Oral and Maxillofacial Radiology

Transcription

1 Majma ah University College of Dental Medicine Oral and Maxillofacial Radiology [Laboratory Manual] Assist. Prof. Kheirallah M. Mohd Malik Afroz Maxillofacial Surgery and Diagnostic Sciences Department /4-44

2 Majma'ah University College of Dental Medicine Maxillofacial Surgery and Diagnostic Sciences Department /4-44 Oral and Maxillofacial Radiology LABORATORY MANUAL Assist. Prof. Kheirallah M. Mohd Malik Afroz 2

3 Contents X-RAY MACHINE INFECTION CONTROL MEASURES PROTECTION GUIDELINES RADIOGRAPHY LAB.PRINCIPLES INTRAORAL RADIOGRAPHIC TECHNIQUES MANUAL PROCESSING EVALUATION SHEETS

4 SESSION - I X-ray Machine Description Objective At the end of session students must know. The components of x ray machine 2. The working principle of the x ray tube head. The importance of each component of x ray machine X-ray Machine Is Divided to: a. 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 (see figure 2). b. 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. c. The Extension Arm. The tube head is attached to the metal extension arm by means of a yoke that can revolve 60 degrees horizontally where it is connected. The construction of the yoke also provides vertical movement as well. 4

5 d. The Tube Head. Inside the metal tube housing is the x-ray tube. The diagram in figures, 2, represents a dental x-ray tube head and a dental x-ray tube. This tube emits radiation in the form of photons or x-rays. 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. 5

6 Figure Dental x-ray tube head and dental x-ray tube. 6

7 Figure 2 A representation of a control panel, x-ray tube head, and assembly.. High frequency x ray generator; 2.Mobile stand containing the main power board;.control timer unit; 4. X ray exposure switch 5. x ray exposure button; 6. Horizontal arm 7. Rectangular arm; 8. On/off switch with LED; 9. Handle 0.Front Brakes 7

8 Figure Tube head with the filament of the cathode emitting electrons. 8

9 Figure 4 A representation of a control panel.. Warning ionizing Radiation 2. Exposure Time : Emitted Dose Indicator. Display 4. X Ray exposure Button 5. X ray Emission Control Light 6. Ready State 7. Exposure Time Selector. on for digital sensors Low time 2. Off Longer exposure time for films and phosphor plates 8. Warning 9. Selection Knob 9

10 SESSION - 2 Infection control measures Objectives At the end of session students must know. Different steps involved in taking the radiograph 2. Infection control method to be followed in each step of taking a radiograph Infection control procedures for dental radiography can be divided into segments or component. During all the radiographic procedures the dental radiographic operator should be aware not to touch any surfaces that can be cross contaminated. A- Preparing to take dental radiographs Surfaces to be covered include: - Chair headrest 2- Control adjustment - Exposure buttons 4- Control panels 5- X-ray tube heads After the patient has been seated, hands can be washed or disinfected, dried, and gloves placed. B- Taking dental radiographs - Place the film into disposable film holder. 2- Place the sterilized film holder which contains the film into patient mouth. Gloves should always be worn when taking radiographs and handling film packets. Other personal protecting equipment should be used when the spattering of patient body fluids is likely. 0

11 C- After taking dental radiographs - A sterilized paper cup or paper towel should be ready. 2- Take off the film holder with the film from patient mouth. - Uncover the plastic wrap of the film and place it in the paper cup or the paper towel. 4- Remove all the used plastics that cover chair headrest, control adjustments, exposure buttons, control panels, and x-ray tube heads. 5- Remove the gloves D- Developing dental radiographs - A new glove can be used for more protection. 2- Assure films are dried. - Open the film packets only in the designated area. 4- Place the film in the processor. 5- Throw packets cover and content into appropriate waste container. 6- Clean the area and then remove the gloves.

12 Figure 6 X-ray Tube head with plastics cover. Protection Guidelines SESSION - Objectives At the end of session students will know. Various guidelines for protection from x rays 2. Various methods to be followed to protect from radiation. Different materials available for the protection from radiation. 2

13 Operator Protection guidelines - You must avoid the primary beam. 2-You must stand at least 6 feet (.8 m) away from the x-ray tube head during x-ray exposure. When this distance is not possible, a protective barrier must be used. - To avoid the primary beam (which travels in a straight line) you must be positioned perpendicular to the primary beam or at a 90-5 degree angle to the beam. 4- You must never hold a film in place for a patient during x-ray exposure. 5- You must never hold the tube head during x-ray exposure. 6- During exposure use lead apron, that is placed over the patient s chest and lap to protect the reproductive and blood forming tissues from scatter radiation. Use of a lead apron is recommended for all intraoral and extraoral films. 7-Remember to use lead apron to protect you. Figure 7 Position and Distance Rule during x-ray exposure.

14 Figure 8 Lead apron and thyroid collar. Patient protection guidelines - Use a lead apron to protect the patient, 2- Use thyroid collar to protect the patient, - Avoid the patient the unnecessary exposure for x-ray, 4- In case of pregnancy, AVOID exposure to radiographic x-rays. 4

15 Radiography Lab. Principles o No student will attend the radiology lab without full uniform (scrub and lab coat). o For each session ONLY one x-ray film and two gloves will be handed out to each student. o Infection control is ESSENTIAL. Do not work without gloves and do not use a single pair twice or for different purposes. o One film holder will be given to each student till the end of the semester, after which he/she should return it to the designated instructor. o Radiation protection for both the instructor and the patient is MANDATORY. Each should wear a lead apron. When taking an x-ray, both the instructor & student have to be at least 2 meters away from the machine. o Each radiographic film has to be safely kept with the student in a plastic covered film holder until the end of the semester for evaluation. o After finishing every student has to clean their place at the end of each session. 5

16 Intraoral Radiographic Techniques SESSION 4 Objectives At the end of session students will know. Different techniques available for exposing intra oral radiographs 2. Most widely used technique. Procedure of each technique 4. Advantages and disadvantages of the technique. Paralleling technique Bisection of the angle technique The American Academy of Oral and Maxillofacial Radiology and the American Association of Dental Schools recommend the use of the paralleling technique because it provides the most accurate image. The Paralleling Technique A. Basic Rules: - Film placement: Position the film so that it will cover the teeth. - Film position: Position the film parallel to the long axis of the tooth. The film in the film holder must be placed away from the teeth and toward the middle of the mouth. - Vertical angulations: Direct the central ray of the x-ray beam perpendicular to the film and the long axis of the tooth. - Horizontal angulations: Direct the central ray of the x-ray beam through the contact areas between the teeth. - Central ray: Center the x-ray beam on the film to ensure that all areas of the film are exposed. 6

17 Figure 9 The paralleling technique. Figure 0 Central ray and film placement in the paralleling technique. B. Tips for Film Placement: - The white side of the film always faces the teeth. - The anterior films are always placed vertically. - The posterior films are always placed horizontally. - The identification dot on the film is always placed in the slot of the film holder (dot in the slot). - Always position the film holder away from the teeth and toward the middle of the mouth. - Always center the film over the areas to be examined. - Always place the film parallel to the long axis of the teeth. 7

18 Figure Mandibular cuspid region. Figure 2 Mandibular incisors region. Figure Mandibular premolar region. 8

19 Figure 4 Mandibualr molar region. SESSION 5 The Bisecting Technique Objectives At the end of the session students should be able to. Know the procedure of bisecting angle technique 2. The concept of isometry. The angulations and its importance in this technique The bisection of the angle technique is based on a geometric principle of bisecting a triangle. (Bisecting means dividing into two equal parts) The angle formed by the long axis of the teeth and the film is bisected, and the x-ray beam is directed perpendicular to the bisecting line. (Perpendicular means at a right angle to the film) Angulations guidelines for bisecting-angle projection Projection Incisors Canines Premolars molars Maxilla* Mandible* * when the occlusal plane is oriented parallel with the floor. 9

20 Figure 5 The Bisecting technique. Figure 6 Maxillary canine exposure. 20

21 Figure 7 Mandibular canine exposure. Figure 8 Mandibular incisors exposure. 2

22 Figure 9 Maxillary premolar exposure. Figure 20 Maxillary incisors exposure. 22

23 Figure 2 Maxillary molars exposure. Figure 22 Mandibular molar exposure. 2

24 Figure 2 Mandibular premolar exposure. SESSION 6 The Bite-wing Technique Objectives At the end of the session student will be able to. To know the principles of bitewing technique 2. To know the procedure of this technique. The angulations used in this technique Basic Principles of the Bite-wing Technique: -The film is placed in the mouth parallel to the crowns of both the upper and lower teeth. - The film is stabilized when the patient bites on the bite-wing tab or bite-wing film holder. 24

25 - The central ray of the x-ray beam is directed through the contacts of the teeth, using a +0 vertical angulation. Figure 24 Central ray is directed through the contacts of the teeth. 25

26 Figure 25 Premolar bite-wing film placement and radiograph. Figure 26 Molar bite-wing film placement and radiograph. SESSION 7 Types Of Dental X-Ray Film Objectives at the end of session students will know. Different types of x ray films 2. Contents of the intra oral x ray film packet. Three types of x-ray film used in dental radiography: 26

27 I. Intraoral film II. Extraoral film III. Duplicating film Figure 27 Composition of intraoral film. I. Intraoral Film Is dental x-ray film that placed inside the mouth during x- ray exposure, which used to examine the teeth and supporting structures. Intraoral Film Packets Contents Dental x-ray film packets have four basic components: 27

28 Figure 28 Intraoral Film Packets Contents. X-Ray Film The intraoral x-ray film is a double-emulsion (emulsion on both sides) type of film. Double-emulsion film is used instead of single-emulsion (emulsion on one side) film because it requires less radiation exposure to produce an image. A film packet may contain one film (one-film packet) or two films (two-film packet). A two-film packet produces two identical radiographs with the same amount of exposure necessary to produce a single radiograph. The two-film packet is used when a duplicate record of a radiographic examination is needed (e.g., for insurance claims, patient referrals). In one corner of the intraoral x-ray film, a small raised bump known as the identification dot is found; the raised bump is used to determine film orientation. After the film is 28

29 processed, the raised identification dot is used to distinguish between the left and right sides of the patient. 2. Paper Film Wrapper is a black paper protective sheet that covers the film and shields the film from light.. Lead Foil Sheet is a single piece of lead foil that found within the film packet and is located behind the film wrapped in black protective paper. The thin lead foil sheet is positioned behind the film to shield the film from backscattered (secondary) radiation that results in film fog. 4. An embossed (stamped) pattern is placed on the lead foil sheet by the film manufacturer; the pattern is visible on a processed radiograph if the film packet is positioned in the mouth backward and then exposed. 5. Outer Package Wrapping is a soft vinyl (plastic) paper wrapper that tightly seals the film packet, protective black paper, and lead foil sheet. This outer wrapper serves to protect the film from exposure to light and saliva. The outer wrapper of the film packet has two sides: Tube side and label side. a. Tube Side: is solid white and has a raised bump in one corner that corresponds to the identification dot on the x- ray film. When placed in the mouth, the white side (tube side) of the film packet must face the teeth and the tube head. 29

30 b. Label Side: has a flap that is used to open the film packet to remove the film prior to processing. The label side is color-coded to distinguish between one-film and two-film packets and between film speeds. When placed in the mouth, the color- coded side (label side) of the packet must face the tongue. SESSION - 8 Intraoral Film Types Figure 29 Intraoral films, A, Size 4 occlusal film B, Size 2 film C, Size film.. Periapical Film used to examine the entire tooth (crown and root) and supporting bone; this type of film shows the tip of the tooth root, surrounding structures, and the crown. 2. Bite-Wing Film used to examine the crowns of both the maxillary and mandibular teeth on one film. The bite-wing film is particularly useful in examining the interproximal tooth surfaces and evaluating the height of alveolar bone. 0

31 The bite-wing film has a wing attached to the tube side of the film in which the patient bites to stabilize the film, hence the term bite-wing. Bite-wing films may be available with tabs attached to the film or may be constructed from a periapical film and bitewing loop.. Occlusal Film used for examination of large areas of the maxilla or mandible. The occlusal film is so named because the patient occludes or bites on the entire film to support it between the occlusal surfaces of the teeth. The occlusal film is larger than periapical or bite-wing films. Figure 0 Bite-Wing Film. Intraoral film sizes: Intraoral film is manufactured in five sizes to accommodate the varying mouth sizes of children, adolescents, and adults. Size 0: is the smallest intraoral film available and is used for very small children. Size : is used primarily to examine the anterior teeth in adults. Size 2: also known as the standard film: used to examine the anterior and posterior teeth in adults (The most frequent use).

32 Size : this film is longer and narrower than the standard Size 2 film and is used only for bite-wings. This bite-wing film shows all the posterior teeth on one side of the arch in one radiograph. Size 4: Occlusal Film: used to show large areas of the upper or lower jaw. Film speed: Film speed refers to the amount of radiation required to produce a radiograph of standard density, (sensitivity). Film speed determines how much radiation and how much exposure time are necessary to produce an image on a film. For example, a fast film requires less radiation exposure because the film responds more quickly; a fast film responds more quickly because the silver halide crystals in the emulsion are larger. The larger the crystals, the faster the film speed. An alphabetical classification system is used to identify film speed. X-ray films are given speed ratings ranging from A speed (the slowest) to F speed (the fastest). Only D-speed film and E-speed film are used for intraoral radiography. E-speed film requires one-half the exposure time of D- speed film and has comparable image contrast and resolution. The use of E-speed film results in less radiation exposure for the patient. E-speed film is a faster because of the larger crystals and the increased amount of silver bromide in the emulsion. The speed of a film is clearly indicated on the label side of the intraoral film packet as well as on the outside of the film box or container. 2

33 SESSION 9 II. Extraoral Film Objectives. Student will be able to understand the working principle of Orthopantomogram 2. Student will be able to know the indications for each extra oral radiographs. Students will be able to interpret the extra oral radiographs Is dental x-ray film that is placed outside of the mouth during x-ray exposure, which used examine large areas of the skull or jaws. Examples of common extraoral films include panoramic (Orthopantomogram OPG) and cephalometric films; a panoramic film shows a panoramic (wide) view of the upper and lower jaws on a single radiograph, whereas a cephalometric film exhibits the bony and soft tissue areas of the facial profile. Figure Panoramic x-ray (Orthopantomogram OPG); shows a panoramic (wide) view of the upper & lower jaws on a single radiograph.

34 Figure 2 Cephalometric radiograph; cephalometric film shows the bony & soft tissue areas of the facial profile. III. Duplicating Film A duplicate radiograph is one that is identical to the original. In dentistry, duplicate radiograph is useful when a patient is referred to a specialist, for insurance claims, and as teaching aids. A special film, duplicating film, is required to make a duplicate radiograph. SESSION 0 Manual film Processing Objectives at the end of session students will know. Procedure for manual processing 2. Advantages and disadvantages of manual processing 4

35 Processing is a series of steps that changes the latent image on the exposed film into a radiograph by producing a visible image on the film. Steps of processing. Developing. 2. Rinsing under running water.. Fixing. 4. Proper washing. 5. Drying. Processing Technique (manual) - Open the film - Remove all the components that you do not need under safe light. - Do not hold the film by your fingers direct but from the periphery. - Put it in the hanger and remix the solution before start the processing. - Start with developer by agitates the hanger until you can see the picture start appearing. - Rinsing in water path. (5-20 second) - Start fixing stage. - Do proper washing. - Dry the film. Note. Time-temperature method; if temperature is 20 degree, developing time is 5 minutes and fixing time is 0 minutes. Film-Processing Solutions Film-processing solutions are available in the following forms: Powder Ready-to-use liquid Liquid concentrate 5

36 Figure Film processing solutions (ready to use). Figure 4 Processing tanks showing developing and fixing tanks inserts in bath of running water 6

37 SESSION Common problems in x-ray film development Objectives. Students will be able to. Light radiographs processing errors: - Underdevelopment (temperature too low; time too short; thermometer inaccurate). Figure 5 Underdeveloped Film. - Depleted developer solution. - Diluted or contaminated developer. - Excessive fixation. underexposure: - Insufficient milliamperage. - Insufficient kilovoltage peak. - Insufficient time. - Film-source distance too great. - Film packet reversed in mouth. 2. Dark radiographs processing errors: - Overdevelopment (temperature too high; time too long) 7

38 Figure 6 Overdeveloped Film. - Developer concentration too high. - Inadequate fixation. - Accidental exposure to light. - Improper safe lighting. Overexposure: -Excessive milliamperage. - Excessive kilovoltage peak. - Excessive time. - Film-source distance too short.. Insufficient contrast: - Under development. - Under exposure. - Excessive kilovoltage peak. - Excessive film fog. 4. Film fog: - Improper safe lighting. - Light leaks - Overdevelopment - Contaminated solutions - Deteriorated film 8

39 Figure 7 Fogged Film. 5. Dark spots or lines: - Fingerprint contamination. - Black wrapping paper sticking to film surface. - Film in contact with tank or another film during fixation. - Film contaminated with developer before processing. - Excessive bending of film. - Static discharge to film before processing. - Excessive roller pressure during automatic processing. - Dirty roller in automatic processing. Figure 8 Developer Spots. 6. Light spots: - Film contaminated with fixer before processing. - Film in contact with tank or another film during development. - Excessive bending of film. 9

40 7. Yellow or brown stains: - Depleted developer. - Depleted fixer. - Insufficient washing. - Contaminated solution. 8. Blurring: -Movement of patient. -Movement of x-ray tube head. -Double exposure. Figure 9 Fixer Spots. 9. Partial images: -Top of film not immersed in developing solution. -Misalignment of x-ray tube head (cone cut). 40

41 Figure 40 Developer Cut-Off. Figure 4 Fixer Cut-Off. 0. Emulsion peel: -Abrasion of image during processing. -Excessive time in wash water. 4

42 Evaluation Sheets 42

43 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 4

44 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 44

45 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 45

46 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 46

47 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 47

48 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 48

49 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 49

50 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 50

51 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 5

52 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 52

53 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 5

54 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 54

55 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 55

56 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Time: Patient`s Name: Radiographic Technique: Tooth Number: 56

57 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 Evaluation Sheet Date: Patient`s Name: Radiographic Technique: Tooth Number: Time: 57

58 Infection Control LAB. & Time Management Follow The Instructions Of Protection Film Quality Scientific Knowledge & Instructor signature: Procedure Evaluation 2 58

59 59