RADIOLOGY IN PEDIATRIC DENTISTRY
RADIOLOGY IN PEDIATRIC DENTISTRY
INTRODUCTION
The dental profession aims to provide the highest quality of care, using technology and science to improve oral health.
Radiographs aid in evaluating and diagnosing oral diseases.
Dentists must balance the benefits of radiographs with the risks of X-ray exposure, considering cumulative effects over time.
TERMINOLOGIES
RADIATION – Energy transmitted as waves or particles through space and matter.
X-RADIATION – High-energy radiation produced by colliding electron beams with a metal target in an X-ray tube.
RADIOLOGY – The study of radiation, including X-rays and radioactive substances, in diagnosing and treating diseases.
AMPERE (A) – Unit measuring electric current.
KILOPEAK (kVp) – Unit measuring tube voltage in dental radiology.
TARGET – Part of the anode struck by high-speed electrons, producing X-rays and heat.
HISTORY
November 8, 1895: Wilhelm Conrad Roentgen discovered X-rays.
1896: Otto Walkoff took the first dental radiograph.
1896: C. Edmund Kells introduced the paralleling technique.
1904: Weston Price developed the bisecting technique.
1920: Machine-made periapical film packets became available.
1920: Franklin W. McCormack conceptualized paralleling technique in dental radiography.
1925: Howard Riley Raper redefined the bisecting technique.
1947: F. Gordon Fitzgerald revived the paralleling technique and introduced the long-cone paralleling technique.
CHARACTERISTICS OF AN IDEAL RADIOGRAPH
Radiographic density: Overall darkness of the radiograph.
Should not be too dark or too light
Latitude of the film: Range of exposures usefully recorded.
Adequate radiographic contrast: Differences in density to distinguish structures.
Speed of the film: Radiation amount needed for standard density.
Sharpness: Ability to define edges precisely.
Resolution: Ability to record closely spaced structures separately.
Image quality: Overall appearance of the radiograph.
RADIATION PHYSICS
Radiation is energy transmission through space and matter.
Occurs in two forms:
Particulate: Atomic nuclei or subatomic particles at high velocity.
Electromagnetic: Energy movement through space as electric and magnetic fields.
Ionization: Electrically neutral atom loses an electron, becoming a positive ion and a free (negative) electron.
The formation of this ion pair is ionization.
X-RAY PRODUCTION
Dental X-ray machines have an evacuated tube, cathode (tungsten filament for electron source), and anode (tungsten target in copper stem).
When powered, the cathode heats up, producing electrons that flow to the anode, generating X-rays.
PROPERTIES OF X-RAYS
Invisible.
Travel at the speed of light (3 \times 10^8 m/sec).
Travel in straight lines.
Cannot be deflected.
Affect photographic plates.
Produce fluorescence with substances like bariopalladium crystals.
Can penetrate opaque objects.
X-RAY FILMS
Components:
Overcoat
Emulsion
Base (0.18 mm)
Emulsion
Overcoat
X-ray film composition:
Base: polyester polyethylene terephthalate
Adhesive
Emulsion: silver halide grains in a vehicle matrix
Emulsion is sensitive to X-rays and visible light, recording the image.
Made of silver halide (silver bromide) grains in a gelatinous or nongelatinous vehicle matrix.
Base provides support and flexibility for handling.
Made of polyester polyethylene terephthalate.
Translucent base casts no patterns on the radiograph.
INTRAORAL X-RAY FILM
Small raised dot for orientation; positioned facing the X-ray tube.
Film packet contents:
Opening tab
Lead foil sheet
Black lightproof paper wrapper
Film
Lead foil protects the film from secondary radiation and reduces patient exposure.
Absorbs residual X-ray beam.
Crucially absorbs radiation if film is placed in reverse.
SPEED OF FILM
Indicates the radiation amount needed to produce a standard density image.
Fast film needs less exposure.
The fastest available dental film has a speed rating of F.
Films with D or faster speed ratings are appropriate for intraoral radiography.
GENERAL STEPS FOR TAKING A RADIOGRAPH IN A CHILD
Film placement should occur only when the X-ray machine is ready.
Use child-friendly terms like "picture" and "camera" instead of "radiograph" and "X-ray machine."
Using the Tell-Show-Do technique allows the patient to inspect and touch the film.
Manage uncooperative children with tender loving care, firmness, and voice control.
Seat the patient upright, adjusting the chair low for maxillary projections and high for mandibular projections.
Remove glasses or appliances.
Cover the patient with a lead apron.
Adjust X-ray unit settings for proper kVp, mA, and exposure time.
Position the tube head appropriately.
Wash hands thoroughly.
Position the film with a holding device near the tooth.
Adjust X-ray tube angulation.
Expose the film.
MANAGING DIFFICULT/ GAGGING PATIENTS
Dampen the film slightly.
Insert the film horizontally, then rotate vertically.
Curve the film to avoid soft tissue impingement.
Use topical anesthetics or psychological techniques to avoid gag reflex.
Allow the child to sit with a parent.
Psychological techniques:
Panting like a dog.
Moving the leg and pointing the toe.
Placing salt on the tongue tip (distraction).
Pharmacological:
Topical 2% xylocaine or topical anesthetic rinses.
Bent film radiographic technique: for young children unable to tolerate film placement.
The patient bites on a film with a sharp right-angle bend at the top.
The bent part serves as a bite tab.
Instruct the child to bite softly to avoid cusp marks and distortion.
Foam tabs are available.
Use size 1 or 2 films.
Straighten the film for processing.
PROCESSING THE FILM
Exposed X-ray film undergoes chemical changes in silver halide crystals in the emulsion.
These form a latent image.
The developing process converts the latent image into a visible image.
Developing solution converts exposed silver halide crystals into metallic silver grains.
The process begins at latent image sites, reducing silver ions to metallic silver.
Unexposed crystals remain unaffected during this process.
After developing, the film is rinsed for 30 seconds with gentle agitation before fixing.
Rinsing dilutes the developer, slowing the process.
Fixing solution dissolves and removes undeveloped silver halide crystals.
Unexposed crystals cause film opacity.
The fixer also hardens and shrinks the emulsion.
After fixing, the film is washed with water to remove silver compounds or thiosulfate ions.
TYPES OF DENTAL X RAYS
Two main types:
Intraoral (film inside the mouth)
Extraoral (film outside the mouth)
Intraoral x-rays are the most common.
Bite-wing x-rays
Periapical x-rays
Occlusal x-rays
Extraoral x-rays:
Panoramic x-rays
Tomograms
Cephalometric projections
Dental computed tomography (CT)
Cone Beam CT
MRI imaging
PERIAPICAL RADIOGRAPHY
Intraoral technique to show individual teeth and surrounding tissues.
Indications:
Determine root end condition
Evaluate pulp treatment
Detect developmental abnormalities
Detect pathological changes
Detect alterations in periodontal membrane and furcation area
Diagnose pulp calcification or root resorption
Space analysis in mixed dentition
Periapical films come in three sizes:
Size 0: for small children (Pedo film)—22×35 mm
Size 1: narrow, for anterior teeth—24×40 mm
Size 2: standard size for adults—31×41 mm
PARALLELING TECHNIQUE
Also known as the Right-angle/Long-cone technique.
Principles:
Image receptor/digital sensor placed parallel to the long axis of the tooth using a holder.
X-ray tubehead positioned at right angles to the film and tooth.
Long cone beam reduces magnification and increases definition.
Film position:
Maxillary incisors & canine: vault of palate
Mandibular incisors & canine: floor of mouth in line with lower canine or first premolars
Maxillary premolars & molars: midline of palate
Mandibular premolars & molars: lingual sulcus
Positioning of tubehead:
Vertical angulation: central ray perpendicular to film & long axis of teeth
Horizontal angulation: central ray through contact area between teeth
Advantages:
Accuracy
Simplicity
Duplication
Periodontal bone level assessment
No cone cutting
Disadvantages:
Film placement difficulty
Increased exposure time
Holders must be autoclaved
BISECTING ANGLE TECHNIQUE
Also known as the Short Cone Technique
Principle:
Ciezynski’s rule of isometry: 2 triangles are equal when they share one complete side & have 2 equal angles.
Film is placed close to teeth
Angle between the long axis of teeth & long axis of film is bisected
X-Ray tubehead is positioned at right angles to bisecting line
Actual length of tooth in mouth = length of tooth on image
Film placement:
Film is placed close to teeth
Anterior: vertical
Posterior: horizontal
Film holders or digital methods can be used.
Position of tubehead:
Vertical angulation: central ray perpendicular to imaginary bisector.
Examples of vertical angulation (Permanent dentition):
Maxillary:
Incisor: +40°
Premolar: +30°
Canine: +45°
Molar: +20°
Mandibular:
Incisor: -15°
Premolar: -10°
Canine: -20°
Molar: -5°
Horizontal angulation: central ray perpendicular to the curvature of the arch and through contact areas of teeth.
Examples:
Incisors: 90 degrees
Canines: 45 degrees
Premolars: 30 degrees
Molars: 0 degrees to transcondylar plane
Point of entry of x-ray beam examples:
Maxillary:
Incisor: tip of nose
Canine: ala of nose
Premolar: pupillary perpendicular to A-T line
Molars: outer canthus of eye perpendicular to A-T line
Mandibular:
Incisor: tip of the chin
Canine: angle of mouth
Premolar: w pupillary line
Molars: outer canthus of eye
Third molar: ICM behind outer canthus
Advantages:
Can be used without film holders
Positioning is simple & quick
Short cone-decreased exposure time
Image of tooth = length of tooth
Disadvantages:
Image distortion, buccal roots are foreshortened
Short PID :image magnification
Angulation problems, cone cutting
Unnecessary exposure: finger holding technique
Shadow of zygoma
PERIAPICAL TECHNIQUE - MODIFICATIONS
Shallow palate:
Use cotton rolls
Increase vertical angulation
Bony growth:
Mandibular tori
Maxillary tori
Mandibular premolar region:
Film placement modifications.
Film lower edge curved or softened.
Gagging:
Relax & reassure the patient
Distract the patient
Topical LA agents in mouthwash/spray
Film packet flat in mouth (in occlusal plane)
Endodontics:
Difficulties: film placement & stabilization, identification & separation of root canals, assessing root canal length.
Solutions:
Special endodontic image receptor holders
Separating root canals: taking 2 radiographs with different horizontal angulations
Root canal length:
Pre-operative long cone radiograph
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Small size of mouth:
For infants below 3 years: use size 0 intraoral periapical films.
Very small children:
Paralleling technique is often not possible.
Use modified bisecting angle technique.
The parent may need to hold the film or the child and film.
Mentally disabled children:
Use intraoral film with bitewing tabs for film position control.
Attach an 18-inch length of floss through a hole in the tab for retrieval.
Patient wears a lead apron with a thyroid shield.
Helpers wear lead-lined aprons and gloves.
If the patient cannot open their mouth, use extraoral radiographs like panoramic, lateral jaw, or 45° projections.
Desensitization:
Explain the procedure in easily understood terms (Tell-Show-Do).
Allow the child to touch and examine the radiographic film and camera.
Obtain the least difficult radiograph first (e.g., anterior occlusal).
Gradually expose the child to stimuli of increasing intensity.
"Lollipop Radiograph": Attach a radiograph to a sugarless lollipop; the child associates it with pleasure.
Use bubble gum flavored toothpaste to make posterior radiographs more pleasant.
INTERPROXIMAL (BITEWING) EXAMINATION
Records coronal and cervical portions of teeth, along with alveolar bone.
Indications:
Presence of interproximal caries
Overhanging restorations
Improperly fitting crowns
Recurrent caries beneath restorations
Resorption of the alveolar bone.
Films often have a tab projection for the patient to bite on.
Sizes:
Adults: size 2 film
Children: size 1 film
Small children: size 0 film.
Size 3 is also available.
Uses:
Detect interproximal caries
Determine pulp chamber configuration and depth of carious lesions, or restoration proximity to pulp space
Record width of spaces
Determine presence or absence of premolar crowns
Determine relation of the occlusal plane
OCCLUSAL FILM
Held in position by having the patient bite lightly on it.
Provides right-angle views to periapical films.
Size: usually 57×76 mm.
Uses:
Identify presence, shape, and position of midline supernumerary teeth and swellings
Determine impaction of canines
Determine palatal expansion
Assess the extent of trauma to the teeth
RADIOGRAPHIC SURVEY
Types:
Four-film survey:
Maxillary and mandibular occlusal radiographs
Two posterior bitewing radiographs.
Eight-film survey:
Maxillary and mandibular anterior occlusal radiographs
Four molar periapical radiographs
Two posterior bitewings
Twelve film survey:
Maxillary and mandibular permanent incisor periapical radiographs
Four primary canine periapical radiographs
Four molar periapical radiographs
Two posterior bitewing radiographs
Sixteen film survey:
Twelve-film survey plus four permanent molar radiographs
Recommendations by various authors (Davis, Law, Lewis; Braham RL, Morris ME; Forrester DJ; Lincoln R and Sidney Finn):
Vary by age and dentition stage, detailing specific numbers and types of films to be used for primary, mixed, and young permanent dentition.
EXTRAORAL RADIOGRAPHY
Types:
Panoramic view
Lateral jaw projection
Lateral skull (cephalometric radiograph)
Posteroanterior
Water’s view (Sinus)
Reverse Towne
Submentovertex
Temporomandibular joint projections
PANORAMIC RADIOGRAPHS
Discovered by Dr. H. Numata in 1933
Also called Orthopantomography/maxillo-mandibular radiography/Pan tomography/Rotational tomography.
Mechanism by which the x-ray film and the x-ray source move simultaneously in opposite direction at the same speed.
Visualizes both maxilla and mandible with associated structures.
Patient positioning and head alignment.
Demonstrate machine and its working to patient
A-P positioning: Maxillary and Mandibular incisors on biteblock and mid-sagittal plane centered in image layer.
Proper positioning of chin and occlusal plane
Back and spine should be kept erect and neck in extended position.
Instruct the patient to swallow and touch the tongue on the palate.
Advantages:
Broad coverage of facial tissue.
Fewer amounts of radiation exposure and it are easy for children.
Can be used in patients with diffic8ult mouth opening
Disadvantages:
Unequal magnification and lack of fine details.
Difficult visualization of mandibular anterior region.
Cephalometry: Technique for abstracting complexities of the human head into a geometric scheme. Indications include assessing facial and jaw growth and pre- and post-treatment changes.
Lateral oblique view:
The film used is 5 X 7 inches screen film.
Indications:
To visualize mandibular Molar to Premolar region.
To detect the pathology extending from condyle to body of the mandible.
PA View/Postero Anterior View:
Film used is 8 x 10 inch film.
Central x-ray beam generated from behind and through the skull.
Used to evaluate the skull for pathology, trauma, or developmental anomalies.
Used to see the frontal sinus, ethmoidal sinus, orbit, and nasal cavity.
Reverse Towne View:
8 x 10 inch film is used.
Used in the fracture of the neck of condyle, and ramus of mandible.
Radiograph is taken in the open mouth position.
Submento Vertex View:
8 x 10 inch film is used.
Taken to see the fracture of the zygomatic arch and position of the base of the skull.
Transpharyngeal view:
Also called ‘Mc queen view’ or infracranial view.
Helps visualize the shape of the condyle and fractures of the condyle & condylar neck.
EXTRAORAL VS INTRAORAL STUDY
A study comparing extraoral periapical radiography (EOPAR) and intraoral periapical radiography (IOPAR) for determining endodontic working length found no significant statistical difference.
EOPA technique with an angulation of +35° can be used as an alternative to IOPA for mandibular premolars in apprehensive children, dental phobic patients with low pain threshold, neurological difficulties, and exaggerated gag reflex.
OBJECT LOCALIZATION PROCEDURES
Used when localizing an object buccally or lingually is needed for surgical intervention.
Techniques:
Right angle technique (Miller’s)
Tube shift technique (Clark’s) SLOB Rule
Right angle technique:
Two projections taken at right angles to one another.
Identify the position of the object on each radiograph relative to anatomic landmarks.
Best for the mandible; superimposition may obscure the area of interest in the maxilla.
Tube shift technique:
Also called buccal object rule or Clarke’s rule.
Rationale based on the relative positions of radiographic images changing with projection angle.
The buccal object rule (SLOB) states that an image of any lingually oriented object appears to move in the same direction as a moving X-ray source, while the image of any buccally oriented object appears to move in the opposite direction from a moving X-ray source.
Two periapical X-rays are taken.
The first periapical X-ray is taken in a routine manner.
The second one is taken keeping the film in the same position and shifting the cone either mesially or distally.
In case of midline structures, the second X-ray is always taken by shifting the cone distally.
GUIDELINES FOR PRESCRIBING RADIOGRAPHS (AAPD 2017)
Factors:
Patient category (child or adolescent)
Type of visit (new or recall patient)
Stage of dental development (primary or transitional dentition)
Risk for dental caries (low or high risk)
Presence or absence of certain conditions (see chart)
Recommendations provided in chart form for new and recall patients, varying by dentition stage and caries risk. These are just recommendations. Always do what is best for your patient.
OBJECTIVES WHILE TAKING RADIOGRAPHS FOR CHILDREN
Minimize radiation exposure using the ALARA (as low as reasonably attainable) principle.
Prevent retakes.
Children are at higher risk due to:
Tissues in a growth period
Longer lifespan
Cumulative radiation effects due to smaller stature
Increased frequency of radiographs due to carious activity
RADIATION PROTECTION
Minimize harmful effects from diagnostic exposure.
Use the ALARA concept.
Methods of minimizing exposure:
Prescribing needed radiographs based on professional judgment and guidelines.
Proper equipment: X-ray tube head with aluminum filters, lead collimator, and position indicating device (PID).
Aluminum filtration: Absorbs long wavelength X-rays, reducing somatic exposure by up to 57%.
Lead collimation: Restricts the size and shape of the X-ray beam to reduce patient exposure.
Position indicating device/cone (PID):
Directs the X-ray beam.
Types: conical, rectangular, and round.
Long cones are more useful as they cause less divergence.
Rectangular cones irradiate 80-85 percent less tissue than short circular cones.
Thyroid collar: Protects the thyroid gland; reduces exposure by 50%; recommended for all intraoral films
Lead apron: Protects reproductive and blood-forming tissues; reduces scattered radiation to 98%; recommended for all intraoral and extraoral films
Fast film: The single most effective method of reducing exposure to X-radiation. E-speed is twice as fast as D-speed film and requires only one half the exposure time.
Film holding devices: Stabilize the film position.
Proper film handling and correct film processing procedures improve radiograph quality.
Dark room free from light leaks,
Adequate dark room safe-lighting
Time-temperature processing.
OPERATOR PROTECTION GUIDELINES
Used to provide basic safety information that is needed when working with X-radiation.
Include recommendations on distance, position, and shielding.
Avoid the primary beam.
Stay 6 feet away from the X-ray tube during the procedure.
Use protective barriers.
Position at a 90 to 135° angle to the beam.
Never hold a film in place for a patient.
Never hold a tube head.
Stand behind a protective barrier like lead screens.
Monitor X-ray machine for leakage radiation.
Use a personnel monitoring device (film badge) at waist level for dosage calculation.
RADIOGRAPHIC INFECTION CONTROL
Concerns arise from saliva contamination.
Precautions:
Training of staff in infection control procedures
Clinical staff should be vaccinated
Cover open wounds on hands with waterproof dressings
Wear latex gloves for all radiographic procedures
Wash gloved hands under running water
Use a disinfectant (povidone-iodine 7.5%, surgical scrub, or chlorhexidine 4%) before and after X-raying every patient
Place film packets and holders on disposable trays
Use barrier envelopes to prevent salivary contamination
Introduce film packets into daylight loading processors using clean hands or washed gloves
Rinse and autoclave or discard film holders/bite blocks/bite pegs after each use
Wipe X-ray equipment with a surface disinfectant (sodium hypochlorite, quaternary ammonium aldehyde, or peroxidase)
RECENT ADVANCES IN PEDIATRIC DENTAL RADIOGRAPHY
Digital radiography
Digital subtraction radiography
Computed tomography (CT)
Tuned aperture computed tomography (TACT)
Cone beam computed tomography
Xero radiography
MRI
PET scan
DIGITAL RADIOGRAPHY
Conventional film is replaced by an image receptor.
Types:
Charge-coupled device (CCD)
Storage phosphor (SP) systems
CCD includes a sensor with a pixel array on a silicon chip that converts X-ray energy to electrons.
The analog signal is converted to a digital signal and displayed on the computer monitor as shades of gray.
Smaller areas result in better resolution.
Advantages: Images can be stored, modified, and manipulated.
Accurate as traditional films for caries detection.
DIGITAL SUBTRACTION RADIOGRAPHY
Cancels out the anatomic background to enhance subtle changes.
A subtraction image is obtained by subtracting gray values for each coordinate.
Non-zero results indicate changes like demineralization progress.
Used in laboratory studies for primary and recurrent caries diagnosis.
Limited popularity in routine clinical examination due to the problem of image registration.
COMPUTED TOMOGRAPHY (CT)
Developed by Hounsfield; known as CAT scanning.
X-ray beam attenuation is used to project a shadow onto an image receptor.
Allows for a 3D representation of a 2D image.
Indications:
Investigations of intracranial diseases
Preoperative assessment of maxillary alveolar bone height and thickness before inserting implants
Investigations of suspected intracranial and spinal cord damage investigation
Assessment of fractures involving orbits and nasoethmoidal complex, cranial base, and cervical spine fractures
Tumor staging; assessment of site, size, and extent of benign and malignant tumors’
Investigations of tumors and tumor-like discrete swelling intrinsic and extrinsic to the salivary glands
Investigation of the temporomandibular joint (TMJ)
Advantages:
Eliminates superimposition of images outside the area of interest
Ability to rotate images and add or subtract components
Structural relationships of hard and soft tissues can be observed directly
Quick and patient-friendly
Excellent image quality
Limitations:
Greater blurring effect compared to conventional systems
Metallic objects produce streak artifacts
Expensive
Clinical applications in children:
Diagnosis of neonatal maxilla and disorders involving auditory ossicles and TMJ
Detailed view of dental arches and positioning of supernumerary teeth
Identification of the extent of cysts and tumors
Skeletal and dental relationships in orthodontic cases
Evaluation of facial trauma
TUNED APERTURE COMPUTED TOMOGRAPHY (TACT)
Diagnostic method based on digital radiography.
Constructs radiographic slices of different thicknesses of teeth.
The slices can be viewed for the presence of radiolucencies.
Slices can be brought together in a three-dimensional computer model called the pseudohologram.
Performs adequately in detecting small primary and recurrent caries lesions.
Not significantly better than film radiography and digital radiography for occlusal and approximal caries diagnosis.
Application of TACT can improve diagnostic accuracy on caries detection.
CONE BEAM CT (CBCT)
Also called dental volumetric tomography or cone-beam volumetric tomography.
Developed for angiography in 1982 and applied to maxillofacial imaging.
Uses a 2D digital array providing an area detector rather than a linear detector as CT does.
Requires only a single scan for capturing necessary data.
CBCT data reconstruction and viewing is performed on a personal computer.
Advantages:
Fast scanning time
Applications in pediatric dentistry:
For pediatric patients having malocclusions and craniofacial anomalies, including cleft lip and palate.
Assessment and determination of the position of unerupted teeth.
Provides a relationship between the dentition for assessment of treatment planning.
Limitations:
Related to cone beam projection geometry, detector sensitivity, and contrast resolution that produce images that lack the clarity and utility of conventional CT images.
XERO RADIOGRAPHY
Electrostatic imaging technique using a xerographic copying process to record images.
Developed by Dr. Robert C. McMaster in 1950.
A picture of the body is recorded on paper rather than on film.
A plate of selenium on aluminum oxide is charged uniformly.
X-ray photon impinges the selenium which diffuses out charges in proportion to the X-ray energy.
Reusable paper plates attract toner particles based on the charge distribution.
Photographic developers are not needed.
Requires more radiation exposure.
Applications include mammography, skull, larynx, respiratory tract, TMJ, mandible, paraosseous soft tissues, and dental structures.
Advantages:
Simultaneous evaluation of multiple tissues with different thicknesses and densities on one film
Accidental film exposure is impossible
High-resolution images
No special skills are required
Dark room is unnecessary
Multiple copies can be made simultaneously
Cost-effective.
Offers well-defined and sharp bone details with soft tissue imaging.
MAGNETIC RESONANCE IMAGING (MRI)
Uses magnetism, radio waves, and a computer to produce images of body structures.
Uses non-ionizing radiation from the radio frequency band.
A non-invasive modality that uses electrical signals generated to produce an image without X-rays.
Indications:
Assessing intracranial lesions, especially those involving the posterior cranial fossa, the pituitary, and the spinal cord
In the head, trauma to the brain can be seen as bleeding or swelling
Staging the tumor: Evaluating the size, site, and extent of all soft tissue tumors and tumor-like lesion involving all areas, including the salivary gland, pharynx, larynx, and orbit
Study the extent of soft tissue tumors and tumor like lesions involving salivary gland, the pharynx, and the larynx
Allows 3D visualization of carious lesions and determining its extent and relationship with tooth structures.
POSITRON EMISSION TOMOGRAPHY (PET SCAN)
F-Fluorodeoxyglucose positron emission tomography (F-FDG PET) provides information about tissue metabolism.
Identifies increased glycolytic activity in malignant cells.
More sensitive than CT or MRI in detecting cervical node metastases; can identify morphologically normal metastatic nodes.
Drawback: relatively poor anatomic resolution.
CONCLUSION
Proper and innovative radiographic techniques help obtain diagnostic radiographs with minimum harm and maximum comfort.
Many modifications are available for intraoral and extraoral techniques.
The technique depends on the patient and situation.
Modifications can act as substitutes for conventional methods.
REFERENCES
Mcdonald and avery’s dentistry for the child and adolescent
Fundamentals of pediatric dentistry- R J Mathewson
Textbook of pedodontics-Shobha tandon
Pediatric dentistry .Principles and practice-M.S.Muthu
Textbook of pediatric dentistry-S G damle
Textbook of pediatric dentistry-Nikhil Marwah
White and pharoah-oral radiology principles and interpretation
The reference manual of pediatric dentistry- prescribing dental radiographs -2017 recommendation
Radiographic Techniques