Year 4 (Clinical) Flashcards
What are indications for surgical endodontics?
- Periradicular disease associated with a tooth where iatrogenic or developmental anomalies prevent non-surgical RCT being undertaken
- Periradicular disease in a root-filled tooth where non-surgical root canal retreatment cannot be undertaken or has failed or when it may be detrimental to the retention of the tooth
- Where a biopsy of a periradicular tissue is required
- Where visualisation of the periradicular tissues and tooth root is required when perforation or root fracture is suspected
- Where it may no longer be expedient to undertake prolonged non-surgical RCT because of patient consideration
Define molar incisor hypomineralisation (MIH)
Hypomineralisation of systemic origin of 1-4 first permanent molars and frequently incisors
What is the prevalence of MIH?
3.6-25% (1 in 10 people are affected)
What is the clinical presentation of MIH?
- Large demarcated opacities, whitish-yellow or yellowish-brown in colour
- May be associated with post-eruptive breakdown resulting in exposed dentine and sensitivity (this is usually associated with the molars and rarely the incisors)
What is the aetiology of MIH?
- Thought to occur between birth to 18 months
- Occurs due to disturbance during the maturation phase of amelogenesis which causes damage to the ameloblast
- Some of the causes of this disturbance include;
a) Asthma
b) Pneumonia
c) Otitis media
d) Antibiotics
e) Tonsilitis
f) Dioxins in breast milk
g) Hypoxia at birth
How do you diagnose MIH?
- By examining wet, clean permanent molars and incisors
- Done at the dental age of 8
- Clinical findings include;
a) Absence or presence of demarcated opacities
b) Post eruption breakdown
c) Atypical restorations (failed restorations are often due to fracture)
d) Extractions due to MIH
e) Failure of eruption of molars/incisors (severe MIH)
Describe the histological feature of MIH
- Increased carbon and magnesium
- Decreased calcium and phosphorus (which makes it much weaker)
- Decreased hardness and modulus of elasticity
- Increased vascularity (suggesting inflammatory changes within the pulpal tissues)
What are the dental problems associated with MIH?
- Poor aesthetics due to demarcation
- Increased sensitivity which may affect toothbrushing
- Increased caries level as their teeth break down much quicker
- Increased anxiety due to increased dental complication
When is the ideal time to extract a first permanent molar?
- At the dental age between 8-10 years old
- There should be radiographic evidence of calcification of the bifurcation of the second permanent molar teeth
- Ideally the third molars should also be present
List some of the treatments that could help patients with MIH
- Fluoride varnish
- Tooth mousse (casein phosphopeptide amorphous calcium phosphate) which works to remineralise teeth and helps with sensitivity problems
- Applying fissure sealant and pre treat with 5% sodium hypochlorite (if they are not broken down)
- Composite restorations (good aesthetics with superior wear resistance)
- Stainless steel crowns in teeth with post eruptive breakdown and those with cuspal involvement
- Cast gold/composite/ceramic onlays
- Microabrasion of anterior teeth with shallow defects
- Composite veneers
- Porcelain veneers in late adolescence
What are effects of non nutritive sucking (NNS) on the developing dentition?
- Decreased overbite or anterior open bite
- Increased over jet
- Higher incidence of class II canines or molars
- Narrowing of the maxillary arch and increased mandibular arch width (leading to increased possibility of cross bite)
What are non dental effects of NNS?
- Negative effect on breast feeding
- Increased risk of otitis media
- Increased risk of GI infection
- Increased risk of oral colonisation with candida
- Calloused and wrinkled digits
- Consumption of honey during first year of life is linked to infant botulism
What are benefits of NNS?
- Decreases peripheral sensitivity in newborns
2. Has a protective effect against Sudden Infant Death Syndrome (SIDS)
Describe the management of NNS
- Reminder therapy such as adhesive bandage on the finger
- Reward therapy
- Elastic bandage around the elbow at night
- Applying bitter tasting substance on finger
- A fixed appliance with molar bands and anterior crib
- Psychological assessment
At which age does the BSPD recommend to stop NNS?
By the age of 5
What are the different classification of crossbites?
- Skeletal: crossbite with underlying skeletal basis (due to constricted maxilla and wide mandible)
- Dental: crossbite due to distortion of dental arch when jaws are of normal proportion
- Functional: crossbite caused by occlusal interference that requires the mandible to shift to achieve maximum occlusion
What is the aetiology of local crossbite?
- Crowding (commonest cause): tooth is displaced from arch due to lack of space
- Early loss of second primary molar: causing the premolars to erupt buccal or lingual to the arch
- Over retention of primary tooth
- Trauma to primary tooth
How does NNS cause crossbite?
- Digit sucking is linked to posterior crossbite
2. This is due to forces exerted on the buccal segment as result of the negative pressure generated during digit sucking
Describe the management of a dental crossbite
- In the presence of a deep overbite, a posterior bite block is first needed to correct the overbite
- There must be adequate space in the arch to move the tooth into
- After the crossbite has been corrected an adequate overbite is recreated to create stability for the new occlusion
What kind of appliance is used to correct a crossbite?
Removable appliance
- Creates tipping movement
- Has good anterior retention
- Buccal capping is used to open up the bite
- Z springs are the active component used to create the tipping movement
What are the advantages of using a removable appliance?
- Easy to clean the teeth and appliance
- Can transmit forces to blocks of teeth
- Can tip teeth
- Removes occlusal inference
- Less chair-side time than fixed appliance
What are the disadvantages of using removable appliance?
- May be left out of the mouth
- Can affect speech
- Inefficient for multiple tooth movements
How often should patients with active removable appliance be seen?
Every 3-4 weeks as more frequent activation will increase risk of anchorage loss and root resorption
When would fixed appliance be indicated for the management of crossbite?
- When the apex of the incisor in crossbite is palatally positioned
- When there is insufficient overbite to retain the corrected crossbite (fixed appliance enables the lower incisors to be moved lingually at the same time as the upper is moved labially)
- When there are other aspects of malocclusion requiring fixed appliance are present
What are the advantages of fixed appliance?
- Reduces need for patient cooperation
- Increased control of tooth movements
- Movement is possible in all 3 planes of space
What occurs in an ectopic first permanent molar (FPM)?
When there is alteration of the molar’s eruption pathway leading to contact in the prominence of the distal surface of the second primary molar leading to surface resorption of the primary molar.
What are the two types of ectopic FPM?
- Reversible (jump)
2. Irreversible (hold)
What is the prevalence of ectopic FPM?
- 3-4% in the general population
2. 20% in the cleft lip population
What are the clinical presentation of ectopic FPM?
- Canting of the occlusal plane of the second primary molar
- Delayed eruption of the FPM
- Distal cusp of FPM appearing before the mesial cusp
- Mobile second primary molar
What is the radiographic presentation of ectopic FPM?
- Upper FPM is superiorly and mesially positioned
2. Atypical resorption of the upper second primary molar
When is FPM usually diagnosed?
Between the ages of 5-7
How do you manage ectopic FPM?
- Monitor: 66% are the jump type thus spontaneous self correction usually occurs
- Separation: for the hold type, eruption is aided by separating the second primary molar from the FPM with wedge/wire/elastic
When is a tooth defined as having delayed eruption?
When the tooth on one side of the arch has erupted and six months later there is no sign of the equivalent on the other side.
What are the generalised causes of delayed eruption?
- Down syndrome
- Cleidocranial dysostosis (congenital disorder where there is delayed ossification of midline structures)
- Gardner syndrome
- Cleft lip and palate
- Malnutrition
- Hereditary gingival fibromatosis
- Prematurity/low birth weight
What are localised causes of delayed eruption?
- Supernumerary tooth
- Congenital absence
- Crowding
- Delayed exfoliation of primary predecessor
- Traumatic injuries to primary teeth
- Dilaceration
- Primary failure of eruption
List features of supernumerary teeth
- The most common cause of delayed eruption of the maxillary permanent incisor tooth
- Prevalence of 2% in the permanent dentition and less than 1% in the primary dentition
- Supernumerary in primary dentition > supernumerary in the permanent dentition
- Commonly occurring in the maxillary midline and third molar area
What are the different classification of supernumerary teeth?
- Supplemental (resembles a tooth): usually at the end of a tooth series (2s, 5s and 8s)
- Conical (peg shaped): often presents as a mesiodens between upper central incisors (rarely delays eruption)
- Tuberculate (barrel shaped): commonly palatal to central incisors (classically associated with delayed eruption)
What are the two forms of odontomes (tumour of odontogenic origin)?
- Complex: totally disorganised
2. Compound: bear some similarity to normal tooth
What is the most common cause of dilaceration and at which age is the permanent tooth at most risk of damage?
- Intrusion or avulsion of A or B into the developing tooth germ
- Under the age of 3 is when trauma is most likely to cause dilaceration to the permanent successor as the tooth germ is undergoing development
What are the different managements of supernumerary tooth?
- When we notice supernumerary in a young child, we first observe it as not all supernumerary cause delay in eruption
- However when it creates an obstruction, we will surgically remove it
* in the case of delayed eruption of 1, removal of the supernumerary along with the C allows the 2 to drift into the space which promotes eruption of the 1
What is the prevalence of ectopic canine?
A prevalence of 1.5% with 85% being palatally displaced and 15% bucally. It is twice as common in females
What is the aetiology of ectopic canine?
- Polygenic and multifactorial
- Absent/diminutive lateral incisors
- Class II Div 2 malocclusion
- 8% of ectopic canines are bilateral which suggests a genetic link
What are the risks associated with ectopic canine?
- Root resorption of adjacent teeth
- Cystic changes
- Partial eruption subjects the tooth to the bacteria in the oral environment thus making them susceptible to infection
- Loss of arch length
What are the clinical signs suggestive of an ectopic permanent canine?
- Prolonged retention of the primary canine beyond 14 years
- Delayed eruption of the permanent canine
- Absence of labial canine bulge
- Presence of palatal bulge
- Distal tipping/mobility/loss of vitality of lateral incisors
When is cone beam CT indicated for ectopic canine?
To assess root resorption of the lateral incisor
What are the different treatment options for an ectopic canine?
- Extraction of the primary canines before the age of 11: as 78% revert to normal path after the extraction
- No active treatment: to monitor the ectopic canine and maintain the primary canine
- Auto transplantation of the canine: must be done as atraumatic as possible to avoid ankylosis
- Extraction of the ectopic canine and movement of the first pre molar to fill the space
- Prosthetic replacement of the canine
- Surgical exposure of the ectopic canine and orthodontic alignment of the tooth into the arch
What causes infraocclusion of teeth?
- As a result of ankylosis, the tooth remains static
- However eruption of adjacent teeth continues
- This results in the infraocclusion tooth lying below the occlusal plane
What is the prevalence of infraoccluding primary molars?
- It has a prevalance of 9%
- It is x10 more common in the primary dentition
- Usually develops during the early mixed dentition
- May affect both the maxilla and mandible
- May be bilateral or unilateral
When is surgical intervention of the infraoccluded primary molar indicated?
- When the infraoccluded tooth has reached below the gingival margins
- When the FPM (6) has tipped over it
What are the three severity of infraocclusion?
- Slight submergence: the entire occlusal surface is located at least 1mm below the occlusal plane of the adjacent non-ankylosed teeth
- Moderate submergence: the entire occlusal plane is located approximately level with the contact area of one or both adjacent tooth surfaces
- Severe submergence: the entire occlusal surface is level with or below the gingival margin of one of both adjacent tooth surfaces
What are the consequence of infraoccluded teeth?
- Delayed exfoliation (by 6-12 months compared to contralateral tooth)
- Denuding of proximal root surface
- Increased difficulty of extraction
- Reduced alveolar bone support
- Progression of submergence
- Delayed eruption of successor
- Over eruption of opposing tooth
- Damage to adjacent teeth
What are the effects of infraoccluded primary molar to the adjacent teeth?
A) Damege
1. Carious lesion to the adjacent FPM as patient in unable to clean the area
2. Exposed cementum on the mesial aspect of FPM may cause loss of periodontal attachment
B) Tipping
1. When the trans-septal fibres that link approximal root surfaces together are pulled below the occlusal plane, it causes tipping of the adjacent teeth
C) Retained Root Fragments
1. This may be retained when a brittle ankylosis tooth is extracted or may occur when infraoccluded tooth exfoliates
Define hypodontia
The developmental absence of one or more teeth in the primary or permanent dentition excluding third permanent molars
What is the prevalence of hypodontia?
- 0.1-0.9% in the primary dentition
- 3.5-6.5% in the permanent dentition
- Mandibular second premolar > maxillary lateral incisor > maxillary second premolars > mandibular incisors
What is the aetiology of hypodontia?
A) Environmental 1. Infection: rubella, osteomyelitis 2. Trauma 3. Drugs: thalidomide 4. Chemotherapy 5. Radiotherapy B) Genetic 1. Autosomal dominant trait with incomplete penetrance
What are the presentation of ectodermal dysplasia?
- Multiple missing teeth (a syndrome linked to hypodontia)
- Fine sparse hair
- Maxillary hypoplasia (lack of bone to lack of teeth)
- Eversion of the lips
- Pigmentation around eyes/mouth
- Small conical teeth
What is the genetic basis of ectodermal dysplasia?
Commonly X linked hypohydrotic form
What are the dental manifestations of Down syndrome?
- Hypodontia (prevelance of 40-60%)
- Microdontia (small teeth)
- Ectopic canine teeth
- Taurondontism (long coronal aspect of root canal usually occurring in the FPM)
- Infraocclusion
What is the management of hypodontia?
- Accept the space present
- Space closure
- Redistribution of space
- Removable partial denture
- Adhesive and conventional bridgework
- Transplant
- Implants
What are the factors contributing to high frequencies of medical emergencies in the dental practice?
- High anxiety and stress
- Medically compromised patient
- Physiological stress
- Potent drugs used in dentistry
What are the common cause of collapse?
- Cardiac arrest
- Fainting
- Hypoglycaemia
- Anaphylaxis
- Epilepsy
- Steroid insufficiency
What is the cause of cardiac arrest?
- Sudden loss of an effective heartbeat resulting in acute failure of cardiac output
- This could develop as result of
a) Myocardial infarction
b) Hypoxia
c) Severe hypotension from other cause
d) Respiratory arrest
e) Anaesthetic overdose
What kind of heart rhythm would you see in patient who are having a cardiac arrest?
- Ventricular fibrillation (where the heart looks like a bag of worms)
- In this scenario you can use a defibrillator which stops the heart momentarily to allow the nodes to regain control of coordinating the heart muscles
What are signs and symptoms of a cardiac arrest?
A) Immediate Signs 1. Sudden loss of consciousness 2. Absent pulse B) Late Signs 1. Cyanosis 2. Dilated pupils and absent light reflex 3. Unmeasurable BP
What is the management of cardiac arrest?
- Lay patient flat or head down
- Get help
- Starts BLS
What are steps that could be taken to prevent patients fainting in the surgery?
- Note any previous history
- Check that patient has eaten
- Comfortable environment
- Minimise stress
- Lie patient supine when giving LA
What are signs and symptoms of fainting?
- Patient feel dizzy, weak and nausea (can prevent faint by lying them down)
- Pale, cold and clammy skin
- Loss of consciousness
a) Shallow and irregular breathing
b) Pulse is weak, threads and slowly
c) BP drops
d) Muscle twitching and convulsion (this happens if you don’t lay them down flat)
What causes postural hypotension?
- Prolonged periods of lying down
- Common in the elderly
- Common in patient on anti hypertensive
- Influenced by alcohol
What is the signs and symptoms of postural hypotension and its management?
A) Signs and symptoms 1. Collapsing on standing B) Management 1. Lay patient flat or head down 2. Slowly transition the patient to standing
What are the signs and symptom of hypoglycaemia?
A) Effects on brain 1. Increasing drowsiness 2. Disorientation 3. Excitability 4. Slurred speech B) Effects due to release of adrenaline (sympathetic response) 1. Shaking 2. Sweating 3. Palpitation 4. Pins and needles
What is the management of hypoglycaemia?
A) Conscious patient 1. 50g of glucose orally (as a drink) 2. Alternative: any other forms of sugar B) Unconscious patient 1. 1mg glucagon IM 2. Alternative: 50ml of 30% glucose IV 3. Put the patient in recovery position 4. Once the patient gains consciousness > administer glucose
What common causes of anaphylaxis in the dental practice?
- Drugs such a penicillin or LA agent
- Latex
- Chlorhexidane
What are the signs and symptom of anaphylaxis?
- Facial flushing/swelling
- Urticaria (hives)
- Wheeze/difficulty breathing
- Loss of consciousness
- Rapid weak pulse
- Falling BP
- Pallor going in cyanosis
- Cardiac arrest (end result)
What is anaphylaxis?
A severe and systemic type I hypersensitivity reaction
What is the management of anaphylaxis?
- Lay head down and maintain airway
- Oxygen
- 0.5ml if 1:1000 adrenaline IM
- Call for medical help
- Additional medication:
a) Antihistamine: chlorphenamine 10-20mg IV
b) Hydrocortisone: 200mg IM or IV (helps with mast cell degranulation)
What are the signs and symptoms of epilepsy?
A) Aura phase 1. The part affected depends on the part of brain having excessive activity (could be hearing etc) B) Tonic phase (muscles contract) 1. Loss do consciousness 2. May cry out or become cyanotic C) Clonic phase 1. Jerking of limbs 2. Tongue may be bitten 3. Incontinence or frothing at mouth
What is the management of epilepsy?
A) During fit 1. Protect patient from injury B) After fit 1. Recovery position 2. Maintain airway C) When conscious 1. Sympathy and reassurance 2. Observe until fully recovered 3. Send home with escort
How does status epilepticus vary from grand mal seizure?
Status epilepticus involves prolonged and repeated fits which leads to inability of the brain to go back to its normal state
What is the management of status epilepticus?
- After 5 minutes of continuous fits, administer 10mg of liquid midazolam bucally
- Alternative: diazepam 10mg IV
- Monitor respiration (as midazolam is a respiratory depressant)
- Give oxygen
- Call for help
What are the two main causes of a steroid collapse?
- Primary adrenal insufficiency (Addison’s disease)
2. Secondary adrenal insufficiency due to chronic steroid use
How is steroid cover provided?
A) Minor surgery
1. Double the normal dose of oral steroid the night before and day of operation
2. 100mg hydrocortisone IM 30mins before or IV immediately before the procedure
B) Major surgery
1. 200mg hydrocortisone IM 30 minutes before or IV immediately before the procedure and 6 hourly for up to 72 hours
What are the signs and symptoms of a steroid collapse?
- Pallor
- Loss of consciousness
- Rapidly falling blood pressure
- Weak pulse
- Failure to regain consciousness when laid flat