCJ. this article presents 2 cases of CMCJ treated in our hospital. Their clinical data, treatment and prognosis were analyzed retrospectively.
文摘Medication-related osteonecrosis of the jaws (MRONJ) is a relatively new disease. MARX reported first cases in 2003. MRONJ relates to oral and parenteral bisphosphonates as well as to the so-called target cancer therapies but the list of medications only grows. Although MRONJ is a relatively rare condition, it can be associated to significant morbidity with feeding limitations and intense pain. More severe cases can lead to potentially life-threatening infections. Every patient initiating bisphosphonate and/or target cancer therapy must visit a dentist before starting medication because preventive measures for MRONJ are much more effective compared to surgical management of the lesions. Surgical resolution can be especially difficult to obtain in the coexistence of certain complication factors like wider bone exposures, history of nitrogen containing bisphosphonates use (mainly zolendronate) and immunodeficiency. Recently, researchers have given attention to laser therapy associated to photosensitive agents as a possible option to management of some MRONJ lesions. Our case report demonstrates the use of photodynamic therapy in a denosumab related lesion in the mandible. It seems that denosumab related lesions are more amenable to treatment and total resolution because of the marked differences between its chemical and metabolic characteristics when compared to bisphosphonates.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(Grant No.PAPD-2018-87)Jiangsu Province Capability Improvement Project through Science,Technology and Education-Jiangsu Provincial Research Hospital Cultivation Unit(Grant No.YJXYYJSDW4)Jiangsu Provincial Medical Innovation Center(Grant No.CXZX202227).
文摘Inflammatory jaw bone diseases are common in stomatology,including periodontitis,peri-implantitis,medication-related osteonecrosis of the jaw,radiation osteomyelitis of the jaw,age-related osteoporosis,and other specific infections.These diseases may lead to tooth loss and maxillofacial deformities,severely affecting patients'quality of life.Over the years,the reconstruction of jaw bone deficiency caused by inflammatory diseases has emerged as a medical and socioeconomic challenge.Therefore,exploring the pathogenesis of inflammatory diseases associated with jaw bones is crucial for improving prognosis and developing new targeted therapies.Accumulating evidence indicates that the integrated bone formation and dysfunction arise from complex interactions among a network of multiple cell types,including osteoblast-associated cells,immune cells,blood vessels,and lymphatic vessels.However,the role of these different cells in the inflammatory process and the'rules'with which they interact are still not fully understood.Although many investigations have focused on specific pathological processes and molecular events in inflammatory jaw diseases,few articles offer a perspective of integration.Here,we review the changes and mechanisms of various cell types in inflammatory jaw diseases,with the hope of providing insights to drive future research in this field.
文摘目的系统评价使用双膦酸盐药物(bisphosphonates,BPs)患者种植体早期失败率及种植术后药物相关性颌骨坏死(medication-related osteonecrosis of the jaw,MRONJ)发生率,为临床评估相关风险提供依据。方法计算机检索Cochrane Library、Wiley Online Library、PubMed、中国知网、万方数据知识服务平台,收集纳入各数据库建库至2022年5月发表的关于使用BPs患者种植体早期失败或种植术后发生MRONJ的临床研究。采用Stata 15.0软件对种植体早期失败率进行单组率Meta分析。结果共纳入13篇文献,其中口服BPs患者植入1182颗种植体,静脉注射BPs患者植入79颗,共计1261颗种植体。口服BPs患者合并种植体早期失败率为1.7%(95%CI:0.3%~3.9%),MRONJ发生率为0。静脉注射BPs患者种植体早期失败率为0,MRONJ发生率为5.6%。结论口服BPs患者种植体早期失败率及术后MRONJ发生率低,与健康人群基本相当。静脉使用BPs患者种植术后发生MRONJ风险较高,临床适应证选择应慎重。