BACKGROUND Percutaneous radiofrequency ablation(RFA)is an effective treatment for unresectable hepatocellular carcinoma(HCC)and a minimally invasive alternative to hepatectomy for treating tumour recurrence.RFA is oft...BACKGROUND Percutaneous radiofrequency ablation(RFA)is an effective treatment for unresectable hepatocellular carcinoma(HCC)and a minimally invasive alternative to hepatectomy for treating tumour recurrence.RFA is often performed using contrast-enhanced computed tomography(CECT)and/or ultrasonography.In recent years,angiographic systems with flat panel image detectors and advanced image reconstruction algorithms have broadened the clinical applications of cone-beam computed tomography(CBCT),including RFA.Several studies have shown the effectiveness of using CBCT for immediate treatment assessments and follow-ups.AIM To assess the treatment response to RFA for HCC using CBCT.METHODS Forty-eight patients(44 men;aged 37-89 years)with solitary HCC[median size:3.2(1.2-6.6)cm]underwent RFA and were followed for 25.6(median;13.5-35.2)mo.Image fusion of CBCT and pre-operative CECT or magnetic resonance imaging(MRI)was used for tumour segmentation and needle path and ablation zone planning.Real-time image guidance was provided by overlaying the threedimensional image of the tumour and needle path on the fluoroscopy image.Treatment response was categorized as complete response(CR),partial response(PR),stable disease(SD),or progressive disease(PD).Disease progression,death,time to progression(TTP),and overall survival(OS)were recorded.Kaplan-Meier and Cox regression analyses were performed.RESULTS Initial post-RFA CECT/MRI showed 38 cases of CR(79.2%),10 of PR(20.8%),0 of SD,and 0 of PD,which strongly correlated with the planning estimation(42 CR,87.5%;6 PR,12.5%;0 SD;and 0 PD;accuracy:91.7%,P<0.01).Ten(20.8%)patients died,and disease progression occurred in 31(35.4%,median TTP:12.8 mo)patients,resulting in 12-,24-,and 35-mo OS rates of 100%,81.2%,and 72.2%,respectively,and progression-free survival(PFS)rates of 54.2%,37.1%,and 37.1%,respectively.The median dose-area product of the procedures was 79.05 Gy*cm2(range 40.95-146.24 Gy*cm2),and the median effective dose was 10.27 mSv(range 5.32-19.01 mSv).Tumour size<2 cm(P=0.008)was a significant factor for OS,while age(P=0.001),tumour size<2 cm(P<0.001),tumour stage(P=0.010),and initial treatment response(P=0.003)were significant factors for PFS.CONCLUSION Reliable RFA treatment planning and satisfactory outcomes can be achieved with CBCT.展开更多
Background: The vast percentage of the alveolar bone resorption process happens within the first 12 to 24 weeks post extraction;however, this phenomenon is chronic, and the alveolar ridge continues to resorb. In order...Background: The vast percentage of the alveolar bone resorption process happens within the first 12 to 24 weeks post extraction;however, this phenomenon is chronic, and the alveolar ridge continues to resorb. In order to prevent this reduction or at least recompense the loss of bone dimensions, the alveolar ridge preservation (ARP) technique was developed. Objectives: This research studied the vertical and horizontal bone dimensional changes as a result of non-molar teeth extraction alone against extraction with alveolar ridge preservation utilizing composite (bioceramics/collagen) graft by cone-beam computed tomography radiographies analyses. Material and Methods: This research was a randomized split-mouth controlled trial. 12 patients need extraction of the maxillary non-molar teeth were enrolled and allocated into 2 groups. 12 sockets after atraumatic extraction were filled with a composite graft in the role of the test group, 12 sockets left to unassisted healing after atraumatic extraction without any graft materials in the role of the control group. Two CBCT radiographs were taken at baseline and at 4 months after extraction for comparison. Both vertical and horizontal resorptions of the alveolar ridge were analyzed between test and control group by CBCT radiographs. Results: 4 months after extraction, there was a mean of vertical alveolar bone resorption compared with the baseline (0.56 ± 0.15 mm) in the test group and (1.47 ± 0.30 mm) in the control group. Whereas it was a mean of horizontal alveolar bone resorption compared with the baseline (0.90 ± 0.16 mm) in the test group and (2.26 ± 0.30 mm) in the control group. Therefore, there was a significant difference between the two groups. Conclusions: Within the limitations of this research, we demonstrated that the osteogen-plug technique significantly decreased the reduction of the bone dimensional in comparison to the tooth extraction alone, and showed that the dimensional change of the alveolar ridge after tooth extraction was minimized by using an osteogen-plug.展开更多
<strong>Objectives: </strong>Odontoma is the most common type of odontogenic tumors. Many studies have analyzed the statistical associations between odontoma location and patient age and sex, according to ...<strong>Objectives: </strong>Odontoma is the most common type of odontogenic tumors. Many studies have analyzed the statistical associations between odontoma location and patient age and sex, according to the histological tumor type. However, few studies have assessed odontoma morphological characteristics using cone-beam computed tomography (CBCT). We aimed to evaluate the association between odontoma location and size. <strong>Methods:</strong> We performed CBCT on patients with odontomas (19 patients;10 women, 9 men;average age, 12.6 [range, 6 - 34] years) according to the pathology type at a university hospital between April 2008 and February 2017. The locations of the lesions were noted, and their sizes were measured on CBCT images. Buccolingual, mesiodistal, and vertical diameters of the lesions were recorded on the same slice with the greatest diameters on axial, coronal, and sagittal CBCT images. <strong>Results: </strong>Altogether, 9 (47.4%) and 10 (52.6%) odontomas were located in the mandible and maxilla, respectively. There was no significant difference in the mesiodistal and vertical diameters on the CBCT image between the mandibular and maxillary groups when the odontoma size was compared with location (p < 0.05). However, the average diameters in only the buccolingual diameter were significantly greater in the maxilla. There were no significant differences between the two groups according to sex, age, or histological type. <strong>Conclusions: </strong>These data suggest that the sizes of odontomas in the maxilla are affected by bone expansion in the buccolingual direction, but they may be invariable in most settings. Three-dimensional assessment across the age groups suggests a lack of variation in size.展开更多
4-Dimensional cone-beam computed tomography(4D-CBCT)offers several key advantages over conventional 3DCBCT in moving target localization/delineation,structure de-blurring,target motion tracking,treatment dose accumul...4-Dimensional cone-beam computed tomography(4D-CBCT)offers several key advantages over conventional 3DCBCT in moving target localization/delineation,structure de-blurring,target motion tracking,treatment dose accumulation and adaptive radiation therapy.However,the use of the 4D-CBCT in current radiation therapy practices has been limited,mostly due to its sub-optimal image quality from limited angular sampling of conebeam projections.In this study,we summarized the recent developments of 4D-CBCT reconstruction techniques for image quality improvement,and introduced our developments of a new 4D-CBCT reconstruction technique which features simultaneous motion estimation and image reconstruction(SMEIR).Based on the original SMEIR scheme,biomechanical modeling-guided SMEIR(SMEIR-Bio)was introduced to further improve the reconstruction accuracy of fine details in lung 4D-CBCTs.To improve the efficiency of reconstruction,we recently developed a U-net-based deformation-vector-field(DVF)optimization technique to leverage a population-based deep learning scheme to improve the accuracy of intra-lung DVFs(SMEIR-Unet),without explicit biomechanical modeling.Details of each of the SMEIR,SMEIR-Bio and SMEIR-Unet techniques were included in this study,along with the corresponding results comparing the reconstruction accuracy in terms of CBCT images and the DVFs.We also discussed the application prospects of the SMEIR-type techniques in image-guided radiation therapy and adaptive radiation therapy,and presented potential schemes on future developments to achieve faster and more accurate 4D-CBCT imaging.展开更多
Background:C-arm-based flat-panel detector cone-beam computed tomography(CBCT)venography has never been used in the management of iliac vein compression syndrome(IVCS).This study aimed to determine the technical feasi...Background:C-arm-based flat-panel detector cone-beam computed tomography(CBCT)venography has never been used in the management of iliac vein compression syndrome(IVCS).This study aimed to determine the technical feasibility and safety of CBCT venography in the diagnosis of IVCS compared with conventional venography(CV).Methods:Twenty patients with clinical manifestations of lower extremity venous insufficiency were prospectively enrolled between May 2018 and December 2018.Each patient underwent both CV and CBCT venography.The feasibility and safety of CBCT venography were assessed by technical success rate and complication rate.The relationships between the clinical indexes and the results of CBCT venography and CV were analyzed with correlation analysis.The consistency of the diagnosis of IVCS using each modality was analyzed by the kappa test.Results:The technical success rate was 100%for CBCT venography and for CV,without any complications.Compared with CV,CBCT venography was able to show more details of adjacent tissues which might be helpful for making etiological diagnosis.The stenosis rate under CBCT venography had excellent consistency with that under CV(kappa=0.78,Chi-square test).The stenosis rate under CBCT venography was positively correlated with the presence of collateral veins(odds ratio 1.12,95%confidence interval:[1.00,1.26],P=0.049),while the stenosis rate under CV was not.Unexpectedly,only one patient had a venous pressure gradient of more than 2 mmHg(1 mmHg=0.133 kPa).Conclusions:For the diagnosis of IVCS,C-arm-based CBCT venography was technically feasible,with good safety.The presence of collateral veins on CBCT was clinically significant.A C-arm fluoroscopy-based technique that combines CV and CBCT might be a promising protocol for the management of IVCS during a single session.展开更多
Aim:To evaluate the effectiveness of using cone-beam computed tomography(CBCT)in transcatheter arterial chemoembolization(TACE)to detect hapatocellular carcinoma(HCC)nodules and their feeding arteries.Methods:Twenty-f...Aim:To evaluate the effectiveness of using cone-beam computed tomography(CBCT)in transcatheter arterial chemoembolization(TACE)to detect hapatocellular carcinoma(HCC)nodules and their feeding arteries.Methods:Twenty-four patients with HCCs who underwent TACE using CBCT in addition to conventional digital subtraction angiography(DSA)were enrolled.After both conventional DSA and CBCT through the hepatic artery were acquired,TACE were performed.The nodules were defined as an HCC when dense accumulation of iodized oil was found within the nodule on CT obtained 2 weeks after the TACE.The number of detected nodules and identified feeding arteries,and their correlations with anatomical locations were assessed.Results:A total of 39 HCC nodules(tumor diameter,7-40 mm;mean,17.4±7.9 mm)were detected.Thirty-one nodules were detected by DSA alone but 8 nodules were additionally detected by adding CBCT to DSA.There were 53 feeding arteries associated with the 39 HCC nodules.Among these arteries,21 were identified by DSA alone;however,47 were identified by combining CBCT with DSA.Additional feeding arteries,especially for the nodules located at the right and caudate lobes,were identified by CBCT.On the other hand,there was no difference in detection of nodules between the anatomical locations by CBCT.Conclusion:The use of CBCT in addition to DSA offers potential for increasing the number of detected nodules,and the number of their feeding arteries at the right and caudate lobes.CBCT might improve the quality of TACE procedure for HCC than DSA alone.展开更多
BACKGROUND Fused teeth usually involve several complications,such as the development of caries in the groove between fused crowns,tooth impaction,diastemas,aesthetic and periodontal problems,and pulpal pathosis,due to...BACKGROUND Fused teeth usually involve several complications,such as the development of caries in the groove between fused crowns,tooth impaction,diastemas,aesthetic and periodontal problems,and pulpal pathosis,due to the complex anatomical structure of fused teeth.A thorough diagnosis is paramount to forming an accurate treatment plan and obtaining a favourable prognosis.With the advent of cone-beam computed tomography(CBCT),accurate 3-dimensional images of teeth and their surrounding dentoalveolar structures can now be readily obtained,and the technology can accurately provide a minimally invasive approach to acquire detailed diagnostic information.Therefore,we utilize CBCT data herein to generate a digital model for the infected region in a patient,and this model enables us to better plan the management of his case.CASE SUMMARY This report details the diagnosis and endodontic treatment of a rare case involving a fused maxillary second molar and two paramolars with apical periodontitis.The patient experienced pain upon biting and cold sensitivity in the area of the maxillary left molar.No caries or other defects were identified in these teeth,and a normal response to a pulp electric viability test was observed.With the aid of CBCT and digital model technology,we initially suspected that the infection originated from the isthmus between the maxillary second molar and two paramolars.Therefore,we only treated the isthmus by an endodontic approach and did not destroy the original tooth structure;furthermore,the vital pulp was retained,and good treatment outcomes were observed at the 24-month follow-up.CONCLUSION This finding may provide new insights and perspectives on the diagnosis and treatment of fused teeth.展开更多
Cone-beam computed tomography(CBCT) was developed and introduced specifically for dento-maxillofacial imaging. CBCT possesses a number of advantages over medical CT in clinical practice, such as lower effective radiat...Cone-beam computed tomography(CBCT) was developed and introduced specifically for dento-maxillofacial imaging. CBCT possesses a number of advantages over medical CT in clinical practice, such as lower effective radiation doses, lower costs, fewer space requirements,easier image acquisition, and interactive display modes such as mutiplanar reconstruction that are applicable to maxillofacial imaging. However, the disadvantages of CBCT include higher doses than two-dimensional imaging; the inability to accurately represent the internal structure of soft tissues and soft-tissue lesions; a limited correlation with Hounsfield Units for standardized quantification of bone density; and the presence of various types of image artifacts, mainly those produced by metal restorations. CBCT is now commonly used for a variety of purposes in oral implantology, dentomaxillofacial surgery, image-guided surgical procedures, endodontics, periodontics and orthodontics. CBCT applications provide obvious benefits in the assessment of dentomaxillofacial region, however; it should be used only in correct indications considering the necessity and the potential hazards of the examination.展开更多
BACKGROUND The use of advanced platelet-rich fibrin(A-PRF)membranes for guided bone and tissue regeneration in through-and-through defects after endodontic surgery was explored in three cases.CASE SUMMARY Herein,three...BACKGROUND The use of advanced platelet-rich fibrin(A-PRF)membranes for guided bone and tissue regeneration in through-and-through defects after endodontic surgery was explored in three cases.CASE SUMMARY Herein,three patients presented to the endodontic clinic suffering from apical periodontitis,associated with large bone resorption and related to previously endodontically treated teeth.Periapical surgery was indicated in these cases and the osteotomy site was covered by A-PRF membrane.Cone-beam computed tomography(CBCT)was used to assess the cases before and after the surgery.CONCLUSION Four months post-surgery,the recall CBCT scan showed complete obliteration of the osteotomy with newly formed bone.A-PRF membrane showed promising results and was an advantageous addition to surgical endodontic treatment.展开更多
BACKGROUND Morphological anomalies of teeth,including talon cusp,dens evaginatus,gemination,fusion,concrescence,root dilaceration,and taurodontism,always involve changes in the enamel,cementum and dentin.Diagnosing co...BACKGROUND Morphological anomalies of teeth,including talon cusp,dens evaginatus,gemination,fusion,concrescence,root dilaceration,and taurodontism,always involve changes in the enamel,cementum and dentin.Diagnosing concrescent teeth through routine clinical examination alone is difficult,and most cases of concrescence are found accidentally during extraction.A definite preoperative diagnosis of concrescence would contribute to a better treatment plan and fewer undesirable complications CASE SUMMARY A 47-year-old woman who complained of left maxillary first molar loss for half a year presented to our department seeking treatment by dental implant restoration.Panoramic radiography and cone-beam computed tomography(CBCT)showed an unclear boundary between the distal root of the second molar and the mesial root of the third molar.The teeth were extracted under local anesthesia,and a definite diagnosis of concrescence was made by histopathological examination.CONCLUSION CBCT is a useful tool for diagnosing and planning the management of tooth concrescence and may be beneficial for reducing unnecessary complications.展开更多
Kissing molars (KMs), first reported by Van Hoof in 1973, refer to molars with occlusal surfaces that contact each other in a single follicular space while their roots extend in opposite directions. This is a case of ...Kissing molars (KMs), first reported by Van Hoof in 1973, refer to molars with occlusal surfaces that contact each other in a single follicular space while their roots extend in opposite directions. This is a case of a 20-year-old male who presented with complaints of right mandibular molar pain with cold water contact and occlusion. Panoramic and cone-beam computed tomography (CBCT) images revealed impaction of the right mandibular third and fourth molars, with the occlusal surfaces contacting each other while the roots extended in opposite directions. KMs are classified according to the impaction of the mandibular first and second molars (Class I), second and third molars (Class II), and third and fourth molars (Class III). Our patient was considered Class III. Given the patient’s preference for surgical treatment, successful teeth extraction and extirpation were performed under intravenous sedation. The patient’s postoperative course was unremarkable. We describe a case of KMs Class III with a cystic variant assessed by panoramic and CBCT images. We additionally review all KMs Class III reported in the literature.展开更多
Double teeth refer to two teeth that are totally or partially joined by dentin and maybe their pulps. These developmental anomalies may be the result of either gemination or fusion. This is a case of a 15-year-old Ind...Double teeth refer to two teeth that are totally or partially joined by dentin and maybe their pulps. These developmental anomalies may be the result of either gemination or fusion. This is a case of a 15-year-old Indo-Trinidadian male who presented with the fusion of a mandibular third molar with a distomolar as an incidental finding. The patient had his general dental care provided by a paediatric dentist and was referred to an oral and maxillofacial radiologist, orthodontist, and oral surgeon for consultation. A Cone-beam CT was taken to supplement the plain film periapical and orthopantomogram radiographs. It showed the three-dimensional orientation of the double molar and the extent of joining. This is the first case of fusion of a mandibular third molar to a distomolar being reported in the Caribbean.展开更多
Generally being considered as a safe area for surgical approaches, the region between the mental foramina presents important anatomical structures. The objective of this study was to measure the dimensions of the geni...Generally being considered as a safe area for surgical approaches, the region between the mental foramina presents important anatomical structures. The objective of this study was to measure the dimensions of the genial plexus and its three-dimensional location in CBCT images, correlating the characteristics of this structure with dental presence, sex and age of patients. A total of 149 cone beam computer tomography (CBCT) scans of dentate (n = 74) and edentulous patients (n = 75) were selected, 59 male and 90 female, aged 18 - 86 years. Measurements of width and length of the genial canal were performed, and the shortest distances of the genial plexus were determined in relation to the alveolar bone crest, the buccal cortical bone and the base of the mandible. The results indicated significant differences between the dentate and edentulous groups for the mandibular canal length (p = 0.030), distance from alveolar crest (p < 0.001), and distance from buccal cortical bone (p < 0.001), with significantly higher values in dentate patients. As for gender, the distances between the genial plexus and the alveolar bone crest (p < 0.001) and the buccal cortical bone (p = 0.028) were significantly shorter for females. Regarding age, only the distance between the genial plexus and the alveolar crest showed a significant difference (p < 0.001), and the smallest values were measured in the older patients. It can be concluded that there are variations of the genial plexus in relation to gender, age and between edentulous and dentate patients. Therefore, the anterior region of the mandible, especially the midline should be observed with caution when undergoing surgical procedures, such as removal of bone grafts and installation of dental implants.展开更多
Objectives: To assess the relationships between the maxillary first molar and the maxillary sinus floor in a group of patients referred to a dental clinic. Methods: Ninety-seven patients were recruited for this study....Objectives: To assess the relationships between the maxillary first molar and the maxillary sinus floor in a group of patients referred to a dental clinic. Methods: Ninety-seven patients were recruited for this study. The distances between the examined roots (mesio-buccal, disto-buccal and palatal) as well as furcations, and the sinus floor, were evaluated using cone beam computed tomography, and grouped as follows: class 0: distance = 0 mm;class 1: 0 mm < distance < 2 mm;class 2: 2 mm ≤ distance < 4 mm;class 3: 4 mm ≤ distance < 6 mm;class 4: 6 mm ≤ distance. The Spearman’s Rank Correlation coefficient was used to test the univariate associations between furca-tion-sinus floor distance and each root class. Results: The prevalence of class 0 was the highest for the palatal root (44.33%), followed in descending order by mesio-buccal (40.21%), and disto-buccal (38.14%) roots. The highest correlation coefficient was recorded when assessing the relationship between furcation-sinus floor distance and palatal root classes (rho = 0.66, p < 0.001, n = 97). Conclusions: Altogether, the results suggest that the palatal root of the maxillary first molar not only had the closest relationship with the sinus floor, but also proved to be the best predictor for the furcation-sinus floor distance. The clinician should be aware of the anatomical and morphological details of this root, especially when taking surgical decisions.展开更多
BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third...BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third molar(IMM3)near the IAN to prevent IAN injury during IMM3 extraction.METHODS Between January 1996 and March 2022,25 patients with IMM3 roots near the IAN were enrolled.The first stage of the operation consisted of grinding a major part of the IMM3 crown with a high-speed turbine dental drill to achieve sufficient space between the mandibular second molar and IMM3.After 6 months,when the root tips were observed to be away from the IAN on X-ray examination,the remaining part of the IMM3 was completely removed.RESULTS All IMM3s were extracted easily without symptoms of IAN injury after extraction.CONCLUSION Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases.展开更多
Background:Mass fatality incidents occur due to environmental,medical,vehicle,industrial,or terrorist events that can involve large numbers of victims.Identification of these victims is of utmost importance in these s...Background:Mass fatality incidents occur due to environmental,medical,vehicle,industrial,or terrorist events that can involve large numbers of victims.Identification of these victims is of utmost importance in these situations.Cone-beam computed tomography(CBCT)may be helpful in some forensic contexts,offering several advantages for postmortem forensic imaging.Aim:The research study aims to evaluate the sexual dimorphism of the maxillary sinus and inter coronoid distance to estimate sex by using CBCT.Materials and Methods:In 40 CBCT scans of 20 males and 20 females,maxillary sinuses height,width and inter coronoid distances of mandible were measured for forensic analysis.In high quality,reconstructed images ofbilateral maxillary sinuses,height,and width were measured,and in mandible,inter coronoid was measured in axial view.Results were tabulated and analyzed using an unpaired r-test and discriminant function analysis used to compare difierences in the measured parameters between males and females.Results:Mean values of inter coronoid in males and females are(♂=88.1,♀=78.1).The maxillary sinus right side height and width(♂=32.2,♀=24.6)(♂=19.7,♀=19.6)left side height and width(♂=32.7,♀=23.6)(♂=18.1,♀=17.8),respectively.A statistically significant(P<0.05)difference was found in maxillary sinus and inter coronoid distance between males and females.Results showed significantly larger dimensions of maxillary sinus and inter coronoid distance in males compared to females.The correct predictive accuracy rate of sex detennination was 100% in females and 90% in males with overall accuracy of 95%.Conclusion:The present study showed the importance of maxillary sinus dimensions and inter coronoid distance in sex estimation using cone-beam computed tomography in forensic medicine.展开更多
文摘BACKGROUND Percutaneous radiofrequency ablation(RFA)is an effective treatment for unresectable hepatocellular carcinoma(HCC)and a minimally invasive alternative to hepatectomy for treating tumour recurrence.RFA is often performed using contrast-enhanced computed tomography(CECT)and/or ultrasonography.In recent years,angiographic systems with flat panel image detectors and advanced image reconstruction algorithms have broadened the clinical applications of cone-beam computed tomography(CBCT),including RFA.Several studies have shown the effectiveness of using CBCT for immediate treatment assessments and follow-ups.AIM To assess the treatment response to RFA for HCC using CBCT.METHODS Forty-eight patients(44 men;aged 37-89 years)with solitary HCC[median size:3.2(1.2-6.6)cm]underwent RFA and were followed for 25.6(median;13.5-35.2)mo.Image fusion of CBCT and pre-operative CECT or magnetic resonance imaging(MRI)was used for tumour segmentation and needle path and ablation zone planning.Real-time image guidance was provided by overlaying the threedimensional image of the tumour and needle path on the fluoroscopy image.Treatment response was categorized as complete response(CR),partial response(PR),stable disease(SD),or progressive disease(PD).Disease progression,death,time to progression(TTP),and overall survival(OS)were recorded.Kaplan-Meier and Cox regression analyses were performed.RESULTS Initial post-RFA CECT/MRI showed 38 cases of CR(79.2%),10 of PR(20.8%),0 of SD,and 0 of PD,which strongly correlated with the planning estimation(42 CR,87.5%;6 PR,12.5%;0 SD;and 0 PD;accuracy:91.7%,P<0.01).Ten(20.8%)patients died,and disease progression occurred in 31(35.4%,median TTP:12.8 mo)patients,resulting in 12-,24-,and 35-mo OS rates of 100%,81.2%,and 72.2%,respectively,and progression-free survival(PFS)rates of 54.2%,37.1%,and 37.1%,respectively.The median dose-area product of the procedures was 79.05 Gy*cm2(range 40.95-146.24 Gy*cm2),and the median effective dose was 10.27 mSv(range 5.32-19.01 mSv).Tumour size<2 cm(P=0.008)was a significant factor for OS,while age(P=0.001),tumour size<2 cm(P<0.001),tumour stage(P=0.010),and initial treatment response(P=0.003)were significant factors for PFS.CONCLUSION Reliable RFA treatment planning and satisfactory outcomes can be achieved with CBCT.
文摘Background: The vast percentage of the alveolar bone resorption process happens within the first 12 to 24 weeks post extraction;however, this phenomenon is chronic, and the alveolar ridge continues to resorb. In order to prevent this reduction or at least recompense the loss of bone dimensions, the alveolar ridge preservation (ARP) technique was developed. Objectives: This research studied the vertical and horizontal bone dimensional changes as a result of non-molar teeth extraction alone against extraction with alveolar ridge preservation utilizing composite (bioceramics/collagen) graft by cone-beam computed tomography radiographies analyses. Material and Methods: This research was a randomized split-mouth controlled trial. 12 patients need extraction of the maxillary non-molar teeth were enrolled and allocated into 2 groups. 12 sockets after atraumatic extraction were filled with a composite graft in the role of the test group, 12 sockets left to unassisted healing after atraumatic extraction without any graft materials in the role of the control group. Two CBCT radiographs were taken at baseline and at 4 months after extraction for comparison. Both vertical and horizontal resorptions of the alveolar ridge were analyzed between test and control group by CBCT radiographs. Results: 4 months after extraction, there was a mean of vertical alveolar bone resorption compared with the baseline (0.56 ± 0.15 mm) in the test group and (1.47 ± 0.30 mm) in the control group. Whereas it was a mean of horizontal alveolar bone resorption compared with the baseline (0.90 ± 0.16 mm) in the test group and (2.26 ± 0.30 mm) in the control group. Therefore, there was a significant difference between the two groups. Conclusions: Within the limitations of this research, we demonstrated that the osteogen-plug technique significantly decreased the reduction of the bone dimensional in comparison to the tooth extraction alone, and showed that the dimensional change of the alveolar ridge after tooth extraction was minimized by using an osteogen-plug.
文摘<strong>Objectives: </strong>Odontoma is the most common type of odontogenic tumors. Many studies have analyzed the statistical associations between odontoma location and patient age and sex, according to the histological tumor type. However, few studies have assessed odontoma morphological characteristics using cone-beam computed tomography (CBCT). We aimed to evaluate the association between odontoma location and size. <strong>Methods:</strong> We performed CBCT on patients with odontomas (19 patients;10 women, 9 men;average age, 12.6 [range, 6 - 34] years) according to the pathology type at a university hospital between April 2008 and February 2017. The locations of the lesions were noted, and their sizes were measured on CBCT images. Buccolingual, mesiodistal, and vertical diameters of the lesions were recorded on the same slice with the greatest diameters on axial, coronal, and sagittal CBCT images. <strong>Results: </strong>Altogether, 9 (47.4%) and 10 (52.6%) odontomas were located in the mandible and maxilla, respectively. There was no significant difference in the mesiodistal and vertical diameters on the CBCT image between the mandibular and maxillary groups when the odontoma size was compared with location (p < 0.05). However, the average diameters in only the buccolingual diameter were significantly greater in the maxilla. There were no significant differences between the two groups according to sex, age, or histological type. <strong>Conclusions: </strong>These data suggest that the sizes of odontomas in the maxilla are affected by bone expansion in the buccolingual direction, but they may be invariable in most settings. Three-dimensional assessment across the age groups suggests a lack of variation in size.
基金This work was supported in part by grants from the US National Institutes of Health,Nos.R01 EB020366 and R01 EB027898the Cancer Prevention and Research Institute of Texas,Nos.RP130109 and RP160661from the University of Texas Southwestern Medical Center(Radiation Oncology Seed Grant).
文摘4-Dimensional cone-beam computed tomography(4D-CBCT)offers several key advantages over conventional 3DCBCT in moving target localization/delineation,structure de-blurring,target motion tracking,treatment dose accumulation and adaptive radiation therapy.However,the use of the 4D-CBCT in current radiation therapy practices has been limited,mostly due to its sub-optimal image quality from limited angular sampling of conebeam projections.In this study,we summarized the recent developments of 4D-CBCT reconstruction techniques for image quality improvement,and introduced our developments of a new 4D-CBCT reconstruction technique which features simultaneous motion estimation and image reconstruction(SMEIR).Based on the original SMEIR scheme,biomechanical modeling-guided SMEIR(SMEIR-Bio)was introduced to further improve the reconstruction accuracy of fine details in lung 4D-CBCTs.To improve the efficiency of reconstruction,we recently developed a U-net-based deformation-vector-field(DVF)optimization technique to leverage a population-based deep learning scheme to improve the accuracy of intra-lung DVFs(SMEIR-Unet),without explicit biomechanical modeling.Details of each of the SMEIR,SMEIR-Bio and SMEIR-Unet techniques were included in this study,along with the corresponding results comparing the reconstruction accuracy in terms of CBCT images and the DVFs.We also discussed the application prospects of the SMEIR-type techniques in image-guided radiation therapy and adaptive radiation therapy,and presented potential schemes on future developments to achieve faster and more accurate 4D-CBCT imaging.
文摘Background:C-arm-based flat-panel detector cone-beam computed tomography(CBCT)venography has never been used in the management of iliac vein compression syndrome(IVCS).This study aimed to determine the technical feasibility and safety of CBCT venography in the diagnosis of IVCS compared with conventional venography(CV).Methods:Twenty patients with clinical manifestations of lower extremity venous insufficiency were prospectively enrolled between May 2018 and December 2018.Each patient underwent both CV and CBCT venography.The feasibility and safety of CBCT venography were assessed by technical success rate and complication rate.The relationships between the clinical indexes and the results of CBCT venography and CV were analyzed with correlation analysis.The consistency of the diagnosis of IVCS using each modality was analyzed by the kappa test.Results:The technical success rate was 100%for CBCT venography and for CV,without any complications.Compared with CV,CBCT venography was able to show more details of adjacent tissues which might be helpful for making etiological diagnosis.The stenosis rate under CBCT venography had excellent consistency with that under CV(kappa=0.78,Chi-square test).The stenosis rate under CBCT venography was positively correlated with the presence of collateral veins(odds ratio 1.12,95%confidence interval:[1.00,1.26],P=0.049),while the stenosis rate under CV was not.Unexpectedly,only one patient had a venous pressure gradient of more than 2 mmHg(1 mmHg=0.133 kPa).Conclusions:For the diagnosis of IVCS,C-arm-based CBCT venography was technically feasible,with good safety.The presence of collateral veins on CBCT was clinically significant.A C-arm fluoroscopy-based technique that combines CV and CBCT might be a promising protocol for the management of IVCS during a single session.
文摘Aim:To evaluate the effectiveness of using cone-beam computed tomography(CBCT)in transcatheter arterial chemoembolization(TACE)to detect hapatocellular carcinoma(HCC)nodules and their feeding arteries.Methods:Twenty-four patients with HCCs who underwent TACE using CBCT in addition to conventional digital subtraction angiography(DSA)were enrolled.After both conventional DSA and CBCT through the hepatic artery were acquired,TACE were performed.The nodules were defined as an HCC when dense accumulation of iodized oil was found within the nodule on CT obtained 2 weeks after the TACE.The number of detected nodules and identified feeding arteries,and their correlations with anatomical locations were assessed.Results:A total of 39 HCC nodules(tumor diameter,7-40 mm;mean,17.4±7.9 mm)were detected.Thirty-one nodules were detected by DSA alone but 8 nodules were additionally detected by adding CBCT to DSA.There were 53 feeding arteries associated with the 39 HCC nodules.Among these arteries,21 were identified by DSA alone;however,47 were identified by combining CBCT with DSA.Additional feeding arteries,especially for the nodules located at the right and caudate lobes,were identified by CBCT.On the other hand,there was no difference in detection of nodules between the anatomical locations by CBCT.Conclusion:The use of CBCT in addition to DSA offers potential for increasing the number of detected nodules,and the number of their feeding arteries at the right and caudate lobes.CBCT might improve the quality of TACE procedure for HCC than DSA alone.
基金Supported by the Innovative Talents Promotion Program-Youth Science and Technology Star Project,No. 2019KJXX-086Shaanxi Provincial Natural Science Basic Research Foundation of China,No. 2019JM-376National Nature Science Foundation of China,No. 81970929
文摘BACKGROUND Fused teeth usually involve several complications,such as the development of caries in the groove between fused crowns,tooth impaction,diastemas,aesthetic and periodontal problems,and pulpal pathosis,due to the complex anatomical structure of fused teeth.A thorough diagnosis is paramount to forming an accurate treatment plan and obtaining a favourable prognosis.With the advent of cone-beam computed tomography(CBCT),accurate 3-dimensional images of teeth and their surrounding dentoalveolar structures can now be readily obtained,and the technology can accurately provide a minimally invasive approach to acquire detailed diagnostic information.Therefore,we utilize CBCT data herein to generate a digital model for the infected region in a patient,and this model enables us to better plan the management of his case.CASE SUMMARY This report details the diagnosis and endodontic treatment of a rare case involving a fused maxillary second molar and two paramolars with apical periodontitis.The patient experienced pain upon biting and cold sensitivity in the area of the maxillary left molar.No caries or other defects were identified in these teeth,and a normal response to a pulp electric viability test was observed.With the aid of CBCT and digital model technology,we initially suspected that the infection originated from the isthmus between the maxillary second molar and two paramolars.Therefore,we only treated the isthmus by an endodontic approach and did not destroy the original tooth structure;furthermore,the vital pulp was retained,and good treatment outcomes were observed at the 24-month follow-up.CONCLUSION This finding may provide new insights and perspectives on the diagnosis and treatment of fused teeth.
文摘Cone-beam computed tomography(CBCT) was developed and introduced specifically for dento-maxillofacial imaging. CBCT possesses a number of advantages over medical CT in clinical practice, such as lower effective radiation doses, lower costs, fewer space requirements,easier image acquisition, and interactive display modes such as mutiplanar reconstruction that are applicable to maxillofacial imaging. However, the disadvantages of CBCT include higher doses than two-dimensional imaging; the inability to accurately represent the internal structure of soft tissues and soft-tissue lesions; a limited correlation with Hounsfield Units for standardized quantification of bone density; and the presence of various types of image artifacts, mainly those produced by metal restorations. CBCT is now commonly used for a variety of purposes in oral implantology, dentomaxillofacial surgery, image-guided surgical procedures, endodontics, periodontics and orthodontics. CBCT applications provide obvious benefits in the assessment of dentomaxillofacial region, however; it should be used only in correct indications considering the necessity and the potential hazards of the examination.
基金Supported by the Princess Nourah Bint Abdulrahman University Researchers Supporting Project,No.PNURSP2023R363.
文摘BACKGROUND The use of advanced platelet-rich fibrin(A-PRF)membranes for guided bone and tissue regeneration in through-and-through defects after endodontic surgery was explored in three cases.CASE SUMMARY Herein,three patients presented to the endodontic clinic suffering from apical periodontitis,associated with large bone resorption and related to previously endodontically treated teeth.Periapical surgery was indicated in these cases and the osteotomy site was covered by A-PRF membrane.Cone-beam computed tomography(CBCT)was used to assess the cases before and after the surgery.CONCLUSION Four months post-surgery,the recall CBCT scan showed complete obliteration of the osteotomy with newly formed bone.A-PRF membrane showed promising results and was an advantageous addition to surgical endodontic treatment.
基金Supported by the Applied Basic Research Program of the 920th Hospital of the Joint Logistics Support Force,No.2019YGB15。
文摘BACKGROUND Morphological anomalies of teeth,including talon cusp,dens evaginatus,gemination,fusion,concrescence,root dilaceration,and taurodontism,always involve changes in the enamel,cementum and dentin.Diagnosing concrescent teeth through routine clinical examination alone is difficult,and most cases of concrescence are found accidentally during extraction.A definite preoperative diagnosis of concrescence would contribute to a better treatment plan and fewer undesirable complications CASE SUMMARY A 47-year-old woman who complained of left maxillary first molar loss for half a year presented to our department seeking treatment by dental implant restoration.Panoramic radiography and cone-beam computed tomography(CBCT)showed an unclear boundary between the distal root of the second molar and the mesial root of the third molar.The teeth were extracted under local anesthesia,and a definite diagnosis of concrescence was made by histopathological examination.CONCLUSION CBCT is a useful tool for diagnosing and planning the management of tooth concrescence and may be beneficial for reducing unnecessary complications.
文摘Kissing molars (KMs), first reported by Van Hoof in 1973, refer to molars with occlusal surfaces that contact each other in a single follicular space while their roots extend in opposite directions. This is a case of a 20-year-old male who presented with complaints of right mandibular molar pain with cold water contact and occlusion. Panoramic and cone-beam computed tomography (CBCT) images revealed impaction of the right mandibular third and fourth molars, with the occlusal surfaces contacting each other while the roots extended in opposite directions. KMs are classified according to the impaction of the mandibular first and second molars (Class I), second and third molars (Class II), and third and fourth molars (Class III). Our patient was considered Class III. Given the patient’s preference for surgical treatment, successful teeth extraction and extirpation were performed under intravenous sedation. The patient’s postoperative course was unremarkable. We describe a case of KMs Class III with a cystic variant assessed by panoramic and CBCT images. We additionally review all KMs Class III reported in the literature.
文摘Double teeth refer to two teeth that are totally or partially joined by dentin and maybe their pulps. These developmental anomalies may be the result of either gemination or fusion. This is a case of a 15-year-old Indo-Trinidadian male who presented with the fusion of a mandibular third molar with a distomolar as an incidental finding. The patient had his general dental care provided by a paediatric dentist and was referred to an oral and maxillofacial radiologist, orthodontist, and oral surgeon for consultation. A Cone-beam CT was taken to supplement the plain film periapical and orthopantomogram radiographs. It showed the three-dimensional orientation of the double molar and the extent of joining. This is the first case of fusion of a mandibular third molar to a distomolar being reported in the Caribbean.
文摘Generally being considered as a safe area for surgical approaches, the region between the mental foramina presents important anatomical structures. The objective of this study was to measure the dimensions of the genial plexus and its three-dimensional location in CBCT images, correlating the characteristics of this structure with dental presence, sex and age of patients. A total of 149 cone beam computer tomography (CBCT) scans of dentate (n = 74) and edentulous patients (n = 75) were selected, 59 male and 90 female, aged 18 - 86 years. Measurements of width and length of the genial canal were performed, and the shortest distances of the genial plexus were determined in relation to the alveolar bone crest, the buccal cortical bone and the base of the mandible. The results indicated significant differences between the dentate and edentulous groups for the mandibular canal length (p = 0.030), distance from alveolar crest (p < 0.001), and distance from buccal cortical bone (p < 0.001), with significantly higher values in dentate patients. As for gender, the distances between the genial plexus and the alveolar bone crest (p < 0.001) and the buccal cortical bone (p = 0.028) were significantly shorter for females. Regarding age, only the distance between the genial plexus and the alveolar crest showed a significant difference (p < 0.001), and the smallest values were measured in the older patients. It can be concluded that there are variations of the genial plexus in relation to gender, age and between edentulous and dentate patients. Therefore, the anterior region of the mandible, especially the midline should be observed with caution when undergoing surgical procedures, such as removal of bone grafts and installation of dental implants.
基金supported by the Sectoral Operational Program Human Resources Development(SOP HRD)financed by the European Social Fundby the Romanian Government under the contract number POSDRU/89/1.5/S/64109(author#3).
文摘Objectives: To assess the relationships between the maxillary first molar and the maxillary sinus floor in a group of patients referred to a dental clinic. Methods: Ninety-seven patients were recruited for this study. The distances between the examined roots (mesio-buccal, disto-buccal and palatal) as well as furcations, and the sinus floor, were evaluated using cone beam computed tomography, and grouped as follows: class 0: distance = 0 mm;class 1: 0 mm < distance < 2 mm;class 2: 2 mm ≤ distance < 4 mm;class 3: 4 mm ≤ distance < 6 mm;class 4: 6 mm ≤ distance. The Spearman’s Rank Correlation coefficient was used to test the univariate associations between furca-tion-sinus floor distance and each root class. Results: The prevalence of class 0 was the highest for the palatal root (44.33%), followed in descending order by mesio-buccal (40.21%), and disto-buccal (38.14%) roots. The highest correlation coefficient was recorded when assessing the relationship between furcation-sinus floor distance and palatal root classes (rho = 0.66, p < 0.001, n = 97). Conclusions: Altogether, the results suggest that the palatal root of the maxillary first molar not only had the closest relationship with the sinus floor, but also proved to be the best predictor for the furcation-sinus floor distance. The clinician should be aware of the anatomical and morphological details of this root, especially when taking surgical decisions.
文摘BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third molar(IMM3)near the IAN to prevent IAN injury during IMM3 extraction.METHODS Between January 1996 and March 2022,25 patients with IMM3 roots near the IAN were enrolled.The first stage of the operation consisted of grinding a major part of the IMM3 crown with a high-speed turbine dental drill to achieve sufficient space between the mandibular second molar and IMM3.After 6 months,when the root tips were observed to be away from the IAN on X-ray examination,the remaining part of the IMM3 was completely removed.RESULTS All IMM3s were extracted easily without symptoms of IAN injury after extraction.CONCLUSION Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases.
文摘Background:Mass fatality incidents occur due to environmental,medical,vehicle,industrial,or terrorist events that can involve large numbers of victims.Identification of these victims is of utmost importance in these situations.Cone-beam computed tomography(CBCT)may be helpful in some forensic contexts,offering several advantages for postmortem forensic imaging.Aim:The research study aims to evaluate the sexual dimorphism of the maxillary sinus and inter coronoid distance to estimate sex by using CBCT.Materials and Methods:In 40 CBCT scans of 20 males and 20 females,maxillary sinuses height,width and inter coronoid distances of mandible were measured for forensic analysis.In high quality,reconstructed images ofbilateral maxillary sinuses,height,and width were measured,and in mandible,inter coronoid was measured in axial view.Results were tabulated and analyzed using an unpaired r-test and discriminant function analysis used to compare difierences in the measured parameters between males and females.Results:Mean values of inter coronoid in males and females are(♂=88.1,♀=78.1).The maxillary sinus right side height and width(♂=32.2,♀=24.6)(♂=19.7,♀=19.6)left side height and width(♂=32.7,♀=23.6)(♂=18.1,♀=17.8),respectively.A statistically significant(P<0.05)difference was found in maxillary sinus and inter coronoid distance between males and females.Results showed significantly larger dimensions of maxillary sinus and inter coronoid distance in males compared to females.The correct predictive accuracy rate of sex detennination was 100% in females and 90% in males with overall accuracy of 95%.Conclusion:The present study showed the importance of maxillary sinus dimensions and inter coronoid distance in sex estimation using cone-beam computed tomography in forensic medicine.
