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Dental Radiograph Technique, Medinna Rasha - 2506557816 - Coggle Diagram
Dental Radiograph Technique
Intraoral Radiographic Techniques
Techniques
Periapical (PA): Shows full tooth (crown to apex) + surrounding alveolar bone.
Bitewing (BW): Shows crowns of both upper and lower teeth simultaneously in one image.
Occlusal: Broad view of the entire maxilla or mandible using a larger sensor/film.
Parallel vs. Bisecting
Parallel: Receptor is placed parallel to the long axis of the tooth; X-ray beam is directed perpendicular to both.
Bisecting: Receptor is placed close to/touching the tooth; X-ray beam is directed perpendicular to the imaginary bisector line between the tooth axis and receptor axis.
Purpose: Bitewing vs. Periapical
Bitewing: Specifically targets interproximal caries detection and evaluation of alveolar crestal bone levels.
Periapical: Targets root morphology, periapical pathology (infections), and endodontic assessments.
Occlusal Technique Indications
When the required diagnostic area is too large for a periapical film.
Locating impacted teeth, foreign bodies, salivary stones (sialoliths), or jaw fractures.
Evaluating bucco-lingual expansion of bone caused by cysts or tumors.
When patients cannot tolerate normal intraoral holders (e.g., severe pediatric or trismus patients).
Managing a Strong Gag Reflex
Preferred Technique: Bisecting angle technique.
Why: The film/sensor is placed flatter along the occlusal plane and does not need to be pushed as deeply into the floor of the mouth or palate, minimizing soft palate stimulation.
Pediatric vs. Adult Techniques
Pediatric: Small oral cavity makes holder placement tough. Modified bisecting techniques (flat occlusal film placement) and smaller receptor sizes are preferred.
Adult: Anatomically accommodating; the paralleling technique using specialized receptor holders is highly preferred for reproducibility.
Dimensional Accuracy: Parallel vs. Bisecting
Parallel Technique: Advantages: High geometric accuracy, minimal distortion, minimal magnification.
Disadvantages: Difficult to place comfortably in shallow palates or sensitive mouths.
Bisecting Technique:
Advantages: Easy, fast, and highly versatile for difficult anatomy.
Disadvantages: Prone to dimensional distortion (foreshortening/elongation) and inaccurate bone-level representation.
Extraoral Radiographic Techniques
Techniques Used
Panoramic Radiography (OPG).
Cephalometric Radiography (Lateral and Posteroanterior).
Skull projections: Waters, Submentovertex (SMV), and Reverse Towne.
Panoramic vs. Cephalometric
Panoramic: Broad screening tool for overall dentition, jaw pathologies, bone retained lesions, and general dental development.
Cephalometric: Standardized skull tracking used to evaluate skeletal patterns, growth, and craniofacial relationships.
Lateral Cephalometric in Orthodontics
Enables cephalometric tracing to assess relationship of maxilla to mandible.
Allows metric evaluation of soft tissue profiles and skeletal growth classifications (Class I, II, III).
Purpose of Waters Projection (Occipitomental View)
Provides optimal visualization of the paranasal sinuses (primarily the maxillary sinuses).
Clears the petrous ridges of the temporal bone out of the sinus field by projecting them downwards.
Suspected Maxillary Fracture Projection
Preferred Plain Film: Waters projection (excellent for midfacial trauma and orbital floor/maxillary sinus border visualization).
Note: In modern clinical practice, 3D Computed Tomography (CT) is typically preferred over standard plain skull views for trauma evaluation.
Evaluating TMJ Disorders (TMD)
Screening: Panoramic views (limited bony detail).
Osseous/Bony Changes: Tomography or Cone-Beam Computed Tomography (CBCT).
Soft Tissue/Disc Displacement (Gold Standard): Magnetic Resonance Imaging (MRI).
Submentovertex (SMV) Projection Uses
Visualizing the base/basilar structure of the skull.
Evaluating zygomatic arch fractures (requires a lighter, underexposed view).
Analyzing condylar position asymmetries relative to the cranial base.
Radiographic Quality Evaluation Criteria
Criteria for Diagnostically Acceptable Intraoral Images
Correct patient and date identification.
Adequate anatomic coverage of the field of interest.
Proper sensor placement and angulation without overlapping contacts.
Ideal density and contrast, free from processing or technical artifacts.
Criteria for Adequate Coverage
Periapical: Must capture the entire crown, entire root length, plus an extra 2–3 mm of periapical bone past the apex.
Bitewing: Must capture both maxillary and mandibular crowns plus the interproximal alveolar crestal heights clearly.
Why Objects Must Be Positioned at the Center
Reduces Geometric Distortion: Diverging peripheral rays of the X-ray beam cause distortion; the central ray is the straightest and most geometrically accurate.
Prevents Cone-Cut: Ensures the full central beam path exposes the image receptor evenly.
Contrast vs. Detail vs. Sharpness
Contrast: The variation in dark and light density values between adjacent areas (controlled primarily by kVp).
Detail (Resolution): The exact clarity and replication of minute, distinct structures.
Sharpness: The crisp definition and crispness of geometric boundaries/structural edges.
Horizontal Angulation Error Effect
Causes overlapping of interproximal contact zones.
Diagnostic consequence: Masks early proximal enamel caries, making accurate diagnosis impossible.
Vertical Angulation Error Effect
Too Steep (Excessive Angulation): Causes foreshortening (teeth look abnormally short).
Too Flat (Insufficient Angulation): Causes elongation (teeth look abnormally long).
High-Quality Panoramic Criteria
Symmetrical structures right-to-left.
Anterior teeth crisp, sharp, and centered precisely inside the focal trough.
Palatoglossal air space eliminated (tongue pressed to palate) and free of ghost-image artifacts.
Poor-Quality Lateral Cephalometric Signs
Blurriness from patient movement.
Double borders of skull anatomy indicating a rotated or tilted head position.
Teeth not clenched firmly in centric occlusion.
Factors Causing Radiographic Failure
Main Failure Categories
Technical Errors: Operator mistakes during placement, beam alignment, or setting selection.
Processing Errors: Errors occurring during physical darkroom development or digital processing stages.
Patient Factors: Movement, anatomical anomalies, or gagging reflex issues.
Technical vs. Processing Errors
Technical: Happens prior to or during the X-ray exposure step (e.g., cone-cuts, angulation shifts, incorrect PID targeting).
Processing: Happens after exposure during chemical development or sensor readout (e.g., chemical contamination, over-development, film scratches).
Angulation Errors
Horizontal Errors: Result in overlapping interproximal spaces, rendering a film useless for decay detection.
Vertical Errors: Distort apparent tooth lengths, rendering a film useless for endodontic root measurements or periodontal bone tracking.
Broad Error Breakdown (Intraoral vs. Extraoral)
Intraoral Errors: Film placement drops, excessive receptor bending/creasing, cone-cuts, or reversed film placement.
Extraoral Errors: Patient positioning outside the designated focal trough, failure to remove metallic jewelry (causing ghost artifacts), or failing to stand entirely still during long panoramic cycles.
Medinna Rasha - 2506557816