Dental radiography & periodontitis Flashcards
Why radiograph teeth?
What should you radiograph?
Additional information about teeth and alveolar bone.
Does not replace clinical exam, but always necessary in dentistry – in dogs additional clinically relevant info 20%, and in cats 40%, in small dogs 30%.
Always x-ray
– extractions
- dental fractures, dental hard tissue defects
- teeth with periodontal pathology
(gingival pocketing, furcation involvement etc.) - masses, missing teeth, discolored teeth etc.
Current recommendations full mouth series always.
Options for radiographic imaging of
teeth. (5)
Digital intraoral - direct digital sensor
Digital intraoral - indirect, phosphoric plate technology
Conventional intraoral x-ray film with dental x-ray device
Conventional intraoral x-ray film with conventional (full-body) x-ray device (nondigital?)
Extraoral – conventional or dental x-ray device (rabbits and especially rodents)
Lowest exposure with?
And highest?
digital radiography
(device must enable time down to 0.02 sec, so-called dental x-ray devices usually have fixed kV and mA, can only adjust time)
conventional film intraoral with dental x-ray a bit higher
and when using conventional large x-ray for intraoral radiography, exposure required is highest
(focal distance reduced to 30-40 cm, mAs 10-15 and kV according to size of patient 40-65)
Commonly used intraoral film sizes.
2 (adult human periapical, appr. 3x4 cm)
and 4 (occlusal, appr. 5,5x7cm).
Raised dot in the corner of film always oriented with raised/high side towards the x-ray beam (allows later identification of left or right side)
NB! Logic of side determination differs in intraoral vs extraoral film placement!
Digital intraoral - direct digital sensor
Direct digital sensor now available sizes 1(+), 2, 4 (depending on producers)
Digital intraoral - indirect, phosphoric plate technology
phosphoric sensor plates available in many different sizes (depending on producers), at least sizes 2 ja 4, but also several others
(0, 1, 3, 4c, 5), also rabbit intraoral plates.
Parallel projection for which teeth?
mandibular molars and (distal) premolars
Bisecting angle projection for which teeth?
(+/- tube shift) all teeth other than mandibular molars and distal premolars
mandibular molars and (distal) premolars should be imaged with what projection?
Parallel projection
all teeth other than mandibular molars and distal premolars should be imaged with what projection?
Bisecting angle projection (+/- tube shift)
Describe Parallel projection
for mandibular molars and (distal)
premolars
The plane of film/sensor and the plane of the object (tooth) axis are parallel and the x-ray beam is angled perpendicularly, at a 90° angle, or ‘crosswise’ to the planes of sensor and the tooth axis.
Describe Bisecting angle projection.
For all teeth other than mandibular molars and distal premolars.
Film/sensor is placed as parallel to palate as possible (for easier calculation of the angle).
An angle will be formed between the plane of the film/sensor and the plane of the axis of the object (tooth).
This angle is bisected (divided into two equal parts).
The plane of the bisecting line is the new plane that the x-ray beam will be directed perpendicularly at.
What is Tube shift?
e.g. in order to view 3 roots of the same tooth without root superimposition
Retaining the same angulation of the x-ray beam (in vertical plane) the x-ray head is ‘walked’ around the object (in the horizontal plane) so that the object can
be imaged from another ‘viewpoint’.
enamel and dentin hypoplasia due to death of ameloblasts due to previous insult + retained and damaged canine
supernumerary tooth + tooth resorption
if pulp is extra wide (e.g. compared to contralateral side) is dead.
+ periapical lucency due to crown fracture with exposed pulp canal
most common oral disease in our patients,
prevalence up to 80-90%
Periodontal disease = gingivitis and periodontitis
Enamel in animals is very thin, like 1mm.
The alveolar bone should come up to the cementoenamel junction, if it doesn’t then there is bone loss.
Total attachment loss is the combined total of
periodontal pocketing and root exposure.
AL
attachment loss - how many mm has the level of tooth attachment
(periodontal tissues – gingiva, alveolar bone, periodontal ligament – normally
have their upper or coronal attachment margin at the level of cementoenamel
junction) migrated apically – towards the root – compared to normal.
AL is not the same as PD!
AL is calculated, taking into account whether
a) there exists a pathological PD
b) there is GR
c) there is GH
PD
probing depth – measurement in mm from the bottom of gingival sulcus
(normal – in a dog less than 2-3 mm, in a cat less than 0.5-1 mm) or
periodontal pocket (pathological) to the gingival margin.
AL is not the same as PD!
AL is calculated, taking into account whether
a) there exists a pathological PD
b) there is GR
c) there is GH
GR
gingival recession is the extent of exposure of root surface in mm –
how much has the normal attachment level migrated apically, while PD is still
normal.
GH
gingival hyperplasia/overgrowth – PD is over normal measurement (in mm), while the normal attachment level of periodontal tissues to cementoenamel junction has been preserved
4 attachment tissues for teeth
periodontal ligament
cementum
gingiva
alveolar bone
Periodontal disease stage 1 (PD1) is characterized by
Gingivitis, no attachment loss.
How do you evaluate attachment loss?
AL is calculated, taking into account whether:
a) there exists a pathological PD
b) there is GR
c) there is GH
- measure gingival sulcus depth with dental probe e.g. 4 mm
(edge of free gingiva to bottom of sulcus) - assess whether you have gingival recession (eyeball it) e.g. 2 mm
- any gingival hyperplasia forming a pseudopocket? in this example, no.
- 4mm + 2 mm = 6 mm of AL
Periodontal disease stage 2 versus stage 3.
Periodontal disease stage 2 (PD2):
- Attachment loss > 25 %
- Furcation involvement stage 1
- First mild radiographic changes
Periodontal disease stage 3 (PD3):
- Attachment loss 25 % - 50%
- Furcation involvement stage 2
- Radiographic changes
(horizontal and vertical alveolar bone
loss)
Describe Periodontal disease stage 4
Periodontal disease stage 4 (PD4)
Attachment loss <50%
Furcation involvement stage 3
?
carnassial tooth malformation
?
dental root ankylosis
?
periapical inflammation with bone loss
pathological fracture due to severe periodontal disease
Describe Alveolar bone expansion or chronic alveolar osteitis in cats.
Alveolar bone ‘expands’.
Iit is thickened, more porous; often vertical bone loss combined with widening of the
periodontal ligament space (alveolar bone ‘moves away from the tooth’)
possible pathological probing depth
(canines, premolars) and/or in case of canine, even extrusion aka supereruption, where canine is moving out of the
alveolus slowly over the time.
When this is bad, the teeth just need to be extracted.
hand scaler
dental curette
