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
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
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
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
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
In order to clarify the preparation process parameters of manufactured sand,optimize its quality,and analyze the effect of its grading on the microstructure of concrete,the three-dimensional models of jaw crusher,vibr...In order to clarify the preparation process parameters of manufactured sand,optimize its quality,and analyze the effect of its grading on the microstructure of concrete,the three-dimensional models of jaw crusher,vibrating screen and conveyor belt were established by using SolidWorks 2016 software.Rocky DEM4.5 software was used to simulate the initial crushing,screening,and transportation stages of the manufactured sand preparation process,with Linear Spring Dashpot as the normal contact model and Coulomb as the tangential contact model;furthermore,the key process parameters were defined.The manufactured sand grading model was then proposed,thereby,the influence of the grading of manufactured sand on the distribution of pore structure in concrete and the interfacial transition zone(ITZ)was studied.The experimetal results show that the particle size of granite,after being crushed in the jaw crusher,is primarily concentrated between 80 and 130 mm,with a crushing energy consumption typically below 100000 J.However,certain instances of granite exhibit higher energy consumption due to undergoing multiple crushings within the chamber.At the same time,the granite causes significant wear on the jaw crusher plate.Furthermore,the tilt angle of the vibrating screen should be adjusted to between 10 and 15 degrees,while the layout angle of the conveyor belt needs to be set at 16 degrees.The proposed manufactured sand grading model is feasible,and the pore diameter distribution inside concrete increases with an increase in the fineness modulus of manufactured sand.展开更多
Background: Bisphosphonates are compounds similar to inorganic pyrophosphates, with anti-angiogenic, anti-inflammatory, anti-bone resorption, and antitumor effects. They are used to prevent bone metastases in cancer a...Background: Bisphosphonates are compounds similar to inorganic pyrophosphates, with anti-angiogenic, anti-inflammatory, anti-bone resorption, and antitumor effects. They are used to prevent bone metastases in cancer and treat osteoporosis. However, a major side effect is osteonecrosis of the jaw (ONJ), first reported in 2003, which is the exposure of necrotic bone in the mouth, often accompanied by infection. Prevention and treatment of ONJ remain challenging due to a lack of reliable epidemiological data on its incidence and risk factors. The aim of our work is to estimate the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to analyze its correlations with different risk factors reported in the literature. Methods: A retrospective observational study was conducted in the Oncology, Rheumatology and Maxillofacial Surgery Department of the Mohamed VI University Hospital;Marrakech, based on complete medical records during the period 2017 to 2022, as well as consultations of patients under bisphosphonates in these departments during July and August 2022. Statistical analysis was performed using IBM SPSS version 16.0. Results: Of the 107 patients included in this study, 60.7% were women, and 56.1% were between 40 and 65 years old. 100% of the patients suffered from a general pathology. Regarding treatment with BP, 103 patients were treated with Zoledronate, 4 with Risedronate, and 5 with Ibandronate. 103 patients received this treatment intravenously, while 4 patients received it orally. Regarding Oral health, only 12.1% of patients reported a poor oral health. 99.1% of patients were informed of the need for oral preparation prior to BP treatment, but only 71.02% received dental treatment, mainly tooth extraction. None of the patients were diagnosed with BRONJ. Conclusions: While the global incidence of ONJ ranges from 0.8% to 12%, our finding is zero. Most previous studies are retrospective with limited patient numbers like our study. To accurately assess the prevalence of ONJ, further prospective epidemiological studies with standardized protocols and thorough follow-up over several years are essential.展开更多
背景与目的：近年来，随着技术发展，越来越多的基于能量传递的止血工具广泛问世并应用于开放性外科手术中。超声刀Focus刀头（Harmonic Focus，HF）及Ligasure Small Jaw刀头（LSJ）都是专为开放性甲状腺手术量身定做的。本文拟对北京...背景与目的：近年来，随着技术发展，越来越多的基于能量传递的止血工具广泛问世并应用于开放性外科手术中。超声刀Focus刀头（Harmonic Focus，HF）及Ligasure Small Jaw刀头（LSJ）都是专为开放性甲状腺手术量身定做的。本文拟对北京协和医学院中国医学科学院肿瘤医院HF及LSJ完成的开放性甲状腺手术患者的临床资料进行病例对照分析，以期比较HF及LSJ在开放性甲状腺手术中的应用效果。探讨HF及LSJ用于开放性甲状腺手术的有效性及安全性。方法：选取本院过去1年内甲状腺癌初治患者，由同一外科医师主刀使用HF或LSJ完成甲状腺全切除＋中央区清扫术，纳入HF组100例，LSJ组104例。通过比较两组手术时间及术后第1天引流量，比较两者在甲状腺手术中应用的有效性。通过比较两组术后并发症来评估安全性。结果：有效性：HF组平均手术时间为（95．8±18．0）min，LSJ组平均手术时间为（97．8±19．1）min，差异无统计学意义（P=-0．363）；术后首日引流量HF组为（35．2±20．3）mL，LSJ组为（36．3±23．8）mL，差异无统计学意义（P=0．977）。安全性：HF组出现暂时性声带麻痹者1例（1．0％），LSJ组术后伤口出现术区血肿者1例（1．0％）；暂时I生甲状旁腺功能低下者HF组18例（18．O％），LSJ组16例（15．4％）；HF组术后首日甲状旁腺素平均下降（12．3±12．8）pg／mL，LSJ组平均下降（13．9±13．4）μg／mL；血清离子钙HF组平均下降（0．20±0．13）mg／dL，LSJ组平均下降（0．20±0．16）mg／dL，差异均无统计学意义（P均〉0．05）。结论：HF及LSJ在开放性甲状腺手术中均安全、有效，手术并发症相当。展开更多
The paper presents theoretical and experimental results on an original anthropomorphic gripping concept. Compared to the existing anthropomorphic grippers, this gripper is very simple, yet it has the advantage of high...The paper presents theoretical and experimental results on an original anthropomorphic gripping concept. Compared to the existing anthropomorphic grippers, this gripper is very simple, yet it has the advantage of high performance in terms of gripping possibilities and a very low manufacturing cost. Source of inspiration was the human hand, which is able to catch objects by only using two fingers. The analyzed anthropomorphic gripper has two fingers, with two phalanxes each, and is based on a new mechanism with articulated bars. The kinematic analysis performed on the gripping mechanism reveals the optimal displacement in the translational coupling, which was experimentally validated. The gripping possibilities were increased by attaching clamping jaws to each phalanx. The clamping jaws have been attached by means of spherical couplings, thus offering the possibility to catch objects with any type of surface. By carrying out gripping tests with different objects, we underline the importance of a safe use of the two-fingered anthropomorphic grippers in different applications. Due to the innovative mechanical structure, the gripper can insure the minimal gripping conditions, whilst the complexity of the objects that can be gripped make it suitable for the use in robots.展开更多
The article introduces a new method for three-dimensional reproduction of edentulous dental casts,and wax occlusion rims with jaw relation by using a commercial high-speed line laser scanner and reverse engineering so...The article introduces a new method for three-dimensional reproduction of edentulous dental casts,and wax occlusion rims with jaw relation by using a commercial high-speed line laser scanner and reverse engineering software and evaluates the method’s accuracy in vitro.The method comprises three main steps：（i）acquisition of the three-dimensional stereolithography data of maxillary and mandibular edentulous dental casts and wax occlusion rims;（ii）acquisition of the three-dimensional stereolithography data of jaw relations;and（iii）registration of these data with the reverse engineering software and completing reconstruction.To evaluate the accuracy of this method,dental casts and wax occlusion rims of 10 edentulous patients were used.The lengths of eight lines between common anatomic landmarks were measured directly on the casts and occlusion rims by using a vernier caliper and on the three-dimensional computerized images by using the software measurement tool.The direct data were considered as the true values.The paired-samples t-test was used for statistical analysis.The mean differences between the direct and the computerized measurements were mostly less than 0.04 mm and were not significant（P.0.05）.Statistical significance among 10 patients was assessed using one-way analysis of variance（P,0.05）.The result showed that the 10 patients were considered statistically no significant.Therefore,accurate three-dimensional reproduction of the edentulous dental casts,wax occlusion rims,and jaw relations was achieved.The proposed method enables the visualization of occlusion from different views and would help to meet the demand for the computer-aided design of removable complete dentures.展开更多
Objective:Osteoradionecrosis of the jaws(ORNJ)is among the most serious oral complications of head and neck cancer treatment with radiation therapy.This study aimed to examine the level of symptom distress and interfe...Objective:Osteoradionecrosis of the jaws(ORNJ)is among the most serious oral complications of head and neck cancer treatment with radiation therapy.This study aimed to examine the level of symptom distress and interference of ORNJ in head and neck cancer patients in China.Methods:A cross-sectional study was conducted to profile patient reported symptom severity.Ninetyfive hospitalized ORNJ patients were recruited.Participants completed the MD Anderson Symptom Inventory-Head and Neck Module-Chinese version.Results:The percentage of participants who reported that they experienced at least one type of symptom was 97.9%,and 85.2%patients reported interference.The 10 most severe symptoms were as follows:limited mouth opening,problem with teeth/gums,difficulty swallowing/chewing,dry mouth,oral malodor,difficulty with voice/speech,dental ulcer,tinnitus/ear obstruction,skin pain/burning/rash,and difficulty hearing.The problem of limited mouth opening was more severe in patients with longer time to onset of ORNJ after radiotherapy.The interference of patients positively correlated with core symptoms(r=0.612),head and neck symptoms(r=0.709),and ORNJ symptoms(r=0.440)(P<0.01).The longer time to the onset of ORNJ after radiotherapy was positively and significantly correlated with symptom distress(r=0.479,P<0.001),and mouth opening correlated negatively with symptom distress(r=-0.298,P=0.003).Conclusions:ORNJ patients suffered mainly from limited mouth opening and other maxillofacial symptoms.The problem of limited mouth opening was more severe in patients with longer time to onset of ORNJ after radiotherapy.ORNJ patients commonly had symptom distress,which influenced their quality of life.展开更多
This article provides an overview of metastases to jaws （M J）, mainly concerning the differences between American and Chinese patients, and exploring the relationship between the primary tumors＇ prevalence （PTP） ...This article provides an overview of metastases to jaws （M J）, mainly concerning the differences between American and Chinese patients, and exploring the relationship between the primary tumors＇ prevalence （PTP） and constituent ratio of MJ. Information concerning of 399 MJ cases in 215 papers, including one new case in our hospital, was subjected to statistic analysis. The main clinical features of M J, such as constituent ratio of PTP and that of M J, metastatic sites, treatments, and prognosis were summarized. Breast, lung, kidney, prostate and thyroid （in descending order） were the leading primary sites of MJ. Furthermore, the constituent ratio of MJ was found to be correlated with that of PTP in all subjects including American and Chinese subjects in our study. As to metastatic sites in the mandible, a specific ＂M＂ shaped pattern appeared regardless of the tumor type or constituent ratio,,; of MJ were in all subjects. Almost all subjects received traditionary palliative treatments, and the prognosis was quite poor. The PTP had a significant impact on the constituent ratio of MJ. However, it was the properties of the microenvironment rather than characteristics or constituent ratios of tumor cells, that decided the metastatic sites in various tumor subjects.展开更多
The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks.Investigation was conducted on fo...The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks.Investigation was conducted on four different rock samples namely marble,dolomite,limestone and granite which were representatively selected from fragmented lumps in quarries.Unconfined compressive strength and Point load tests were carried out on each rock sample as well as crushing time and size analysis.The results of the strength parameters of each sample were correlated with the crushing time and the grain size distribution of the rock types.The results of the strength tests show that granite has the highest mean value of 101.67 MPa for Unconfined Compressive Strength(UCS) test,6.43 MPa for Point Load test while dolomite has the least mean value of 30.56 MPa for UCS test and 0.95 MPa for Point Load test.According to the International Society for Rock Mechanic(ISRM) standard,the granite rock sample may be classified as having very high strength and dolomite rock sample,low strength.Also,the granite rock has the highest crushing time(21.0 s) and dolomite rock has the least value(5.0 s).Based on the results of the investigation,it was found out that there is a great influence of strength properties on crushing time of rock types.展开更多
BACKGROUND Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects.Jaw cysts are anoth...BACKGROUND Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects.Jaw cysts are another common benign disease of the maxillofacial region which may lead to pathological bone fracture,loss of teeth,and infection.However,whether bone grafts are beneficial for bone regeneration in jaw cystic lesions and when bone grafts should be used remains unclear.AIM To study the efficacy of bone grafts compared to spontaneous healing in the treatment of jaw cystic lesions.METHODS A literature search was performed in Medline,Cochrane Library and Embase to identify related articles published in English in the last ten years.The following key words and Me SH terms were used:“jaw cyst”,“cystic lesion”,“odontogenic cyst”,“periapical cyst”,“dentigerous cyst”,“follicular cyst”,“keratocyst”,“treatment”,“surgery”,“bone graft”,“enucleation”,“cystectomy”,and“bone regeneration”.Case reports,clinical trials,clinical studies,observational studies and randomized controlled trials were included.Study quality was evaluated.RESULTS Ten studies(n=10)met the inclusion criteria.Five studies reported spontaneous bone healing after enucleation,three studies investigated the efficacy of various bone grafts,and two randomized comparative studies focused on the comparison between spontaneous healing and bone grafting.Over 90%of bone regeneration occurred within 6 mo after bone grafting.The bone regeneration rate after cystectomy showed great variation,ranging from 50%to 100%after 6 mo,but reaching over 90%after 12 mo.CONCLUSION While the long-term superiority of bone grafting compared with spontaneous healing after cystectomy is unclear,bone grafts accelerate the process of healing and significantly increase bone quality.展开更多
BACKGROUND The odontogenic jaw cyst is a cavity containing liquid,semifluid or gaseous components,with the development of the disease.In recent years,with the rapid development of oral materials and the transformation...BACKGROUND The odontogenic jaw cyst is a cavity containing liquid,semifluid or gaseous components,with the development of the disease.In recent years,with the rapid development of oral materials and the transformation of treatment of jaw cysts,more options are available for treatment of postoperative bone defect of jaw cysts.Guided bone regeneration(GBR)places biomaterials in the bone defect,and then uses biofilm to separate the proliferative soft tissue and the slow-growing bone tissue to maintain the space for bone regeneration,which is widely used in the field of implantology.AIM To observe the clinical effect of GBR in repairing bone defect after enucleation of small and medium-sized odontogenic jaw cysts.METHODS From June 2018 to September 2020,13 patients(7 male,6 female)with odontogenic jaw cysts were treated in the Department of Oral Surgery,Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine.Adults without hypertension,heart disease,diabetes or other systemic diseases were selected.The diagnosis was based on the final pathological results:11 cases were diagnosed as apical cysts,one as primordial cyst,and one as dentigerous cyst.The lesions were located in the maxilla in seven cases,and in the mandible in six cases.All cases were treated with the same method of enucleation combined with GBR.RESULTS Three to four months after the operation,the boundary between the implant site and the surrounding normal stroma was not obvious in patients with small-sized odontogenic jaw cysts.The patients with tooth defects were treated with implant after 6 mo.For the patients with medium-sized odontogenic jaw cysts,the density of the center of the implant area was close to the normal mass at 6 mo after surgery,and there was a clear boundary between the periphery of the implant area and the normal mass.The boundary between the periphery of the implant area and the normal mass was blurred at 8-9 mo after surgery.Patients with tooth defects were treated with implants at>6 mo after the operation.CONCLUSION Enucleation combined with guided bone regeneration in small and medium-sized odontogenic jaw cysts can shorten the time of osteogenesis,increase the amount of new bone formation,reduce complications,and improve quality of life.展开更多
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Funded by the National Natural Science Foundation of China(Nos.U21A20150,51978339,and 52178237)。
文摘In order to clarify the preparation process parameters of manufactured sand,optimize its quality,and analyze the effect of its grading on the microstructure of concrete,the three-dimensional models of jaw crusher,vibrating screen and conveyor belt were established by using SolidWorks 2016 software.Rocky DEM4.5 software was used to simulate the initial crushing,screening,and transportation stages of the manufactured sand preparation process,with Linear Spring Dashpot as the normal contact model and Coulomb as the tangential contact model;furthermore,the key process parameters were defined.The manufactured sand grading model was then proposed,thereby,the influence of the grading of manufactured sand on the distribution of pore structure in concrete and the interfacial transition zone(ITZ)was studied.The experimetal results show that the particle size of granite,after being crushed in the jaw crusher,is primarily concentrated between 80 and 130 mm,with a crushing energy consumption typically below 100000 J.However,certain instances of granite exhibit higher energy consumption due to undergoing multiple crushings within the chamber.At the same time,the granite causes significant wear on the jaw crusher plate.Furthermore,the tilt angle of the vibrating screen should be adjusted to between 10 and 15 degrees,while the layout angle of the conveyor belt needs to be set at 16 degrees.The proposed manufactured sand grading model is feasible,and the pore diameter distribution inside concrete increases with an increase in the fineness modulus of manufactured sand.
文摘Background: Bisphosphonates are compounds similar to inorganic pyrophosphates, with anti-angiogenic, anti-inflammatory, anti-bone resorption, and antitumor effects. They are used to prevent bone metastases in cancer and treat osteoporosis. However, a major side effect is osteonecrosis of the jaw (ONJ), first reported in 2003, which is the exposure of necrotic bone in the mouth, often accompanied by infection. Prevention and treatment of ONJ remain challenging due to a lack of reliable epidemiological data on its incidence and risk factors. The aim of our work is to estimate the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to analyze its correlations with different risk factors reported in the literature. Methods: A retrospective observational study was conducted in the Oncology, Rheumatology and Maxillofacial Surgery Department of the Mohamed VI University Hospital;Marrakech, based on complete medical records during the period 2017 to 2022, as well as consultations of patients under bisphosphonates in these departments during July and August 2022. Statistical analysis was performed using IBM SPSS version 16.0. Results: Of the 107 patients included in this study, 60.7% were women, and 56.1% were between 40 and 65 years old. 100% of the patients suffered from a general pathology. Regarding treatment with BP, 103 patients were treated with Zoledronate, 4 with Risedronate, and 5 with Ibandronate. 103 patients received this treatment intravenously, while 4 patients received it orally. Regarding Oral health, only 12.1% of patients reported a poor oral health. 99.1% of patients were informed of the need for oral preparation prior to BP treatment, but only 71.02% received dental treatment, mainly tooth extraction. None of the patients were diagnosed with BRONJ. Conclusions: While the global incidence of ONJ ranges from 0.8% to 12%, our finding is zero. Most previous studies are retrospective with limited patient numbers like our study. To accurately assess the prevalence of ONJ, further prospective epidemiological studies with standardized protocols and thorough follow-up over several years are essential.
文摘背景与目的：近年来，随着技术发展，越来越多的基于能量传递的止血工具广泛问世并应用于开放性外科手术中。超声刀Focus刀头（Harmonic Focus，HF）及Ligasure Small Jaw刀头（LSJ）都是专为开放性甲状腺手术量身定做的。本文拟对北京协和医学院中国医学科学院肿瘤医院HF及LSJ完成的开放性甲状腺手术患者的临床资料进行病例对照分析，以期比较HF及LSJ在开放性甲状腺手术中的应用效果。探讨HF及LSJ用于开放性甲状腺手术的有效性及安全性。方法：选取本院过去1年内甲状腺癌初治患者，由同一外科医师主刀使用HF或LSJ完成甲状腺全切除＋中央区清扫术，纳入HF组100例，LSJ组104例。通过比较两组手术时间及术后第1天引流量，比较两者在甲状腺手术中应用的有效性。通过比较两组术后并发症来评估安全性。结果：有效性：HF组平均手术时间为（95．8±18．0）min，LSJ组平均手术时间为（97．8±19．1）min，差异无统计学意义（P=-0．363）；术后首日引流量HF组为（35．2±20．3）mL，LSJ组为（36．3±23．8）mL，差异无统计学意义（P=0．977）。安全性：HF组出现暂时性声带麻痹者1例（1．0％），LSJ组术后伤口出现术区血肿者1例（1．0％）；暂时I生甲状旁腺功能低下者HF组18例（18．O％），LSJ组16例（15．4％）；HF组术后首日甲状旁腺素平均下降（12．3±12．8）pg／mL，LSJ组平均下降（13．9±13．4）μg／mL；血清离子钙HF组平均下降（0．20±0．13）mg／dL，LSJ组平均下降（0．20±0．16）mg／dL，差异均无统计学意义（P均〉0．05）。结论：HF及LSJ在开放性甲状腺手术中均安全、有效，手术并发症相当。
文摘The paper presents theoretical and experimental results on an original anthropomorphic gripping concept. Compared to the existing anthropomorphic grippers, this gripper is very simple, yet it has the advantage of high performance in terms of gripping possibilities and a very low manufacturing cost. Source of inspiration was the human hand, which is able to catch objects by only using two fingers. The analyzed anthropomorphic gripper has two fingers, with two phalanxes each, and is based on a new mechanism with articulated bars. The kinematic analysis performed on the gripping mechanism reveals the optimal displacement in the translational coupling, which was experimentally validated. The gripping possibilities were increased by attaching clamping jaws to each phalanx. The clamping jaws have been attached by means of spherical couplings, thus offering the possibility to catch objects with any type of surface. By carrying out gripping tests with different objects, we underline the importance of a safe use of the two-fingered anthropomorphic grippers in different applications. Due to the innovative mechanical structure, the gripper can insure the minimal gripping conditions, whilst the complexity of the objects that can be gripped make it suitable for the use in robots.
基金the Twelfth Five-Year National Key Technologies Research and Development Program of China(grant no.2012BAI07B00)the National High Technology Research and Development Program(‘863’Program)of China(grant nos.2013AA040801 and 2013AA040802)+1 种基金the National Natural Science Foundation of China(grant no.81271181)the Scientific Research Innovation Foundation for Youth Doctors of Peking University School of Stomatology(2011)
文摘The article introduces a new method for three-dimensional reproduction of edentulous dental casts,and wax occlusion rims with jaw relation by using a commercial high-speed line laser scanner and reverse engineering software and evaluates the method’s accuracy in vitro.The method comprises three main steps：（i）acquisition of the three-dimensional stereolithography data of maxillary and mandibular edentulous dental casts and wax occlusion rims;（ii）acquisition of the three-dimensional stereolithography data of jaw relations;and（iii）registration of these data with the reverse engineering software and completing reconstruction.To evaluate the accuracy of this method,dental casts and wax occlusion rims of 10 edentulous patients were used.The lengths of eight lines between common anatomic landmarks were measured directly on the casts and occlusion rims by using a vernier caliper and on the three-dimensional computerized images by using the software measurement tool.The direct data were considered as the true values.The paired-samples t-test was used for statistical analysis.The mean differences between the direct and the computerized measurements were mostly less than 0.04 mm and were not significant（P.0.05）.Statistical significance among 10 patients was assessed using one-way analysis of variance（P,0.05）.The result showed that the 10 patients were considered statistically no significant.Therefore,accurate three-dimensional reproduction of the edentulous dental casts,wax occlusion rims,and jaw relations was achieved.The proposed method enables the visualization of occlusion from different views and would help to meet the demand for the computer-aided design of removable complete dentures.
基金Nurturing funds for nursing young talents of Sun Yat-sen University(N2018Y02)
文摘Objective:Osteoradionecrosis of the jaws(ORNJ)is among the most serious oral complications of head and neck cancer treatment with radiation therapy.This study aimed to examine the level of symptom distress and interference of ORNJ in head and neck cancer patients in China.Methods:A cross-sectional study was conducted to profile patient reported symptom severity.Ninetyfive hospitalized ORNJ patients were recruited.Participants completed the MD Anderson Symptom Inventory-Head and Neck Module-Chinese version.Results:The percentage of participants who reported that they experienced at least one type of symptom was 97.9%,and 85.2%patients reported interference.The 10 most severe symptoms were as follows:limited mouth opening,problem with teeth/gums,difficulty swallowing/chewing,dry mouth,oral malodor,difficulty with voice/speech,dental ulcer,tinnitus/ear obstruction,skin pain/burning/rash,and difficulty hearing.The problem of limited mouth opening was more severe in patients with longer time to onset of ORNJ after radiotherapy.The interference of patients positively correlated with core symptoms(r=0.612),head and neck symptoms(r=0.709),and ORNJ symptoms(r=0.440)(P<0.01).The longer time to the onset of ORNJ after radiotherapy was positively and significantly correlated with symptom distress(r=0.479,P<0.001),and mouth opening correlated negatively with symptom distress(r=-0.298,P=0.003).Conclusions:ORNJ patients suffered mainly from limited mouth opening and other maxillofacial symptoms.The problem of limited mouth opening was more severe in patients with longer time to onset of ORNJ after radiotherapy.ORNJ patients commonly had symptom distress,which influenced their quality of life.
文摘This article provides an overview of metastases to jaws （M J）, mainly concerning the differences between American and Chinese patients, and exploring the relationship between the primary tumors＇ prevalence （PTP） and constituent ratio of MJ. Information concerning of 399 MJ cases in 215 papers, including one new case in our hospital, was subjected to statistic analysis. The main clinical features of M J, such as constituent ratio of PTP and that of M J, metastatic sites, treatments, and prognosis were summarized. Breast, lung, kidney, prostate and thyroid （in descending order） were the leading primary sites of MJ. Furthermore, the constituent ratio of MJ was found to be correlated with that of PTP in all subjects including American and Chinese subjects in our study. As to metastatic sites in the mandible, a specific ＂M＂ shaped pattern appeared regardless of the tumor type or constituent ratio,,; of MJ were in all subjects. Almost all subjects received traditionary palliative treatments, and the prognosis was quite poor. The PTP had a significant impact on the constituent ratio of MJ. However, it was the properties of the microenvironment rather than characteristics or constituent ratios of tumor cells, that decided the metastatic sites in various tumor subjects.
文摘The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks.Investigation was conducted on four different rock samples namely marble,dolomite,limestone and granite which were representatively selected from fragmented lumps in quarries.Unconfined compressive strength and Point load tests were carried out on each rock sample as well as crushing time and size analysis.The results of the strength parameters of each sample were correlated with the crushing time and the grain size distribution of the rock types.The results of the strength tests show that granite has the highest mean value of 101.67 MPa for Unconfined Compressive Strength(UCS) test,6.43 MPa for Point Load test while dolomite has the least mean value of 30.56 MPa for UCS test and 0.95 MPa for Point Load test.According to the International Society for Rock Mechanic(ISRM) standard,the granite rock sample may be classified as having very high strength and dolomite rock sample,low strength.Also,the granite rock has the highest crushing time(21.0 s) and dolomite rock has the least value(5.0 s).Based on the results of the investigation,it was found out that there is a great influence of strength properties on crushing time of rock types.
基金supported by the investigator-initiated trial "The observation of bone healing after filling with bone grafts of cystic lesions in jaws: a single-center prospective study" at First Affiliated Hospital, School of Medicine, Zhejiang University
文摘BACKGROUND Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects.Jaw cysts are another common benign disease of the maxillofacial region which may lead to pathological bone fracture,loss of teeth,and infection.However,whether bone grafts are beneficial for bone regeneration in jaw cystic lesions and when bone grafts should be used remains unclear.AIM To study the efficacy of bone grafts compared to spontaneous healing in the treatment of jaw cystic lesions.METHODS A literature search was performed in Medline,Cochrane Library and Embase to identify related articles published in English in the last ten years.The following key words and Me SH terms were used:“jaw cyst”,“cystic lesion”,“odontogenic cyst”,“periapical cyst”,“dentigerous cyst”,“follicular cyst”,“keratocyst”,“treatment”,“surgery”,“bone graft”,“enucleation”,“cystectomy”,and“bone regeneration”.Case reports,clinical trials,clinical studies,observational studies and randomized controlled trials were included.Study quality was evaluated.RESULTS Ten studies(n=10)met the inclusion criteria.Five studies reported spontaneous bone healing after enucleation,three studies investigated the efficacy of various bone grafts,and two randomized comparative studies focused on the comparison between spontaneous healing and bone grafting.Over 90%of bone regeneration occurred within 6 mo after bone grafting.The bone regeneration rate after cystectomy showed great variation,ranging from 50%to 100%after 6 mo,but reaching over 90%after 12 mo.CONCLUSION While the long-term superiority of bone grafting compared with spontaneous healing after cystectomy is unclear,bone grafts accelerate the process of healing and significantly increase bone quality.
基金Supported by the National Natural Science Foundation of China,No. 31800816Fundamental Research Program Funding of the Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,No. JYZZ109
文摘BACKGROUND The odontogenic jaw cyst is a cavity containing liquid,semifluid or gaseous components,with the development of the disease.In recent years,with the rapid development of oral materials and the transformation of treatment of jaw cysts,more options are available for treatment of postoperative bone defect of jaw cysts.Guided bone regeneration(GBR)places biomaterials in the bone defect,and then uses biofilm to separate the proliferative soft tissue and the slow-growing bone tissue to maintain the space for bone regeneration,which is widely used in the field of implantology.AIM To observe the clinical effect of GBR in repairing bone defect after enucleation of small and medium-sized odontogenic jaw cysts.METHODS From June 2018 to September 2020,13 patients(7 male,6 female)with odontogenic jaw cysts were treated in the Department of Oral Surgery,Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine.Adults without hypertension,heart disease,diabetes or other systemic diseases were selected.The diagnosis was based on the final pathological results:11 cases were diagnosed as apical cysts,one as primordial cyst,and one as dentigerous cyst.The lesions were located in the maxilla in seven cases,and in the mandible in six cases.All cases were treated with the same method of enucleation combined with GBR.RESULTS Three to four months after the operation,the boundary between the implant site and the surrounding normal stroma was not obvious in patients with small-sized odontogenic jaw cysts.The patients with tooth defects were treated with implant after 6 mo.For the patients with medium-sized odontogenic jaw cysts,the density of the center of the implant area was close to the normal mass at 6 mo after surgery,and there was a clear boundary between the periphery of the implant area and the normal mass.The boundary between the periphery of the implant area and the normal mass was blurred at 8-9 mo after surgery.Patients with tooth defects were treated with implants at>6 mo after the operation.CONCLUSION Enucleation combined with guided bone regeneration in small and medium-sized odontogenic jaw cysts can shorten the time of osteogenesis,increase the amount of new bone formation,reduce complications,and improve quality of life.
