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1.
Clin Oral Investig ; 27(12): 7881-7888, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37993703

RESUMO

OBJECTIVE: To compare the dosimetry between convex triangular fields of view (FOV) and similar dimension cylindrical FOVs of two cone-beam computed tomography (CBCT) models. METHODS: Optically stimulated luminescence dosimeters (OSLDs) were placed in fiducial anatomical locations in an anthropomorphic phantom representing an adult head male for dosimetry scans. Convex triangular FOVs (100 × 80 mm/maxilla-mandible; 100 × 50 mm mandible; 100 × 50 mm/maxilla) from Veraviewepocs 3D R100 (J. Morita, Kyoto, Japan) (R100) and Veraview® X800 (J. Morita, Kyoto, Japan) (X800) and cylindrical FOVs from R100 and X800 (80 × 80 mm/maxilla-mandible; 80 × 50 mm/mandible; 80 × 50 mm/maxilla) were obtained, resulting in 12 different scan protocols. Equivalent doses for each relevant organ/tissue and the effective dose for each protocol were calculated. Mean effective doses were compared by the two-way analysis of variance (ANOVA) with Tukey's post hoc test to evaluate the effect of the FOV and device (α = 0.05). RESULTS: The effective doses ranged between 69 and 324 µSv for the convex triangular FOVs and 76 and 332 µSv for the cylindrical FOVs. Convex triangular FOVs from the R100 device had effective doses 2.3 to 15.3% lower than their corresponding cylindrical FOVs with similar height (p < 0.05), and that difference ranged between 8.8 and 11.8% for the X800 device (p < 0.05). CONCLUSION: Convex triangular fields of view delivered slightly lower effective doses than the cylindrical fields of view of similar dimensions in the R100 and X800 CBCT devices. CLINICAL RELEVANCE: Understanding the influence of the image geometry formation in effective dose allows optimization to reduce patient dose.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Radiometria , Adulto , Masculino , Humanos , Doses de Radiação , Tomografia Computadorizada de Feixe Cônico/métodos , Mandíbula/diagnóstico por imagem , Maxila , Imagens de Fantasmas
2.
Clin Oral Investig ; 24(12): 4501-4510, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32488487

RESUMO

OBJECTIVES: To investigate the frequency and reasons for retaking cone beam computed tomography (CBCT) scans in an oral and maxillofacial radiology imaging clinic in a dental institution. MATERIALS AND METHODS: A retrospective cohort chart audit of the patient image database was performed for 1737 patients attending the Diagnostic Imaging clinic at the Prince Philip Dental Hospital from February 2016 to May 2019, and the rate of, and reasons for, CBCT image re-exposure was tallied. Patient demographics (age and gender) and CBCT acquisition parameters (CBCT unit, field-of-view (FOV), scanned region of interest, and exposure time) were recorded and correlated to retake analysis. RESULTS: The retake rate was 4.6% (80/1737). The most common reasons for re-exposure were incomplete FOV coverage (57.5%) and motion artifacts (27.5%). Patients under 12 years of age had a significantly higher risk for motion artifacts. CBCT for the temporomandibular joint (TMJ) had a significantly higher risk for incomplete FOV coverage. CONCLUSIONS: Children (less than 12 years of age) demonstrate a higher frequency of retakes, principally due to motion artifacts. TMJ CBCT examinations have a higher frequency of retakes due to an incomplete FOV coverage. CLINICAL RELEVANCE: Information regarding the frequency and reasons for CBCT retakes is beneficial to identify procedures, practices, or patients susceptible to additional radiation exposure and implement appropriate and specific quality control protocols.


Assuntos
Artefatos , Tomografia Computadorizada de Feixe Cônico , Criança , Humanos , Imagens de Fantasmas , Estudos Retrospectivos , Articulação Temporomandibular
3.
Clin Oral Implants Res ; 29 Suppl 16: 393-415, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30328204

RESUMO

OBJECTIVE: The aim of this systematic review was to identify, review, analyze, and summarize available evidence on the accuracy of linear measurements when using maxillofacial cone beam computed tomography (CBCT) specifically in the field of implant dentistry. MATERIAL AND METHODS: The search was undertaken in April 2017 in the National Library of Medicine database (Medline) through its online site (PubMed), followed by searches in the Cochrane, EMBASE, ScienceDirect, and ProQuest Dissertation and Thesis databases. The main inclusion criterion for studies was that linear CBCT measurements were performed for quantitative assessment (e.g., height, width) of the alveolar bone at edentulous sites or measuring distances from anatomical structures related to implant dentistry. The studies should compare these values to clinical data (humans) or ex vivo and/or experimental (animal) findings from a "gold standard." RESULTS: The initial search yielded 2,516 titles. In total, 22 studies were included in the final analysis. Of those, two were clinical and 20 ex vivo investigations. The major findings of the review indicate that CBCT provides cross-sectional images that demonstrate high accuracy and reliability for bony linear measurements on cross-sectional images related to implant treatment. A wide range of error has been reported when performing linear measurements on CBCT images, with both over- and underestimation of dimensions in comparison with a gold standard. A voxel size of 0.3 to 0.4 mm is adequate to provide CBCT images of acceptable diagnostic quality for implant treatment planning. CONCLUSIONS: CBCT can be considered as an appropriate diagnostic tool for 3D preoperative planning. Nevertheless, a 2 mm safety margin to adjacent anatomic structures should be considered when using CBCT. In clinical practice, the measurement accuracy and reliability of linear measurements on CBCT images are most likely reduced through factors such as patient motion, metallic artefacts, device-specific exposure parameters, the software used, and manual vs. automated procedures.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Implantação Dentária Endóssea , Implantes Dentários , Planejamento de Assistência ao Paciente , Processo Alveolar/anatomia & histologia , Processo Alveolar/diagnóstico por imagem , Processo Alveolar/cirurgia , Animais , Bases de Dados Factuais , Ossos Faciais/anatomia & histologia , Ossos Faciais/diagnóstico por imagem , Ossos Faciais/cirurgia , Humanos , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Maxila/cirurgia , Reprodutibilidade dos Testes , Software
4.
Clin Oral Implants Res ; 29 Suppl 16: 436-442, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30328201

RESUMO

OBJECTIVES: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed. MATERIALS AND METHODS: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. RESULTS: Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. CONCLUSIONS: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care.


Assuntos
Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico/métodos , Imageamento Tridimensional/métodos , Cirurgia Assistida por Computador/métodos , Consenso , Bases de Dados Factuais , Implantação Dentária Endóssea , Técnica de Moldagem Odontológica , Prótese Dentária Fixada por Implante , Humanos , Boca Edêntula/cirurgia , Planejamento de Assistência ao Paciente , Medidas de Resultados Relatados pelo Paciente , Reprodutibilidade dos Testes , Software
5.
Clin Oral Investig ; 22(4): 1783-1793, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29188451

RESUMO

OBJECTIVE: The objective of the study was to compare estimates of pediatric cumulative exposure and lifetime attributable risk (LAR) of radiation-induced cancer from dental radiology between cleft palate (CP) subjects and age- and gender-matched controls (non-CP), with and without orthodontic treatment. MATERIALS AND METHODS: The radiation exposure frequency of CP subjects and non-CP controls with and without orthodontic treatment was compared for two-dimensional radiography (intra-oral, panoramic and cephalometric radiography), computed tomography (CT), and cone-beam CT (CBCT) using cumulative radiation dose as an estimate. From this dose estimate, the age- and gender-dependent risk for radiation-induced stochastic effects was calculated for each patient group. RESULTS: CP patients received more radiographic examinations than non-CP controls, with the exception of intra-oral radiographs. The cumulative dose to CP patients was considerably higher (1963 µSv at the age of 20 years) than non-CP patients with (597 µSv) and without (383 µSv) orthodontic treatment, primarily due to the higher frequency of CT scanning. Accordingly, CP patients had a three to five times higher LAR than non-CP patients. CONCLUSIONS: This study suggests a significantly higher lifetime radiation exposure to CP patients than non-CP controls from dental radiographic procedures. Diagnostic benefits from the use of CT and CBCT in children must be justified and appropriate dose optimization strategies implemented. CLINICAL RELEVANCE: The present study indicates the need for proper justification and optimization of pediatric exposures in dentistry, with a special focus on high-risk groups.


Assuntos
Fissura Palatina/diagnóstico por imagem , Exposição à Radiação , Radiografia Dentária , Cefalometria , Criança , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Neoplasias Induzidas por Radiação/etiologia , Ortodontia Corretiva , Radiografia Panorâmica , Estudos Retrospectivos , Risco , Tomografia Computadorizada por Raios X
6.
Am J Orthod Dentofacial Orthop ; 153(6): 842-851, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29853242

RESUMO

INTRODUCTION: We aimed to investigate the incidence and severity of orthodontically induced inflammatory root resorption (OIIRR) on maxillary incisors with clear aligner therapy using cone-beam computed tomography and to identify possible risk factors. METHODS: The root lengths of maxillary incisors were measured on orthogonal images from pretreatment and posttreatment cone-beam computed tomography examinations of 160 patients who received comprehensive orthodontic treatment with clear aligners. RESULTS: Mean absolute reductions in root length varied between 0.47 ± 0.61 mm and 0.55 ± 0.70 mm and were not significantly different between maxillary central and lateral incisors. The prevalence of severe OIIRR, defined as both maxillary central incisors experiencing greater than a 25% reduction in root length, was found to be 1.25%. Potential risk factors included sex, malocclusion, crowding, and posttreatment approximation of apices to the cortical plates. Race, interproximal reduction, previous trauma to the teeth, elastics, age, treatment duration, and pretreatment approximation of apices to the cortical plates did not significantly affect the amount of OIIRR. CONCLUSIONS: Comprehensive treatment with clear aligners resulted in minimal root resorption. Sex, malocclusion, crowding, and posttreatment approximation to the cortical plates significantly affected the percentage of change in root length. Posttreatment approximation of root apices to the palatal cortical plate showed the strongest association for increased OIIRR.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Aparelhos Ortodônticos/efeitos adversos , Ortodontia Corretiva/efeitos adversos , Reabsorção da Raiz/diagnóstico por imagem , Reabsorção da Raiz/etiologia , Adulto , Feminino , Humanos , Incidência , Incisivo , Masculino , Maxila , Desenho de Aparelho Ortodôntico , Estudos Retrospectivos , Fatores de Risco , Reabsorção da Raiz/epidemiologia
7.
Periodontol 2000 ; 74(1): 116-139, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28429477

RESUMO

Contemporary periodontal therapy has evolved to become more interdisciplinary and increasingly involves more complex treatments, including bone and soft-tissue regenerative procedures. Therapeutic options require an imaging modality or combination of techniques that are capable of providing a diagnostic osseous baseline and facilitating quantification of smaller increments of bony change, both loss and additive, which are comparable over time. Intra-oral and panoramic radiography are the modalities most commonly used to identify the location, quantify the amount and the pattern of alveolar bone loss and determine response to therapy. Cone-beam computed tomography imaging offers specific advantages for periodontal diagnosis in that three-dimensional images of dental and alveolar bone structures can be rendered with accuracy. Cone-beam computed tomography has been shown to be clinically efficacious in demonstrating localized defects, such as furcation involvement and intrabony vertical and buccal/lingual defects, and in assessing the effects of regenerative therapy. In these situations, limited-field-of-view, high-resolution protocols are indicated.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Periodontite/diagnóstico por imagem , Periodontite/terapia , Radiografia Dentária Digital/métodos , Radiografia Panorâmica/métodos , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/terapia , Humanos , Imageamento Tridimensional/métodos , Interpretação de Imagem Radiográfica Assistida por Computador
8.
Artigo em Inglês | MEDLINE | ID: mdl-35060966

RESUMO

This article presents a retrospective case series of implant site development using titanium mesh (Ti-mesh) in the maxilla. A total of 58 mesh procedures in combination with several different bone grafts (allograft, cellular allograft, and bovine xenograft) and biologics (including recombinant human platelet-derived growth factor, autogenous platelet-rich growth factor, and recombinant human bone morphogenetic protein-2) were performed in 48 patients. Ti-mesh guided bone regeneration procedures were performed 2 to 3 months after extraction of nonrestorable/hopeless teeth, and the implants were placed 6 to 8 months postaugmentation. The mean initial ridge width was 2.0 ± 1.0 mm, and the mean horizontal gain after Ti-mesh procedures was 4.7 ± 1.6 mm. The ridge width was first measured on the cross-sectional presurgical CBCT image and then confirmed clinically during surgical procedures. No statistical difference in the horizontal gain was found among different combinations of bone grafts and biomaterials. Ti-mesh exposure occurred 22% of the time. The middle-aged adults (odds ratio [OR] = 8.59; P = .046) and older adults (OR = 16.66; P = .02) had significantly higher chances of mesh exposure compared to young adults. While all implants were successfully placed, about 56% of the implants had < 2 mm of bone to the facial aspect of the osteotomy and received additional contour augmentation when placed in a prosthetically appropriate position for a screw-retained restoration. This study demonstrates that although Ti-mesh procedures result in significant bone regeneration in narrow alveolar ridges to predictably allow implant placement, the age-related mesh exposure rate and frequency of need for additional contour grafting should be discussed with patients.


Assuntos
Aumento do Rebordo Alveolar , Implantes Dentários , Idoso , Animais , Regeneração Óssea , Transplante Ósseo , Bovinos , Estudos Transversais , Implantação Dentária Endóssea , Humanos , Maxila/diagnóstico por imagem , Maxila/cirurgia , Pessoa de Meia-Idade , Estudos Retrospectivos , Telas Cirúrgicas , Titânio , Adulto Jovem
9.
Gen Dent ; 59(2): 136-44, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21903524

RESUMO

Digital radiography has created a growing opportunity for computer-aided diagnostic (CAD) tools. The Logicon Caries Detector (LCD), with upgraded CAD software based on user feedback, was re-evaluated for its effectiveness via a retrospective clinical study. Using the upgraded LCD software, 12 dentists (evaluators) blindly assessed 17 radiographs taken by another (attending) dentist, who restored 28 proximal surfaces. The attending dentist confirmed the presence of early dentinal caries, as well as identifying 48 surfaces as caries-free or with enamel caries only subject to noninvasive treatment. The radiographs, imported into the software using a digital imaging and communications in medicine (DICOM) reader, were visually assessed under typical operatory lighting conditions, then with the aid of the software's density analysis tool. The effectiveness of the evaluators was gauged by calculating two measures of performance, sensitivity and specificity, for the detection and classification of dentinal caries. Sensitivity among all evaluator dentists was 30% with the initial image; 34% with the brightness and contrast adjusted image; 39% when the image was sharpened; and 69% when the density analysis tool was utilized. Specificity was found to be 97% with the initial image; 95% with the brightness and contrast adjusted image; 93% with the sharpened image; and 94% when the density analysis tool was used. Compared to the unaided eye, the LCD can significantly improve dentists' ability to detect and classify caries. Dentists may be able to find twice as much early dentinal caries requiring restoration (or at least aggressive noninvasive treatment) than previously, while not unnecessarily restoring additional healthy teeth. The LCD enables dentists to obtain more information from dental digital radiography than is possible with the unaided eye, leading to improved patient care.


Assuntos
Cárie Dentária/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/normas , Radiografia Dentária Digital/normas , Tratamento Dentário Restaurador sem Trauma/métodos , Cárie Dentária/classificação , Esmalte Dentário/diagnóstico por imagem , Esmalte Dentário/patologia , Restauração Dentária Permanente/métodos , Dentina/diagnóstico por imagem , Dentina/patologia , Humanos , Variações Dependentes do Observador , Fotografia Dentária , Intensificação de Imagem Radiográfica/normas , Estudos Retrospectivos , Sensibilidade e Especificidade , Método Simples-Cego , Software , Gravação em Vídeo
10.
Artigo em Inglês | MEDLINE | ID: mdl-33528451

RESUMO

The purpose of this prospective study was to evaluate the success rates and prosthetic complications of implants with a modified sandblasted and acid-etched (SLA) surface inserted for posterior single-implant crown restorations. Final crowns were placed 3 to 4 weeks after surgery, and patient follow-up spanned 10 years in a private practice setting. A total of 22 patients (8 women, 14 men) with 25 posterior implants placed (16 mandible, 9 maxilla) were selected, including only implants for posterior single-implant crowns with insertion torque values of ≥ 35 Ncm at placement. Twenty-one implants passed the reverse torque test at 3 to 4 weeks after implant placement, and final restorations were placed. Three patients (4 implants) had "spinners," and there was one patient dropout after completion of the final restoration. All patients were recalled for clinical exams, digital periapical radiographs, and clinical photos at short-term (≤ 5 years) and long-term (> 5 years) follow-up appointments. The Community Periodontal Index of Treatment Needs was also determined at the initial and follow-up visits. Crestal bone level was measured at crown placement (T1), short-term follow-up (T2; mean: 29.4 months), and long-term follow-up appointments (T3; mean: 114.4 months). Twenty patients (23 implants) returned for examination at T2, and 15 (18 implants) were available at T3. For the 17 implants available at all evaluations, statistically significant bone loss was found from T1 to T2 (0.23 ± 0.30 mm), and the mean crestal bone level appeared stable from T2 to T3. Based on clinical and radiographic findings, the success rate for the implants and restorations at T2 and T3 was graded as 100%. Therefore, it can be stated that an early loading protocol of 3 to 4 weeks using a modified SLA surface at premolar/molar single-tooth locations can result in favorable clinical and radiographic long-term results.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Perda do Osso Alveolar/diagnóstico por imagem , Coroas , Implantação Dentária Endóssea , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Feminino , Seguimentos , Humanos , Masculino , Osseointegração , Estudos Prospectivos , Titânio
11.
Alpha Omegan ; 103(2): 62-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20645632

RESUMO

Cone beam computed tomography (CBCT) is a diagnostic imaging modality that has shown rapid adoption in clinical dental practice over the past 10 years. CBCT images provide high quality, accurate 3-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. The purpose of this article is to provide (1) an introduction to maxillofacial CBCT technology, (2) an understanding of the relative patient radiation dose, and (3) to underline the appropriate use of CBCTas a diagnostic imaging modality with specific clinical applications.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Radiografia Dentária/métodos , Artefatos , Tomografia Computadorizada de Feixe Cônico/instrumentação , Tomografia Computadorizada de Feixe Cônico/estatística & dados numéricos , Humanos , Posicionamento do Paciente , Doses de Radiação
12.
J Am Dent Assoc ; 151(4): 287-296, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32222177

RESUMO

BACKGROUND: The authors conducted a survey of the American Academy of Pediatric Dentistry (AAPD) to determine awareness of the Image Gently Campaign in Dentistry (IGCD) and to ascertain radiologic practices, including radiation dose-reduction strategies such as rectangular collimation. METHODS: An institutional review board approved an electronic survey sent to 7,087 AAPD members covering practitioner demographic characteristics, radiographic techniques, and dose-reduction practices, including rectangular collimation. Responses were tabulated and analyzed using binomial tests, χ2 tests, and Fisher exact tests. RESULTS: A total of 1,124 pediatric dentists or residents in pediatric dentistry responded, (response rate 16%, margin of error ± 2.7%). The largest group (23.8%) graduated after 2010. More than 90% indicated that they followed American Dental Association (ADA)-AAPD radiation exposure guidelines, but only 33.5% were aware of IGCD. Almost all respondents used direct digital systems, storage phosphor plates, or both. Only 22.3% (n = 220) used rectangular collimation. Nonusers indicated that they were unfamiliar with collimation (33.3%) or concerned about potential for increased cone cuts (30.2%), 11.6% of respondents were unaware of any regulatory requirements for inspections of radiographic equipment recurring at regular intervals, and 4.1% of respondents considered use of lead aprons optional. CONCLUSIONS: Although the pediatric dentists surveyed believe they are in compliance with ADA-AAPD guidelines, most are unaware of IGCD recommendations. Use of digital radiography is almost ubiquitous, but use of rectangular collimation is limited. PRACTICE IMPLICATIONS: Dentists treating children should be familiar with ADA-AAPD radiation exposure guidelines and should consider using the dose-reduction strategies recommended by IGCD.


Assuntos
Exposição à Radiação , Radiografia Dentária Digital , Criança , Odontólogos , Humanos , Doses de Radiação , Inquéritos e Questionários , Estados Unidos
13.
Oral Surg Oral Med Oral Pathol Oral Radiol ; 129(2): e212-e223, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31416715

RESUMO

This case series describes a reconstruction method applied to a cone beam computed tomography (CBCT) projection data set that used selected basis projection images to improve diagnostic image quality for patients who moved during the radiographic procedure. Reconstructed volumetric data from 6 patients at 2 institutions initially exhibited characteristic double contour images as a result of motion artifacts. For each case, the CBCT basis images from the entire projection data set were displayed as a cine sequence, and patient movement was identified during the first or last 90-degrees of a full 360-degree acquisition trajectory. Employing a useful reconstruction function of proprietary software, a secondary reconstruction was performed by discarding data acquired during the first and last 90-degree rotation. For all cases, this method provided a volumetric data set without motion artifact. General practitioners can apply this clinical method, whenever appropriate, to avoid a rescan and keep patient exposure "as low as diagnostically acceptable."


Assuntos
Artefatos , Tomografia Computadorizada de Feixe Cônico , Algoritmos , Humanos , Processamento de Imagem Assistida por Computador , Movimento , Imagens de Fantasmas
14.
Angle Orthod ; 79(1): 150-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19123719

RESUMO

OBJECTIVE: To compare the in vitro reliability and accuracy of linear measurements between cephalometric landmarks on cone beam computed tomography (CBCT) 3D volumetric images with varying basis projection images to direct measurements on human skulls. MATERIALS AND METHODS: Sixteen linear dimensions between 24 anatomic sites marked on 19 human skulls were directly measured. The skulls were imaged with CBCT (i-CAT, Imaging Sciences International, Hatfield, Pa) at three settings: (a) 153 projections, (b) 306 projections, and (c) 612 projections. The mean absolute error and modality mean (+/- SD) of linear measurements between landmarks on volumetric renderings were compared to the anatomic truth using repeated measures general linear model (P < or = .05). RESULTS: No difference in mean absolute error between the scan settings was found for almost all measurements. The average skull absolute error between marked reference points was less than the distances between unmarked reference sites. CBCT resulted in lower measurements for nine dimensions (mean difference range: 3.1 mm +/- 0.12 mm to 0.56 mm +/- 0.07 mm) and a greater measurement for one dimension (mean difference 3.3 mm +/- 0.12 mm). No differences were detected between CBCT scan sequences. CONCLUSIONS: CBCT measurements were consistent between scan sequences and for direct measurements between marked reference points. Reducing the number of projections for 3D reconstruction did not lead to reduced dimensional accuracy and potentially provides reduced patient radiation exposure. Because the fiducial landmarks on the skulls were not radio-opaque, the inaccuracies found in measurement could be due to the methods applied rather than to innate inaccuracies in the CBCT scan reconstructions or 3D software employed.


Assuntos
Cefalometria/métodos , Tomografia Computadorizada de Feixe Cônico , Imageamento Tridimensional/métodos , Crânio/diagnóstico por imagem , Cadáver , Estudos Transversais , Humanos , Imagens de Fantasmas
16.
J Am Dent Assoc ; 139 Suppl: 14S-19S, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18539867

RESUMO

BACKGROUND AND OVERVIEW: The impact of digital imaging on dental practice depends upon the degree of planning conducted before implementation. Digital technologies have the potential to improve diagnosis; facilitate patient treatment procedures; and streamline storage, transfer and retrieval. These technologies also provide for secure backup of patients' image data, critical to re-establishing the practice should fire, flood or earthquake occur. CONCLUSIONS: The decision to invest in digital radiographic equipment should be a simple one for dental practitioners. Although digital x-ray sensors have long equaled analog film for diagnostic tasks, they have several advantages over film radiography, including immediate image production with solid-state devices; interactive display on a monitor with the ability to enhance image features and make direct measurements; integrated storage with access to images through practice management software systems; security of available backup and off-site archiving; perfect radiographic duplicates to accompany referrals; security mechanisms to identify original images and differentiate them from altered images; the ability to tag information such as a patient identifier, date of exposure and other relevant details; and interoperability of the Digital Imaging and Communications in Medicine file format. CLINICAL IMPLICATIONS: Most clinicians should contemplate integrating, at a minimum, intraoral digital x-ray sensors and a digital panoramic system into their practices.


Assuntos
Radiografia Dentária Digital , Periféricos de Computador , Sistemas Computacionais , Registros Odontológicos , Humanos , Administração da Prática Odontológica , Sistemas de Informação em Radiologia , Software
17.
Dent Clin North Am ; 52(4): 707-30, v, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18805225

RESUMO

This article on x-ray cone-beam CT (CBCT) acquisition provides an overview of the fundamental principles of operation of this technology and the influence of geometric and software parameters on image quality and patient radiation dose. Advantages of the CBCT system and a summary of the uses and limitations of the images produced are discussed. All current generations of CBCT systems provide useful diagnostic images. Future enhancements most likely will be directed toward reducing scan time; providing multimodal imaging; improving image fidelity, including soft tissue contrast; and incorporating task-specific protocols to minimize patient dose.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Artefatos , Apresentação de Dados , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Doses de Radiação , Intensificação de Imagem Radiográfica/métodos , Radiografia Dentária/métodos , Software , Tecnologia Radiológica , Fatores de Tempo
18.
Angle Orthod ; 78(3): 387-95, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18416632

RESUMO

OBJECTIVE: To compare accuracy of linear measurements made on cone beam computed tomographic (CBCT) derived 3-dimensional (3D) surface rendered volumetric images to direct measurements made on human skulls. MATERIALS AND METHODS: Twenty orthodontic linear measurements between anatomical landmarks on 23 human skulls were measured by observers using a digital caliper. The skulls were imaged with CBCT and Dolphin 3D (version 2.3) software used to generate 3D volumetric reconstructions (3DCBCT). The linear measurements between landmarks were computed by a single observer three times and compared to anatomic dimensions using Student's t-test (P < or = .05). The intraclass correlation coefficient (ICC) and absolute linear and percentage error were calculated. RESULTS: The ICC for 3DCBCT (0.975 +/- 0.016) was significantly less than for skull (0.996 +/- 0.007) measurements. Mean percentage measurement error for 3DCBCT (2.31% +/- 2.11%) was significantly higher than replicate skull measurements (0.63% +/- 0.51%). Statistical differences between 3DCBCT means and true dimensions were found for all of the midsagittal measurements except Na-A and six of the 12 bilateral measurements. The mean percentage difference between the mean skull and 3D-based linear measurements was -1.13% (SD +/- 1.47%). Ninety percent of mean differences were less than 2 mm, and 95% confidence intervals were all less than 2 mm except for Ba-ANS (3.32 mm) and Pog-Go(left) (2.42 mm). CONCLUSIONS: While many linear measurements between cephalometric landmarks on 3D volumetric surface renderings obtained using Dolphin 3D software generated from CBCT datasets may be statistically significantly different from anatomic dimensions, most can be considered to be sufficiently clinically accurate for craniofacial analyses.


Assuntos
Cefalometria/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Ossos Faciais/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Cefalometria/estatística & dados numéricos , Queixo/anatomia & histologia , Queixo/diagnóstico por imagem , Estudos Transversais , Ossos Faciais/diagnóstico por imagem , Humanos , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Osso Nasal/anatomia & histologia , Osso Nasal/diagnóstico por imagem , Órbita/anatomia & histologia , Órbita/diagnóstico por imagem , Ortodontia , Reprodutibilidade dos Testes , Sela Túrcica/anatomia & histologia , Sela Túrcica/diagnóstico por imagem , Crânio/anatomia & histologia , Crânio/diagnóstico por imagem , Base do Crânio/anatomia & histologia , Base do Crânio/diagnóstico por imagem , Software
19.
J Dent Educ ; 72(2): 135-41, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18250393

RESUMO

Currently in North America, there is an active dialogue going on about the state of predoctoral dental education and the need for curriculum change, innovation, and the adoption of contemporary, competency-based educational models. At the institutional level, curriculum committees struggle with requests from faculty to add new content to an overburdened didactic and clinic schedule. This article will describe potential solutions centering on the role and scope of the biomedical sciences in predoctoral dental education. The authors propose that dental educators and institutions reconsider the current admission prerequisites and curriculum content of the biomedical sciences in predoctoral programs. The proposed changes are intended to eliminate content redundancy between undergraduate and predoctoral dental education by integration of the biomedical sciences--in particular, biochemistry, microbiology, and physiology--into other clinically oriented coursework and learning experiences in the curriculum based on a pathophysiology model that fosters students' comprehension of the etiology of oral and systemic diseases encountered by the general dental practitioner. The authors explore how changes in the biomedical science prerequisites for dental school matriculation and associated modifications in curriculum focus and content would impact admissions testing, composition of national board exams, and strategies for teaching and learning within dental schools.


Assuntos
Disciplinas das Ciências Biológicas/educação , Currículo , Educação Pré-Odontológica , Bioquímica/educação , Educação Baseada em Competências , Educação em Odontologia , Avaliação Educacional , Docentes de Odontologia , Estudos de Viabilidade , Odontologia Geral/educação , Humanos , Aprendizagem , Licenciamento em Odontologia , Microbiologia/educação , América do Norte , Fisiologia/educação , Aprendizagem Baseada em Problemas , Desenvolvimento de Programas , Critérios de Admissão Escolar , Faculdades de Odontologia/organização & administração , Ensino/métodos
20.
J Okla Dent Assoc ; 99(10): 16-21, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19093388

RESUMO

BACKGROUND AND OVERVIEW: The impact of digital imaging on dental practice depends upon the degree of planning conducted before implementation. Digital technologies have the potential to improve diagnosis; facilitate patient treatment procedures; and streamline storage, transfer and retrieval. These technologies also provide for secure backup of patients' image data, critical to re-establishing the practice should fire, flood or earthquake occur. CONCLUSIONS: The decision to invest in digital radiographic equipment should be a simple one for dental practitioners. Although digital x-ray sensors have long equaled analog film for diagnostic tasks, they have several advantages over film radiography, including immediate image production with solid-state devices; interactive display on a monitor with the ability to enhance image features and make direct measurements; integrated storage with access to images through practice management software systems; security of available backup and off-site archiving; perfect radiographic duplicates to accompany referrals; security mechanisms to identify original images and differentiate them from altered images; the ability to tag information such as a patient identifier, date of exposure and other relevant details; and interoperability of the Digital Imaging and Communications in Medicine file format. CLINICAL IMPLICATIONS: Most clinicians should contemplate integrating, at a minimum, intraoral digital x-ray sensors and a digital panoramic system into their practices.

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