Intraoral Radiography **Dr Dayea Oh** **OMF Radiologist** Intraoral Radiography **Dr Dayea Oh** **OMF Radiologist** # Learning Objectives - By the end of the lecture, the student should be able to: > Understand Intraoral Radiography **techniques**: > - Bitewing radiographs > - Periapical radiographs > - Paralleling > - Bisecting Angle > - Occlusal radiographs > - Understand localisation of an object using intra-oral radiographs > - SLOB rule > - Know technical errors in taking intraoral radiographs - By the end of the lecture, the student should be able to: - Understand Intraoral Radiography **techniques**: - Bitewing radiographs - Periapical radiographs - Paralleling - Bisecting Angle - Occlusal radiographs - Understand localisation of an object using intra-oral radiographs - SLOB rule - Know technical errors in taking intraoral radiographs Based on the provided image and text, here is the content formatted as requested. # Text Transcription ### Basic Radiographic Terminology **Radiopaque vs Radiolucent** **Radiopaque vs Radiolucent** <b>Fig. 1.1</b> A typical dental radiograph. The image shows the various black, grey and white radiographic shadows. The metallic amalgam fillings have totally stopped the X-ray beam so they appear white or radiopaque. <left> Right Posterior Bitewing Radiograph </left> Conventional Radiograph = 2D picture made up of a variety of black, white and grey superimposed shadows • The white or radiopaque shadows on a film represent the various dense structures within the object which have totally stopped the X-ray beam. • The black or radiolucent shadows represent areas where the X-ray beam has passed through the object and has not been stopped at all.   **Fig. 1.1** A typical dental radiograph. The image shows the various black, grey and white radiographic shadows. The metallic amalgam fillings have totally stopped the X-ray beam so they appear white or radiopaque. Right Posterior Bitewing Radiograph Conventional Radiograph = 2D picture made up of a variety of black, white and grey superimposed shadows - The white or radiopaque shadows on a film represent the various dense structures within the object which have totally stopped the X-ray beam. - The black or radiolucent shadows represent areas where the X-ray beam has passed through the object and has not been stopped at all. Clinical radiograph showing the right posterior teeth. The image displays high-density white areas corresponding to metallic amalgam fillings (radiopaque), which have stopped the X-ray beam. Darker grey and black areas represent less dense tooth structures and spaces where the beam passed through (radiolucent). Schematic diagram of the human dentition divided into four quadrants: UR (Upper Right), UL (Upper Left), LR (Lower Right), and LL (Lower Left). Each quadrant shows the arrangement of teeth with standard numbering (1-8) indicating specific tooth positions. # Intraoral Radiography ‘Intra’ = inside ‘oral’ = mouth Radiography – the techniques involved in producing the various radiographic images Radiology – the interpretation of radiographic images (radiographs) ‘Intra’ = inside ‘oral’ = mouth Radiography – the techniques involved in producing the various radiographic images Radiology – the interpretation of radiographic images (radiographs) Types of Intraoral Radiographs **THREE (3) Types** 1. Bite-wing Radiographs (BW) 2. Periapical Radiographs (PA) 3. Occlusal Radiographs / Occlusographs **THREE (3) Types** 1. Bite-wing Radiographs (BW) 2. Periapical Radiographs (PA) 3. Occlusal Radiographs / Occlusographs      Clinical photo showing a dentist in white scrubs operating dental equipment on a patient seated in a dental chair. The setup includes an overhead light arm and monitor. Photo of a red intraoral camera device with a flexible cable and handle, designed for capturing images inside the mouth. Photo of a white disposable bite block or cheek retractor used in dentistry to separate teeth during procedures. Clinical photo of a male patient wearing a protective neck drape with an intraoral sensor positioned in his mouth for radiographic imaging. Radiograph labeled 'Left Posterior Bitewing (BW)' showing the crowns of posterior teeth and the alveolar bone crest, typically used to detect interproximal caries and periodontal bone loss. **Upper (or Maxillary) Left Posterior Periapical (PA)** **Anterior Maxilla Occlusograph**     Upper (or Maxillary) Left Posterior Periapical (PA) Anterior Maxilla Occlusograph Clinical photo showing a female patient in profile with an intraoral periapical (PA) X-ray film being placed inside her mouth. The X-ray machine tubehead is positioned to the side of her face, aimed at the upper left posterior teeth. Radiograph showing the upper left posterior teeth (premolars and molar). Visible features include dental restorations on the first molar and a radiolucent area near the root apex of the second premolar. Clinical photo showing a male patient in profile with an occlusal film placed between his maxillary anterior teeth. An X-ray tubehead is positioned above the palate to capture the image. Occlusal radiograph of the anterior maxilla (upper front teeth). The image shows the crowns and roots of the central and lateral incisors, as well as the canine, viewed from above. The top right of the page has the text: **Analogue radiography → images are chemically processed** The main title on the page is: **Film Sizes (Analogue)** Then the text reads: FIVE (5) Sizes 1. Size 0 • Used in children for both PA and BW 2. Size 1 • Used for adult anterior PA (using paralleling technique) 3. Size 2 • Used for adult posterior PA & BW • Used for adult anterior PA (using bisecting-angle technique) • Used for occlusographs in children • **Most commonly used** 4. Size 3 • Extra-long BW (*not commonly used*) 5. Size 4 • Used for occlusographs in adults On the right side, displayed in a graphic form: - **0:** CHILD PA, BW - **1:** ADULT ANTERIOR PA - **2:** ADULT PA, BW - **4:** ADULT OCCLUSAL FILM  Analogue radiography → images are chemically processed FIVE (5) Sizes 1. Size 0 - Used in children for both PA and BW 2. Size 1 - Used for adult anterior PA (using paralleling technique) 3. Size 2 - Used for adult posterior PA & BW - Used for adult anterior PA (using bisecting-angle technique) - Used for occlusographs in children - Most commonly used 4. Size 3 - Extra-long BW (not commonly used) 5. Size 4 - Used for occlusographs in adults On the right side, displayed in a graphic form: - **0:** CHILD PA, BW - **1:** ADULT ANTERIOR PA - **2:** ADULT PA, BW - **4:** ADULT OCCLUSAL FILM A visual diagram illustrating the relative sizes and uses of five different analogue dental radiographic films. The diagram consists of four rounded rectangles arranged to show size progression: Size 0 (labeled 'CHILD PA, BW'), Size 1 ('ADULT ANTERIOR PA'), Size 2 ('ADULT PA, BW'), and Size 4 ('ADULT OCCLUSAL FILM'). This visual serves as a direct comparison for the textual list on the left. Bitewing (BW) Radiographs Indications Film holder vs Bite tab   Bitewing (BW) Radiographs Indications Film holder vs Bite tab Bitewing (BW) Radiograph: A black and white dental X-ray image showing the crowns of upper and lower posterior teeth. It is used to detect interproximal caries and assess bone levels. Clinical photo demonstrating a child undergoing a bitewing radiograph procedure. The child is seated in a dental chair with a bite tab device positioned at their mouth to hold the film/sensor. **A** **B** **C** **A** **B** **C**   **A** **B** **C** **A** **B** **C** Clinical photo showing a patient undergoing dental radiography with a bitewing film holder in place, alongside an inset of the resulting bitewing radiograph displaying multiple teeth. Black and white photograph displaying three different types of dental film holders labeled A, B, and C. The image includes callouts pointing to these items from the text 'Film holder techniques' and 'Paper / Adhesive tab techniques'. The holders appear to be made of plastic or metal and are designed for intraoral use. # BW Coverage ## ADULT * size 2 film * Distal canines * Premolars * Molars ## CHILD * size 0 film * Canine * All primary molars * Crown of first permanent molar (if erupted)    #### BW Coverage **ADULT** - size 2 film - Distal canines - Premolars - Molars **CHILD** - size 0 film - Canine - All primary molars - Crown of first permanent molar (if erupted) A comparative diagram illustrating Bitewing (BW) radiographic coverage for adults versus children. The figure contains two distinct panels side-by-side. The left panel is labeled 'ADULT' and specifies the use of a 'size 2 film', showing a shaded rectangular area covering the distal canines, premolars, and molars. The right panel is labeled 'CHILD' and specifies the use of a 'size 0 film', showing a smaller shaded rectangular area covering the canine, all primary molars, and the crown of the first permanent molar if erupted. A clinical photograph showing a male patient in a dental setting with a bite block inserted between their teeth, demonstrating the position for taking a bitewing X-ray. An intraoral radiograph (bitewing image) displaying multiple posterior teeth crowns and interproximal areas, serving as a visual example of the imaging technique discussed in the main diagram. BW Coverage **"LEFT POSTERIOR BITEWING"** Radiograph    BW Coverage **"LEFT POSTERIOR BITEWING"** Radiograph Clinical photo of a male patient seated in a dental chair with a protective bib. A dental professional is performing an intraoral radiograph procedure on the left posterior region using a small rectangular sensor or film holder. A cropped dental radiograph (bitewing) showing the upper and lower posterior teeth on the left side of the mouth. The image displays the crowns and interproximal surfaces of molars and premolars, typically used to detect decay between teeth and assess bone levels. An anatomical diagram illustrating the full dentition of the human mouth. A blue shaded area highlights the specific region covered by a "Left Posterior Bitewing" radiograph, corresponding to the last four teeth (premolars and molars) of the left upper and lower jaws. This visual explains the field of view for the procedure mentioned in the text. BW – Positioning **Patient Position:** * Remove all dentures, glasses and other metallic objects eg. piercings in line of primary beam * Patient’s head is supported by head-rest (of dental chair) * Patient bites on to the holder/tab * Ideally, the occlusal plane is parallel to the floor (sit-up position) **Beam / X-ray Cone Position:** * Parallel to, and directed through, the occlusal plane FILM IS PARALLEL TO THE CROWNS X-RAY BEAM DIRECTED THROUGH THE OCCLUSAL PLANE AND CONTACT POINTS PATIENT BITES ON PLASTIC ARM TO STABILIZE HOLDER    #### Patient Position - Remove all dentures, glasses and other metallic objects (e.g., piercings in line of primary beam) - Patient’s head is supported by head-rest (of dental chair) - Patient bites on to the holder/tab - Ideally, the occlusal plane is parallel to the floor (sit-up position) #### Beam / X-ray Cone Position - Parallel to, and directed through, the occlusal plane FILM IS PARALLEL TO THE CROWNS X-RAY BEAM DIRECTED THROUGH THE OCCLUSAL PLANE AND CONTACT POINTS PATIENT BITES ON PLASTIC ARM TO STABILIZE HOLDER Clinical photo showing a patient in a dental chair with their head supported by a headrest. The patient is biting on a plastic holder/tab used to stabilize the X-ray film/sensor. This visual demonstrates the 'Patient Position' described in the text. Radiograph (X-ray) image showing teeth, likely demonstrating the result of proper positioning or serving as an example of the anatomy being imaged. It corresponds to the 'BW – Positioning' topic. Schematic diagram illustrating the alignment for Bitewing radiography. It shows the relationship between the film, the occlusal plane, and the X-ray beam. Labels indicate: 'FILM IS PARALLEL TO THE CROWNS', 'PATIENT BITES ON PLASTIC ARM TO STABILIZE HOLDER', and 'X-RAY BEAM DIRECTED THROUGH THE OCCLUSAL PLANE AND CONTACT POINTS'. The diagram visually reinforces the text instructions regarding parallelism and stabilization. # BW Technique 1. Film Holder Use the holder at all times, if possible **VERTICAL AND HORIZONTAL ANGULATIONS ESTABLISHED BY THE HOLDER** **LESS TECHNIQUE SENSITIVE**       #### Film Holder Use the holder at all times, if possible **VERTICAL AND HORIZONTAL ANGULATIONS ESTABLISHED BY THE HOLDER** **LESS TECHNIQUE SENSITIVE** Clinical photograph showing a radiograph of posterior teeth with a film holder in place. The image demonstrates the correct positioning of the film packet within the holder against the tooth surfaces. Clinical photograph showing a radiograph of posterior teeth. This image appears to demonstrate an incorrect or alternative placement compared to panel A, likely illustrating the importance of proper angulation and contact as taught by the film holder technique. Clinical photograph of a female patient demonstrating the placement of a film holder on her upper teeth. The holder is positioned horizontally across the anterior teeth. Clinical photograph of a female patient demonstrating the placement of a film holder on her lower teeth. The holder is positioned horizontally across the anterior teeth. Schematic diagram illustrating the alignment of dental anatomy (teeth) relative to the Position Indicating Device (PID). It shows how the vertical and horizontal angulations are established by the holder, ensuring the X-ray beam is parallel to the long axis of the teeth and perpendicular to the film plane. Photograph displaying three different types of film holders labeled A, B, and C. These are plastic devices designed to hold intraoral radiographic film packets securely against the teeth for consistent imaging. **Receptor Placement.** Place the receptor between the tongue and the teeth, far enough from the lingual surface of the teeth to prevent interference by the palate on closing and parallel to the long axes of the teeth. The anterior border of the receptor should extend beyond the contact area between the mandibular canine and the first premolar. Hold the receptor in place until the patient’s mouth is completely closed. Holding the receptor while closing prevents it from being displaced distally. **Note: the film / receptor is sitting far away from the teeth when used with holder (thus, *not* creating any angulation)**    **Receptor Placement.** Place the receptor between the tongue and the teeth, far enough from the lingual surface of the teeth to prevent interference by the palate on closing and parallel to the long axes of the teeth. The anterior border of the receptor should extend beyond the contact area between the mandibular canine and the first premolar. Hold the receptor in place until the patient’s mouth is completely closed. Holding the receptor while closing prevents it from being displaced distally. **Note: the film / receptor is sitting far away from the teeth when used with holder (thus, *not* creating any angulation)** Line drawing diagram illustrating the placement of a dental receptor holder between the tongue and teeth. The image shows a cross-section of the mandible with teeth (canine and premolar) and the L-shaped receptor positioned parallel to the tooth axes. Clinical photograph showing a patient undergoing a dental X-ray procedure, demonstrating the use of an intraoral receptor holder. Dental radiograph displaying the resulting image quality from the receptor placement technique shown in the other figures. # BW Technique 2. Paper / Adhesive Tab * Horizontal and vertical angulations of primary beam must be **manually adjusted by operator** * **No guidance** unlike that provided by a film holder * **Very technique sensitive** * **Unrepeatable**   #### Paper / Adhesive Tab - Horizontal and vertical angulations of primary beam must be **manually adjusted by operator** - **No guidance** unlike that provided by a film holder - **Very technique sensitive** - **Unrepeatable** A dental radiograph (X-ray) showing the upper and lower posterior teeth. The image serves as a clinical example of the 'BW Technique' described in the text. A close-up photograph of an intraoral film packet with the adhesive tab pulled back to expose the film holder. The text 'PRESS DOWN' is visible on the paper backing, demonstrating the manual placement mechanism mentioned in the slide's description. // IMAGES // PAGE TEXT # HORIZONTAL ALIGNMENT OF THE CONE *no film holder* **WHY?** * Ensures the beam will clear the contact points so we can detect interproximal caries * Ensure we cover all the film with the cone **HOW?** * Ensure that the film covers all the teeth * Try to keep the film as close to the lingual surfaces of the teeth as possible * Avoid bending the film * Align the cone so that it is *parallel to the arch* **Diagrams:**   #### Horizontal Alignment of the Cone *no film holder* **WHY?** - Ensures the beam will clear the contact points so we can detect interproximal caries - Ensure we cover all the film with the cone **HOW?** - Ensure that the film covers all the teeth - Try to keep the film as close to the lingual surfaces of the teeth as possible - Avoid bending the film - Align the cone so that it is *parallel to the arch* Labeled diagram illustrating the U-shaped dental arch. It depicts a set of teeth in an arch shape with a film holder positioned against the lingual surfaces and arrows indicating the direction of the x-ray beam to clear contact points. Labeled diagram illustrating the V-shaped dental arch. Similar to the U-shaped diagram, it shows the arch form, film placement, and beam alignment relative to the teeth. **wrong horizontal alignment** ❎ - overlapping of teeth FIG. 9-4 **Horizontal overlapping of crowns is the result of misdirection of the central ray.**    **wrong horizontal alignment** ❎ - overlapping of teeth FIG. 9-4 **Horizontal overlapping of crowns is the result of misdirection of the central ray.** Labelled diagram demonstrating the effect of horizontal angulation on dental radiographs. The top panel shows an 'INCORRECT' setup with solid lines indicating misdirected X-ray beams, resulting in a radiograph where teeth appear to have 'OVERLAPPED CONTACTS'. The bottom panel shows a 'CORRECT' setup with dashed lines indicating properly parallel beams, resulting in a radiograph with 'OPEN CONTACTS'. Labels include 'FILM', 'X-RAY BEAM DIRECTION', and comparative outcomes. Small clinical photo of a periapical radiograph showing multiple teeth with crowns that are horizontally overlapping due to incorrect beam alignment. This visual demonstrates the diagnostic finding of overlap caused by improper technique. Clinical radiograph (photo) illustrating severe horizontal overlapping of tooth crowns — a classic sign of misdirected central ray during exposure. The image serves as a real-world example of the principle described in Figure 8-4 and reinforces the caption’s explanation that such artifacts stem from technical error rather than anatomical anomaly. # VERTICAL ALIGNMENT OF THE CONE *no film holder* * 20º * 0º * +8 to +10 * AIM FOR PRIMARY BEAM TO PASS + 8 to +10 FROM THE OCCLUSAL PLANE * WE ONLY ADJUST THE VERTICAL WHEN USING TABS NOT FILM HOLDERS!! The film / receptor sits right next to the teeth, creating slanting   #### Vertical Alignment of the Cone *no film holder* - 20º - 0º - +8 to +10 - AIM FOR PRIMARY BEAM TO PASS +8 to +10 FROM THE OCCLUSAL PLANE - WE ONLY ADJUST THE VERTICAL WHEN USING TABS NOT FILM HOLDERS!! The film / receptor sits right next to the teeth, creating slanting A schematic diagram illustrating the vertical alignment of a dental X-ray cone. It depicts two teeth with a central horizontal line representing the occlusal plane. A dashed beam originates from the right side, labeled '+8 to +10', and aims to pass through the gap between the teeth at that specific height relative to the occlusal plane. On the left, an orange line indicates the angle of the receptor, marked with '20°' at the top and '0°' at the bottom, showing how the film sits slanted next to the teeth. An arrow points to the bottom part of the receptor with the caption: 'The film / receptor sits right next to the teeth, creating slanting'. Text boxes on the right provide instructions: 'AIM FOR PRIMARY BEAM TO PASS + 8 to +10 FROM THE OCCLUSAL PLANE' and 'WE ONLY ADJUST THE VERTICAL WHEN USING TABS NOT FILM HOLDERS!!' A small clinical photograph (radiograph) inset in the top-right corner showing a bitewing X-ray of posterior teeth. # BW – Clinical Problems * **Mandibular Tori** * Bone overgrowth on the lingual surface of the mandible * Difficult to place film * *How to correct:* Use the thinnest film eg. Analogue film or digital PSP plate (photostimulable phosphor plate) and place it lingual to the torus * **Missing Teeth** * Difficult to stabilise / hold film * *How to correct:* Place cotton rolls in the edentulous (missing teeth) space to prevent film rotation. *If you examine the patient first you will avoid the majority of mistakes & retakes*  #### Clinical Problems - **Mandibular Tori** - Bone overgrowth on the lingual surface of the mandible - Difficult to place film - *How to correct:* Use the thinnest film (e.g., analogue film or digital PSP plate) and place it lingual to the torus - **Missing Teeth** - Difficult to stabilise / hold film - *How to correct:* Place cotton rolls in the edentulous space to prevent film rotation *If you examine the patient first you will avoid the majority of mistakes & retakes* Clinical radiograph (X-ray) of the posterior mandible. The image displays the crowns and roots of multiple teeth. Notably, there is a large, radiopaque bony structure visible on the lingual aspect of the tooth roots, consistent with a Mandibular Torus as described in the text. This visual serves to demonstrate the anatomical feature causing clinical problems during film placement. Periapical (PA) Radiographs **Indications** **Paralleling Technique Vs Bisecting Angle Technique**  #### Indications #### Paralleling Technique Vs Bisecting Angle Technique Clinical radiograph (Periapical X-ray) showing the roots and crowns of four adjacent teeth. The image displays dental anatomy including the enamel, dentin, pulp chambers, and periodontal ligament space. A bright white restoration is visible on one of the anterior teeth. # Periapical (PA) Radiographs Periapical = around the apex The intention is to visualize the crown, root and periapical tissues **Indications**: * Periapical inflammation / pathology * Root resorption * Root fractures * Endodontic therapy (pre, peri & post) * Localisation of impacted, missing, supernumerary teeth and foreign bodies * Implant status **Techniques**: 1. Paralleling (long cone) 2. Bisecting Angle  Periapical = around the apex The intention is to visualize the crown, root and periapical tissues #### Indications - Periapical inflammation / pathology - Root resorption - Root fractures - Endodontic therapy (pre, peri & post) - Localisation of impacted, missing, supernumerary teeth and foreign bodies - Implant status #### Techniques 1. Paralleling (long cone) 2. Bisecting Angle A composite figure showing a periapical (PA) radiograph of lower molars alongside a clinical photograph. The left panel displays the X-ray image revealing the crowns, roots, and apices of the teeth. The right panel shows a patient in a dental chair with a film holder positioned near their mouth, demonstrating the procedure for taking such an image. # PA Coverage **A** * Long axis of the film packet vertical * Anterior teeth * 2–3 mm beyond the incisal edge **B** * Long axis of the film packet horizontal * Posterior teeth * 2–3 mm beyond the occlusal plane •Cover 2-3 mm beyond the crowns •Demonstrate all roots •Demonstrate the apical tissues ‘occlusal dot’ marked on film    **A** - Long axis of the film packet vertical - Anterior teeth - 2–3 mm beyond the incisal edge **B** - Long axis of the film packet horizontal - Posterior teeth - 2–3 mm beyond the occlusal plane - Cover 2-3 mm beyond the crowns - Demonstrate all roots - Demonstrate the apical tissues ‘occlusal dot’ marked on film Labeled diagram illustrating PA film coverage. Panel A shows anterior teeth with the long axis of the film packet vertical, indicating coverage 2-3 mm beyond the incisal edge. Panel B shows posterior teeth with the long axis of the film packet horizontal, indicating coverage 2-3 mm beyond the occlusal plane. Composite image showing a clinical photo of a patient holding a bitewing holder and an accompanying radiograph demonstrating the resulting dental X-ray. Close-up photograph of a finger holding a rectangular film packet. An arrow points to a small mark on the corner of the film, labeled as the 'occlusal dot'. Ideal PA Sufficient film to record the apical tissues Parallel X-ray beam meeting both the tooth and film at right angles Film and tooth parallel and in contact Ideal Tooth/Film relationship not possible to achieve because of anatomic limitations Techniques used in periapical imaging are therefore a compromise from this ideal • Same size • Same shape • Good contrast • Good detail    #### Ideal PA Sufficient film to record the apical tissues Parallel X-ray beam meeting both the tooth and film at right angles Film and tooth parallel and in contact Ideal Tooth/Film relationship not possible to achieve because of anatomic limitations Techniques used in periapical imaging are therefore a compromise from this ideal - Same size - Same shape - Good contrast - Good detail Clinical photograph showing a female patient in a dental setting. She is wearing a blue neck collar and has her mouth open to accommodate an intraoral X-ray sensor positioned inside the cheek. Dental radiograph (periapical X-ray) displaying three posterior teeth with visible roots and crowns. The image demonstrates high contrast and detail, consistent with the 'Ideal PA' criteria mentioned in the text. Schematic diagram illustrating the theoretical 'Ideal PA' (Periapical) technique. It features a central tooth cross-section flanked by film on the left. Callouts point to specific geometric relationships: 'Film and tooth parallel and in contact', 'Sufficient film to record the apical tissues', and 'Parallel X-ray beam meeting both the tooth and film at right angles'. Below the diagram, text explains that this ideal is unachievable due to anatomic limitations. - Film parallel to the long axis of the tooth - Primary beam perpendicular to the film    - Film parallel to the long axis of the tooth - Primary beam perpendicular to the film Labelled diagram illustrating the Paralleling Technique for dental radiography. The image shows a hand holding a film holder with an intraoral film placed parallel to the long axis of a tooth. A PID (Position Indicating Device) is positioned above to direct the primary beam perpendicularly onto the film. Clinical photo showing a patient's mouth during a dental X-ray procedure using the paralleling technique. The patient has a bite block in place and is wearing a protective apron. Dental radiograph displaying multiple teeth with visible crowns and roots. The image demonstrates the clarity achievable with the paralleling technique, showing distinct anatomical structures. # PA – 1. Paralleling Technique **The longer the cone, the more parallel the beam** **A** **Short spacer cone** **Diverging X-ray beam** Extensive magnification of the image **Fig. 8.3** Diagrams showing the magnification of the image that results from using **A** a short cone and a diverging X-ray beam and **B** a long cone and a near-parallel X-ray beam. **B** **Long spacer cone** **Near-parallel X-ray beam** Minimal magnification of the image   **The longer the cone, the more parallel the beam** **A** Short spacer cone Diverging X-ray beam Extensive magnification of the image **B** Long spacer cone Near-parallel X-ray beam Minimal magnification of the image Fig. 8.3 Diagrams showing the magnification of the image that results from using A a short cone and a diverging X-ray beam and B a long cone and a near-parallel X-ray beam. Diagram illustrating the paralleling technique. It shows a tooth positioned parallel to a vertical film plane. The X-ray beam is depicted as parallel rays traveling from right to left. A dashed line indicates the central ray perpendicular to both the film and the long axis of the tooth. Text annotation explains: 'For the tooth and the film to be parallel they have to be positioned some distance apart'. Figure 8.3 containing two comparative diagrams labeled A and B. Panel A depicts a 'Short spacer cone' resulting in a 'Diverging X-ray beam' and 'Extensive magnification of the image'. Panel B depicts a 'Long spacer cone' resulting in a 'Near-parallel X-ray beam' and 'Minimal magnification of the image'. An external text note states: 'The longer the cone, the more parallel the beam'. **EXAMPLES OF FILM HOLDERS** **With PID guidance rings** Paralleling technique always requires **FILM HOLDERS**     #### Examples of Film Holders With PID guidance rings Paralleling technique always requires **film holders**. Labelled figure showing three types of film holders (labeled A, B, and C) used in dental radiography. Each holder consists of a ring structure to align the PID guidance with the tooth and a bite block for patient stabilization. Close-up photograph of two metal film holders equipped with PID guidance rings. The image highlights the structural design intended for the paralleling technique. Clinical photograph of a female patient undergoing a dental X-ray procedure using a film holder device. Dental radiograph (X-ray) displaying teeth with restorations, demonstrating the result of an intraoral radiographic exposure. PA – 1. Paralleling Technique - Optimally achieved using film holders with PID guidance rings - ++ Accuracy - Less technique sensitive - horizontal and vertical angulations determined by film holder - Recommended for: - Endodontic therapy = accurate measurement of length is critical - Long term evaluation of crestal bone height around implants  - Optimally achieved using film holders with PID guidance rings - ++ Accuracy - Less technique sensitive - horizontal and vertical angulations determined by film holder - Recommended for: - Endodontic therapy = accurate measurement of length is critical - Long term evaluation of crestal bone height around implants Composite figure containing two images. Left panel is a clinical photograph showing a female patient with blonde hair wearing a blue dental bib, demonstrating the paralleling technique by holding a film holder against her teeth while an X-ray tube head is positioned to capture the image. Right panel is a dental radiograph (X-ray) of posterior teeth, likely illustrating the result of the paralleling technique. # Paralleling Technique – Advantages * Dimensionally accurate * Accurate determination of bone height * Accurate assessment of dental caries * Reduced superimposition of the zygoma * Reduced skin exposure due to greater kVp and parallel beam   - Dimensionally accurate - Accurate determination of bone height - Accurate assessment of dental caries - Reduced superimposition of the zygoma - Reduced skin exposure due to greater kVp and parallel beam Clinical photo showing a patient's head with a paralleling device positioned in the mouth to align the X-ray sensor parallel to the teeth. Radiograph (X-ray) demonstrating the result of the paralleling technique, showing clear images of teeth and bone structure with minimal distortion or superimposition. Paralleling Technique – Disadvantages • More difficult to place film • More uncomfortable for the patient • Higher kVp machine required • Long cone and film holders required   #### Disadvantages - More difficult to place film - More uncomfortable for the patient - Higher kVp machine required - Long cone and film holders required Clinical photo demonstrating the paralleling technique. The image shows a patient's head with a film holder inserted into the mouth to position dental film parallel to the teeth and the X-ray cone directed towards it. Radiograph showing the result of the paralleling technique. It displays four maxillary posterior teeth with clear root structures and crowns, illustrating proper alignment achieved by the method described in the slide. PA – 2. Bisecting Angle Technique CENTRAL RAY OF X-RAY BEAM AIMED THROUGH APEX BISECTING LINE FILM • X-ray beam is directed perpendicular to the bisecting line • Vertical angulation must be determined manually * Receptor is placed as close to tooth as possible Central axis of tooth Imaginary bisector Collimated beam Central ray Receptor In any 90-degree arc, there is one angle (bisecting angle) that will allow an x-ray beam to cast an **accurate shadow** of the tooth on the film.   CENTRAL RAY OF X-RAY BEAM AIMED THROUGH APEX BISECTING LINE FILM - X-ray beam is directed perpendicular to the bisecting line - Vertical angulation must be determined manually - Receptor is placed as close to tooth as possible Central axis of tooth Imaginary bisector Collimated beam Central ray Receptor In any 90-degree arc, there is one angle (bisecting angle) that will allow an x-ray beam to cast an **accurate shadow** of the tooth on the film. Diagram illustrating the Bisecting Angle Technique. It shows a tooth (in blue) and an angled film. Labels indicate 'CENTRAL RAY OF X-RAY BEAM AIMED THROUGH APEX' pointing to the beam path, 'BISECTING LINE' showing the angle between the tooth and film, and 'FILM'. The diagram demonstrates that the central ray is directed perpendicular to the bisecting line. Detailed anatomical cross-section of a tooth and receptor. Labels identify 'Central axis of tooth', 'Imaginary bisector', 'Collimated beam', 'Central ray', and 'Receptor'. This figure visually explains how the x-ray beam intersects the tooth to create an accurate shadow on the film. # **Film Holders Used in Bisecting Angle Technique** [Image showing close-up of dental film holder in patient’s mouth] **Snap-A-Ray / “Alligator”** **Note: no beam aiming device** https://dooclip.me/video/bzreH0NM4fk?id=bzreH0NM4fk   [Image showing close-up of dental film holder in patient’s mouth] **Snap-A-Ray / “Alligator”** **Note: no beam aiming device** https://dooclip.me/video/bzreH0NM4fk?id=bzreH0NM4fk A clinical photograph showing a close-up of a dental film holder in a patient's mouth. A labeled product photograph of a white dental film holder device with yellow and blue components. Central ray of the X-ray beam aimed through the tooth apex Long axis of the tooth Bisecting line Long axis of the film 2-3 mm of film visible beyond the incisal edge Vertical angulation  Central ray of the X-ray beam aimed through the tooth apex Long axis of the tooth Bisecting line Long axis of the film 2-3 mm of film visible beyond the incisal edge Vertical angulation Labelled diagram illustrating the principle of the bisecting angle technique (Cieszynski's rule of isometry). The central ray of the X-ray beam is aimed through the tooth apex. Key labeled components include: Long axis of the tooth, Bisecting line, Long axis of the film, Vertical angulation, and a note indicating '2-3 mm of film visible beyond the incisal edge'. A small inset radiograph in the top right corner shows four teeth. BISecting ANGLE TECHNIQUE - HORIZONTAL ANGULATION • Horizontal angulation must be corrected manually PID → Same as the bite tab technique in bitewing (BW)   #### Horizontal Angulation - Horizontal angulation must be corrected manually - PID → Same as the bite tab technique in bitewing (BW) Diagram illustrating the correct horizontal angulation for the bisecting angle technique. It shows a set of teeth with vertical lines representing X-ray beams passing perpendicularly through them without any overlap. Diagram illustrating the incorrect horizontal angulation for the bisecting angle technique. It shows a set of teeth with angled lines representing X-ray beams that result in overlapping images. Vertical angulation faults   #### Vertical angulation faults Labelled diagram illustrating 'Vertical angulation faults' in dental radiography. It contains two panels: Panel A shows a scenario where the 'Vertical angulation' is 'too large', resulting in an 'Image foreshortened'. Panel B shows a scenario where the 'Vertical angulation' is 'too small', resulting in an 'Image elongated'. Both diagrams depict X-ray beam paths relative to tooth anatomy. Composite figure demonstrating effects of vertical angulation errors using both schematic drawings and clinical radiographs. The top section illustrates 'OVERANGULATION = FORESHORTENING' with a diagram showing the X-ray beam direction and apex image, alongside a corresponding radiograph of teeth exhibiting foreshortening. The bottom section illustrates 'UNDERANGULATION = ELONGATION' with a similar diagram and radiograph showing elongation. Modified bisecting angle technique – upper anterior CONE A c film D X° B “Sao Biscuit” technique for kids Modified bisecting angle technique – lower anterior C b Y° A CONE film #### Modified bisecting angle technique – upper anterior CONE A c film D X° B “Sao Biscuit” technique for kids #### Modified bisecting angle technique – lower anterior C b Y° A CONE film  Comparison figure displaying radiographic results of two dental imaging techniques. Top row labeled 'Bisecting Angle Technic' shows distorted images of a screw and multiple screws due to magnification errors. Bottom row labeled 'Paralleling Technic' shows accurate, undistorted images of the same objects with correct proportions. Occlusal Radiographs /Occlusographs   Occlusal Radiographs / Occlusographs Clinical photo of a patient in a dental setting. The patient is biting down on a radiographic film or sensor placed between their teeth (occlusal view) while wearing a protective lead apron. Occlusal radiograph showing the maxillary anterior region. The image displays the crowns and roots of the upper front teeth arranged in an arch shape. A large, rounded radiopaque mass is visible within the bone near the canine/premolar area. Occlusal Radiographs /Occlusographs • Largest intraoral film • Will visualize hard palate, floor of mouth, dentition Demonstrates: • Trauma / pathology • Eg. Alveolar bone fracture, Salivary stones, etc. • Localization unerupted/impacted teeth • Localization supernumerary teeth • View developing anterior dentition  - Largest intraoral film - Will visualize hard palate, floor of mouth, dentition Demonstrates: - Trauma / pathology - Eg. Alveolar bone fracture, Salivary stones, etc. - Localization unerupted/impacted teeth - Localization supernumerary teeth - View developing anterior dentition Clinical radiograph showing occlusal views of dentition. The left panel displays a maxillary arch view with multiple teeth visible, while the right panel shows a mandibular arch view. These images serve as visual examples for the topic 'Occlusal Radiographs / Occlusographs'. **MAXILLARY ANTERIOR OCCLUSAL** Above the nose bridge Primary beam +65° from film This projection shows the palate, zygomatic processes of the maxilla, anteroinferior aspects of each antrum, nasolacrimal canals, teeth from second molar to second molar, and nasal septum.      #### Maxillary Anterior Occlusal Above the nose bridge Primary beam +65° from film This projection shows the palate, zygomatic processes of the maxilla, anteroinferior aspects of each antrum, nasolacrimal canals, teeth from second molar to second molar, and nasal septum. Radiograph showing a dental arch view of the upper teeth. Radiograph showing a frontal view of the upper teeth and jaw structure. Line drawing diagram illustrating the Maxillary Anterior Occlusal radiographic projection. The image shows a side profile of a human head with an X-ray tube angled at +65° from the film placed in the mouth. Labels indicate 'Above the nose bridge' for positioning and 'Primary beam +65° from film' for the angle. Clinical photograph of a patient's face demonstrating the correct placement of the occlusal film above the nose bridge as part of the Maxillary Anterior Occlusal procedure. Radiograph resulting from the Maxillary Anterior Occlusal projection, displaying the palate, zygomatic processes, anterior aspects of the maxillary sinuses, nasolacrimal canals, nasal septum, and teeth from the second molar to the second molar. VERTEX OCCLUSAL Above the head → more anatomic structures exposed 😞 Very rarely used - no longer recommended Dosage +++ Proximity to retinal tissues #### Vertex Occlusal Above the head → more anatomic structures exposed 😞 Very rarely used - no longer recommended Dosage +++ Proximity to retinal tissues **MANDIBULAR TRUE OCCLUSAL** Primary beam perpendicular to film This projection reveals the **lingual** and **buccal** plates of the **mandible** from **second** **molar** to **second** **molar**. When this view is made to examine the floor of the mouth (**e.g.**, for **sialoliths**), the exposure time should be reduced to half the time used to create an image of the **mandible**. #### Mandibular True Occlusal Primary beam perpendicular to film This projection reveals the **lingual** and **buccal** plates of the **mandible** from **second molar** to **second molar**. When this view is made to examine the floor of the mouth (e.g., for sialoliths), the exposure time should be reduced to half the time used to create an image of the **mandible**.   Radiograph of the mandible showing the dental arch with multiple teeth and fillings visible. Radiograph of the maxilla showing the upper dental arch with several teeth and fillings visible. Localisation of Objects Using Intra-oral Film  Localisation of Objects Using Intra-oral Film A composite radiograph showing two views of maxillary teeth labeled 'Fig. 2a' and 'Fig. 2b'. The image demonstrates the clinical finding described in the OCR context: ectopic eruption or displacement of a tooth (likely an incisor) relative to its adjacent neighbors. LOCALIZATION USING INTRA-ORAL FILMS TO DETERMINE: - Bucco-lingual location of impacted teeth such as unerupted ectopic canines - Location of a foreign body in the bucco-lingual dimension Handy if you don’t have access to 3D imaging eg. Cone Beam CT      TO DETERMINE: - Bucco-lingual location of impacted teeth such as unerupted ectopic canines - Location of a foreign body in the bucco-lingual dimension Handy if you don’t have access to 3D imaging e.g. Cone Beam CT Title of the slide: LOCALIZATION USING INTRA-ORAL FILMS Heading indicating the purpose of the method: TO DETERMINE: Bullet point describing the first application: Bucco-lingual location of impacted teeth such as unerupted ectopic canines Bullet point describing the second application: Location of a foreign body in the bucco-lingual dimension Italicized note explaining utility when 3D imaging is unavailable: Handy if you don't have access to 3D imaging eg. Cone Beam CT Techniques for Localisation • Two Techniques 1. Tube Shift Technique / Parallex Technique / Clark’s Rule i. Horizontal Shift ii. Vertical Shift 2. Right Angle Technique / Miller’s Technique Techniques for Localisation - **Two Techniques** 1. Tube Shift Technique / Parallex Technique / Clark’s Rule - Horizontal Shift - Vertical Shift 2. Right Angle Technique / Miller’s Technique #1 - The Tube Shift Technique * Two PA images taken * Film #1 = centered over area of interest and taken * Film #2 - tube is shifted EITHER HORIZONTALLY OR VERTICALLY 30-40º and second image is taken * Tube may be shifted in either the **HORIZONTAL** or VERTICAL directions * The direction of motion of the impacted tooth/ foreign body relative to the tube movement shows its location Same Lingual, Opposite Buccal (SLOB rule or Clark's Rule)  **#1 - The Tube Shift Technique** - Two PA images taken - Film #1 = centered over area of interest and taken - Film #2 - tube is shifted EITHER HORIZONTALLY OR VERTICALLY 30-40º and second image is taken - Tube may be shifted in either the **HORIZONTAL** or VERTICAL directions - The direction of motion of the impacted tooth/foreign body relative to the tube movement shows its location Same Lingual, Opposite Buccal (SLOB rule or Clark's Rule) Procedural text outlining the 'Tube Shift Technique' for dental localization. It details a two-step process: first taking a PA image centered on the area of interest, then shifting the x-ray tube either horizontally or vertically by 30-40 degrees to take a second image. The description explains that the direction of the tooth's motion relative to the tube movement indicates its location (lingual or buccal), referencing the SLOB rule.  Clinical procedure diagram demonstrating the Horizontal Tube Shift Technique for panoramic radiography. The image is split into two panels showing a patient in a dental chair: left panel shows the initial position (PA#1) with the x-ray tube head angled to the side; right panel shows the second position (PA#2) with the tube head shifted horizontally. Below the images, text labels indicate 'PA#1', an arrow pointing right, instructions 'Shift tube 40-45° horizontal / Vertical PID angulation constant', another arrow pointing right, and 'PA#2'. # HORIZONTAL TUBE SHIFT **(Normal Position)** | MESIAL | | :--- | | **Lingual** | | | **Buccal** | | | | | | | | | | | | |▲| |●| | | |▲| | | |▲| |▲| | |▲| |●| | |▲| | | | **DISTAL** | | | MESIAL | | :--- | **DISTAL** <--> **MESIAL** *Right upper / maxillary periapical* *(paralleling technique)*   **HORIZONTAL TUBE SHIFT** **(Normal Position)** | MESIAL | | :--- | | **Lingual** | | | **Buccal** | | | | | | | | | | | | |▲| |●| | | |▲| | | |▲| |▲| | |▲| |●| | |▲| | | | **DISTAL** | | | MESIAL | | :--- | **DISTAL** <--> **MESIAL** *Right upper / maxillary periapical* *(paralleling technique)* Schematic diagram illustrating the concept of 'Horizontal Tube Shift' in dental radiography. It shows a vertical stack of circular cross-sections representing teeth (labeled with lingual and buccal surfaces) aligned next to a vertical line representing the image receptor. A red triangle points leftward from one tooth, indicating the direction of tube shift, while a yellow circle indicates the object position relative to the receptor. Radiographic illustration showing three molar teeth. A red triangle is superimposed on the central tooth to indicate the focal trough or area of interest. An arrow below indicates the horizontal axis between Distal and Mesial directions. # HORIZONTAL TUBE SHIFT – DISTAL SHIFTT   **HORIZONTAL TUBE SHIFT – DISTAL SHIFT** Diagram illustrating the 'Horizontal Tube Shift - Distal Shift' effect in dental radiography. It shows a vertical arrangement of teeth with labels 'MESIAL' at the top and 'DISTAL' at the bottom. A black vertical line on the left is labeled 'Lingual', while the space to its right is labeled 'Buccal'. Dashed lines representing X-ray beams diverge from the source (implied bottom right) towards the film/sensor (implied top left), demonstrating how objects further distally appear shifted mesially relative to those closer lingually. Schematic diagram showing three teeth in profile view within a dark gray rectangular frame. An orange triangle sits above the central tooth, and a yellow circle sits above the rightmost tooth. Below the teeth, an arrow points left labeled 'DISTAL' and an arrow points right labeled 'MESIAL', indicating directional shifts or positions related to the horizontal tube shift phenomenon. HORIZONTAL TUBE SHIFT – MESIAL SHIFT MESIAL DISTAL DISTAL MESIAL Lingual Buccal   **HORIZONTAL TUBE SHIFT – MESIAL SHIFT** MESIAL DISTAL DISTAL MESIAL Lingual Buccal Diagram illustrating a horizontal tube shift (mesial shift). It shows a vertical arrangement of orange circles representing teeth or anatomical structures. Labels indicate 'Lingual' on the left and 'Buccal' on the right. Dashed lines represent diverging X-ray beams originating from a red triangular object (representing the X-ray source) positioned to the left. A yellow circle is shown in the beam path. Boxes labeled 'MESIAL' at the top and 'DISTAL' at the bottom define the directional axes. The diagram visually demonstrates how the mesial shift of the X-ray source affects the projection of the objects. Schematic representation of a dental radiograph showing a mesial shift. Three white tooth shapes are depicted against a dark gray background. Above the central tooth, a yellow circle and an orange triangle are positioned, likely representing anatomical landmarks or artifacts. Below the teeth, a double-headed arrow indicates directionality between 'DISTAL' (left) and 'MESIAL' (right), clarifying the orientation of the shift being demonstrated.     Clinical radiograph showing a maxillary anterior region. A supernumerary tooth (mesiodens) is visible in the midline between the central incisors, appearing to impinge upon or be associated with the developing permanent teeth. Clinical radiograph showing a different view of the same maxillary anterior region. The supernumerary tooth is clearly visualized as an extra conical structure located mesial to the right central incisor and distal to the left central incisor, causing displacement of adjacent roots. Schematic diagram illustrating the anatomical relationship of the supernumerary tooth shown in the first radiograph. It depicts the long axis of the supernumerary tooth angling towards the roots of the adjacent central incisors, visually explaining the displacement seen in the X-ray. Schematic diagram illustrating the anatomical relationship corresponding to the second radiograph. It shows the supernumerary tooth positioned between the two central incisors, demonstrating how it occupies space that would otherwise allow for normal root development. VERTICAL TUBE SHIFT TECHNIQUE Right lower / mandibular periapical (paralleling technique)    **VERTICAL TUBE SHIFT TECHNIQUE** Right lower / mandibular periapical (paralleling technique) Diagram illustrating the vertical tube shift technique. Shows a single tooth with dashed lines indicating horizontal levels, an orange triangle pointing left (representing the X-ray beam direction), and a yellow circle representing the target area. A standalone orange icon representing a dental X-ray tube head or positioner. Radiographic diagram of four teeth in the right lower jaw. An orange triangle overlaid on the third tooth indicates the X-ray beam path for a periapical radiograph using the paralleling technique. Increasing vertical angulation (Ascending) Lingual Buccal  **Increasing vertical angulation (Ascending)** Lingual Buccal Labelled diagram illustrating the concept of increasing vertical angulation in dental radiography. The diagram is split into two parts: a side-view on the left showing a single tooth with 'Lingual' and 'Buccal' labels indicating direction, and a top-down view on the right showing four teeth in a row. A red triangle and yellow circle are used to indicate specific points or movements related to the procedure. DECREASE VERTICAL ANGULATION (Descending) Lingual Buccal   **DECREASE VERTICAL ANGULATION (Descending)** Lingual Buccal Labeled diagram illustrating 'DECREASE VERTICAL ANGULATION (Descending)'. The image displays a tooth with green dashed lines indicating the angle of X-ray beam divergence. An orange triangle on the left is labeled 'Lingual' and an orange irregular shape on the right is labeled 'Buccal', demonstrating the spatial relationship of anatomical structures relative to the beam path. Intraoral radiograph showing four teeth. A yellow circle highlights the crown area of the third tooth from the left, and an orange triangle marks the root area of the same tooth, likely indicating the focal trough or specific region of interest for vertical angulation adjustment. **Vertical Tube Shift Technique using Occlusograph & Extra-oral Panoramic Radiograph**  **Vertical Tube Shift Technique using Occlusograph & Extra-oral Panoramic Radiograph** Occlusograph radiograph showing the dental arch with a radiopaque wire tracing the occlusal plane. A red circle highlights a specific area on the mandibular anterior teeth region. **QUIZ** * **What types of I/O radiographs are these?** 1. Right Posterior BW + Right Upper Posterior PA 2. Left Posterior BW + Left Lower Posterior PA 3. Right Posterior BW + Right Lower Anterior PA 4. Right Posterior BW + Right Lower Posterior PA 5. Left Posterior BW + Left Upper Posterior PA * **Which technique was used to locate the ‘radiopacity’?** 1. Horizontal Tube Shift 2. Right Angle Technique 3. Vertical Tube Shift * **Where is the radiopacity (arrow point)?** 1. Lingual 2. Buccal   **QUIZ** - **What types of I/O radiographs are these?** 1. Right Posterior BW + Right Upper Posterior PA 2. Left Posterior BW + Left Lower Posterior PA 3. Right Posterior BW + Right Lower Anterior PA 4. Right Posterior BW + Right Lower Posterior PA 5. Left Posterior BW + Left Upper Posterior PA - **Which technique was used to locate the ‘radiopacity’?** 1. Horizontal Tube Shift 2. Right Angle Technique 3. Vertical Tube Shift - **Where is the radiopacity (arrow point)?** 1. Lingual 2. Buccal Clinical radiograph showing a dental X-ray of the right posterior region. The image displays teeth with restorations (fillings) and an arrow pointing to a small radiopacity in the bone adjacent to the tooth roots. Clinical radiograph showing a second view of the same dental area as the first image. It includes an arrow indicating a specific feature for comparison or localization analysis. TECHNIQUES FOR LOCALIZATION #2 - The right angle technique (Miller’s Technique) **Two radiographs are taken** **The second is taken at right angles to the first** Eg. periapical + true occlusal film • The occlusal film will determine the bucco-lingual position of the object *(Not commonly practiced)*  TECHNIQUES FOR LOCALIZATION **#2 - The right angle technique (Miller’s Technique)** Two radiographs are taken. The second is taken at right angles to the first. E.g. periapical + true occlusal film - The occlusal film will determine the bucco-lingual position of the object *(Not commonly practiced)* Medical diagram illustrating the right angle technique (Miller's Technique) for object localization. It consists of two panels: Panel A shows a close-up radiograph view of three teeth with a dark circular marker indicating an object located buccal to the central tooth root; Panel B displays a panoramic dental arch layout showing the corresponding position of the black dot in relation to the lower jaw anatomy.   Clinical radiograph showing a close-up view of the maxillary anterior teeth. The image displays the crowns and roots of several incisors with visible restorations (fillings). It is used to demonstrate specific dental anatomy or pathology in conjunction with the SLOB rule context. Occlusal radiograph of the maxillary arch displaying the full row of upper teeth from left to right. This image serves as an example of an occlusograph used to determine the buccal-lingual (B/L) position of impacted teeth, illustrating that unlike periapical views, it does not follow the standard SLOB rule for localization. FILM FAULTS • **Errors in the surgery** • Errors in the darkroom *(not covered in this lecture)* • Errors in film processing *(not covered in this lecture)* #### Film Faults - **Errors in the surgery** - Errors in the darkroom *(not covered in this lecture)* - Errors in film processing *(not covered in this lecture)* # ERRORS IN THE SURGERY * Overexposure – dark image * Underexposure – light image * Patient motion – blurred image * Film exposed to white light before processing * Analogue film or digital Photostimulable Phosphor (PSP) plate * Not removing foreign objects such as ear-rings, spectacles, body jewellery (including tongue studs), hair clips, hearing aids, neck chains * Poor patient positioning and incorrect technique – distorted images * Cone-cutting * Elongation * Foreshortening * Damaged Film * Double Exposed Film #### Errors in the Surgery - Overexposure – dark image - Underexposure – light image - Patient motion – blurred image - Film exposed to white light before processing - Analogue film or digital Photostimulable Phosphor (PSP) plate - Not removing foreign objects such as ear-rings, spectacles, body jewellery (including tongue studs), hair clips, hearing aids, neck chains - Poor patient positioning and incorrect technique – distorted images - Cone-cutting - Elongation - Foreshortening - Damaged Film - Double Exposed Film A B A B A B C D A **For your own learning…** **Identify Errors** A B A B A B C D A **For your own learning…** **Identify Errors** Partial immersion in developer Over developed Fixer splashed on film before processing Cone cutting Elongation Not washing adequately post development or developer on film before processing Forshortening 1. Not exposed 2. Left in wash over-night 3. Put into fixer before developer Film positioned backwards  - Partial immersion in developer - Over developed - Fixer splashed on film before processing - Cone cutting - Elongation - Not washing adequately post development or developer on film before processing - Foreshortening 1. Not exposed 2. Left in wash over-night 3. Put into fixer before developer - Film positioned backwards Labelled composite radiograph figure demonstrating various dental X-ray processing errors. The image is organized into a grid of film strips with specific callouts pointing to defects: 'Partial immersion in developer' (top left), 'Over developed' (top right), 'Fixer splashed on film before processing' (top middle-right), 'Cone cutting' (middle left), 'Elongation' (middle center), 'Forshortening' (middle right), and 'Film positioned backwards' (bottom right). Additional text notes include causes for artifacts such as 'Not washing adequately post development or developer on film before processing' and numbered steps for under-exposed films ('1. Not exposed', '2. Left in wash over-night', '3. Put into fixer before developer'). Next lecture on digital & analogue films  A humorous composite image juxtaposing a photograph of a white cat sitting on a printer with a radiographic-style overlay of paw prints. The text 'CAT SCAN' is overlaid at the bottom right, playing on the medical term for CT scans. [^1]: Original PDF page 1: [[L2.Intraoral Radiography.pdf#page=1|L2.Intraoral Radiography, p.1]] [^2]: Original PDF page 2: [[L2.Intraoral Radiography.pdf#page=2|L2.Intraoral Radiography, p.2]] [^3]: Original PDF page 3: [[L2.Intraoral Radiography.pdf#page=3|L2.Intraoral Radiography, p.3]] [^4]: Original PDF page 4: [[L2.Intraoral Radiography.pdf#page=4|L2.Intraoral Radiography, p.4]] [^5]: Original PDF page 5: [[L2.Intraoral Radiography.pdf#page=5|L2.Intraoral Radiography, p.5]] [^6]: Original PDF page 6: [[L2.Intraoral Radiography.pdf#page=6|L2.Intraoral Radiography, p.6]] [^7]: Original PDF page 7: [[L2.Intraoral Radiography.pdf#page=7|L2.Intraoral Radiography, p.7]] [^8]: Original PDF page 8: [[L2.Intraoral Radiography.pdf#page=8|L2.Intraoral Radiography, p.8]] [^9]: Original PDF page 9: [[L2.Intraoral Radiography.pdf#page=9|L2.Intraoral Radiography, p.9]] [^10]: Original PDF page 10: [[L2.Intraoral Radiography.pdf#page=10|L2.Intraoral Radiography, p.10]] [^11]: Original PDF page 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