Seminar 1: Diagnosis Flashcards
What is diagnosis?
Identification of a disease from its signs and symptoms
What are the sources of pain from a tooth?
Dentinal
Pulpal
Periradicular
Non odontogenic
What are the sources of dental inflammation ?
Pulpal
Periapical
Periodontal
What is the mobility classification known as?
Millers
Class 1/2/3
What direction of movement is there in a Millers class 3 case?
Movement in occlusal apical direction
What are the nerve fibres within the pulp
A beta
A delta
C Fibres
Where are A beta fibres located within the tooth?
Pulp AND PDL
Where are C fibres located?
Centrally located
Where are A delta fibres located?
Peripherally in the pulp
What type of pulp fibres are unmyelinated?
C Fibres
Between A delta and C fibres which respond to hyper-osmotic stimuli e.g sweet
A delta
Between A delta and C fibre which respond in hypoxic environments
C fibres
Which fibres respond to increase in pressure?
A beta and C
Which fibres respond to increases in inflammatory mediators?
C fibres
Why does inflamed pulpal tissue respond less readily to LA?
Neurogenic inflammation
What is Neurogenic inflammation?
-inflammation arising from the local release by afferent neurons of inflammatory mediators such as Substance P
-release of these pro-inflammatory mediators is triggered by the activation of ion channels that are the principal detectors of noxious environmental stimuli
What are the three names for dentine hypersensitivity theories?
Hydrodynamic theory
Direct innervation
Odontoblast receptor
What is the pathophysiology behind the hydrodynamic theory?
Movement of dentinal fluid within the dentinal tubules stimulates A delta fibres via a method of mechano transduction.
In which direction of fluid movement is there more pain?
Outward
What is the pathophysiology behind the odontoblast receptor theory?
Odontoblast process acts as a sensory nerve and transmits pain
Why was the odontoblast receptor theory rejected?
The odontoblast receptor is not capable of producing neural impulses
What is the pathophysiology behind Direct innervation?
Nerve endings penetrate dentine and extend to EDJ allowing them to be directly stimulated - THIS IS NOT TRUE
features of non odontogenic pain include?
No obvious cause LA does not affect pain Can cross midline Difficult to reproduce Often lasts for long periods of time++
Where are the spaces in the maxilla infection can spread?
Buccal space
Canine Space
Infratemporal -> orbit
Where are the spaces in the mandible infection can spread?
Sublingual Submental Submandibular Parotid Parapharangeal spaces Carotid sheath
What is Perisistent Dentoalveolar Pain?
Malacarne et al 2017
- PDAP is when there is pain from a tooth or prev tooth site in the absence of clinical and radiographic signs
- Diagnosis of exclusion
Risk factors increasing risk of PDAP?
Pain lastig 3 months Pre op tooth pain TTP Hx of painful treatment in head and neck female
What are the possible reasons for false positives ?
Anxious patient
Liquefaction necrosis
Contact with metal restorations or adjacent teeth
Tooth only partially necrotic
What are the causes of false negative ?
Patel and Ford 2004 Incomplete root development Recent trauma Sclerosed canals Recent ortho activation Psychotic patients
What does sensitivity mean in terms of pulp tests ?
Probability result will be positive when the disease is present
What does specificity mean in terms of pulp tests ?
Probability test is negative and disease is absent
What is predicative value ?
Ability of the test to foretell what the diagnosis is
What methods exist for carrying out assessment on teeth?
Light Thermal Electrical Pressure LA test cavity Crown surface Temp
In which circumstances is using light as part of the assessment stage helpful?
Cracked teerh
If the patient is feeling sensation in the PDL on biting/use of tooth sleuth, what may thus indicate ?
Non vital Cracked tooth
Are pulp tests more accurate in vital or necrotic cases?
Necrotic
When using pulp tests what are you trying to assess?
Assessment of nerve response via thermal and EPT
Assessment of vascularity via Laser Doppler
Pulp testing carried out chairside aims to do what?
Uses neural response as an indirect way of assessing blood supply
A positive pulp tests indicated the pulp is free of inflammation? T/F
False
What is the mechanism behind the EPT?
Delivers a gradual increase in electrical current which causes ionic movement stimulating nerve response
The use of hot water creates more outward or inward movement of dentinal fluid?
Inward
Why does cold testing create a more severe response than hot tests ?
Cold tests created outward fluid movement which elicits more pain and than in ward movement
What is the limitation of using heat as a pulp test?
Left for excessive time can cause pulpal damage
What type of neuronal response happens with heat application ?
With heat you can get a biphasic response from A delta then C fibres
What temp is ethyl chloride ?
-41 degrees celcius
According to Patel and Ford 2014 if there is NO responses with EPT in what percentage of cases does this indicate necrosis ?
70%
What are the requirements when using EPT?
Tooth must be dry
Separate teeth with Mylar strip
Test the point of tooth nearest pulp horn which is highest density of nerves
Test lingual and buccal separately
How does crown surface temp work with pulp testing?
Teeth with intact blood supply have higher surface temp than non vital
What do you use to assess crown surface temp?
Cholesteric Crystals and thermal imaging
What pulp testing method according to Patel and Ford 2004 is good for traumatised teeth?
Pulse oximetry - use two diodes to calculate percentage of oxygenated vs deoxy blood
What are radiographs ?
Ionising radiation that is able to detect changes in atomic weight of tissues
What is the fastest speed film?
F speed
What are the types of digital detectors ?
Charged couple device (CCD)
Complimentary Metal Oxide semi conductors (CMOS)
Between conventional and digital radiographs which have better spatial resolution?
Conventional
Between conventional and digital which are more sensitive at detecting lesions affecting lamina dura and cancellous bone?
Digital
Lesions in cortical bone are easier to detect than those in cancellous bone. T/F
True. No matter if conventional or digital films
What three methods are there for taking intra oral periapicals ?
Paralleling
Bisecting angle
Parallax
What angle is the X-ray beam directed to the tooth in parallel radiographs ?
90 degrees
What is the advantage of paralleling technique for X-rays?
Less distortion
Easier to compare since uses beam aiming device
What is the disadvantage of paralleling ?
Difficult for patients with shallow palate / gag reflex and rubber dam
How do you take a bisected angle X-ray?
Angle between film and tooth is visualised and bisected and beam placed
What is the risk of bisecting angle?
Distortion
In what cases May you consider bisected angle X-ray?
Shallow palate
Small mouths
What are the limitations of radiographs ?
If lesion only in cancellous bone can be difficult to see
Radiation dose
Super imposition of structures
What are the benefits of CBCT?
38% more lesions picked up
How does CBCT work?
Cone shaped pulse X-ray projects into an X-ray in three planes
Why are CBCTs better posteriorly than anteriorly?
Because the bone is thinner posteriorly and easier to eliminate noise
What are the disadvantages of CBCT
Cost
Higher radiation dose
Need spec training
Less readily available
Why are teeth TTP?
Occurs only in partial or total necrosis and associated with localised tissue oedema
What is apical periodontitis
Inflammation of periodontium at the portals of entry of the root canal system
What is the pathophysiology behind the lesion forming in chronic apical periodontitis?
Bone Tissue adjacent to infection becomes replaced by inflammatory cell infiltrate - bone resorbed over root since bone is less resistant to resorption than root
What is the lamina dura?
This encases the teeth in cortical bone and is an extension of the jaw bone
What are the causes of changes in appearance of the lamina dura?
Infection X-ray tube angulation Occlusal stress Systemic disorders eg pagets or parathyroid disease Overlying anatomy Nutrient canals
With regards to traumatised teeth what are the potential fates of the pulp ?
Re vascularisation and Reinnervation
Aseptic pulp necrosis
Infected chronic AP
When comparing radiographs and CBCT which is more reliable in detecting RCT success?
CBCT- identified up to 14 x more failures
Patel et Al 2019
In trauma cases what radiographs are ideal?
Two PAs and occlusal view
Give three features pathognomic of a vertical root fracture
Single isolated pocket
Coronally located gingival fistula
Lateral radiolucency on X-ray
