Cephalograms & Other 2D Extraoral Views **Dr Dayea Oh** **OMF Radiologist** Dr Dayea Oh OMF Radiologist # Learning Objectives * What are intensifying screens? * Understanding the purpose of using intensifying screens in extraoral radiography * Understanding differences between Cephalograms and Skull Views * What are the clinical indications for: * Lateral cephalogram (Lat Ceph) * Frontal Views * Submentovertex (SMV) Projection * Water’s View * Reverse Towne View * Lateral Oblique (or Oblique Lateral) Radiograph - What are intensifying screens? - Understanding the purpose of using intensifying screens in extraoral radiography - Understanding differences between Cephalograms and Skull Views - What are the clinical indications for: - Lateral cephalogram (Lat Ceph) - Frontal Views - Submentovertex (SMV) Projection - Water's View - Reverse Towne View - Lateral Oblique (or Oblique Lateral) Radiograph # Extraoral Radiography * Extra(=outside)Oral(=mouth) Radiography * X-ray source and image receptor are placed OUTSIDE the mouth * **General indications:** * Patient is unable to open mouth * Severe gag reflex * Trauma * Impacted third molars * Extensive jaw pathology * TM joint assessment * Orthodontic & orthognathic treatment planning Extraoral radiography involves placing the X-ray source and image receptor outside the mouth. #### General Indications - Patient is unable to open mouth - Severe gag reflex - Trauma - Impacted third molars - Extensive jaw pathology - TM joint assessment - Orthodontic & orthognathic treatment planning X-ray Cassette (Analogue) A cassette ID window screens light-tight seal film B screen-film cassette screen emulsion screen film base emulsion CASSSETTE FRONT FRONT PADDING INTENSIFYING SCREEN SUPPORT LAYER PHOSPHOR LAYER EMULSION LAYER DOUBLE-COATED FILM SUPPORT LAYER EMULSION LAYER INTENSIFYING SCREEN PHOSPHOR LAYER SUPPORT LAYER LEAD FOIL BACK PADDING CASSSETTE BACK   The cassette consists of the following layers (from front to back): - Cassette front - Front padding - Intensifying screen - Support layer - Phosphor layer - Emulsion layer (double-coated film) - Support layer (film base) - Emulsion layer - Intensifying screen - Phosphor layer - Support layer - Lead foil - Back padding - Cassette back Labelled diagram showing the external components of an X-ray cassette. The image displays a 'cassette' with an 'ID window', 'screens', and a 'light-tight seal'. A separate 'film' sheet is shown positioned inside the cassette. This view illustrates the assembly of the protective casing and internal film. Detailed cross-sectional diagram of an analogue screen-film cassette, illustrating its layered construction from top to bottom. Visible layers include: 'CASSSETTE FRONT', 'FRONT PADDING', 'INTENSIFYING SCREEN' (with 'SUPPORT LAYER' and 'PHOSPHOR LAYER'), 'DOUBLE-COATED FILM' (containing two 'EMULSION LAYER's on 'SUPPORT LAYER's), a second 'INTENSIFYING SCREEN' (with 'SUPPORT LAYER' and 'PHOSPHOR LAYER'), 'LEAD FOIL', 'BACK PADDING', and 'CASSSETTE BACK'. Labels point specifically to these structural elements. Intensifying Screen • Used to reduce radiation exposure • Film (AgBr) is sensitive to **UV** and **blue light** • Intensifying screen makes the film 10-60 times more sensitive to x-rays • Screens are placed on each side of the film (double coated film) to help increase image sharpness.  - Used to reduce radiation exposure - Film (AgBr) is sensitive to **UV** and **blue light** - Intensifying screen makes the film 10-60 times more sensitive to x-rays - Screens are placed on each side of the film (double coated film) to help increase image sharpness. Labelled diagram illustrating the cross-section of an intensifying screen system. The image shows a stack of layers including 'Base', 'Phosphor', and 'Coat' on both sides of a central 'Film'. X-ray beams are depicted penetrating through the layers, while phosphors emit light (shown as fan-shaped rays) to expose the film. # Intensifying Screen ## Phosphor layer * Composed of **phosphor crystals** * **Inorganic salts** * calcium tungstate (CaWO$_4$): **blue light** * lanthanum oxybromide (LaOBr): **blue light** * gadolinium oxysulfide (Gd$_2$O$_2$S): **green light** * **Rare earth elements** * Have better light conversion efficacy * Lanthanum, gadolinium and yttrium #### Phosphor Layer Composition - Composed of **phosphor crystals** - **Inorganic salts** - calcium tungstate (CaWO$_4$): **blue light** - lanthanum oxybromide (LaOBr): **blue light** - gadolinium oxysulfide (Gd$_2$O$_2$S): **green light** - **Rare earth elements** - Have better light conversion efficacy - Lanthanum, gadolinium and yttrium # Intensifying Screen ## Base + Reflective Layer * **Base** = Polyester plastic that ~0.25 mm thick (*mechanical support*) * Reflective layer reflects light emitted from the phosphor layer back toward the x-ray film * This reflective base increases the light emission of the intensifying screen but also results in image fogging "unsharpness" because of the divergence of light rays reflected back to the film.  - **Base** = Polyester plastic that ~0.25 mm thick (*mechanical support*) - Reflective layer reflects light emitted from the phosphor layer back toward the x-ray film - This reflective base increases the light emission of the intensifying screen but also results in image fogging "unsharpness" because of the divergence of light rays reflected back to the film. A labeled cross-section diagram of an intensifying screen showing four distinct layers from top to bottom: Protective Layer, Phosphor Layer, Reflective Layer, and Base. The diagram visually represents the structural components described in the OCR text, with arrows pointing to each layer. # Intensifying Screen ## Protective layer • Polymer coat (≤15 µm thick) is placed over the phosphor layer to protect the phosphor and to provide a surface that can be cleaned  - Polymer coat (≤15 µm thick) is placed over the phosphor layer to protect the phosphor and to provide a surface that can be cleaned A labeled cross-sectional diagram of an intensifying screen showing four distinct layers from top to bottom: Protective Layer, Phosphor Layer, Reflective Layer, and Base. Each layer is clearly marked with text labels and arrows pointing to its corresponding region in the diagram. > **Intensifying Screen – Screen-Film Speed** - Fast screen-films are used in dentistry (speed of 400 or more) - They contain **large phosphor crystals** - Thick - Reduced radiation exposure - Rapidly conversion of x-ray photons into visible light at the expense of decreased image sharpness --- **TABLE 5-3.** Speed class of various screen-film combinations* | | Screens | Films | |--------------------|------------------|------------------| | Kodak | Lanex Fine | TMG, TML | 100 | | | | TMH | 250 | | | Medium | | 600 | | | Regular | | 800 | | | Fast | | 1200 | | 3M | Trimax 2 | XD/A, XL/A | 100 | | | 4 | | 200 | | | 8 | *XM* | 800 | | | 12 | | 1200 | | Du Pont | Quanta Detail | 10T, 10TL | 100 | | | Fast Detail | | 200 | | | Rapid | | 400 | **TMG, XD/A, 10T:** Medium detail, medium speed, high contrast **TML, XL/A, 10TL:** Medium detail, medium speed, wide latitude **TMH, XM:** Low detail, high speed, high contrast **The descriptions of these films should be used only to compare the films with others by the same manufacturer.*  #### Screen-Film Speed - Fast screen-films are used in dentistry (speed of 400 or more) - They contain **large phosphor crystals** - Thick - Reduced radiation exposure - Rapidly conversion of x-ray photons into visible light at the expense of decreased image sharpness | Manufacturer | Screen | Film | Speed | |--------------|--------|------|-------| | Kodak | Lanex Fine | TMG, TML | 100 | | | | TMH | 250 | | | Medium | | 600 | | | Regular | | 800 | | | Fast | | 1200 | | 3M | Trimax 2 | XD/A, XL/A | 100 | | | 4 | | 200 | | | 8 | *XM* | 800 | | | 12 | | 1200 | | Du Pont | Quanta Detail | 10T, 10TL | 100 | | | Fast Detail | | 200 | | | Rapid | | 400 | **TMG, XD/A, 10T:** Medium detail, medium speed, high contrast **TML, XL/A, 10TL:** Medium detail, medium speed, wide latitude **TMH, XM:** Low detail, high speed, high contrast *The descriptions of these films should be used only to compare the films with others by the same manufacturer.* A structured table listing the speed class of various screen-film combinations. It is organized into columns for Manufacturer (Kodak, 3M, Du Pont), Screen types (e.g., Lanex Fine/Medium/Regular/Fast, Trimax numbers, Quanta Detail/Fast/Rapid), Film types (TMG, TML, TMH, XD/A, XL/A, XM, 10T, 10TL), and corresponding Speed values ranging from 100 to 1200. The table includes descriptive footnotes at the bottom categorizing films by detail level, speed, and contrast. Fig. 2-9b On film/screen combination.  Fig. 2-9b: On film/screen combination. Radiograph showing a lateral view of the mandible (jawbone) with teeth visible. A black dot marks a specific region within the bone structure. The caption indicates this is an image pattern resulting from direct film exposure. Common Extra-oral Views Common Extra-oral Views ```html <table border="1" cellspacing="0"> <tr> <th colspan="2">Patient placement</th> <th>Lateral Ceph</th> <th>SMV</th> <th>Waters</th> <th>PA Ceph</th> <th>Reverse Towne</th> <th colspan="3">Oblique Lateral</th> </tr> <tr> <td colspan="2">Film parallel to midsagittal plane</td> <td>Canthomeatal line parallel to film</td> <td>Canthomeatal line at 37° with film</td> <td>Canthomeatal line at 10° with film</td> <td>Canthomeatal line at –30° with film</td> <td>Film in contact with cheek at molar area</td> <td>Beam in contact with cheek at ramus area</td> </tr> <tr> <td colspan="2">Central beam</td> <td>Beam perpendicular to film</td> <td>Beam perpendicular to film</td> <td>Beam perpendicular to film</td> <td>Beam perpendicular to film</td> <td>Beam aims at the molar-premolar area</td> <td>Beam aims at the ramus area</td> </tr> <tr> <td colspan="2">Diagram of patient placement</td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> <tr> <td colspan="2" rowspan="2">Illustration of patient placement</td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> <tr> <td></td> </tr> <tr> <td colspan="2" rowspan="2">Skull view</td> <td></td> </tr> <tr> <td></td> </tr> <tr> <td colspan="2" rowspan="2">Resultant image</td> <td></td> </tr> <tr> <td></td> </tr> </table> ```  | Patient placement | Lateral Ceph | SMV | Waters | PA Ceph | Reverse Towne | Oblique Lateral | |-------------------|--------------|-----|--------|---------|---------------|-----------------| | Film parallel to midsagittal plane | Canthomeatal line parallel to film | Canthomeatal line at 37° with film | Canthomeatal line at 10° with film | Canthomeatal line at –30° with film | Film in contact with cheek at molar area | Beam in contact with cheek at ramus area | | Central beam | Beam perpendicular to film | Beam perpendicular to film | Beam perpendicular to film | Beam perpendicular to film | Beam aims at the molar-premolar area | Beam aims at the ramus area | | Diagram of patient placement | | | | | | | | Illustration of patient placement | | | | | | | | | | | | | | | | Skull view | | | | | | | | | | | | | | | | Resultant image | | | | | | | | | | | | | | | A detailed table comparing seven different skull X-ray projections: Lateral Ceph, SMV, Waters, PA Ceph, Reverse Towne, Oblique Lateral Body, and Oblique Lateral Ramus. The table is organized into rows labeled 'Patient placement', 'Central beam', 'Diagram of patient placement', 'Illustration of patient placement', 'Skull view', and 'Resultant image'. Each column corresponds to a specific projection type and includes text descriptions of film/beam alignment, schematic diagrams of patient positioning, photographic illustrations of patients in those positions, anatomical skull views (radiographs), and the final resultant radiographic images. # Lateral Cephalogram (Lat Ceph) - Cephalogram = standardised view - Reproducible - True Lateral Skull projection - Midsagittal line parallel to film - X-ray beam perpendicular to film - Soft tissue definition achieved by aluminium wedge filter - Indications: - **Orthodontic and orthognathic assessment (pre, peri and post)** - Anteroposterior (AP) relationships between the maxilla, mandible, and cranial base - Skeletal, dental and soft tissue relationships - Other (less common) - Skull bone disorder (Paget's, Multiple myeloma, hyperparathyroidism etc.) - Paranasal sinus diseases - Trauma - Cranial base and Midface CEPHALOSTAT  #### Overview - Cephalogram = standardised view - Reproducible - True Lateral Skull projection - Midsagittal line parallel to film - X-ray beam perpendicular to film - Soft tissue definition achieved by aluminium wedge filter #### Indications - **Orthodontic and orthognathic assessment (pre, peri and post)** - Anteroposterior (AP) relationships between the maxilla, mandible, and cranial base - Skeletal, dental and soft tissue relationships - Other (less common) - Skull bone disorder (Paget's, Multiple myeloma, hyperparathyroidism etc.) - Paranasal sinus diseases - Trauma - Cranial base and Midface #### Cephalostat CEPHALOSTAT Clinical photo showing a patient positioned in a CEPHALOSTAT device for a lateral cephalogram. The image demonstrates the standardized view setup described in the text, with the patient's head aligned to ensure the midsagittal line is parallel to the film and the X-ray beam is perpendicular.  Lateral cephalometric radiograph of the head and neck with superimposed yellow measurement lines, angles, and distances. Visible anatomical landmarks include the cervical spine, mandible, maxilla, nasal cavity, and skull base. A circular marker is present on the soft tissue anterior to the cervical spine. Multiple angular measurements (e.g., 75.33°, 106.79°, 129.06°) and linear distances (e.g., 9.53mm, 13.10mm, 28.26mm) are annotated in blue and white text. The image includes a reference URL at the bottom right: https://jklsoftware.com/products/cephworx/. This figure serves as a diagnostic tool for orthodontic or surgical analysis. <b>Lat Ceph Patient Positioning</b> * Patient placed in cephalostat * Midsagittal line parallel to receptor * Frankfort plane horizontal to floor * Markers – forehead / infraorbital rests, and ear rods * Teeth in maximum intercuspation (MIP) OR mandible in most retruded position with posterior teeth occluding * Lips fully rested (closed or open)  - Patient placed in cephalostat - Midsagittal line parallel to receptor - Frankfort plane horizontal to floor - Markers – forehead / infraorbital rests, and ear rods - Teeth in maximum intercuspation (MIP) OR mandible in most retruded position with posterior teeth occluding - Lips fully rested (closed or open) Lateral cephalometric radiograph (Lat Ceph) of a patient's skull in profile. The image demonstrates the correct positioning described in the text: the midsagittal line is parallel to the receptor, and the Frankfort plane appears horizontal. Anatomical landmarks such as the mandible, maxilla, cervical spine, and teeth are clearly visible, with markers noted on the forehead/infraorbital region. * Orbital Roof * Greater Sphenoid Wing * Sella Turcica * Condyles * Ramus * Frontal Sinus Frontal Sinus Nasal Bone Maxillary Sinus Maxilla Mandible Cervical spine Soft palate tongue Lat Ceph Landmarks   #### Lat Ceph Landmarks - Orbital Roof - Greater Sphenoid Wing - Sella Turcica - Condyles - Ramus - Frontal Sinus - Frontal Sinus - Nasal Bone - Maxillary Sinus - Maxilla - Mandible - Cervical spine - Soft palate - tongue Lateral Cephalometric radiograph (X-ray) of the skull. Visible anatomical structures include: Orbital Roof, Greater Sphenoid Wing, Sella Turcica, Condyles, Ramus, Cervical spine, Frontal Sinus, Nasal Bone, Maxillary Sinus, Maxilla, Mandible, Soft palate, and tongue. Line drawing diagram titled 'Lat Ceph Landmarks' illustrating cephalometric hard tissue landmarks on a lateral profile view. Key points labeled include: S (Sella), N (Nasion), Po (Prion), Cd (Condylion), Pt (Pterygomaxillary fissure), Or (Orbitale), Ar (Articulare), PNS (Posterior nasal spine), ANS (Anterior nasal spine), A (A point), B (B point), Pog (Pogonion), Gn (Gnathion), Me (Menton). Anatomy + Landmarks Labelled Pterygoid plates, Clivus, Pterygoid spine, Pterygomaxillary fissure, Posterior clinoid processes, Sella turcica, Anterior clinoid processes, Sphenoid sinus, Planum sphenoidale, Posterior maxillary sinus, Roof of orbit, Pterygoid maxilla, Ethmoid air cells, Nasion, Nasal bone, Lens of eye, Lower eyelid, Frontal process of zygoma, Inferior rim of orbit, Floor of orbit, Zygomatic process of maxilla, Anterior nasal spine, Point A, Hard palate, Tooth bud, Point B, Base of middle cranial fossa, External auditory meatus, Mastoid air cells, Mastoid process, Occipital condyle, Posterior arch of atlas, Anterior arch of atlas, Dens axis, Posterior pharyngeal wall, Earlobe, Salpingopharyngeal fold, Superior border of inferior turbinate, Soft palate, Inferior border of zygomatic arch, Dorsum of tongue, Hyoid bone  #### Anatomy and Landmarks Labelled - Pterygoid plates - Clivus - Pterygoid spine - Pterygomaxillary fissure - Posterior clinoid processes - Sella turcica - Anterior clinoid processes - Sphenoid sinus - Planum sphenoidale - Posterior maxillary sinus - Roof of orbit - Pterygoid maxilla - Ethmoid air cells - Nasion - Nasal bone - Lens of eye - Lower eyelid - Frontal process of zygoma - Inferior rim of orbit - Floor of orbit - Zygomatic process of maxilla - Anterior nasal spine - Point A - Hard palate - Tooth bud - Point B - Base of middle cranial fossa - External auditory meatus - Mastoid air cells - Mastoid process - Occipital condyle - Posterior arch of atlas - Anterior arch of atlas - Dens axis - Posterior pharyngeal wall - Earlobe - Salpingopharyngeal fold - Superior border of inferior turbinate - Soft palate - Inferior border of zygomatic arch - Dorsum of tongue - Hyoid bone Labelled radiograph: A lateral cephalometric X-ray of a skull with numerous anatomical landmarks identified by lines and text labels. Visible labels include Pterygoid plates, Clivus, Sella turcica, Nasion, Nasal bone, Zygomatic process of maxilla, Hard palate, Tooth bud, Hyoid bone, and various cranial and facial structures.  Lateral cephalometric radiograph (X-ray) of a human skull in profile. The image displays the skeletal anatomy including the cranium, nasal cavity, maxilla, mandible, cervical spine, and teeth. # Postero-anterior (PA) / Frontal Projections - Frontal / PA Ceph, PA Skull, PA Mandible, Rotated PA, - **Indications**: - **PA Ceph**: Facial asymmetry (developmental or traumatic) - **PA Skull** - Trauma - Paranasal sinuses - Skull bone disorders (Paget’s disease, Multiple myeloma, and Hyperparathyroidism) - **PA Mandible** - Fractures (post 1/3 body, angles, rami, and low condylar necks). - **Patient positioning**: - Canthomeatal line 0 to +10° - 0° for PA skull, PA mandible - **+10° for PA CEPH** - Chin and forehead touch film - Beam perpendicular to film horizontal  - Frontal / PA Ceph, PA Skull, PA Mandible, Rotated PA #### Indications - **PA Ceph**: Facial asymmetry (developmental or traumatic) - **PA Skull** - Trauma - Paranasal sinuses - Skull bone disorders (Paget’s disease, Multiple myeloma, and Hyperparathyroidism) - **PA Mandible** - Fractures (post 1/3 body, angles, rami, and low condylar necks) #### Patient positioning - Canthomeatal line 0 to +10° - 0° for PA skull, PA mandible - **+10° for PA CEPH** - Chin and forehead touch film - Beam perpendicular to film horizontal Clinical photo demonstrating patient positioning for a PA Cephalometric projection. The image shows a subject in profile view with their head secured against a vertical film holder using a forehead rest and chin support. A head positioning device is attached to the top of the head. Text at the bottom identifies this as 'PA Ceph'.  A composite figure illustrating the Posteroanterior (PA) Skull radiographic projection. The figure is divided into two panels: Panel A shows a clinical photograph of a female patient positioned with her forehead and nose against the image receptor, facing an X-ray tube head. Panel B provides a corresponding line-art anatomical diagram of a human skull in profile, with arrows indicating the direction of the central ray entering the posterior aspect of the skull and exiting anteriorly towards the film.   Clinical photograph labeled 'A' showing a patient positioning for a radiographic examination. A person with blonde hair and glasses is seen in profile, placing their head against the vertical film holder of an X-ray machine. Anatomical line diagram labeled 'B' illustrating the correct skull position relative to the X-ray beam. It shows a lateral view of a human skull with the chin tucked down and nose touching a vertical surface, while a horizontal arrow indicates the direction of the central ray entering from the side (Mandibular Oblique/PA projection).  Radiograph: A PA (Posteroanterior) cephalogram of a human skull. The image displays the cranial vault, facial bones, maxilla, and mandible in frontal view. Dental structures including teeth are visible within the alveolar processes. Radiopaque markers are present on either side of the head, likely for positioning or measurement reference.  A labeled radiograph (X-ray) of a human skull in the posteroanterior (PA) view. The image displays multiple anatomical structures with white lines pointing to specific regions and corresponding text labels on the right side. Visible labels include: Sagittal Suture at the top midline; Lambdoid Suture lower down; Frontal Sinus; Crista Galli; Cribiform Plate; Ethmoid Sinuses; Petrous Ridge; Inferior Orbital Rim; Maxillary Sinus; Mastoid Air Cells; Nasal Septum; and Base of Skull. A 'wiki' logo is visible in the top-right corner.  Clinical radiograph (photo) of the mandible in posteroanterior view. The image displays the maxillary and mandibular teeth, nasal cavity, and maxillary sinuses. Two black circles highlight specific regions: one over the right posterior mandible (indicated by 'R') and another over the left posterior mandible, likely indicating areas of clinical interest such as fractures or pathology. **SMV (Submentover)** ### **Axial plane** ### **Positioning:** * Chin up * Canthomeatal line parallel to film. * X-ray beam perpendicular to film (or up to -5°) ### **Indications:** * Zygomatic arch fractures * Thickness of body of mandible * Skull base ### **Contraindicated** in patients with suspected neck injuries, especially suspected fracture of the odontoid peg.    **SMV (Submentover)** #### Axial plane ##### Positioning - Chin up - Canthomeatal line parallel to film. - X-ray beam perpendicular to film (or up to -5°) ##### Indications - Zygomatic arch fractures - Thickness of body of mandible - Skull base **Contraindicated** in patients with suspected neck injuries, especially suspected fracture of the odontoid peg. Clinical photograph showing patient positioning for a submentovertex (SMV) projection. The patient is seated with their chin elevated and head tilted back to align the canthomeatal line parallel to the film. An X-ray machine head is positioned to direct the beam perpendicular to the film. Schematic diagram illustrating the geometry of an SMV skull projection. It depicts a lateral view of a skull with a horizontal dashed line representing the canthomeatal line. A solid arrow indicates the X-ray beam direction relative to this line, annotated with '5°' to denote the specific angulation required for the projection. Clinical photograph demonstrating the physical setup for an SMV projection. A female patient is shown with her head in an extended position, supported by a wooden headrest device attached to the imaging equipment.  Labelled anatomical radiograph (SMV view) of the skull base. The image displays a central X-ray with superimposed line drawings and text labels identifying key structures including: Frontal sinus, Zygomatic arch, Posterior-lateral wall of the maxillary antrum, Sphenoidal sinus, Foramen ovale, Foramen spinosum, Foramen lacerum, Auditory canal, Odontoid peg (C2), Occipital condyle, Shadow of the cervical spine, Mastoid air cells, Anterior arch of the atlas (C1), Condylar head, Articular eminence, Lateral pterygoid plate, Anterior margin of the middle cranial fossa, Lateral wall of the orbit, Upper and lower incisors superimposed, and Foramen magnum. Mandibular Symphysis Zygomatic Bone Zygomatic Arch Temporal Bone   - Mandibular Symphysis - Zygomatic Bone - Zygomatic Arch - Temporal Bone Lateral radiograph of the mandible and facial bones. Labels identify the Mandibular Symphysis at the top center, Zygomatic Bone on the lateral aspect, Zygomatic Arch below it, and Temporal Bone further posteriorly. Close-up radiographic view showing a discontinuity in the bony structure, circled to highlight a Right zygomatic arch fracture. Waters view **■** Positioning ■ Canthomeatal line at 37° to 45° to film ■ X-ray beam perpendicular to film (standard) ■ Modified Water’s view aka ‘30° Occipitomeatal’ ■ X-ray beam at +30° to horizontal / floor ■ Indications: ● **Paranasal sinuses (maxillary, frontal, and ethmoid).** ■ If assessing the sphenoid sinus, image needs to be taken with mouth open. ● **Midface fractures (Le Fort I/II/III, zygomatic complex, naso-ethmoidal complex, and orbital blow-out).** ■ If midface fracture is suspected. Both standard and modified views are required for traditional imaging. 45° Orbitomeatal line Radiographic plate ← Direction of X-ray bi Water’s radiographic view of skull ## FIG. 11-6. Patient positioning for a Waters projection of the skull.   #### Positioning - Canthomeatal line at 37° to 45° to film - X-ray beam perpendicular to film (standard) - Modified Water’s view aka ‘30° Occipitomeatal’ - X-ray beam at +30° to horizontal / floor #### Indications - **Paranasal sinuses (maxillary, frontal, and ethmoid).** - If assessing the sphenoid sinus, image needs to be taken with mouth open. - **Midface fractures (Le Fort I/II/III, zygomatic complex, naso-ethmoidal complex, and orbital blow-out).** - If midface fracture is suspected. Both standard and modified views are required for traditional imaging. 45° Orbitomeatal line Radiographic plate ← Direction of X-ray beam Water’s radiographic view of skull FIG. 11-6. Patient positioning for a Waters projection of the skull. Line diagram illustrating the geometric positioning for a Waters view X-ray. It shows a lateral profile of a skull with the orbitomeatal line angled at 45° relative to the vertical radiographic plate. An arrow indicates the 'Direction of X-ray beam' pointing horizontally towards the film. Clinical photograph showing a patient in profile undergoing a Waters view X-ray. The patient is seated with their chin elevated and mouth open, aligning the canthomeatal line perpendicular to the floor (or parallel to the image receptor), as described in the text context.  Annotated radiograph of a human skull demonstrating craniofacial anatomy. The image features a black and white X-ray with specific anatomical landmarks identified by text labels and thin arrows pointing to corresponding structures. Visible labels include 'Frontal sinus', 'Orbit', 'Nasal septum', 'Posterior margin of the anterior cranial fossa', 'Post ethmoid sinus', 'Maxillary sinus', 'Fluid level in L.Mx.Sinus' (indicating pathology), 'Coronoid process', and 'Sphenoid sinus'. A bright, high-density object is visible in the maxillary region, likely representing dental hardware or foreign material.  Labelled radiograph of a skull in the Standard Waters View (occipitomental projection). The image includes multiple anatomical callouts pointing to specific structures: Frontal Sinus, Bony Nasal Septum, Anterior Nasal Spine, Maxillary Sinus, Coronoid Process, Maxilla, Condyle, Mastoid, Mandibular Angle, Inferior Orbital Rim, Zygomatic Bone, Zygomatic Arch, Petrous Ridge, Mandible, and Odontoid Process. The watermark 'L wiki' is visible in the top right corner. 30° Occipitomental View (30° OM) **A** **B**   ##### 30° Occipitomental View (30° OM) A B Clinical photograph showing a patient positioned for a cranial imaging procedure. The patient is seated with their head tilted back and chin elevated against a vertical support structure (labeled A). A large radiographic or CT scanner gantry arm extends from the ceiling-mounted equipment toward the patient's head, indicating the setup for an X-ray or scan. Anatomical diagram illustrating the geometry of the 30° Occipitomental View (30° OM). It shows a lateral profile of a human skull with the beam path indicated by an arrow originating from the top right and directed towards the mandible/teeth area. Key angles are annotated: '30°' inside the cranium representing the angle relative to the horizontal plane, and '45°' at the vertical axis where the beam intersects the skull outline. 30° Waters View - Alternative Technique  ##### 30° Waters View - Alternative Technique Labelled radiograph (Waters view) of the facial bones. Visible labels include Frontal Sinus, Right Orbit, Nasal Septum, Left Orbit, Inferior Orbital Margin, Superior Dental Arch, Maxillary Sinus, Zygomatic Arch, Coronoid Process, Sphenoid Sinuses, Body of Mandible, and Odontoid Process. Reverse Towne • Patient positioning: 1. Canthomeatal line **-30°** & x-ray beam horizontal; OR 2. Canthomeatal line horizontal & x-ray beam **-30°** * **Jaws always open!** • Indications: * Condylar neck fractures * TM Joint disorder   #### Patient Positioning - Canthomeatal line **-30°** & x-ray beam horizontal; OR - Canthomeatal line horizontal & x-ray beam **-30°** - **Jaws always open!** #### Indications - Condylar neck fractures - TM Joint disorder Clinical photo demonstrating patient positioning for a Reverse Towne projection. The patient is seated with their head secured in a chin rest and forehead support, facing slightly oblique to the X-ray source. Composite figure illustrating the procedure. Panel A shows a clinical photograph of a patient positioned at an X-ray machine (labeled 'A'). Panel B displays a labeled anatomical diagram of a skull showing the X-ray beam angle relative to the canthomeatal line (labeled 'B').  Annotated radiograph (X-ray) of a skull in the Reverse Towne projection. The image displays detailed anatomical labels pointing to specific structures including: Foramen magnum, Condylar head, Mastoid process, Zygomatic arch, Posterior nasal fossa, Lateral pterygoid plate, Inferior border of the orbit, Nasal septum, Angel of the mandible, Inferior border of the zygoma, Maxillary incisor, Spinous process of a cervical vertebra, and Body of the mandible.  Clinical radiograph (likely an occlusal view of the mandible) showing the dental arch and surrounding bone structure. A black circle highlights a specific region in the right posterior mandible, indicating a focal area of interest for diagnosis or study. # Oblique Lateral Radiography ## Mandibular Body **FIG. 12-7** Anatomic landmarks identified in the oblique lateral projection of the mandibular body. * Hard palate * Inferior border of orbit * Posterior wall of sinus * Posterior wall of zygomatic process of maxilla * Inferior border of zygomatic arch * Dorsum of tongue * Tube side, inferior border of mandible * Inferior border of mandible * Area of osteosclerosis * Hyoid bone ## Mandibular Ramus **FIG. 12-8** Anatomic landmarks identified in the oblique lateral projection of the mandibular ramus. * Articular eminence * Dorsum of soft palate * Posterior wall of maxillary sinus * Hard palate * Zygomatic process of maxilla * Anterior wall of zygomatic process of maxilla * Coronoid process of mandible * Inferior border of maxilla * Zygomatic arch * External oblique ridge of mandible * Mandible canal * Hyoid bone * Mandibular foramen * Dorsum of tongue * Condyle of mandible * Lateral border of mandibular fossa * Medial border of mandibular fossa   #### Mandibular Body **FIG. 12-7** Anatomic landmarks identified in the oblique lateral projection of the mandibular body. - Hard palate - Inferior border of orbit - Posterior wall of sinus - Posterior wall of zygomatic process of maxilla - Inferior border of zygomatic arch - Dorsum of tongue - Tube side, inferior border of mandible - Inferior border of mandible - Area of osteosclerosis - Hyoid bone #### Mandibular Ramus **FIG. 12-8** Anatomic landmarks identified in the oblique lateral projection of the mandibular ramus. - Articular eminence - Dorsum of soft palate - Posterior wall of maxillary sinus - Hard palate - Zygomatic process of maxilla - Anterior wall of zygomatic process of maxilla - Coronoid process of mandible - Inferior border of maxilla - Zygomatic arch - External oblique ridge of mandible - Mandible canal - Hyoid bone - Mandibular foramen - Dorsum of tongue - Condyle of mandible - Lateral border of mandibular fossa - Medial border of mandibular fossa Radiograph showing anatomic landmarks identified in the oblique lateral projection of the mandibular body. Labels include: Hard palate, Inferior border of orbit, Posterior wall of sinus, Posterior wall of zygomatic process of maxilla, Inferior border of zygomatic arch, Dorsum of tongue, Tube side/inferior border of mandible, Hyoid bone, Area of osteosclerosis, and Inferior border of mandible. Radiograph showing anatomic landmarks identified in the oblique lateral projection of the mandibular ramus. Labels include: Articular eminence, Dorsum of soft palate, Posterior wall of maxillary sinus, Hard palate, Zygomatic process of maxilla, Anterior wall of zygomatic process of maxilla, Coronoid process of mandible, Inferior border of maxilla, Zygomatic arch, External oblique ridge of mandible, Mandible canal, Hyoid bone, Mandibular foramen, Dorsum of tongue, Condyle of mandible, Lateral border of mandibular fossa, and Medial border of mandibular fossa.     Top-right schematic diagram showing an overhead view of a skull. It illustrates the Oblique Lateral Positioning technique with a cassette placed against the side of the face and the X-ray beam directed obliquely through the jaw area. Clinical photograph (labeled A) demonstrating the patient positioning for the procedure. The patient is holding a rectangular cassette against the side of their face while looking towards the X-ray tube head. Lateral anatomical diagram of a human skull showing the specific angles and geometry required for the Oblique Lateral Positioning to visualize the mandible. Close-up clinical photograph (labeled B) showing the anatomy of the lower jaw and teeth in profile, illustrating the area of interest being investigated by the radiographic projection. References * Oral Radiology Principles and Interpretation-White and Pharoah * Essentials of Dental Radiography and Radiology – Whaites and Drage * http://www.wikiradiography.net/page/Facial+Bones+Radiographic+Anatomy - Oral Radiology Principles and Interpretation-White and Pharoah - Essentials of Dental Radiography and Radiology – Whaites and Drage - http://www.wikiradiography.net/page/Facial+Bones+Radiographic+Anatomy [^1]: Original PDF page 1: [[L9 Cephs and Other EO Views.pdf#page=1|L9 Cephs and Other EO Views, p.1]] [^2]: Original PDF page 2: [[L9 Cephs and Other EO Views.pdf#page=2|L9 Cephs and Other EO Views, p.2]] [^3]: Original PDF page 3: [[L9 Cephs and Other EO Views.pdf#page=3|L9 Cephs and Other EO Views, p.3]] [^4]: Original PDF page 4: [[L9 Cephs and Other EO Views.pdf#page=4|L9 Cephs and Other EO Views, p.4]] [^5]: Original PDF page 5: [[L9 Cephs and Other EO Views.pdf#page=5|L9 Cephs and Other EO Views, p.5]] [^6]: Original PDF page 6: [[L9 Cephs and Other EO Views.pdf#page=6|L9 Cephs and Other EO Views, p.6]] [^7]: Original PDF page 7: [[L9 Cephs and Other EO Views.pdf#page=7|L9 Cephs and Other EO Views, p.7]] [^8]: Original PDF page 8: [[L9 Cephs and Other EO Views.pdf#page=8|L9 Cephs and Other EO Views, p.8]] [^9]: Original PDF page 9: [[L9 Cephs and Other EO Views.pdf#page=9|L9 Cephs and Other EO Views, p.9]] [^10]: Original PDF page 10: [[L9 Cephs and Other EO Views.pdf#page=10|L9 Cephs and Other EO Views, p.10]] [^11]: Original PDF page 11: [[L9 Cephs and Other EO Views.pdf#page=11|L9 Cephs and Other EO Views, p.11]] [^12]: Original PDF page 12: [[L9 Cephs and Other EO Views.pdf#page=12|L9 Cephs and Other EO Views, p.12]] [^13]: Original PDF page 13: [[L9 Cephs and Other EO Views.pdf#page=13|L9 Cephs and Other EO Views, p.13]] [^14]: Original PDF page 14: [[L9 Cephs and Other EO Views.pdf#page=14|L9 Cephs and Other EO Views, p.14]] [^15]: Original PDF page 15: [[L9 Cephs and Other EO Views.pdf#page=15|L9 Cephs and Other EO Views, p.15]] [^16]: Original PDF page 16: [[L9 Cephs and Other EO Views.pdf#page=16|L9 Cephs and Other EO Views, p.16]] [^17]: Original PDF page 17: [[L9 Cephs and Other EO Views.pdf#page=17|L9 Cephs and Other EO Views, p.17]] [^18]: Original PDF page 18: [[L9 Cephs and Other EO Views.pdf#page=18|L9 Cephs and Other EO Views, p.18]] [^19]: Original PDF page 19: [[L9 Cephs and Other EO Views.pdf#page=19|L9 Cephs and Other EO Views, p.19]] [^20]: Original PDF page 20: [[L9 Cephs and Other EO Views.pdf#page=20|L9 Cephs and Other EO Views, p.20]] [^21]: Original PDF page 21: [[L9 Cephs and Other EO Views.pdf#page=21|L9 Cephs and Other EO Views, p.21]] [^22]: Original PDF page 22: [[L9 Cephs and Other EO Views.pdf#page=22|L9 Cephs and Other EO Views, p.22]] [^23]: Original PDF page 23: [[L9 Cephs and Other EO Views.pdf#page=23|L9 Cephs and Other EO Views, p.23]] [^24]: Original PDF page 24: [[L9 Cephs and Other EO Views.pdf#page=24|L9 Cephs and Other EO Views, p.24]] [^25]: Original PDF page 25: [[L9 Cephs and Other EO Views.pdf#page=25|L9 Cephs and Other EO Views, p.25]] [^26]: Original PDF page 26: [[L9 Cephs and Other EO Views.pdf#page=26|L9 Cephs and Other EO Views, p.26]] [^27]: Original PDF page 27: [[L9 Cephs and Other EO Views.pdf#page=27|L9 Cephs and Other EO Views, p.27]] [^28]: Original PDF page 28: [[L9 Cephs and Other EO Views.pdf#page=28|L9 Cephs and Other EO Views, p.28]] [^29]: Original PDF page 29: [[L9 Cephs and Other EO Views.pdf#page=29|L9 Cephs and Other EO Views, p.29]] [^30]: Original PDF page 30: [[L9 Cephs and Other EO Views.pdf#page=30|L9 Cephs and Other EO Views, p.30]] [^31]: Original PDF page 31: [[L9 Cephs and Other EO Views.pdf#page=31|L9 Cephs and Other EO Views, p.31]] [^32]: Original PDF page 32: [[L9 Cephs and Other EO Views.pdf#page=32|L9 Cephs and Other EO Views, p.32]] [^33]: Original PDF page 33: [[L9 Cephs and Other EO Views.pdf#page=33|L9 Cephs and Other EO Views, p.33]] [^34]: Original PDF page 34: [[L9 Cephs and Other EO Views.pdf#page=34|L9 Cephs and Other EO Views, p.34]] [^35]: Original PDF page 35: [[L9 Cephs and Other EO Views.pdf#page=35|L9 Cephs and Other EO Views, p.35]] [^36]: Original PDF page 36: [[L9 Cephs and Other EO Views.pdf#page=36|L9 Cephs and Other EO Views, p.36]] [^37]: Original PDF page 37: [[L9 Cephs and Other EO Views.pdf#page=37|L9 Cephs and Other EO Views, p.37]] [^38]: Original PDF page 38: [[L9 Cephs and Other EO Views.pdf#page=38|L9 Cephs and Other EO Views, p.38]]