This document provides an overview of orthopantomography (OPG), also known as panoramic imaging. It discusses the principles of panoramic image formation using reciprocal movement of the x-ray source and image receptor around a central rotation point. Key components of panoramic machines and films are described. Proper patient positioning is emphasized to obtain images of the mandible, midfacial region, dentition and soft tissues within the image layer. Advantages include broad coverage with low radiation dose, while disadvantages include potential for distortion and lack of detail. Indications for OPG use include dental trauma, implants, orthodontics and lesion evaluation.
brief description about CONTENTS Introduction Principles of panoramic imaging Image layer Panoramic machines Panoramic film Patient positioning Interpreting the panoramic imaging INDICATION Advantages Disadvantages Conclusion References
3. INTRODUCTION • Panoramic imaging also called pantomography is a technique for producing a single tomographic image of facial structures that includes both the maxillary and mandibular dental arches and their supporting structures . • This is a curvilinear variant of conventional tomography.
4. PRINCIPLES OF PANORAMIC IMAGE FORMATION • Patero and Numata - describe the principles of panoramic radiography • based on the principle of reciprocal movement of x-ray source and an image receptor around a central point or plane called the image layer, in which the OBJECT of image is located. • OBJECT in front or behind this image are not clearly captured because of their movement relative to the centre of rotation of the receptor and the x-ray source.
5. The film and x-ray tubehead move around the patient in opposite directions in panoramic radiography
6. ROTATION CENTER The pivotal point or axis around which the cassette carrier and tube head rotate is termed rotation center Three basic rotation center used in panoramic radiography Double centre rotation Triple centre rotation moving centre rotation The location and number of rotational centers INFLUENCE size and shape of focal trough
7. IMAGE LAYER • Also known as focal trough • It is a three dimensional curved zone where the structures lying within this layer are reasonably well defined on final panoramic image. • The structures seen on a panoramic image are primarily those located within image layer. • OBJECTSoutside the image layer are blurred magnified are reduced in size. Even distorted to the extent of not being recognizable. • This shape of image layer varies with the brand of equipment used.
8. FOCAL TROUGH
9. FACTORS AFFECTING SIZE OF IMAGE LAYER: Arc path Velocity of receptor and X-ray tube head Alignment of x-ray beam Collimator width The location of image layer change with extensive machine used so recalibration may be necessary if consistently suboptimal images are produced. As a position of object is moved within the image layer size and shape of image layer change.
10. PANORAMIC UNIT
11. A, Orthophos XG Plus extraoral x-ray machine. B, Orthoralix 8500 extraoral x-ray machine. C, Example of a digital panoramic system
12. PARTS OF PANORAMIC UNITS a. x-ray tube head b. head positioner: chin rest notched bite block forehead rest lateral head support c. exposure controls
13. X-RAY TUBE HEAD: • Similar to intraoral x-ray tube head • Each has a filament to produce electrons and a target to produce x-rays • Collimator is a lead plate with narrow vertical slit • Narrow x-ray beam emerges from collimator minimize patient exposure to radiation
1
brief description about CONTENTS Introduction Principles of panoramic imaging Image layer Panoramic machines Panoramic film Patient positioning Interpreting the panoramic imaging INDICATION Advantages Disadvantages Conclusion References
3. INTRODUCTION • Panoramic imaging also called pantomography is a technique for producing a single tomographic image of facial structures that includes both the maxillary and mandibular dental arches and their supporting structures . • This is a curvilinear variant of conventional tomography.
4. PRINCIPLES OF PANORAMIC IMAGE FORMATION • Patero and Numata - describe the principles of panoramic radiography • based on the principle of reciprocal movement of x-ray source and an image receptor around a central point or plane called the image layer, in which the OBJECT of image is located. • OBJECT in front or behind this image are not clearly captured because of their movement relative to the centre of rotation of the receptor and the x-ray source.
5. The film and x-ray tubehead move around the patient in opposite directions in panoramic radiography
6. ROTATION CENTER The pivotal point or axis around which the cassette carrier and tube head rotate is termed rotation center Three basic rotation center used in panoramic radiography Double centre rotation Triple centre rotation moving centre rotation The location and number of rotational centers INFLUENCE size and shape of focal trough
7. IMAGE LAYER • Also known as focal trough • It is a three dimensional curved zone where the structures lying within this layer are reasonably well defined on final panoramic image. • The structures seen on a panoramic image are primarily those located within image layer. • OBJECTSoutside the image layer are blurred magnified are reduced in size. Even distorted to the extent of not being recognizable. • This shape of image layer varies with the brand of equipment used.
8. FOCAL TROUGH
9. FACTORS AFFECTING SIZE OF IMAGE LAYER: Arc path Velocity of receptor and X-ray tube head Alignment of x-ray beam Collimator width The location of image layer change with extensive machine used so recalibration may be necessary if consistently suboptimal images are produced. As a position of object is moved within the image layer size and shape of image layer change.
10. PANORAMIC UNIT
11. A, Orthophos XG Plus extraoral x-ray machine. B, Orthoralix 8500 extraoral x-ray machine. C, Example of a digital panoramic system
12. PARTS OF PANORAMIC UNITS a. x-ray tube head b. head positioner: chin rest notched bite block forehead rest lateral head support c. exposure controls
13. X-RAY TUBE HEAD: • Similar to intraoral x-ray tube head • Each has a filament to produce electrons and a target to produce x-rays • Collimator is a lead plate with narrow vertical slit • Narrow x-ray beam emerges from collimator minimize patient exposure to radiation
1
Subtraction radiography and morphometric analysis in periodonticsR Viswa Chandra
“A Simple Method to Assess Bone Fill through Digital Subtraction Technique and Morphometric Analysis”- Guest lecture as a part of Dr NTRUHS Zonal CDE programme at Army College of Dental Sciences, Hyderabad, India on 18/1/2014.
IDEAL IMAGE CHARACTERISTICS
FACTORS RELATED TO THE RADIATION BEAM
FACTORS RELATED TO THE OBJECT
FACTORS RELATED TO THE TECHNIQUE
FACTORS RELATED TO RECORDING OF THE ROENTGEN IMAGE OF THE OBJECT
DARK/ LIGHT IMAGE IDEAL IMAGE
IDEAL QUALITY CRIETRIA
this contains the occlusal radiography methods for both maxillary and mandibular different occusal radiographic techniques, principles, classification, indications
Subtraction radiography and morphometric analysis in periodonticsR Viswa Chandra
“A Simple Method to Assess Bone Fill through Digital Subtraction Technique and Morphometric Analysis”- Guest lecture as a part of Dr NTRUHS Zonal CDE programme at Army College of Dental Sciences, Hyderabad, India on 18/1/2014.
IDEAL IMAGE CHARACTERISTICS
FACTORS RELATED TO THE RADIATION BEAM
FACTORS RELATED TO THE OBJECT
FACTORS RELATED TO THE TECHNIQUE
FACTORS RELATED TO RECORDING OF THE ROENTGEN IMAGE OF THE OBJECT
DARK/ LIGHT IMAGE IDEAL IMAGE
IDEAL QUALITY CRIETRIA
this contains the occlusal radiography methods for both maxillary and mandibular different occusal radiographic techniques, principles, classification, indications
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
diagnostic aids part 3, photograph and radiograph.docxDr.Mohammed Alruby
Diagnostic Aids
Part 3
{Radiographs and Photographs}
{BMR and EMG}
Prepared by
Dr. Mohammed Alruby
Radiographs
Means: A procedure that uses a type of high-energy radiation called x-rays to take pictures of areas inside the body. X-rays pass through the body onto film or a computer, where the pictures are made
Types:
Intra-oral radiographs:
Periapical radiographs:
It is necessary for any orthodontic diagnosis for the following reasons:
The pattern and amount of root resorption of deciduous teeth
Presence or absence of permanent teeth, their size, shape, position and relative state of development
Congenital absence of teeth or presence of supernumerary teeth
Character of alveolar bone, lamina dura, and periodontal membrane
Morphology and inclination of permanent teeth roots
Pathological oral condition such as thickened periodontal membrane, periapical infection, root fractures, cysts, retained deciduous teeth
Abnormal path of eruption of permanent teeth
Malposition of individual as: rotation, which requires a larger space on the arch
Very useful in mixed dentition analysis
Recognition of exact position of impacted tooth by using method of parallax: that determine whether the unerupted tooth is located labially or palatally. Two periapical radiograph is taken with the film in the same position in each exposure, but the tube is moved in second exposure about 10cm. if the impacted tooth is moved in the same direction as the tube so the tooth is impacted palatally and the reverse is versa.
Bit-wing radiographs:
Is used mainly for detection of proximal cries, but it is of little value in orthodontic diagnosis
Occlusal film:
Occlusal projection is useful to locate the supernumerary teeth at the midline (mesiodens) and to determine accurately the position of impacted maxillary cuspids
Extra-oral radiographs:
Cephalometric radiographs:
Lateral cephalometric radiographs
PA cephalometric radiographs
Lateral oblique cephalogram:
The patient is directed by 45 degree and take the shot
Since dentofacial structure will be superimposed in the true lateral cephalometric projection, the lateral oblique direction is designed to gives a more accurate recording of the actual tooth position in either the left or right buccal segments depending on which side is approximately perpendicular to the central rays
The lateral oblique cephalogram combines most of advantages of the lateral views, intra-oral periapical survey and panoramic radiograph plus a standard cephalometric registration that makes possible measurements of bone size and eruptive movements so it is of particular size in analysis of developing dentition
Submental vertex cephalometric:
Is used to assess mandibular asymmetry in the transverse and anterior-posterior plane. It is an important aid in detecting asymmetry in the symphysis, body, ramus, and condyle of the mandible. In many cases of asymmetry, this view is important for evaluation of mandibular displacemen
Thorough knowledge of the indications of various extra oral techniques allows accurate and timely diagnosis of various maxillofacial pathologies. Further, we can arrive at a diagnosis with minimum number of x-rays there by reducing patient exposure to radiation.
Science and art that deals with the use of binocular vision for the observation of overlapping photographs or other perspective views and the method by which such views are produced
It is the technique used to create the illusion of depth by presenting two slightly different perspective of the same object to the eyes of viewer
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
brief description about pressable ceramicsCONTENTS: • Introduction • Definition For Dental Ceramics • Definition For Pressable Ceramics • History • Various All Ceramic Systems • Classification • Pressable Ceramics • History • Generation Of Pressable Ceramics • Cerestore – Development Fabrication Advantage Disadvantage 2
3. IPS Empress - Materials And Composition Special Furnace Fabrication Advantage Disadvantage IPS Empress 2- INDICATION Properties Fabrication Method Advantage Disadvantage IPS Emax Press - Microstructure Composition Properties OPC 3G- Development Indication Properties 3
4. INTRODUCTION There have been significant TECHNOLOGICAL advances in the field of dental ceramics over the last 10 years which have made a corresponding increase in the number of materials available. Improvements in strength, clinical performance, and longevity have made all ceramic restorations more popular and more predictable 4
5. DEFINITION FOR DENTAL CERAMICS⁶ An inorganic compound with non metallic properties typically consisting of oxygen and one or more metallic or semi metallic elements (e.g ;Aluminium, Calcium, Lithium, Mangnesium, Potassium, Sodium, Silicon, Tin , Titanium And Zirconium)that is formulated to produce the whole or part of a ceramic based dental prosthesis 5
6. DEFINITION FOR PRESSABLE CERAMICS ⁶ • A ceramic that can be heated to a specified temperature and forced under pressure to fill a cavity in a refractory mold 6
7. HISTORY OF DENTAL CERAMICS ⁶ • 1789-first porcelain tooth material by a French dentist De Chemant • 1774- mineral paste teeth by Duchateau in England • 1808-terrometallic porcelain teeth by Italian dentist Fonzi • 1817- Planteu introduced porcelain teeth in US • 1837- Ash developed improved version of porcelain teeth 7
8. • 1903 – Dr.Charless introduced ceramic crowns in dentistry he fabricate ceramic crown using platinum foil matrix and high fusing feldspathic porcelain excellent esthetics but low flexural strength resulted in failure • 1965- dental aluminous core Porcelain by Mclean and Huges • 1984- Dicor by Adair and Grossman 8
9. 9
10. VARIOUS ALL CERAMIC SYSTEMS Aluminous core ceramics Slip cast ceramics Heat pressed ceramics Machined ceramics Machined and sintered ceramics Metal reinforced system 10
11. MICROSTRUCTURAL CLASSIFICATION⁵ Category 1: Glass-based systems (mainly silica) Category 2: Glass-based systems (mainly silica) with fillers usually crystalline (typically leucite or a different high-fusing glass) a) Low-to-moderate leucite-
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.
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
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.
Title: Sense of Taste
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 structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
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
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
2. CONTENTS
Introduction
Principles of panoramic imaging
Image layer
Panoramic machines
Panoramic film
Patient positioning
Interpreting the panoramic imaging
i. The mandible
ii. Midfacial region
iii.Soft tissues
iv.Dentition
Indication
Advantages
Disadvantages
Conclusion
References
3. INTRODUCTION
Panoramic imaging also called pantomography is a technique for producing a single tomographic
image of facial structures that includes both the maxillary and mandibular dental arches and their
supporting structures .
This is a curvilinear variant of conventional tomography.
PRINCIPLES OF PANORAMIC IMAGE FORMATION
Patero and Numata was first to describe the principles of panoramic radiography
It is based on the principle of reciprocal movement of x-ray source and an image receptor around
a central point or plane called the image layer, in which the object of image is located. Object in
front or behind this image are not clearly captured because of their movement relative to the
centre of rotation of the receptor and the x-ray source.
The following illustration showing the operation of the panoramic machine:
Disk 1 is held stationary and the x-ray source is rotated so that so that central ray constantly
passes through the centre of rotation of disk1 and simultaneously both disk 2 an Although disk 2
moves the receptor on this disk also rotate past the slit .
To obtain optimal image speed of the receptor passing the collimator slit is maintained equal to
the speed at which the x-ray beam sweeps through the object of interest the lead collimator rotate
around the centre of disk 1
4. A patient may replace disk 1 and that object A through D represent teeth and surrounding bone.
Structures on the opposite side of the patient are distorted and appear out of focus.
Structures near the x-ray source are so magnified.
Rotationcenter
The pivotal point or axis around which the cassette carrier and tube head rotate is termed rotation
center
Three basic rotation center used in panoramic radiography
Double centre rotation
Triple centre rotation
moving centre rotation
The location and number of rotational centers influence size and shape of focal trough
Image layer
Also known as focal trough
It is a three dimensional curved zone where the structures lying within this layer are reasonably
well defined on final panoramic image.
5. The structures seen on a panoramic image are primarily those located within image layer.
Objects outside the image layer are blurred magnified are reduced in size. Even distorted to the
extent of not being recognizable. This shape of image layer varies with the brand of equipment
used.
Factors affecting size of image layer:
Arc path
Velocity of receptor and X-ray tube head
Alignment of x-ray beam
Collimator width
The location of image layer change with extensive machine used so recalibration may be
necessary if consistently suboptimal images are produced.
As a position of object is moved within the image layer size and shape of image layer
change.
Panoramic unit
PARTS OF PANORAMIC UNITS
x-ray tube head
exposure controls
head positioner:
6. chin rest
notched bite block
forehead rest
lateral head support
x-ray tube head:
Similar to intraoral x-ray tube head
Each has a filament to produce electrons and a target to produce x-rays
Collimator is a lead plate with narrow vertical slit
Narrow x-ray beam emerges from collimator minimize patient exposure to radiation
Tube head is fixed in position and rotates behind the patient head
Film positioner is used to align the patients teeth accurately in focal trough
Exposure parameter
Power Supply 230V 50 Hz.
Kvp 50-90 KVp
Tube Current 10mA
Focal Spot 0.5mm X 0.5mm
Target Angle 5 Degree
Total Filtration
2.8 mm Al
Focus Distance 51cm
Exposure Time 19 sec
Film Size 15 X 30 cm
Weight Supply Approx. 220 Kg.
7. Panoramic film
Screen film is used available in two sizes:
5x12 inch
6x12 inch
Placed between two intensifying screen in a cassette holder
Sensitive to light emitted from intensifying screens
When exposed to x-ray, screen convert x-ray energy into light
Intensifying screens
Two types
Calcium tungstate –emit blue light
Rare earth –emit green light, less x-ray exposure
Cassette
It is a device used to hold the extra oral film and intensifying screens
Light tight to protect the film from exposure
Two types
Rigid
Flexible
8. Patient positioning and head alignment
Dental appliance earrings ,necklace,hairpins,and any other metallic objects should be
removed
Instruct the patient to stand as tall as possible with back straight and stand erect .Vertical
column must be straight
Instruct the patient to bite on the plastic bite block tooth must be positioned in edge to
edge position in the groove present in the bite block it is used to align the teeth in the
focal trough
Midsagittal plane perpendicular to floor
Frankfort horizontal plane parallel to the floor
Tongue must be positioned on the roof of the mouth
Instruct the patient to remain still while machine is rotating
9. Interpreting panoramic image
The mandible
1. Condylar process and TMJ: a bony rounded radioopaque projection extending from
ramus of mandible
2. Coronoid process: triangular radio opacity posterior to tuberosity region
3. Ramus: shadow of other structure may superimposed over the ramus such as
Pharyngeal airway shadow
Posterior wall of pharynx
Cervical vertebra
Ear lobe
Nasal cartilage
Soft palate and uvula
Dorsum of tongue
Ghost shadow
4. Body and angle : radiopaque bony structure where the ramus join the body of the
mandible
5. Anterior sextant mandibular dentition and alveolus
10. Midfacialregion
Individual bones such as
1. Temporal
2. zygoma
3. mandible
4. frontal
5. Maxilla
6. Sphenoid
7. Ethmoid
8. Vomer
1. articular tubercle 8.anterior nasal spine
2. zygomatic arch 9.floor of maxillary sinus
3. zygomatic process of maxilla 10.developing third molar
4. pterygomaxillary fissure 11.ear lobe
5. orbital rim 12.cervical vertebra
6. inferior nasal choncha
7. nasal septum
8. 7
9. nasal septun
11. 9. Nasal
10. Palate
Cortical boundary of maxilla including posterior border and alveolar ridge
Pterygomaxillary fissure : radiolucent area between the lateral pterygoid plate and
maxilla
Maxillary sinuses: paired radiolucencies located above the apices of premolars and
molars
Zygomatic complex or buttresses of midface: includeslateral and inferior orbital rims
zygomatic process of maxilla zygomatic arch
Nasal cavity and conchae: radiolucent area above the maxillary incissors
TMJ
Maxillary dentition and alveolus
12. Soft tissues
Tongue under the hard palate: radiopaque area superimposed over the maxillary posterior
teeth
Lip line: seen in the region of anterior teeth
Soft palate: extending posteriorly from hard palate
Posterior wall of pharynx
Nasal septum
Ear lobes
Nose and nasolabial fold
13. Dentition
Teeth and supporting alveolar bone are evaluated
Teeth examined for
Gross anomalies of number ,position, and anatomy
Impacted third molars
Endodontic obturations, crowns, fixed restoration
Indication
To evaluate impacted teeth
To evaluate eruption patterns, growth and development
To detect diseases ,lesions and conditions of the jaw
To examine extent of large lesions
To evaluate trauma periodontal bone loss and periapical involvement.
Finding the source of dental pain
Assessment for the placement of dental implants
Orthodontic assessment. pre and post operative
Caries detection especially in the inter-dental region.
Diagnosis of developmental anomalies such as Cherubism, Cleido cranial dysplasia
Carcinoma in relation to the jaws
Tempero mandibular joint dysfunctions and ankylosis
Advantages
Broad coverage of facial bones and teeth
Low patient radiation dose
Convenience of the examination of the patient
Use in patients unable to open their mouth
Short time required
In patient education and case presentation
14. Disadvantage
Image quality are not sharp
Focal trough limitations
Distortion
Expensive equipment cost
Conclusion
As OPG has several advantages in the field of dentistry and its inevitable role in diagnosis every
dentist should know about it.
Compared with the conventional radiographic technique involving atleast 16 intraoral exposures
OPG has several advantage it takes fairly easy; takes one minute and shows entire oral cavity in
one minute however resulting image produce less detail than IOPA
15. References
Freny R.Karjodkar :Text book of Dental and maxillofacial radiology 2nd edition page
number :236-255
Laura Jansen ,Joen M.Ianucci Harring :Dental radiography Principles and techniques of
Oral radiology: 3rd edition page number:305-319
white and pharaoh : Oral radiology principles and interpretation 6th edition; page
number: 175-189
