Radiography Of Periodontal Disease Flashcards
Radiographs are used to…
Radiographs are used to establish disease
Stage (severity)
Grade (rate of progression) and extent
Diagnosis requires information such as..
History
Examination
BPE
Evaluation for historic periodontitis - (Presence of interdental recession even if there s no deep pockets, implies pt has historically suffered from periodontitis)
One the presence of periodontal disease has been established, what are radiographs used for?
To determine the severity and rate of progression of the disease
Radiographic features of a healthy periodontium
- Relationship between the crestal bone margin and the cemento-enamel junction (CEJ) 2-3mm
- Thin, even, well defined, corticated margins to the interdental crestal bone in the posterior regions
- Thin, even, well defined margins to the interdental bone in the anterior regions (bone crest not always evident due to bucco-lingual thin nature of the bone in this region)
- The interdental cortical crestal bone should be dense, even and is continuity with the lamina dura of the adjacent teeth (the junction of the 2 forms a sharp angle)
- Cortical crestal bone should also be thin, even width to the mesial and distal periodontal membrane spaces
What does it mean if the relationship between the crestal bone margin and the cemento-enamel junction (CEJ) is 2-3mm?
If this distance is 2-3mm and there is no clinical signs of loss of attachment then there is no periodontitis
We can see this clearly in the molar region but the problem with the anterior region is that the bucco-lingual width of the crestal bone is so thin that its not reliably reproduced on a radiograph
What shape does the interdental crestal bone make when its continuous with the lamina dura of the adjacent teeth
the junction of the 2 forms a sharp angle
Limitations of radiographs
- 2d view of 3d situation - no bucco-lingual or bucco-palatal info
- Bony defects may be hidden
- Only interproximal bone seen clearly
- Radiographs underestimate bone destruction
- 30-50% of the bone mineral content must be lost before changes are detected radiographically (certain level of decalcification req before detection) - can underestimate degree of clinical attachment loss
- No information on soft tissues
What can radiographs tell you?
- bone loss / reduced bone levels 30-50% threshold
- mobility - changes in periodontal ligament space (you would expect the healthy periodontium to adapt to the normal occlusal forces but when the periodontium reduces, the ability of the dentition and periodontium to adapt to normal occlusal forces is more limited = mobility
- mineralisation and demineralisation changes
- occlusal trauma
- calculus / marginal overhangs
- crown-root ratio
- sclerosis
What is important to evaluate from a radiograph - bone levels?
- Extent - and pattern of bone loss
- Staging - bone loss at the WORST site is used to determine the SEVERITY of the disease
- Grading - % of bone loss / patient age is used to determine the RATE OF PROGRESSION of diseases
Pattern of bone loss - extent
There a 3 described extents within the classification
- Generalised periodontal bone loss - more than 30% teeth affected
- Localised periodontal disease - less than 30% teeth affected
- Molar-incisor pattern
How do we describe the pattern/extent of bone loss clinically?
- Horizontal
- Vertical - discrepancy between 2 sites and this results in an angular bony defect radiographically
- Furcation involvement
Horizontal bone loss
Horizontal reduction in bone loss
Crest of the alveolar bone is horizontal / parallel relative to occlusal plane as such in a healthy periodontium buts its at reduced levels around the roots of the teeth
Creating apical repositioning to the normal level
Loss of buccal and lingual cortices (bone level) and intervening trabecular bone
(Entire bone level horizontally repositions further apical down the teeth) - normally crestal bone level should be 2-3mm but as shown in image, its reduced
Also looks the same on periapical
What structures can horizontal bone loss affect?
Buccal palatal or buccal lingual plates
Crestal bone
Trabecular bone
What causes this appearance?
You can have a differential level of bone loss buccally and palatally/lingually
On probing, the the deepest area you’d feel has the greatest bone loss and is shown as most radiodense
The radiograph shows some intermediate bone loss what does this represent?
Where both of the cortical plates has been lost - which is the less dense portions (shown as dark grey)
The area directly above shows where both of them are intact hence more radio dense
The radiograph is merely projectional and so we cant see where intermediate bone loss has been lost buccal or palatal. What do we do to find out?
6 Point pocket chart
What is vertical bone loss
Discrepancy in degree of bone loss at 2 adjacent sites
Might indicate rapid bone loss
Can be due to anatomy
What is an intrabony defect
Vertical bone loss where one or both cortices are still intact but there is irregular bone loss between them or involving one of the walls
Combined lesions
What does this radiograph show?
Vertical bone loss which results in the radiographic appearance of an angular bony defect
(Look at the triangle of darkness between the 2 teeth) - LHS the 2 has more bone loss and mesial of the 3 the bone loss is less
— There is a differential of bone loss at these 2 adjacent sites
There is some intact bone as well shown as the light grey part at the base of the triangle of darkness (intrabony defect)
What does the radiographic image show
Image shows sickle shape defect and arrow pointing towards furcation of the tooth - angular bony defect involving the furcation resulting in differential density between the mesiobuccal root and where the palatal root is still projected over
Arrow head pointing towards furcation indicates furcation bone loss ion an upper molar
What does the radiograph show
Vertical bone loss resulting in an angular bony defect on the radiograph
What can some vertical defects be due to?
Local anatomy
Vertical bony defect mesial to the molar because the tooth is mesio-angular inclined and there is a redistribution of the occlusal forces because of this
Furcation involvement
- Why is it important to identify?
- How can you detect it?
- What does the radiograph look like?
- What does it look like in upper molars?
- local plaque retention factor, + may be hard for it to clean
- may be detectable by probing
- Radiolucency at furcation
- Radiolucent arrowhead
Why is it easier to detect furcation in mandibular than maxillary molars
Maxillary have third root
Mandibular have 2
Hat does this radiograph show?
Combined lesion
LRMolar has a mesial angular bony defect that extends to the apex
Angular bony defect is mesial and distal - this indicates the buccal or lingual cortex is going to be intact but also buccally and lingually there is a combined lesion
Calculus
May or may not be seen radiographically depending on size, location, and degree of calcification of deposit
Careful probing more accurate
(Radiograph shows horizontal bone loss)
Poorly contoured restorations
- overhang amalgams
- crown margins
- occasional pin perforation
Radiographic views - what do we use to diagnose periodontal disease?
- bitewings
- periapicals
- panoramics
Disadvantages of BW
As apex not seen, bone loss is estimated
Vertical bitewings – limited use
Unlike horizontal bitewings, unlikely to have these already
Classify patient based on BPE codes - why?
- when you do this, you can see what type of radiographs you will need
If the pt has no obvious interdental recession and BPE codes 0/1/2…
then you dont need radiographs for the evaluation of periodontal disease
If the patient has a code 3
Bite wings would be useful if you already have them to see if the pt has a healthy bone level or a reduced bone level
Healthy bone level - treat them for gingivitis and reevaluate
Reduced bone level - evaluate entire root surface length of the entire dentition (OPT or FM periapicals)
If the patient has a code 4
OPT or FM periapicals - you need to assess the whole dentition and type entire root surface length
This is because only with a radiograph can you evaluate the stage and grade of the disease
Other than the stage and grade, what else do you evaluate using a radiograph?
Extent
Generalised, localised, or molar incisor pattern
What is staging
Where you evaluate the entire dentition and the entire root surface length with either FM series periapicals or an OPT and then you need to evaluate the worst site of the disease where the bone loss extends to
How do you determine the stage
Coronal 1/3 of root
Middle 1/3 of root
Apical 1/3 of root
Or if its within 2mm of the CEJ
What is grading
Taking into account the worst site of bone loss and describing it as a % of bone loss
Measuring from just below the CEJ (which is normal crestal bone level) to the apex of the root - this is 100%
- where along this is the degree of bone loss?
- Eg halfway = 50% bone loss… if its to the apex, its 100% bone loss
Once identified the worst site of bone loss, divide this by the patients age = the grade
Eg, 20% bone loss in a 50yr old= 20/50 = 0.4 therefore less than 0.5 therefore Grade A
Eg, 30% bone loss in a 25yr old = 30/50 = 0.6 = Grade B
Patient age 30
Asses radiograph
Vertical bony angular defect LR7
Horizontal bone loss
Worst site of bone loss UR7 / LR7
Bone loss in apical third of root (loss of 80-90% bone)
90% / 30yrs = 3 = Grade C
Diagnosis - Stage 4, Grade C Periodontitis generalised
What’s the pattern of bone loss and diagnosis
Patient 61yrs old
Generalised pattern of bone loss
Furcation involvement UR7
Molar incisors pattern horizontal bone loss
Worst site of bone loss UR7 50%
50% / 61yrs = 0.8
Diagnosis = Generalised, Grade B, Stage 3
