Radiographs

Disclaimer:

All patients or legal guardians with parental responsibility consented for using  fully anonymized information for educational purpose only.

 

IR(M)ER regulations: ALARA rule must be followed for each patient with special needs, including: clnical justification, use of appropriate positioners (eg. Rinn holders), use of collimator, etc.

No obligation to use lead aprons, however thyroid aprons for adolescents in case of occlusal radiographs can be justified.

In exceptional circumstances, following careful risk assessment, lead apron can (must) be used by operator/carer providing a sort of ‘clinical holding’ during x-ray exposure of the special needs patients.

  • routine use of BWs rads for caries detection, assessment of alveolar bone level and absence/presence of permanent successors
  • routine use of standardized film/sensor/plate holders (highly adhesive, ideally disposable)
  • adhesive foldable paper tabs or plastic “alligator” clips if child not comfortable with holder
  • OPG for general review and for orthodontic cases/referrals
  • use of smallest size 0 films/sensors/plates for little children
  • routine use of rectangular collimator which reduces a radiation up to 60%
  • Bimolar techique RHS/LHS for special needs patient or little children not compliant with routine BWs or OPG (brilliant article in BSDH journal 3/2017
  • BWs, BiMolar rads, lateral oblique extraoral or OPG need to be taken before referral for dental treatment under GA
  • Oblique lateral radiographs (bimolars) extremely useful in case f special needs patient not compliant with intraoral radiographs and OPT, eg. severe learning disability. It is recommended to attempt OPT first with better diagnostic value, if not possible – oblique lateral is a second choice. May require a support of radiology dep. staff, family or carer to make a patient calm and steady/still. This person has to wear protective lead apron while taking any radiograph.
  • oblique lateral radiographs work great in partially coop patients with special needs who are unable to open/bite down (intraoral rad holder) or keep still for OPT . Invaluable if susp. dental pathology within lower posterior quadrant: wisdom teeth, mandible fracture, molar-associated periapical periodontitis/abscess, chronic periodontititis, bone loss, interprox caries within lower molars/premolars, cyst/tumour in mandible angle/ramus. Case: severe learning disability, gross grinding all the time, difficult examination, patient indicate some dental problems on LHS. Oblique lateral radiograph reviewed: partially erupted LL8.

 

  • occlusal rads required for any suspected abnormalities within anterior regions, including supernumerary teeth, dental trauma cases, tooth malformations, impacted canines, lateral incisors, etc.
  • occlusal radiograph can be sometimes the only option in case of shallow palate in patients with severe gag reflex
  • to consider a use of thyroid collar for a child and occlusal radiograph (eg. trauma case)
  • periapical rads for selected cases of apical pathologies, acute dental trauma, for RCT procedure, before anticipated surgical extractions
  • Radiographs need to be assessed using quality radiographs scale (score 1, score 2, score 3)
  • sectional DPT useful to reduce radiation dose (ALARA rule)
  • If BWs rads not possible due to patient’s lack of cooperation, OPT seems to be also an useful tool for proximal caries diagnosis.

 

  • occasionally only intraoperative rads are possible, eg. during GA session in hospital setting, cooperation with Radiology Dep. required, radiological assessment under GA using bimolar/lateral oblique radiographs for patients who would not tolerate standard radiographs in the clinic
  • multiple PA sometimes required for full mouth status, eg. severely physically disable patient, wheelchair bound, hardly able to move/walk, it is beneficial to take eg. 3-5 periapical/BWs rads in one session if xray room and facilities are not in the main surgery, particularly if OPG not possible

 

  • Hand held, portable x-ray unit can be useful during GA, thorough risk assessment must be carried out
  • Hand held x-ray unit can be useful for: special needs patients, geriatric patients, domicilary visits

 

portable-xray-unit

 

  • Lead apron/vest not routinely recommended, but can be justified or pregnant patient and urgent dental care requiring radiographs
  • Heavy lead apron may have a ‘calming effect’ in special needs patient (acting as a ‘blanket’)
  • Wheelchair bound patients can be suitable for OPT depending on their physical condition. The main obstacle relates to the shoulders position interfering with OPT machine rotation.
  • In case of a great difficulty to accommodate the patient into x-ray room due to physical immobility, it is advisable to try to take all necessary eg. intraoral radiographs ‘ in one go’ in order to obtain a full intraoral radiographic status.
  • OPT can be potentially useful to diagnose carotid atherosclerosis

 

  • do not be surprised, when attempting to remove retained root of the mandibular molar tooth appears  to be ‘much bigger’ in reality than on the radiograph. Radiograph is ony 2D representation, and anterio-posterior dimension is always smaller (more narrow) than bucco-lingual one (wider)

 

  • in case of particularly third molars, radiographic presentation can be misleading and if the image of root(s) is not clear but even slightly blurred, always consider the atypical anatomy, curved apices, superimposing portions of curved roots, etc.
  • if he apical area of third molar tooth appears to be more ‘radiopaque’ and a slightly blurred, it should be assumed – the apical portion (tip) of the root (usually single) is severely curved and directed towards x-ray beam (“looking at us”). Anticipate difficult extraction, 3D CBCT would be beneficial if surgical xla planned, tooth not suitable for RCT.
  • in case of radiographic presentation revealing eg. buried root with ‘white’ margins fusing with surrounding bone structure trabecula and non-conical shape – to consider the ankylosis, sclerotic PDL and bulky end of the root which can compromise the extraction (may not be easy at all despite of initial assumption).
  • OPG image may not reflect an exact root morphology of wisdom tooth, eg. seems to be separated roots, but actually they were fused together and unable to divide surgically.

opg

 

Tips&Trick:

  • adjust saliva guard sleeve corners for film or phosphor plate to make it more comfortable – very slight cut off, bending corners of disposable cover, use an adhesive tape to make patient comfortable
  • use cotton roll or bite blocks
  • use adhesive tabs to avoid plastic/sharp/uncomfortable elements
  • bend occlusal film
  • modified film holder, eg. snap-Rinn, ‘aligator’ holder for children
  • use of mouth prop
  • helmet with chin strap as a last resort?
  • Velcro strap to stabilise patient?
  • reverse bitewing radiographs
  • sectional OPT as shorter exposure time, uncooperative patient may better tolerate OPT
  • Ceph radiograph instead of OPT for eg. wisdom teeth assessment? (alternative option)
  • 3D CBCT with firm and stable head position
  • lead apron put on special needs patient can make him/her more complaint
  • oblique lateral radiographs extremely useful if patient would not tolerate intraoral rads and OPT

 

Additional radiographic techniques:

CBCT can be also helpful as radiological diagnostic measure for patients with special needs due to: quick processing time, reasonably low radiation dose, which can be similar to DPT (about 200 mGray for sectioned 3D) and stable patient sitting position and ‘fixed’ head position. Example below: severe malocclusion and dentition malformation (patient consent obtained for radiographs use for educational purpose).

Dentition malformation

CBCT axial

CBCT2

 

CBCT canine

bone defect

Sectioned CBCT projection with reduced radiation dose, mimicking OPG in disable patient prior to dental treatment. Sitting position and head suport during CBCT scanning allowed procedure in partially cooperative patient who could not tolerate intraoral radiographs. Note the abnormal endodontic mophology of lower right central incisor, chronić periapical pathology present.

CBCT abnormal endodontic morphology

endo pathology

 

Sometimes only CBCT can confirm clearly the evidence of lesion and allows a proper treatment planning before oral surgery procedure (odontgenic lesion):

lesion-cbct