Introduction to Radiology
Oral and Maxillofacial Radiology I
DSD 343
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Course Credits :3 hours; 1 hr Lecture per week,
2 hrs Practical per week
Prerequisite for :443 DSD / Oral and
Maxillofacial Radiology II
Course Description
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Dental radiology is a branch of dentistry for diagnostic,
treatment planning and following-up purposes. Complete
examination of the oral cavity needs both clinical and
radiographic investigations, therefore this course of dental
radiology offers the way of examining the hidden parts of
teeth and their supporting structures. This course is
considered as an introductory course that includes lectures,
demonstrations and practical applications on the previously
given lectures. It is consisted of a series of weekly lectures
and practical extending over two terms.
The use of x-rays is an essential part of clinical dentistry. As a result,
radiographs are often referred to as the clinician main diagnostic aid. The
range of knowledge of dental radiography and radiology required can be
divided conveniently into four main sections:
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1 -Basic physics and equipment: the production of xrays, their properties and interaction which results in the
formation of the radiographic image.
2 -Radiography :the techniques involved in producing the
various radiographic images as well as the x-ray films and
other radiographic requirements as well as film
processing .
3 -Radiation protection :the protection of patients and
dental staff from the harmful effects of x-rays .
4-Radiology :the interpretation of the radiographic
images.
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This course is primarily concerned with the
first three topics namely physics,
radiography and protection. Only part of
film interpretation for simple lesions as
caries, periodontal and periapical diseases
will be covered. However, the more
comprehensive cases and differential
diagnosis will be covered in the third year
course .
At the end of this course, the
students will be able to :
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Know how x-rays are produced, identify the component parts of the x-ray machine and its accessories
and list and describe the possible interactions of x-rays with matter.
List and describe the different types of intra-oral and extra-oral x-ray films used in dentistry including
their sizes, speeds as well as how to store them properly.
Identify the quality of x-ray image regarding the radiographic density, contrast, sharpness,
magnification and distortion. Also, knows what is required to produce an ideal radiographic image.
List, discuss and practice the step-by-step procedures for both manual and automatic processing.
Make complete intra-oral radiographic survey [CMS] on patients, process, mount then, detect and
retake the unsatisfactory radiographs.
Identify the radiographic anatomical landmarks as seen in radiographs, distinguish between
normalities and normal variations. Also, to differentiate between those landmarks and some
pathological lesions.
List and discuss the common causes of unsatisfactory radiographs, their causes and how to avoid
them.
Discuss the harmful effects of radiation, both the short and long-term effects, whether they are
somatic or genetic.
Protects his patients, the dental staff and people in the immediate environment from the harmful
effects of radiation.
Detect, identify and describe the radiographic appearance of dental caries, periodontal and periapical
pathosis. Also, to identify radiographically the existence of various dental anomalies and regressive
changes that may affect teeth as well as various forms of trauma to the teeth.
Course Contents:
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Introduction Lecture
Radiation Physics (I, II)
Radiation Biology
Radiation Protection
Dental X-ray Equipment and Films
Dental X-ray Image Characteristics
Processing of X-ray Film
Intra-oral Radiographic Techniques (I, II, III)
Normal Radiographic Anatomy
Common Causes of Unsatisfactory Radiographs
Interpretation of Dental Caries and the Assessment of Restorations
Interpretation of Periapical Tissues and Pathosis
Interpretation of Periodontal Tissues and Periodontal Disease
References
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Oral Radiology Principles and Interpretation. 5th
Edition. By White and Pharoh.
Dental Radiography, Principles and Techniques.
2nd Edition. By Joen Haring and Laura Jansen.
Essentials of Dental Radiography and
Radiobiology. 3rd Edition. By Eric Whaites.
Evaluation
Grades will be based on
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Continuous Assessment (Quizzes, Homework, Assignment)
20 marks
Mid-Year Exam
20 marks
Practical
20 marks
Final Exam (Written) 40 marks
Main Diagnostic Aid
Clinical Examination + Radiographs
Diagnosis
Treatment
Knowledge of dental radiography & radiology
1.
Basic physics & equipment the production of Xray, their properties & interactions which result in
the formation of the radiographic image
2.
Radiation protection the protection of patients &
dental staff from the harmful effects of X-ray
3.
Radiography the techniques involved in producing
the various radiographic images
4.
Radiology the interpretation of these radiographic
images
Basic Terms
Radiation: A form of energy carried by waves or a stream of
particles
X-radiation: A high-energy radiation produced by the collision
of a beam of electrons with a metal target in an X-ray tube
X-ray: A beam of energy that has the power to penetrate
substances & record image shadows on photographic film
Radiology: A branch of medical science that deals with the use
of x-ray, radioactive substances, & other forms of radiant
energy in the diagnosis & treatment of disease
Basic Terms
Radiograph: A picture (visible photographic record) on film
produced by the passage of X-ray through an object or body
Dental Radiograph: A photographic image produced on film
by the passage of X-ray through teeth & related structures
Radiography: The art & science of making radiographs by the
exposure of film to X-ray
Dental Radiography: The making of radiographs of the teeth &
adjacent structures by the exposure of film to X-ray
Dental radiographer: Any person who positions, exposes, &
processes dental X-ray film
Uses of Dental Radiographs
To detect lesions, diseases & conditions of the teeth &
surrounding structures that cannot be identified
clinically
To confirm or classify suspected disease
To localize lesions or foreign objects
To provide information during dental procedures
To evaluate growth & development
To illustrate changes secondary to caries, periodontal
disease, & trauma
To document the condition of a patient at a specific
point in time
Discover of X-radiation
• Wilhelm Conrad Roentgen
• A German physicist
• November 8, 1895
Discover of X-radiation
Roentgen was searching for invisible light (cathode rays)
by experimenting with a Crookes vacuum discharge tube
Roentgen´s experimental equipment in1895:
B – Rühm korff induction coil,
C - photographic plate,
T - Hittorf-Crookes evacuated tube
Discover of X-radiation
Roentgen proceeded to make the first radiograph of
human body; he placed his wife’s hand on a photographic
plate & exposed it to the unknown ray for 15 minutes
Discover of X-radiation
Roentgen named his discovery X-ray, the ‘’X’’ referring to
the unknown nature & properties of such ray
Roentgen was awarded the first Nobel Prize ever awarded
in Physics (1901)
After years of Roentgen discovery,
X-ray
roentgen ray, radiology
roentgenology,
& radiographs
roentgenographs
Pioneers in Dental X-radiation
In 1896
German dentist, Otto Walkhoff, made the first dental
radiograph; he submitted himself to 25 minutes of x-ray
exposure
W.J. Morton, a New York physician, made the first dental
radiograph in the United States using a skull
Pioneers in Dental X-radiation
In 1896
C. Edmund Kells, New Orleans dentist, exposed the first
dental radiograph in the United States using a living person
During his many experiments, Kells exposed his hands to
numerous x-rays every day for years. This overexposure to
x-radiation caused the development of numerous cancers
of his hand
Pioneers in Dental X-radiation
William H. Rollins, a Boston dentist, developed the 1st
dental x-ray unit. While experimenting with radiation,
Dr. Rollins suffered a burn to his hand
This initiated an interest in radiation protection and later the
publication of the 1st paper on the dangers associated with
radiation
PARTS AND COMPONENTS OF
THE DENTAL X-RAY
MACHINE
General. The standard structural parts of the dental x-ray machine include a control panel (usually mounted behind a
protective shield); a tube head, which houses the dental x-ray tube; and a flexible extension arm from which the tube
head is suspended.
The Control Panel. The components of the control panel are switches, dials, gauges, and lights. Basically, each control
panel has the same function, the arrangement and location of these components will differ, depending upon the make,
model, and year of construction of the dental x-ray unit. An operator's manual is issued with each unit. The operator
should study it until he is familiar with its operational capability.
The Extension Arm. The tube head is attached to the metal extension arm by means of a yoke that can revolve 360
degrees horizontally where it is connected. The construction of the yoke also provides vertical movement as well.
The Tube Head. Inside the metal tube housing is the x-ray tube. This tube emits radiation in the form of photons or xrays. X-ray photons expose the film. In addition to exposing the film, it also exposes the patient to radiation. Unless
certain protective measures are taken, the x-ray technician may also be exposed
THREE STEP PROCESS OF XRAY PRODUCTION
The First Step. The first step in x-ray
production is to turn on the machine. (If
there is doubt on the part of the x-ray
technician concerning the operation of the
unit, reference should be made to the
operator's manual.) When the unit is turned
on, the filament of the cathode is heated by
electrical current, causing it to emit
electrons
THREE STEP PROCESS OF XRAY PRODUCTION
Electrons speeding toward
the anode (tungsten target)
The Second Step. For the second step of this three-step process, high voltage is
passed across the x-ray tube. When this is done, the electrons or electron cloud
from the filament are drawn across the opening toward the anode. The anode is
made of tungsten and is sometimes called the tungsten target. Figure depicts the
electrons speeding toward the anode (tungsten target).
The Third Step. The third and final step in this three-step process is the
collision of electrons with the anode (tungsten target). This rapid deceleration of
electrons produces x-rays, also referred to as photons. Figure represents
electrons striking the anode (tungsten target) and producing x-ray photons.
RADIATION PROTECTION
General. Filtration and
collimation of the x-ray
beam are very important
safety measures. The filter
and collimator
(diaphragm) block the
majority of the unwanted
x-ray photons. The
diagram will identify the
location of these two
devices.