Bitewing, Periapical, and Panoramic Radiography - 2.5 PDF

**[Bitewing, periapical and panoramic radiography - 2.5]** Intra oral = periapicals, bitewings, occlusals Extra oral = DPT, OPT, OPG, panoral, oblique lateral radiography, skull radiography Cone beam computed tomography Pros and cons of intra oral and OPG radiography +-----------------------+--...

**[Bitewing, periapical and panoramic radiography - 2.5]** Intra oral = periapicals, bitewings, occlusals Extra oral = DPT, OPT, OPG, panoral, oblique lateral radiography, skull radiography Cone beam computed tomography Pros and cons of intra oral and OPG radiography +-----------------------+-----------------------+-----------------------+ | | **Intra-oral** | **DPT** | +=======================+=======================+=======================+ | Resolution | High | Medium due to image | | | | capture technology | | | | and motion of machine | +-----------------------+-----------------------+-----------------------+ | Dose | Low | DPT higher dose than | | | | intra-orals | +-----------------------+-----------------------+-----------------------+ | Distortion of anatomy | Low with correct | Low with correct | | | technique | technique but still | | | | higher than | | | | intra-orals | | | | | | | | Variable | | | | magnification | | | | depending on position | | | | in dental arch | +-----------------------+-----------------------+-----------------------+ | Operator dependence | Highly dependent on | Relatively | | | operatorexpertise | straightforward to | | | | learn technique and | | | | execute reliably | +-----------------------+-----------------------+-----------------------+ | Coverage | Small area -- may be | Large field of view | | | insufficient for | | | | large maxillary or | | | | mandibular pathology | | +-----------------------+-----------------------+-----------------------+ | Patient comfort | May be | Usually well | | | difficult/painful to | tolerated | | | accommodate film + | | | | holder. Gagging may | | | | occur. | | +-----------------------+-----------------------+-----------------------+ Image capture methods - - - - Image capture devices - - - +-----------------+-----------------+-----------------+-----------------+ | | **Photographic | **Computed | **Direct | | | film** | Radiography -- | Digital | | | | indirect | Radiography** | | | | digital** | | +=================+=================+=================+=================+ | Time from | Film must be | Imaging plate | Virtually | | exposure to | chemically | must be read - | instant | | image | processed -- | typically a few | | | availability | typically 5-8 | seconds | | | | minutes | | | +-----------------+-----------------+-----------------+-----------------+ | Patient comfort | Flexible | No flexibility | No flexibility. | | | packages are | | | | | usually easily | | Bulky. | | | accommodated | | | | | | | Cable connected | | | | | to detector | +-----------------+-----------------+-----------------+-----------------+ | Versatility | No scope for | Digital | | | | image | adjustment of | | | | adjustment | density, | | | | | contrast | | | | | sharpness | | | | | possible | | +-----------------+-----------------+-----------------+-----------------+ | Image Viewing | Unique copy -- | Electronic copy | | | and Storage | must be | -- may be | | | | physically | emailed, | | | | present to view | electronically | | | | | archived and | | | | | viewed by | | | | | multiple users | | | | | simultaneously | | +-----------------+-----------------+-----------------+-----------------+ | Cost | Relatively low | Quite high | | | | but has | initial outlay, | | | | consumables | but completely | | | | (film, | re-useable. No | | | | processing | consumables. | | | | chemicals) | Service | | | | | contract may be | | | | | expensive | | +-----------------+-----------------+-----------------+-----------------+ | Safety | Chemicals | No toxic | No toxic | | | require careful | chemicals | chemicals | | | handling and | | | | | disposal | | | | | presents | | | | | additional | | | | | expense | | | +-----------------+-----------------+-----------------+-----------------+ | Infection | Single use -- | Reused - must | | | control | few issues | be adequately | | | | | sealed to | | | | | prevent saliva | | | | | ingress | | +-----------------+-----------------+-----------------+-----------------+ Periapicals Techniques: - - Quality criteria - - - - - - - - - Advantages of paralleling technique: - - - Disadvantages of paralleling techniques: - - - Indications for bisected angle periapical - - - - Horizontal angulation of tubehead - -  Advantages of bisecting angle technique - - Disadvantages of bisecting angle technique - - - - - - Bitewings Indications - - - Bitewing quality criteria - - - - Tab technique advantages - Tab technique disadvantages - Positioning **[OPG]** Only structures within the focal plane (focal trough) are projected sharply onto film and everything else is blurred Focal plane is narrower at the front than the sides Objects further away from detector appear bigger and wider Objects closer to detector appear smaller and narrower  Positioning lines are use for: - - - Slit bea, radiography - - - Indications for panoramic radiograph - - - - - - - - Justification of OPG radiographs - - - Field limitation - - - - - Positioning - Radiation dose Regulations IRR 2018 - protection of worker and public - - - IR(ME)R 2018 - protection of pt - - - Both have replaced IRR 99 and IR(ME)R 2000 from feb 18