CBCT imaging provides 3D imaging of the dental and maxillofacial complex, allowing for improved diagnosis and treatment planning. It involves rotating an x-ray source and detector to capture projection images from different angles, which are then reconstructed into a 3D volume using back projection algorithms. Key components include the x-ray generator, detector, and workstation for image reconstruction and display. CBCT has various applications in orthodontics for assessing dental anomalies, impacted teeth, arch discrepancies, and facilitating treatment. Guidelines recommend its use be justified based on the individual clinical situation and that radiation dose be minimized.
principles, applications, advantages, disadvantages, guidelines, uses of cone beam computed tomography in the field of orthodontics and dentistry in general
EVOLUTION AND DIGITAL EVALUATION USING CONE BEAM COMPUTERIZED TOMOGRAPHY, AND ITS USES IN CLINICAL ORTHODONTICS . PROTOTYPING MODALS, ITS APPLICATIONS IN VARIOUS FIELDS
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Recent advances in diagnosis and treatment planning1 /certified fixed orthod...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
principles, applications, advantages, disadvantages, guidelines, uses of cone beam computed tomography in the field of orthodontics and dentistry in general
EVOLUTION AND DIGITAL EVALUATION USING CONE BEAM COMPUTERIZED TOMOGRAPHY, AND ITS USES IN CLINICAL ORTHODONTICS . PROTOTYPING MODALS, ITS APPLICATIONS IN VARIOUS FIELDS
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Recent advances in diagnosis and treatment planning1 /certified fixed orthod...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
hai this is a nice seminar and inculcated all the recent materials and biomaterials and biomechanics of the invisalign techniques , materials to be used and clinical aspects just have a look to it
Role of cephalometry in orthdodontics /certified fixed orthodontic courses by...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Digital imaging in orthodontics /certified fixed orthodontic courses by India...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Cone beam computed tomography.DR. ANUBHUTI Dental Institute RIMS Anubhuti Singh
Cone beam computed tomography
Carm CT
Cone beam volume CT
Flat panel CT
Extra-oral imaging system specifically designed for three dimensional imaging of the oral and maxillofacial structures
ALARA Principle
Principal of cbct- Field of view
voxel
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
00919248678078
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
hai this is a nice seminar and inculcated all the recent materials and biomaterials and biomechanics of the invisalign techniques , materials to be used and clinical aspects just have a look to it
Role of cephalometry in orthdodontics /certified fixed orthodontic courses by...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Digital imaging in orthodontics /certified fixed orthodontic courses by India...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Cone beam computed tomography.DR. ANUBHUTI Dental Institute RIMS Anubhuti Singh
Cone beam computed tomography
Carm CT
Cone beam volume CT
Flat panel CT
Extra-oral imaging system specifically designed for three dimensional imaging of the oral and maxillofacial structures
ALARA Principle
Principal of cbct- Field of view
voxel
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
00919248678078
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The slideshare gives an overview of the different and recent advancements in the fields of digital imaging and throws a light on the clinical applications.
As we enter in the Modern day, we are witnessing dawn of the new trend in which closed body operating procedures are more often being performed through minimal access. This development is the consequence of vision and work of many dedicated individuals. They include early pioneers of endoscopy who planted the seed and lastly the current pioneers who pushed and expanded these frontiers to give rise the birth of modern laparoscopy. Therapeutic laparoscopic surgery was introduced into the surgical practice recently and within a short span of time, it has become established as defacto standard for the treatment of chronic cholelithiasis and many advanced laparoscopic procedures can be performed safely. Laparoscopic surgery, what we should witness today, may be the culmination of over a hundred years of painstaking efforts from the number of pioneers within the fields of optics, instrumentation and video laparoscopic camera. Few advances in medicine occur in isolation. The innate human curiosity to peer within the body cavities can be traced back to ancient times. However, due to primitive technology and crude instruments, several ambitions were not realized. It is probably safe to say that first laparoscopy would not have been performed had it not been for the efforts of many physicians in 1800s to develop endoscope. The device developed by Theodore Stein in mid 1880 contains all the aspects of the current endoscopic documentation system. There was a crude endoscope and a high intensity light source. Illumination was made by continuously feeding a magnesium wire into an ignition chamber utilizing a clockwise mechanism. Light from this combustion was reflected to the tube utilizing a mirror. Finally the look was focused on to some photographic plate through coupling optics.
A 4 part seminar on 3D cbct technology for seminar presentations. with added technical details and considerations with differences between a CT technology.
Also it features the technical parameters ,uses and how it is considered useful in each departments of medicine and dentistry.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
263778731218 Abortion Clinic /Pills In Harare ,sisternakatoto
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Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
2. CONTENTS
– Introduction
– Evolution
– Principles
– Components of image production
– Selection criteria
– Usage in dentistry
– Conclusion
– references
3. INTRODUCTION
– Cone beam computed tomography (CBCT) imaging is an inherently volumetric image capture
technology providing a data set from which digital images are reformatted and presented on a
display monitor.
– CBCT acquires data volumetrically providing 3D radiographic imaging for the assessment of the
dental and maxillofacial complex facilitating dental diagnosis.
– In orthodontics, 3D imaging can help unravel the complexity of dental and skeletal
malocclusions and improve diagnosis and treatment planning in specific case types
– There are 3 main processes in CBCT imaging : 1) image production
2) visualization
3) interpretation
4. EVOLUTION
– Discovery of x-rays by W.C.Roentgen – 1895
– DXIS , first dental digital panoramic x-rays system – 1995
– development of CT independently by Hounsfield and Cormack in the early 1970s
– Multislice CT (MSCT) or multirow detector CT (MDCT)
– Scanners were developed for craniofacial imaging in late 1990s.
5.
6. PRINCIPLES OF CBCT
– CBCT imaging is performed using a rotating gantry or C –arm
supporting an x -ray source ,and reciprocating area detector.
– A divergent x-ray source, collimated as a cone or more
commonly a pyramid , is directed through the region of
interest (ROI) within the maxillofacial region, and the residual
attenuated photons strike the detector on the opposite side.
– On activation , data are acquired from a series of sequential
exposures as the gantry rotates around a fixed axis of rotation
centered within the patient’s ROI.
7. – Trajectory arc is ideally 360 ˚ but may vary form 180 ˚ to 720˚.
– During rotation , multiple sequential planar projection images are captured.
– These 2-D single projection images constitute the raw primary data and are individually referred
to as BASIS (images appear similar to ceph images except that each is slightly offset from the
next) , FRAME and RAW.
– CBCT exposure incorporates the entire ROI , only one rotational scan of the gantry is necessary
to acquire enough data for volumetric image construction.
– Cone beam geometry captures volumetric data with scan times ranging from less than 5 to
more than 30 seconds.
9. X-RAY GENERATOR
– High voltage generator which provides incoming voltage and current to provide the x-ray tube
with the power needed to produce an x-ray beam of desired peak kilovoltage and current.
10. X-RAY GENERATION
– On some CBCT units both kVp and mA are automatically modulated in near real time by a
feedback mechanism detecting the intensity of transmitted beam , a process called as
AUTOMATIC EXPOSURE CONTROL .
– Exposure factors can be controlled manually or automatically :
• kVp : 60-90
• mA : 6-10
• Pulsed or continuous x-ray generation
- PRIMARY DETERMINANTS of patient exposure : PULSED X-RAY BEAM AND SIZE OF IMAGE FIELD.
11. X – RAY GENERATION
– PATIENT STABILISATION : patient sitting , standing or supine.
Head is stabilized by combination of chin cup , bite fork or other head restraint mechanism.
- X-RAY GENERATOR : can be continuous or pulsed to coincide with the detector activation.
Actual exposure time should be less than scanning time.
This considerably reduces patient radiation dose.
ALARA for CBCT should be adjusted on basis of patient’s size and specific diagnostic task.
14. Methods to reduce radiation dose
– Smaller FOV
– High voltage and beam filtration
– Short exposure time
– Pulsed exposure
– Low resolution
15. – SCAN VOLUME (FOV) : dimensions primarily depends upon detector size, shape, beam
projection geometry and ability to collimate the beam.
– Desirable to limit the field size to the smallest volume that images the ROI.
– SCAN FACTORS : CBCT units are available providing fixed may be 360˚ or partial trajectory
arc or variable rotation angles.
• The speed with which individual images are acquired is called as FRAME RATE.
• Higher frame rate – more information is available to reconstruct the image and increases the
signal –to-noise ratio, producing images with less noise.
• But higher frame rates are usually accomplished with a longer scan time and hence higher
patient dose.
16. – It is desirable to reduce CBCT scan times to as short as possible to reduce motion artifact from
subject movement.
– Obtained by increasing the detector frame rate , reducing the number of projections and
reducing the scan arc.
– Avg. time = 7-30 sec
17. FIELD OF VIEW
– The dimensions of FOV depend on :
• Detector size and shape
• Beam projection geometry and ability to collimate
- Shape of scan volume : cylindrical or spherical
18. LARGE FOV – show roofs of the orbit and nasion
Down to hyoid bone
They have a height equal to or greater than 16 cm.
Entire dentofacial complex scan
MEDIUM FOV - middle of orbits down to menton vertically and from condyle to condyle horizontally.
SMALL FOV – a particular small segment , less than 20 cm in height
20. IMAGE DETECTION
– Most common flat panel configuration consists of a cesium iodide scintillator applied to a thin
film transistor made of amorphous silicon.
– A sensor which has smaller pixel size has better resolution: one pixel can be 0.007 – 0.3 mm
size.
21. MATRIX
– The CT image is represented as the matrix of the number.
– A 2D array of numbers arranged in rows and columns is called matrix.
– Each number represents the value of the image at that location.
22. PIXEL
– Each square in a matrix is called as pixel.
– Also k/a PICTURE element.
– Size : 20-60 micrometers.
23. VOXEL
– The spatial resolution is determined by individual volume elements called voxels.
– Principal determinant of voxel size : pixel size of the detector
– Detectors with smaller pixel size capture fewer x ray photons per voxel and result in more noise.
– To balance it, a good scanner has higher dosage of radiation.
24. GRAYSCALE
– The ability of a CBCT scan to display differences
in attenuation.
– Related to the ability of detector to detect
subtle contrast differences.
– This parameter is called bit depth of the system
and determines the number of shades of gray
available to display the attenuation.
– All current CBCT machines have 12 bit
detectors and are capable of identifying 4096
shades of gray.
25. IMAGE RECONSTRUCTION
– Projection data (acquisition computer)
– Transferred by an ethernet connection
- Processing computer (workstation)
26. – ACQUISITION STAGE : It involves image collection and detector preprocessing for correction
of inherited defects.
– RECONSTRUCTION STAGE: the corrected images are converted into a special presentation
called as sinogram ( a composite image developed from multiple projection images.
– The final image is reconstructed from the sinogram with a filtered back projection algorithm for
volumetric data acquired by CBCT.
27. DISPLAY
– The volumetric data set is a compilation of all available voxels.
– For most CBCT devices , it is presented to the clinician on screen as secondary reconstructed
images in three orthogonal planes (axial , sagittal and coronal).
28. DICOM FILE
– Digital imaging and communication in medicine
– CBCT produces 2 data products :
o The volumetric image data from the scan
o Image report generated by the operator
- All the images are saved in the DICOM format.
29.
30. EVIDENCE BASED
GUIDELINES
– Evidence supporting the use of CBCT in orthodontics Olivier J.C.van Vlijmen (2012)
The authors found no high quality evidence regarding the benefits of CBCT use in orthodontics.
Limited evidences show that CBCT offers better diagnostic potential , leads to better treatment
planning or results in better treatment outcome than do conventional imaging modalities.
Only the results of studies on airway diagnostics provided sound scientific data suggesting that
CBCT use has added value.
33. FACTORS IN DEVELOPING
GUIDELINES
1) History and clinical examination
2) Benefits should outweigh risks
3) New information to aid the patient
4) Not be repeated routinely
5) Diagnosis with lower radiation imaging is questionable
6) Thorough clinical evaluation report should be made
7) Should not be done for soft tissue assessment
8) Use small volume doses
9) Resolution compatible with adequate diagnosis
10) Small FOV for dentoalveolar regions and teeth
11) Avoiding the use of CBCT solely to facilitate the placement of orthodontic appliances such as
aligners and computer bent wires
34. ADVANTAGES
– Rapid scan time – reduces motion artifacts
– Image accuracy
– Interactive display mode
– Multiplanar reformatting
– Comfortable and safe
– Better image with high resolution
– Beam limitation through collimation reduces and limits the radiation to the ROI
– Increased treatment efficiency
– Less radiation exposure
– Minimisation of unexpected issues and negative sequalae
38. DENTAL DEVELOPMENT /
TOOTH MORPHOLOGIES
– CBCT can be used to evaluate developing arch length discrepancies.
– Small to medium FOV recommended
– Evaluation of :
• Presence and absence of unerupted teeth
• Tooth development
• Tooth position
• Bone loss, formation, depth, height and width
• Proximity of adjacent tooth
39. SUPERNUMERARY TOOTH
- CBCT - to precisely localize all supernumerary
teeth, many of which are unerupted or may be
impacted.
- to detail the morphology of the supernumerary
teeth.
- Information derived from CBCT images of
unerupted supernumerary teeth could facilitate
decisions on which of the teeth to retain,
determination of the retrievability of those teeth
and mapping the optimal surgical access to the
teeth.
Ref. CBCT in orthodontics: assessment of treatment outcomes and indications for
its use, 2015,British Institute of Radiology
40. ROOT ABNORMALITIES
– Root position and morphology are critical considerations for ideal orthodontic treatment for
two reasons:
(1) root position and parallelism - critical for an ideal stable occlusion
(2) external apical root resorption (EARR) - common adverse side effects of orthodontic
treatment.
– CBCT radiographs are valuable especially because they allow precise measurements of root
angulation and length before and after orthodontic treatment.
41. – CBCT- extracted panoramic radiographs and is defined as the angle formed by the tooth’s long
axis and the occlusal plane.
44. IMPACTED AND
TRANSPOSED
TEETH
– Most common indication for CBCT in
orthodontics
– enhances the ability to localize impacted
tooth accurately, evaluate their
proximity to other teeth and structures,
determine the follicle size and the
presence of pathology, estimate space
conditions, assess resorption of adjacent
teeth, assist in planning surgical access
and bond placement, and aid in defining
optimal direction for extrusion of these
teeth into the oral cavity.
45.
46. CLEFT LIP AND PALATE
– CBCT may provide more precise information on the numbers, quality and location of teeth in
proximity of the cleft site, eruption status and path of teeth in grafted cleft sites and diagnosing
for implant placement.
– In determining the volume of alveolar defect and therefore, the amount of bone needed for
grafting in patients.
– To determine the success of bone filling after surgery
47.
48. ORTHOGNATHIC AND
CRANIOFACIAL
ANOMALIES SURGICAL
PLANNING
– CBCT combined with computer aided surgical simulation or computer aided
orthognathic surgery offers :
Refining diagnosis and optimizing treatment objectives in 3D
Virtual treatment planning to improve surgical procedures and outcomes
Pre-operative assessment of bone support of the dentition and interdental
spacing for interdental osteotomies ideally is performed with CBCT imaging,
assessment helps to eliminate parallax errors, visualize variations in root
anatomy such as dilacerations, and determine the pre-operative position and
course of the inferior alveolar nerve, which can be useful for planning slight
variations in the position of the sagittal split osteotomy to help minimize injury
to the nerve.
Post-operative assessment with 3D imaging allows a high-resolution
determination of osteotomies and fixation that are essential in implementing
process.
49.
50. ASYMMETRY
– 3D CBCT imaging in the diagnosis and treatment planning of asymmetries , where discrepancies
often manifest in all three planes.
– When large differences exist between bilateral structures , use of MIRRORING technique is
enabled.
– In this tech. the normal side is mirrored onto the discrepant side so as to simulate and visualize
the desired end result.
– CBCT also helps in diagnosing and treatment planning of craniofacial anomalies such as
hemifacial microsomia, cleidocranial dysplasia, and ectodermal dysplasia.
– advantage of CBCT imaging with CFA patients is the increased anatomic detail and
measurement accuracy, which is critical for orthodontic and surgical treatment planning. Digital
3D images can be used to map the distances and directions of dental and skeletal movements
precisely that are needed to optimize the treatment outcome.
52. ALVEOLAR BOUNDARY
CONDITION
– Alveolar boundary conditions are the
depth, height and morphology of alveolar
bone relative to tooth root dimensions,
angulation and spatial position.
– Compromised or limited pretreatment
alveolar boundary conditions may limit or
interfere with the planned or potential
tooth movement, as well as the final
desired spatial position and angulation of
the teeth.
53.
54. TMJ DEGENERATION, PROGRESSIVE BITE
CHANGES, FUNCTIONAL SHIFTS, AND
RESPONSES TO THERAPY
– CBCT images the entire joint with visualization of minor to overt osseous hard tissue
morphologic changes and congruency of bone surfaces that define the joint space resulting
from pathology and adaptive processes and allows for accurate detection and evaluation of
pathological changes.
– Radiographic signs of bony changes associated with TMJ arthritis include irregular and possibly
thickened cortical outlines (sclerosis), erosions, osteophyte formation, subchondral cysts, and
flattening and narrowing of the joint space .
55.
56. TADs – planning and placement
– When placing an endosseous orthodontic TAD, the objective is to anchor the miniscrew
securely in the surrounding bone and to avoid any damage to adjacent anatomical structures.
– CBCT technology allows an exact visual identification of the location, shape, and divergence of
the mesial and distal dental roots, the floor of the maxillary sinus, and the buccal and lingual
wall of the alveolar process.
– Generally, a small FOV, high resolution scan is recommended for placement of TADs.
57. CONCLUSION
– This technique expands the fields for diagnosis and treatment possibilities.
– However , CBCT should be used with careful consideration , it should not be used deliberately
where 2D imaging suffices.
58. REFERENCES
– Cone beam computed tomography in orthodontics : indications , insights and innovations –
Sunil D . Kapila, BDS, MS. PhD
– White and Pharrow , oral radiology
– European Sedentexct guidelines for CBCT - 2012