Dental Radiology in Paediatric Dentistry

• How is radiography used in paediatric dentistry:

  • Caries diagnosis = bitewings
  • Trauma assessment = periapicals/occlusal/DPT
  • Orthodontic treatment planning = lateral cephalometric/DPT
  • Identifying anomalies in dental development = DPT/CBCT
  • Detection of dental/bony pathology = any image, supplemented with additional views if indicated
• Refresher on x-rays:

  • Form of ionising radiation
  • Safety is a priority - to give a patient a radiation dose, it has to be carefully justified
  • Do the benefits outweigh the risks of exposure
  • DO NOT USE RADIOGRAPHS AS A SCREENING TOOL i.e. don't automatically give them to every patient
  • Children (particularly under 10 years old) are susceptible to the effects of ionising radiation
  • Must keep doses as low as practicable (ALARP principle)
• Legislation is in place to:

  • Protect pts (IR(ME)R 2017)
  • Protect workers (you!) and the general public (IRR17)
  • Key people in radiation protection (IRR17)
  • Radiation Protection Advisor (RPA) who is a Medical Physics Expert (Scientist!)
  • Radiation Protection Supervisor (RPS) who is a local person e.g. practice owner
  • Equipment, locations, physical testing (IRR17)
  • Dose limitation (IRR17)
• Radiographic appearance of caries:

  • Demineralisation and eventual cavitation of tooth structure
  • Bitewings best for showing caries on proximal surfaces (mesial, distal)
  • Clinical exam best for buccal & lingual caries
  • Occlusal caries may or may not be seen on radiographs, depending on depth

  
• Lateral cephalometric view:

  • For use in orthodontics
  • Standardised for each pt - reproducible
  • Allows tracing for treatment planning/treatment progress
  • Soft tissues are included
  • Picture shows Class 2 division 1 incisal relationship. Note the overjet!

  
• Proximal caries:

  • Approximately 30% demineralisation is required for radiographic detection of a lesion
  • The thickness of the tooth buccolingually masks the carious lesion when it is small
  • Caries is always more extensive than a radiograph suggests!

  
• Normal dental development:

  • Deciduous = 20
  • Incisors = 8
  • Canines = 4
  • Premolars = 0
  • Molars = 8
• Normal dental development:

  • Permanent = 32
  • Incisors = 8
  • Canines = 4
  • Premolars = 8
  • Molars = 12
• Dental development and abnormalities:

  • Number - increase or decrease
  • Position
  • Form - individual or multiple