Selction criteria Flashcards
how to justify taking radiographs
is it going to change diagnosis/management of pt
5 reasons to take x rays
- pathology affecting tooth or supporting structures
- require knowledge of root or pulpal morphology
- unerupted teeth present
- screening for caries
- localisation of teeth/foreign bodies
name 3 intraoral views
bitewings
periapicals
occlusal views
name 2 extra oral views
dpt/oblique lateral view
lateral cephalometric view
5 indications of bitewings
- caries detection
- caries monitoring
- assessing restorations
- vertical bitewing –> perio pockets up to 6mm
what type of caries are bitewings most useful for
interdental, not clinically evident
by how much do posterior bitewings improve caries diagnosis
x4
2 problem of using x rays to diagnose caries
- requires 50% demineralisation (so caries always bigger than on x ray)
- need good contrast between enamel and dentine
how to get good contrast on x ray
lower kV
when is less contrast needed for bitewings
assessing perio pockets (so higher kV)
european association for paediatric dentistry guidelines of bitewing frequency
only is necessary for adequate tx
- 5yo
- 8-9yo
- 12-14yo (after eruption of premolars and 2nd molars)
intervals between bitewings for pt with
a) low caries risk
b) high caries risk
a) low caries risk: 3 yrs
b) high caries risk:1 year
4 uses of periapical radiographs
- root/pulpal pathology or development
- extent of crown pathology in anterior teeth
- assessment of apical pathology
- assessment of local anatomy including tooth development
2 techniques of periapicals and which is better
- long cone paralleling (better)
- bisecting angle(worse, pt can move film in the mouth, difficult to align)
5 types of occlusal radiographs
- upper standard (nasal occlusal, large bisected angle periapical)
- upper oblique occlusal
- lower 90 degree occlusal
- lower 45 degree occlusal (large bisected angle periapical)
- lower oblique occlusal
4 reasons to use upper standard occlusal
- unable to take periapical view
- trauma (pt cannot take film in mouth)
- palatal pathology
- 2nd view to aid localisation of canines
2 reasons to use upper oblique occlusal
- unable to take periapical or bitewing
- provide view from different angle
4 reasons to use lower 90 degree occlusal
- salivary calculi (lower exposure)
- fracture of anterior mandible
- bucco-lingual expansion of cortical bone
- localisation
3 reasons to take lower 45 degree occlusal
- unable to take periapical
- lesion too large to visualise on intraoral
- anterior fracture of mandible
2 reasons to use lower oblique occlusal
- cannot tolerate periapical
- imaging submandibular gland
can x rays diagnose perio? explain
no. must do clinical examination (eg 6pppc)
4 uses of radiographs in perio
- assess bone loss/furcation
- determine presence of causative factors
- assist in treatment planning
- evaluate tx
guidelines for which radiographs to use for which pocket depth in perio
- 4-5mm pocket (BPE 3): horizontal bitewings
- 6mm+ pockets (BPE4): vertical bitewings/paralleling technique periapicals
- irregular pocketing: bitewings (horizontal/vertical) and paralleling technique periapicals
2 reasons why periapicals are better than DPT perio
- DPT shows all teeth BUT distorts level of bone
- periapical (even full mouth) has lower dose
type of x ray used if perio/endo lesion suspected
paralleling technique periapical
when/what to radiograph for endo
- pre-op: periapical to determine working lengths
- prior to condensation of GP if doubt in integrity of apical construction
- immediately following obturation (baseline and quality)
- asymptomatic teeth: 1yr and 4yrs after tx
when you may need to retake radiograph for endo
if preset file is >2mm from radiographic apex
when to radiograph with trauma
- all but minor trauma
- review radiographs (depending on damage)
when to take DPT with trauma and why
mandibular fracture and additional supporting views (need bucco-lingual view to assess displacement)
average amount of filled teeth in UK dentate adult
7
% adults with at least 1 crown
34%
% adults with >6 crowns
5%
when/what to take radiographs with cons
periapical (using beam aiming device) before any crown/bridge/denture prep
guidance for follow up radiographs of crowned teeth
based on clinical judgement
use posterior bitewings
when to use DPT 7
- prior to dental surgery under GA (eg tumour removal)
- where bony lesion/unerupted tooth is of a size/position which precludes its complete demonstration on intraoral radiographs (eg too posterior)
- prior to clearance/multiple extractions where clinical decision to remove teeth has already been made (eg bc teeth are wobbly)
- ortho assessment
- trauma
- as part of assessment of periodontal bone support where pockets >6mm and no other radiographs available
- implant assessment
when may oblique lateral radiography be used
- when pt cannot tolerate intraorals, eg special needs/ children
- TMJ dysfunction (if history of trauma/unusual symptoms, otherwise clinical diagnosis is fine)
- assessment of condylar head
when to use DPT screening
NEVER. too high dose
4 uses of lat ceph radiographs
- assess skeletal pattern
- angulation of incisors
- orthognathic surgical planning
- lat ceph tracings (measures discrepancies/skeletal profile)
when to use skull views
assess trauma to mandible
what x rays to use for complicated/severe skull fractures and why
CT scan. can see bone and soft tissue (brain)
when is ultrasound used
head/neck lumps
salivary gland disease
pros/cons of ultrasound
safe, quick, effective BUT v operator dependent
when to use sialography
obstructive salivary gland disease to demonstrate strictures and stone mobility
when to use MRI
soft tissue lesions eg salivary tumours/cancer of head and neck
when to use nuclear medicine
(rare) TMJ hyperplasia
how nuclear medicine works
radioisotopes injected –> gamma camera detects radioactivity eg areas of high bone turnover
