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1.
Eur J Radiol ; 138: 109674, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33798932

RESUMEN

OBJECTIVES: We hypothesize that three-dimensional (3D) geometric analyses in weight bearing CT-images of the foot and ankle are more reproducible compared to two-dimensional (2D) analyses. Therefore, we compared 2D and 3D analyses on bones of weight-bearing and non weight-bearing cone-beam CT images of healthy volunteers. METHODS: Twenty healthy volunteers (10 male, 10 female, mean age 37.5 years) underwent weight-bearing and non weight-bearing cone-beam CT imaging of both feet. Clinically relevant height and angle measurements were performed in 2D and 3D (for example: cuboid height, calcaneal pitch, talo-calcaneal angle, Meary's angle, intermetatarsal angle). Three-dimensional measurements were obtained using automated software. Intra-observer and inter-observer agreement were evaluated for all 2D measurements. RESULTS: Overall intraclass correlation coefficients (ICC's) were higher than 0.750 for most 2D measurements, ranging from 0.352 to 0.995. Calcaneal pitch, angle between the first metatarsal (MT1) and proximal phalange 1, between the fifth metatarsal (MT5) and the calcaneus and heights of the sesamoid bones, navicular, cuboid and talus decreased during weight-bearing in both 2D and 3D results (p < 0.01). Meary's angle was not statistically different in 2D (p = 0.627) and 3D (p = 0.765). Higher coefficients of variation in 2D geometric analysis parameters (0.27 versus 0.16) indicate that 3D analyses are more precise compared to 2D (p < 0.01). Results of left and right feet are comparable for 2D and 3D analyses. CONCLUSION: Although 2D and 3D geometrical analyses are fundamentally different, automated 3D analyses are more reproducible and precise compared to 2D analyses. In addition, 3D evaluation better demonstrates differences in bone configurations between weight-bearing and non weight-bearing conditions, which may be of value to demonstrate pathology.


Asunto(s)
Tobillo , Tomografía Computarizada de Haz Cónico , Adulto , Articulación del Tobillo/diagnóstico por imagen , Femenino , Humanos , Masculino , Estándares de Referencia , Soporte de Peso
4.
Artículo en Inglés | MEDLINE | ID: mdl-33819327

RESUMEN

This study evaluated the accuracy of implant placement with surgical-template guidance both in vitro and in vivo. Virtual surgical planning was performed based on the data from CBCT scans and an intraoral scanner. Surgical templates were designed according to the planned implants and manufactured with stereolithography. In vitro, 60 implants were placed in 15 resin models. In vivo, 74 implants were placed in 54 patients. The implants were scanned with CBCT postoperatively. Implant accuracy was evaluated by measuring the following parameters: central deviation at the apex and shoulder, horizontal deviation at the apex and shoulder, vertical deviation at the apex and shoulder, and angular deviation. There were statistically significant in vitro and in vivo deviations for all parameters, and the implant deviations in vivo were significantly greater than those in vitro. When using a mucosa-supported template, horizontal deviations at the apex were significantly greater than when a teeth-supported template was used. Within the limitation of the study design, inaccuracy existed in implant placement guided with a surgical template. More studies are needed to investigate the value of the procedure in future.


Asunto(s)
Implantes Dentales , Cirugía Asistida por Computador , Diseño Asistido por Computadora , Tomografía Computarizada de Haz Cónico , Implantación Dental Endoósea , Humanos , Imagenología Tridimensional , Planificación de Atención al Paciente
5.
Oral Health Prev Dent ; 19(1): 263-270, 2021 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-33881289

RESUMEN

PURPOSE: To use and evaluate two methods for measuring gingival thickness (GT) at mandibular incisors of orthodontic patients and compare their performance in assessing periodontal anatomy through soft tissue thickness. MATERIALS AND METHODS: The sample consisted of 40 consecutive adult orthodontic patients. GT was measured just before bracket placement at both central mandibular incisors, mid-facially on the buccal aspect, 2 mm apically to the free gingival margin with two methods: clinically with an ultrasound device (USD) and radiographically with cone-beam computed tomography (CBCT). RESULTS: CBCT measurements were consistently higher than USD measurements, with the difference ranging from 0.13 mm to 0.21 mm. No statistically significant difference was noted between the repeated CBCT measurements at the right central incisor (bias = 0.05 mm; 95% CI = -0.01, 0.11; p = 0.104). Although the respective results for the left incisor statistically indicated that the measurements were not exactly replicated, the magnitude of the point estimate was small and not clinically significant (bias = 0.06 mm; 95% CI = 0.01, 0.11; p = 0.014). Small differences between CBCT measurements made by the 2 examiners at the left central incisor (bias = 0.06 mm; 95% CI = 0.01, 0.11; p = 0.014) were detected. However, this difference was minor and also not clinically significant. The respective analysis on the right incisor showed no statistically significant difference (bias = 0.05 mm; 95% CI = -0.01, 0.11; p = 0.246). CONCLUSIONS: Based on reproducibility, CBCT imaging for gingival thickness assessment proved to be as reliable as ultrasound determination. However, CBCT consistently yielded higher values, albeit at a marginal level, than did the ultrasound device.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Incisivo , Adulto , Estudios Transversales , Encía/diagnóstico por imagen , Humanos , Incisivo/diagnóstico por imagen , Reproducibilidad de los Resultados
6.
Int J Oral Maxillofac Implants ; 36(2): 307-312, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33909720

RESUMEN

PURPOSE: To evaluate the influence of low-dose protocols, with different numbers of basis images, on the precision of linear bone measurements in CBCT images. MATERIALS AND METHODS: Five polyurethane mandibles, with different levels of bone resorption, were used in this in vitro study. To obtain the reference standard, landmarks were made in the mandibular superior and buccal cortices, and then a digital caliper was used to measure the bone height and thickness at these regions. CBCT images were obtained with the PaX-i3D (Vatech) unit set at 50 kV, 4 mA, 0.2-mm voxel size and 50 × 50-mm field of view. Keeping these parameters fixed, each mandible was scanned twice, with different protocols: Low dose (L) had an acquisition time of 24 seconds and 720 basis images, and ultralow dose (UL) had an acquisition time of 15 seconds and 450 basis images. Then, measurements of bone height and thickness were performed on the images, using the previously determined landmarks as reference. The obtained data were submitted to statistical analysis, with a significance level of .05. Analysis of variance, Student t test, and intraclass correlation coefficient were employed. RESULTS: Regarding bone height, there were no significant differences between the measurements obtained with the L and UL protocols (P = .8648). Additionally, the L and UL protocols did not differ in relation to the reference standard (P = .8717 and P = .9928, respectively). Likewise, there were no significant differences between the measurements obtained with the L and UL protocols (P = .7969) for bone thickness, nor between these protocols and the gold standard (P = .7455). CONCLUSION: Considering the great demand for precise measurements in implantology, protocols of low-dose radiation can be used without compromising clinical planning.


Asunto(s)
Implantes Dentales , Tomografía Computarizada de Haz Cónico Espiral , Tomografía Computarizada de Haz Cónico , Humanos , Mandíbula/diagnóstico por imagen , Reproducibilidad de los Resultados
7.
Braz Oral Res ; 35: e036, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33909858

RESUMEN

Evaluating factors that may influence the nose dimensions and, therefore, contribute to the singularity of a person, is important for obtaining a precise facial reconstruction (FR) in forensic anthropology. Thus, the aim in this study was to evaluate the influence of sex, skeletal class, and facial type on nose dimensions of Brazilian individuals using cone-beam computed tomography (CBCT) scans. CBCT images of 54 males and 67 females were classified according to skeletal class (class I, II, or III) and facial type (brachycephalic, dolichocephalic and mesocephalic). Linear and angular measurements of the nose were performed using the CS 3D Imaging software. The measurements obtained for males and females were compared by one-way ANOVA. Two-way ANOVA was used to compare the measurements in the different skeletal classes and facial types. Significance level was set at 5%. All linear measurements were greater in males (p < 0.05); the angular measurements, however, did not differ between sexes (p > 0.05). Linear and angular measurements of class III males were significantly different from the other classes; the same was observed for the angular measurements in females (p < 0.05). Regarding facial types, some linear measurements were significantly greater in dolichocephalics males (p < 0.05). For females, there was no influence of facial type (p > 0.05), except for the nasal convexity angle. Nose dimensions differed in specific points among different skeletal classes and facial types, and there was sexual dimorphism in all linear nose dimensions. This information may be applicable for nose reconstructions, allowing more reliable FR.


Asunto(s)
Tomografía Computarizada de Haz Cónico Espiral , Brasil , Tomografía Computarizada de Haz Cónico , Cara/diagnóstico por imagen , Femenino , Humanos , Imagenología Tridimensional , Masculino , Nariz/diagnóstico por imagen
8.
Gen Dent ; 69(3): e1-e5, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33908884

RESUMEN

Undetected pulp stones can complicate root canal treatment. Knowledge about the prevalence of this anomaly in specific populations can improve endodontic treatment outcomes. The objective of this study was to use cone beam computed tomography (CBCT) to assess the prevalence of pulp stones in an Iranian subpopulation. In this descriptive, analytical, cross-sectional study, the CBCT scans of 150 (75 female and 75 male) patients aged 15 to 70 years were retrieved from the 2017 to 2018 archives of an Iranian university. A total of 4200 teeth were evaluated for the presence of pulp stones by a senior dental student under the supervision of an experienced oral and maxillofacial radiologist. The panoramic radiographic views were evaluated first, and then each tooth was evaluated on sagittal, coronal, axial, cross-sectional, and multiplanar views with 0.5-mm slice thickness. Data regarding the presence of pulp stones as well as the effects of age, sex, tooth type, and jaw on the presence of pulp stones were analyzed using independent t and chi-square tests. Of 4200 teeth, 571 had pulp stones, yielding prevalence rates of 13.6% in the studied teeth and 76.0% in the study population. The prevalence of pulp stones was higher in female patients, the mandible, anterior teeth, and the mandibular left quadrant. The mandibular left central incisor (tooth 24) had the highest (38.7%) and the maxillary left second premolar (tooth 13) had the lowest (1.3%) prevalence of pulp stones. The high prevalence of pulp stones in this study population suggests that dentists should consider the possible presence of pulp stones when planning endodontic treatment for Iranian patients.


Asunto(s)
Calcificaciones de la Pulpa Dental , Adolescente , Adulto , Anciano , Tomografía Computarizada de Haz Cónico , Estudios Transversales , Calcificaciones de la Pulpa Dental/diagnóstico por imagen , Calcificaciones de la Pulpa Dental/epidemiología , Cavidad Pulpar , Femenino , Humanos , Irán/epidemiología , Masculino , Mandíbula , Persona de Mediana Edad , Prevalencia , Raíz del Diente , Adulto Joven
9.
Artículo en Inglés | MEDLINE | ID: mdl-33805123

RESUMEN

This study investigated the cone-beam computed tomography (CBCT)-based features of the mandibular canal, mental foramen, anterior loop, and accessory mental foramina with respect to age and sex. A total of 306 CBCT mandibular images were included in this retrospective study to measure the mandibular canal location and extension, the mental foramen position, the presence of the anterior loop, and the accessory mental foramina. The measurements were obtained in sagittal, coronal, and axial views. Descriptive statistics are presented. Sex-related differences, correlations, and comparisons were calculated using SPSS at 5% significance level. The mandibular canal was located more coronal and medial in male patients. The majority of cases had the mental foramen located just apical to the mandibular second premolar with a mean height of 2.94 mm and a mean length of 3.28 mm. Age affected the size of the mental foramen. The mental canal in all cases tended to show a coronal direction. Mesial extension of the anterior loop was found in 66.01% of the images while accessory mental foramina were detected in 2.6%. The complexity of the mandibular canal, mental foramen, anterior loop, and accessory mental foramina among Sudanese patients with respect to age and sex was confirmed.


Asunto(s)
Foramen Mental , Grupo de Ascendencia Continental Africana , Tomografía Computarizada de Haz Cónico , Humanos , Masculino , Mandíbula/diagnóstico por imagen , Estudios Retrospectivos
10.
Artículo en Inglés | MEDLINE | ID: mdl-33801033

RESUMEN

There has been growing interest in utilizing information from cone-beam computed tomography (CBCT) to help guide both treatment delivery and prognosis. In this assessment of locally advanced unresectable stage III non-small cell lung cancer (NSCLC) treated with definitive chemoradiation, we aimed to determine the survival advantage associated with using CBCT to measure tumor regression. Patient, tumor, and treatment characteristics were collected. The serial tumor shrinkage for each patient was determined from tumor volume contours on weekly CBCTs. Survival analysis was performed using the Kaplan-Meier technique and a Cox proportional hazards model. At least two-thirds of patients had a tumor volume reduction of at least 5% after each week of chemoradiation. A weekly reduction in tumor volume of 5% or greater seen on the CBCT images during radiation therapy was significantly associated with improved overall survival, which remained significant when adjusted for age, histology, grade, and T- and N-stages (p = 0.0036). Additionally, the presence of N3 disease was associated with a five-fold increased risk of recurrence (p = 0.0006) and a nearly three-fold increased risk of death (p = 0.053) compared with N0-N2 disease. Tumor volume shrinkage observed in the CBCT images during definitive chemoradiation holds promise as a prognostic indicator of stage III NSCLC, especially given its affordability, availability, and applicability. Further evaluation in a prospective fashion is warranted to validate the tumor volume shrinkage and its clinical utility.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Tomografía Computarizada de Haz Cónico Espiral , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/terapia , Tomografía Computarizada de Haz Cónico , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/terapia , Recurrencia Local de Neoplasia , Proyectos Piloto , Pronóstico , Estudios Prospectivos
11.
Artículo en Inglés | MEDLINE | ID: mdl-33801039

RESUMEN

The aim of this in vitro study was to determine whether the process chain influences the accuracy of a computer-assisted dynamic navigation procedure. Four different data integration workflows using cone-beam computed tomography (CBCT), conventional impressions, and intraoral digitization with and without reference markers were analyzed. Digital implant planning was conducted using data from the CBCT scans and 3D data of the oral models. The restoration of the free end of the lower jaw was simulated. Fifteen models were each implanted with two new teeth for each process chain. The models were then scanned with scan bodies screwed onto the implants. The deviations between the planned and achieved implant positions were determined. The evaluation of all 120 implants resulted in a mean angular deviation of 2.88 ± 2.03°. The mean 3D deviation at the implant shoulder was 1.53 ± 0.70 mm. No significant differences were found between the implant regions. In contrast, the workflow showed significant differences in various parameters. The position of the reference marker affected the accuracy of the implant position. The in vitro examination showed that precise implantation is possible with the dynamic navigation system used in this study. The results are of the same order of magnitude that can be achieved using static navigation methods. Clinical studies are yet to confirm the results of this study.


Asunto(s)
Cirugía Asistida por Computador , Diseño Asistido por Computadora , Computadores , Tomografía Computarizada de Haz Cónico , Flujo de Trabajo
12.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(2): 396-401, 2021 Mar 04.
Artículo en Chino | MEDLINE | ID: mdl-33879917

RESUMEN

OBJECTIVE: To analyze the three-dimensional radiographic characteristics of maxillary radi-cular cysts using cone-beam computed tomography (CBCT) and spiral CT. METHODS: Clinical records, histopathological reports, and CBCT or non-enhanced spiral CT images of 67 consecutive patients with maxillary radicular cysts were retrospectively acquired, and radiographic features, including size, shape, expansion, internal structure and relationship with the surrounding tissues, were analyzed. The lesions were divided into three types according to the involved tooth number, as follows: type Ⅰ (single tooth), the epicenter of the cyst was located at the apex of a nonvital tooth, without involvement of the neighbo-ring tooth; type Ⅱ (adjacent tooth involvement), the cyst was located at the apex of a nonvital tooth with involvement of the mesial and/or distal tooth root; and type Ⅲ (multi-teeth), the cyst involved the apexes of ≥4 teeth. Besides, these cysts were classified as another three types on sagittal views, as follows: centripetal, the root apex was oriented centripetally to the center of the cyst; palatal, the cyst was located mainly at the palatal side of the apex; and labial/buccal, the cyst was located mainly at the labial/buccal side of the apex. RESULTS: Totally, 67 patients with maxillary radicular cysts were acquired, including 38 males and 29 females, and their ages ranged from 13 to 77 years. Among them, 46 lesions (68.7%) were located in the anterior maxilla and 65 (97.0%) were round or oval. Labial/buccal cortex expansion was present in 43 cases (64.2%) and palatal cortex expansion in 37 cases (55.2%). The nasal floor was invaded in 27 cases (40.3%), the maxillary sinus was invaginated in 26 cases (38.8%), and root resorption was present in 9 cases (13.4%). The average diameter of lesions was (20.89±8.11) mm mesio-distally and (16.70±5.88) mm bucco-palatally. In spite of the 4 residual cysts, the remaining 63 lesions included 14 type Ⅰ, 26 type Ⅱ and 23 type Ⅲ cysts according to the involved tooth number. Besides, the 63 lesions included 46 centripetal, 15 palatal and 2 buccal cysts on sagittal views. CONCLUSION: The maxillary radicular cysts were frequently well-circumscribed round or oval radiolucency, with significantly different sizes. According to the involved tooth number, it can be divided into single tooth, adjacent tooth involvement and multi-teeth types. On sagittal views, the root-cyst relationship was centripetal in most cases, while a minority of cysts expanded palatally or buccally.


Asunto(s)
Maxilar , Quiste Radicular , Adolescente , Adulto , Anciano , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , Maxilar/diagnóstico por imagen , Persona de Mediana Edad , Quiste Radicular/diagnóstico por imagen , Estudios Retrospectivos , Raíz del Diente , Adulto Joven
13.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(2): 434-436, 2021 Feb 22.
Artículo en Chino | MEDLINE | ID: mdl-33879922

RESUMEN

In recent years, developing new methods to accelerate orthodontic tooth movement (OTM) has attracted extensive attention in the field of orthodontic clinical and scientific research. It reduces orthodontic treatment time and risks. Over the past, various approaches have been done to accelerate orthodontic tooth movement. Several forms of corticotomy techniques have been effective in inducing rapid tooth movement. These techniques activate regional acceleratory phenomenon and create a favorable microenvironment for accelerating tooth movement. Root resorption is one of most common side effects of orthodontic treatment. It affects the long-term viability and health of teeth. However, the effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption still remains unclear. Accelerating tooth movement may have two-side effects on root resorption. Through shortening the treatment period and removing the hyalinized tissues, the acceleration of orthodontic tooth movement could reduce root resorption. The increase of root resorption might be due to the local inflammation and function of cementoclasts/odontoclasts. In this paper, we reviewed the effects of different corticotomy techniques accelerating orthodontic tooth movement on root resorption. Corticotomy techniques deal with mucoperio-steal flaps and bone tissues differently and develop towards minimally invasive. Previous studies on root resorption use two-dimensional images, including apical films and panoramic tomography, to evaluate the degree of root resorption. In recent years, researches measure the volume of root resorption accurately using cone-beam computed tomography (CBCT) and micro-CT. Most studies suggest that the root resorption during acceleration of orthodontic tooth movement through corticotomy techniques is not statistically different from that of traditional orthodontic treatment. Some studies using micro-CT have shown that the root resorption in the groups of corticotomy techniques increases compared with the control group without surgery. Because of the short duration of these studies, the clinical significance is controversial on the overall impact of corticotomy techniques on orthodontic treatment. Accelerating orthodontic tooth movement is still at its emerging phase and need further research in the form of clinical trials to illustrate the effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption.


Asunto(s)
Resorción Radicular , Técnicas de Movimiento Dental , Tomografía Computarizada de Haz Cónico , Humanos , Osteoclastos , Resorción Radicular/etiología , Raíz del Diente , Microtomografía por Rayos X
14.
BMC Oral Health ; 21(1): 206, 2021 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-33894757

RESUMEN

BACKGROUND: In individuals with nasal septal deviation (NSD), compensatory hypertrophy of the nasal turbinates occurs as a protective mechanism of the nasal passage from dry and cold air. NSD associated nasal turbinate hypertrophy is usually recurrent, requiring repetitive imaging. Therefore, a multiplanar imaging modality with a low radiation dose is best suited for long-term follow-up of this condition. This study aimed to evaluate the association of width of inferior turbinates and presence of concha bullosa with the degree of NSD using Cone beam computed tomography (CT). METHODS: The CBCT scans of 100 patients with NSD were selected as per convenience sampling and were evaluated by two maxillofacial radiologists. The width of the non-hypertrophied inferior turbinate (NHT) on the convex side of the NSD, and hypertrophic inferior turbinates (HT) on the concave side of the NSD were measured at three locations. The septal deviation angle (SDA) and the presence of concha bullosa (CB) were determined. RESULTS: A significant difference was observed in the anterior, middle, posterior, and mean widths between HT and NHT (p < 0.001). There was a significant difference in the widths of the HT and NHT among different types of NSD. A strong positive correlation (r = 0.71, p < 0.001) was found between SDA and the mean width of the HT. Age (P = 0.71) and gender (P = 0.65) had no significant difference among different types of NSD. Regression analysis revealed that the presence of CB (p = 0.01) and middle width of the HT (p < 0.001) are significant predictors of SDA and type of NSD. CONCLUSION: The results of the present study reveal that the middle width of the HT and the presence of CB influence the degree of NSD. The present study results recommend the use of CBCT as a substitutive low radiation dose imaging modality for evaluation of NSD, CB, and associated inferior turbinate hypertrophy.


Asunto(s)
Tomografía Computarizada por Rayos X , Cornetes Nasales , Tomografía Computarizada de Haz Cónico , Humanos , Cavidad Nasal , Tabique Nasal/diagnóstico por imagen , Cornetes Nasales/diagnóstico por imagen
16.
BMC Oral Health ; 21(1): 184, 2021 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-33845803

RESUMEN

BACKGROUND: Information regarding the reaction of bone augmentation in terms to sinus mucosa thickness of periodontally compromised molar extraction sites is limited. This retrospective study aimed to analyze the effect of ridge preservation procedures following the extraction of molars with severe periodontitis on the healing pattern of adjacent maxillary sinus mucosal membranes. METHODS: Thirty-one periodontally compromised maxillary molar teeth either receiving ridge preservation (test group, n = 20) or undergoing spontaneous healing (control group, n = 11) were investigated. Cone-beam computed tomography (CBCT) scanning was performed before the extraction procedure and repeated 6 months later. The mucosa thickness (MT) of the adjacent periodontally compromised molar tooth was measured from CBCT images before tooth extraction and after 6 months of healing at nine assigned measurement points. The data were analyzed at α = 0.05. RESULTS: The prevalence of pre-extraction maxillary sinus mucosal thickening was 60.0% and 63.6% in the test and control groups, respectively. The average MT of the thickened sinus mucosa before tooth extraction was 3.78 ± 2.36 mm in the test group and 4.63 ± 3.20 mm in the control group (P = 0.063). The mean mucosal thickening reductions in the thickened MT subjects after 6 months of healing were 2.20 ± 2.05 mm (test group) and 2.64 ± 2.70 mm (control group), P = 0.289. The differences of MT between the time prior to extraction and after 6 months of healing were statistically significant within both groups (P < 0.05). CONCLUSIONS: Following extraction of molars with severe periodontitis, a reduction in swelling of the Schneiderian membrane has been observed regardless of the addition of a DBBM socket graft. However, a mucosal thickness > 2 mm was still frequently observed.


Asunto(s)
Pérdida de Hueso Alveolar , Periodontitis , Tomografía Computarizada de Haz Cónico , Humanos , Diente Molar/diagnóstico por imagen , Diente Molar/cirugía , Mucosa Nasal/diagnóstico por imagen , Periodontitis/diagnóstico por imagen , Proyectos Piloto , Estudios Retrospectivos , Extracción Dental
17.
J Indian Soc Pedod Prev Dent ; 39(1): 79-84, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33885392

RESUMEN

Objective: Metapex/Vitapex is one of the most commonly used obturating materials in pediatric dental practice in recent times. It is available in a premixed syringe which poses numerous practical difficulties. This study aimed to calculate the root canal volume of maxillary and mandibular canine and second molar using cone-beam computed tomography (CBCT) to determine the quantity/grams of obturation material to obturate a single tooth (mass = density × volume). Materials and Method: This nonrandomized clinical trial is comprised of two parts. The first part involved calculation of average root canal volume using CBCT which was used to calculate the quantity/grams of obturating material. This predetermined quantity was used to obturate primary mandibular second molars and canines, and the quality of obturation was assessed. Results: Assessment of quality of obturation showed optimum length obturation in 53.33% primary second molars and 66.66% primary canines. Conclusion: It can be inferred that even with the use of exact predetermined quantity/grams of obturating material, optimum quality obturation could be achieved, thus avoiding wastage, preventing cross contamination, and simultaneously offering good clinical results. Hence, this study opens further gateways to device ampules containing predetermined mass of obturating material for a single use for obturation of a single primary tooth.


Asunto(s)
Cavidad Pulpar , Diente Molar , Niño , Tomografía Computarizada de Haz Cónico , Cavidad Pulpar/diagnóstico por imagen , Humanos , Diente Molar/diagnóstico por imagen , Raíz del Diente , Diente Primario
18.
Sensors (Basel) ; 21(6)2021 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-33801108

RESUMEN

In the design of dental multifunctional Cone Beam Computed Tomography, the linear scanning strategy not only saves equipment cost, but also avoids the demand for patients to be repositioned when acquiring lateral cranial sequence images. In order to obtain panoramic images, we propose a local normalized cross-correlation stitching algorithm based on Gaussian Mixture Model. Firstly, the Block-Matching and 3D filtering algorithm is used to remove quantum and impulse noises according to the characteristics of X-ray images; Then, the segmentation of the irrelevant region and the extraction of the region of interest are performed by Gaussian Mixture Model; The locally normalized cross-relation is used to complete the registration with the multi-resolution strategy based on wavelet transform and Particle Swarm Optimization algorithm; Finally, image fusion is achieved by the weighted smoothing fusion algorithm. The experimental results show that the panoramic image obtained by this method has significant performance in both subjective vision and objective quality evaluation and can be applied to preoperative diagnosis of clinical dental deformity and postoperative effect evaluation.


Asunto(s)
Algoritmos , Tomografía Computarizada de Haz Cónico , Humanos , Procesamiento de Imagen Asistido por Computador
19.
Cochrane Database Syst Rev ; 3: CD014545, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33720395

RESUMEN

BACKGROUND: The detection and diagnosis of caries at the earliest opportunity is fundamental to the preservation of tooth tissue and maintenance of oral health. Radiographs have traditionally been used to supplement the conventional visual-tactile clinical examination. Accurate, timely detection and diagnosis of early signs of disease could afford patients the opportunity of less invasive treatment with less destruction of tooth tissue, reduce the need for treatment with aerosol-generating procedures, and potentially result in a reduced cost of care to the patient and to healthcare services. OBJECTIVES: To determine the diagnostic accuracy of different dental imaging methods to inform the detection and diagnosis of non-cavitated enamel only coronal dental caries. SEARCH METHODS: Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 31 December 2018); Embase Ovid (1980 to 31 December 2018); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 31 December 2018); and the World Health Organization International Clinical Trials Registry Platform (to 31 December 2018). We studied reference lists as well as published systematic review articles. SELECTION CRITERIA: We included diagnostic accuracy study designs that compared a dental imaging method with a reference standard (histology, excavation, enhanced visual examination), studies that evaluated the diagnostic accuracy of single index tests, and studies that directly compared two or more index tests. Studies reporting at both the patient or tooth surface level were included. In vitro and in vivo studies were eligible for inclusion. Studies that explicitly recruited participants with more advanced lesions that were obviously into dentine or frankly cavitated were excluded. We also excluded studies that artificially created carious lesions and those that used an index test during the excavation of dental caries to ascertain the optimum depth of excavation. DATA COLLECTION AND ANALYSIS: Two review authors extracted data independently and in duplicate using a standardised data extraction form and quality assessment based on QUADAS-2 specific to the clinical context. Estimates of diagnostic accuracy were determined using the bivariate hierarchical method to produce summary points of sensitivity and specificity with 95% confidence regions. Comparative accuracy of different radiograph methods was conducted based on indirect and direct comparisons between methods. Potential sources of heterogeneity were pre-specified and explored visually and more formally through meta-regression. MAIN RESULTS: We included 104 datasets from 77 studies reporting a total of 15,518 tooth sites or surfaces. The most frequently reported imaging methods were analogue radiographs (55 datasets from 51 studies) and digital radiographs (42 datasets from 40 studies) followed by cone beam computed tomography (CBCT) (7 datasets from 7 studies). Only 17 studies were of an in vivo study design, carried out in a clinical setting. No studies were considered to be at low risk of bias across all four domains but 16 studies were judged to have low concern for applicability across all domains. The patient selection domain had the largest number of studies judged to be at high risk of bias (43 studies); the index test, reference standard, and flow and timing domains were judged to be at high risk of bias in 30, 12, and 7 studies respectively. Studies were synthesised using a hierarchical bivariate method for meta-analysis. There was substantial variability in the results of the individual studies, with sensitivities that ranged from 0 to 0.96 and specificities from 0 to 1.00. For all imaging methods the estimated summary sensitivity and specificity point was 0.47 (95% confidence interval (CI) 0.40 to 0.53) and 0.88 (95% CI 0.84 to 0.92), respectively. In a cohort of 1000 tooth surfaces with a prevalence of enamel caries of 63%, this would result in 337 tooth surfaces being classified as disease free when enamel caries was truly present (false negatives), and 43 tooth surfaces being classified as diseased in the absence of enamel caries (false positives). Meta-regression indicated that measures of accuracy differed according to the imaging method (Chi2(4) = 32.44, P < 0.001), with the highest sensitivity observed for CBCT, and the highest specificity observed for analogue radiographs. None of the specified potential sources of heterogeneity were able to explain the variability in results. No studies included restored teeth in their sample or reported the inclusion of sealants. We rated the certainty of the evidence as low for sensitivity and specificity and downgraded two levels in total for risk of bias due to limitations in the design and conduct of the included studies, indirectness arising from the in vitro studies, and the observed inconsistency of the results. AUTHORS' CONCLUSIONS: The design and conduct of studies to determine the diagnostic accuracy of methods to detect and diagnose caries in situ are particularly challenging. Low-certainty evidence suggests that imaging for the detection or diagnosis of early caries may have poor sensitivity but acceptable specificity, resulting in a relatively high number of false-negative results with the potential for early disease to progress. If left untreated, the opportunity to provide professional or self-care practices to arrest or reverse early caries lesions will be missed. The specificity of lesion detection is however relatively high, and one could argue that initiation of non-invasive management (such as the use of topical fluoride), is probably of low risk. CBCT showed superior sensitivity to analogue or digital radiographs but has very limited applicability to the general dental practitioner. However, given the high-radiation dose, and potential for caries-like artefacts from existing restorations, its use cannot be justified in routine caries detection. Nonetheless, if early incidental carious lesions are detected in CBCT scans taken for other purposes, these should be reported. CBCT has the potential to be used as a reference standard in diagnostic studies of this type. Despite the robust methodology applied in this comprehensive review, the results should be interpreted with some caution due to shortcomings in the design and execution of many of the included studies. Future research should evaluate the comparative accuracy of different methods, be undertaken in a clinical setting, and focus on minimising bias arising from the use of imperfect reference standards in clinical studies.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Conjuntos de Datos como Asunto , Caries Dental/diagnóstico por imagen , Radiografía Dental/métodos , Adulto , Sesgo , Niño , Tomografía Computarizada de Haz Cónico/estadística & datos numéricos , Dentición Permanente , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Radiografía Dental/estadística & datos numéricos , Radiografía Dental Digital/estadística & datos numéricos , Estándares de Referencia , Sensibilidad y Especificidad , Diente Primario
20.
Eur J Radiol ; 138: 109645, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33725654

RESUMEN

PURPOSE: Cone beam CT (CBCT) imaging assessment of acute ischemic stroke (AIS) patients with large-vessel occlusion (LVO) in the angiosuite may improve stroke workflow and decrease time to recanalization. In order for this workflow to gain widespread acceptance, current CBCT imaging needs further development to improve image quality. Our study aimed to compare the image quality of a new CBCT protocol performed directly in the angiosuite with imaging from multidetector CT as a gold standard. METHODS: AIS patients with an LVO who were candidates for endovascular treatment were prospectively included in this study. Following conventional multidetector CT (MDCT), patients underwent unenhanced cone beam CT (XperCT, Philips) imaging in the angiosuite, using two different protocols: a standard 20.8 s XperCT and/or an improved 10.4 s XperCT protocol. Images were evaluated using both qualitative and quantitative methods. RESULTS: We included 65 patients in the study. Patients received CBCT imaging prior to endovascular treatment; 18 patients were assessed with a standard 20.8 s protocol scans and 47 with a newer 10.4 s scan. The quantitative analysis showed that the mean contrast-to-noise ratio (CNR) was significantly higher for the newer 10.4 s protocol compared with the 20.8 s protocol (2.08 +/- 0.64 vs. 1.15 +/- 0.27, p < 0.004) and the mean image noise was significantly lower for the 10.4 s XperCTs when compared with the 20.8 s XperCTs (6.30 +/- 1.34 vs. 7.82 +/- 2.03, p=<0.003). Qualitative analysis, including 6 measures of image quality, demonstrated that 74.1 % of the 10.4 s XperCT scans were ranked as 'Acceptable' for assessing parenchymal imaging in AIS patients(scoring 3-5 points on a 5-point Likert-scale), compared with 32.4 % of the standard 20.8 s XperCT and 100 % of the MDCT scans. Compared to the MDCT studies, 83 % of the 10.4 s XperCT scans were deemed sufficient image quality for a direct-to-angiosuite selection, compared to only 11 % for the standard 20.8 s scans. The largest image quality improvements included grey/white matter differentiation (59 % improvement), and reduction of image noise and artefacts (63 % & 50 % improvement, respectively). CONCLUSIONS: Continued advances in cone-beam CT allow marked improvements in image quality for the assessment of brain parenchyma, which supports a direct-to-angiosuite approach for AIS patients eligible for thrombectomy treatment.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular , Isquemia Encefálica/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Humanos , Fantasmas de Imagen , Estudios Prospectivos , Accidente Cerebrovascular/diagnóstico por imagen
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