Year 3, Sem 1 Flashcards
What is is the vertical angulation for B/W’s?
5-8 degrees
What are the 3 guiding principles for radiation exposure?
Principle of justification
Principle of optimization
Dose limitation
What are the layers of the imaging plate structure?
- Protective layer
- Phosphor layer (barium-fluorohalide)
- Reflecting layer
- Base
- Backing layer
If the epicentre of the lesion is above vs below the IAC, what is the origin?
Epicentre above IAC: odontogenic origin
Epicentre below IAC: non-odontogenic origin
Briefly describe mechanism of bisphosphonates
Potent suppressor of osteoclastic activity and slow the remodelling process of bone thus leading to an increase in mineral density. It becomes permanently incorporated into bone. Unfortunately, the increase in density of the mandible along with the reduction in blood supply renders the mandible susceptible to bone infection following trauma such as tooth extraction.
Signs of sinister lymph
Hard, fixed, immobile, firm, painless
Signs of sinister oral ulcer
Rolled margins, quick increase in size, non-healing, non-painful, fissuring/cracks, rough, thickened, bleeding spot, appearance of growth
List the 5 principles of the Ottawa Charter and give examples of intervention for each
- Building healthy public policy – community water fluoridation
- Creating supportive environments – healthy options available at school canteens
- Strengthening community action – engage the community to support water fluoridation
- Developing personal skills – discuss smoking cessation
- Reorient health services – educating primary health care workers on oral diseases
What is white sponge naevus?
- Rare
- Familial
- Appears at birth, childhood or adolscence
- Symmetric distribution, corrugated or velvety diffuse
- No tx required
What are fordyce spots?
- Ectopic sebaceous glands
- Common on buccal mucosa, lateral lip
- Yellowish
What is HHT- clinical features, where, tx?
- Uncommon
- Epistaxis
- Red papules 1-2mm, blanch on diascopy
- Located on lip, tongue, B mucosa
- Can be seen on hands, feet, GIT, genitourinary or conjunctival mucosa
- Tx: electro surgery, cryotherapy
What is smokers palate?
- No malignant potential
- Caused by heat
- >45 years age
- Palate is diffusely gray/white
- Slightly elevated papules with punctate red centres
- Tx: smoking cessation
What is leukoedema?
- Common, unknown cause
- Diffuse, grey/white, milky or opalescent
- Folded surface or appear as wrinkles
- Bilateral on B mucosa
- Disappear on stretching
Difference between petechiae, purpura and ecchymosis?
- Petechiae: minute haemorrhage
- Purpura: larger area affected
- Ecchymosis: accumulation over 2cm
Caused by trauma or bleeding disorder
What is fibro-epithelial polyp- what is it, where, clinical features, tx?
- Reactive hyperplasia of connective tissue in response to local irritation or trauma
- Most common on B mucosa
- Smooth surface pink nodule
- 1.5cm or less
- Asymptomatic unless ulceration
- Tx: conservative excision
What is pyogenic granuloma?
- Common tumour like growth caused by local irritaiton or trauma
- Smooth or lobulated
- Surface ulcerated, pink-red-purple
- Bleeds easily
- Can be seen on gingiva, lips, tongue and B mucosa
What is a melanotic macule?
- Flat, brown mucosal discolouration
- Most commonly affects lower lip, gingiva and palate.
- Hyperactivity of melanocytes
- Rarely present larger than 1cm
- Tx: biopsy, excise if in aesthetic zone
What is melanocanthoma?
- Relatively uncommon
- Diffuse, dark pigmentation of large mucosal area
- Asymptomatic, ill-defined, rapidly enlarging
- Tx: biopsy to exclude melanoma
What is smokers melanosis?
- Heavy smoking leads to it
- Response to irritation from tobacco smoke and heat
- Diffuse patchy pigmentation
- Usually seen in anterior md and mx gingiva
What is erythema migrans?
- Affects tongue
- Multiple well demarcated area of erythema/atrophy, surrounded partially by slightly elevated yellowish-white scalloped border
- Atrophy of filiform papillae
What is a hairy tongue?
- Accumulation of keratin of filiform papillae
- Inc keratin production or decreased desquamation
- Possible caused by: AB, poor OH, oxidizing MW, overgrowth of fungi/bacteria, general debilitation
Definition of Leukoplakia?
A predominantly white lesion of the oral mucosa that cannot be characterized clinically or pathologically as any other definable lesion
Difference between macule, papule, plaque, nodule, vesicle, bullae, erosion, pustule, ulcer
- Macule: well circumscribed, flat, change in colour
- Papule: solid raised lesion, <1cm
- Plaque: solid raised lesion, >1cm
- Nodule: solid elevated lesions, present deeper in dermis/mucosa
- Vesicle: elevated blisters containing clear fluid, <1cm
- Bullae: elevated blisters containing clear fluid, >1cm
- Erosion: shallow defect due to loss of epithelium up to basal layer
- Pustule: blisters containing purulent material
- Ulcer: discontinuation of epithelium of skin or mucosa
What is a cyst?
Epithelial lined pathological cavity containing fluid, semi-solid/gaseous material
What are features of jaw cysts?
- Sharply defined radiolucency with smooth borders
- Grow slowly
- Symptomless unless infected
- Rarely large enough to cause pathological fractures
- Fluid may be aspirated
What are characteristics of dentigerous cyst?
- Most common developmental odontogenic cyst
- Cyst encloses crown of an un-erupted tooth
- Formed by cystic changes in dental follicle
- Common in md 3rd molars
- Tooth missing or failed to erupt
- Asymptomatic unless infected
- Well-defined, sclerotic border
- Tx: extract and enucleation or marsupialise if favourable for eruption. If left untreated can transform to ameloblastoma
What are eruption cysts?
- Lies superficially in gingiva overlying unerupted tooth.
- Fluid accumulation within follicular space
- Soft rounded bluish swelling
- Rupture spontaneously upon eruption
What is an odontogenic keratocyst?
- Arise from cell rests of dental lamina
- Grow A-P without causing expansion
- High rate of recurrence
- Asymptomatic
- Well demarcated radiolucency with scalloped radiopaque margin
- May envelop an unerupted teeth without displacing them (would mimic dentigerous cyst)
- Tx: unilocular/small multilocular lesions- enucleation & curettage. Large cysts- excision
What is basal cell naevus syndrome associated with?
- Multiple OKC
- Multiple basal cell carcinomas of skin
- Cleft lip and palate
- Calcification of falx cerebri
- Frontal and parietal bossing
What are gingival cysts of adults?
- Rare
- Dome shaped swelling <1cm
- Sometimes erode underlying bone
- Tx: enucleation, unlikely to recur
What are gingival cysts of infants?
- Small, multiple, whitish nodules or cysts in gingivae
- Very common
- No tx required
What is lateral periodontal cyst?
- Uncommon developmental cyst
- Md premolar area along lateral root surface
- Well-circumcribed
- <1cm
- Tx: conservative enucleation
What is glandular odontogenic cyst?
- Rare
- Anterior region
- Well defined, sclerotic margin
- Small cysts asymptomatic
- Large cysts show expansion and sometimes paraesthesia
- Tx: conservative excision, strong tendency to recur
What is calcifying odontogenic cyst?
- Derived from odontogenic remnants in gingiva or bone
- Well demarcated margin, scattered irregular calcifications
- More common in mx
- More aggressive tx required
What are radicular cysts?
- Most common jaw cyst
- Slow progressing, painless swelling (unless infected)
- Rounded hard swelling initially
- Later becomes egg shell thickness, cracking sensation, fluctuant
- Non-vital tooth associated
- Bone resorption
- Sharply defined, condensed radiopaque periphery
- Adjacent teeth tilted/displaced
What are residual cysts?
- Common cause of swelling in edentulous jaw
- May persist after exo of causative tooth
- Oval/round radiolucency
What is lateral radicular cyst?
- Cyst at side of non-vital tooth
- Result of opening of lateral branch of root canal
How are radicular cysts treated?
- Exo and curettage
- RCT
- Enucleation
What are paradental cysts?
- Result from inflammation around partially erupted tooth
- Affected tooth is vital and shows pericoronitis
- Lower 3rd molars
- Tx: enucleation
What is nasopalatine duct cyst?
- Located within nasopalatine canal or incisive papilla
- Rare
- Slow growing, symmetric swelling
- Often asymptomatic
- Intermittent salty discharge
- Well defined radiolucency, sclerotic margin, may be heart shaped
- Tx: enucleation
What is nasolabial cyst?
- Soft tissue cyst of upper lip
- Uncommon
- Located deep to nasolabial fold
- Tx: simple excision
What is medial palatal cyst?
- Firm/fluctuant swelling of midline
- Asymptomatic
What is dermoid cyst?
Uncommon
Midline of FOM
Size varies
Slow growing, asymptomatic
Rubbery mass
What is solitary (simple) bone cyst?
- Benign, cavity with no epithelial lining (pseudocyst)
- More common in long bones
- Restricted to md
- Asymptomatic
- Well defined radiolucency, scalloping between roots
- Vital teeth, no root resorption
- Tx: surgical exploration and curettage
What is aneurysmal bone cyst?
- Blood filled spaces surrounded by cellular fibrous tissue
- More common in long bones
- Rapidly developing swelling
- Pain
- Malocclusion, mobility, resorption of involved teeth
- Tx: curettage or enucleation
Describe Herpes simplex- type 1&2
- Primary and recurrent infection
- Start with vesicles that rupture into shallow, round ulcers/ Ulcers may coalesce
- Fever
What is varicella (chicken pox)?
- Common in children
- Vesicles rupture to produce round/ovoid ulcers with inflammatory halo
What is zoster (shingles)?
- Reactivation of dormant virus
- Common over 50yrs
- Unilateral along distribution of trigeminal nerve
What is herpangina?
- Coxsackie virus
- Pain and burning on soft palate and uvula
- Numerous vesicles leading to scattered ulceration
- Febrile, cervical lymphadenopathy
What is hand foot and mouth disease?
- Coxsackie virus
- Vesicles rupture to cause small ulcers with erythematous halo
What is syphilis caused by?
Treponema pallidum
What is mycobacterium tuberculosis?
- Bacterial
- Uncommon
- Secondary to pulmonary infection
- Chronic ulcers
What are some haematological causes of ulcers?
- Iron, B12 or folic acid deficiency
- Leukaemia
- Neutropenia
What are some GI causes of ulcers?
- Coeliac disease
- Crohn’s disease
- Ulcerative colitis
What is recurrent aphthous stomatitis?
- Most common non-infectious, non-traumatic ulceration
- Recurrent episodes in otherwise healthy subjects
- Ulcers are superficial, round, with yellow slough and peripheral erythema.
- Predisposing factors are genetics, nutritional deficiencies, hormonal, stress, trauma, smoking
- Minor, major and herpetiform types
What is a minor aphthous ulcer?
- <1cm size
- Prodromal symptoms
- More common among females
- Heals 7-14 days without scarring
What is a major aphthous ulcer?
- 1-3cm
- Longer duration to heal
- Heals with scarring
- Deeper
What is necrotising sialometaplasia?
- Uncommon locally destructive inflammatory condition of salivary glands
- 75% in posterior palate
- 1-5cm size
- Heals spontaneously in 5-6 weeks
What are treatments for ulcers?
- Analgesics
- Antipyretics
- AB
- Improve OH, antiseptic mouthwash
- Eating, nutrition and fluid
What is nociceptive pain?
Pain that arises from actual or threatened damage to non-neural tissue and is due to activation of nociceptors
What is neuropathic pain?
Noxious stimuli are originated from abnormal neural structures (normal somatic structures, abnormal nerves)
What is evidence of neuropathic pain?
- Burning pain
- Spontaneous or triggered
- Ongoing and unremitting
- Disproportionate to stimulus
- May be accompanied by other neurologic signs
- No evidence of tissue damage
- Pain may be initiated or maintained by sympathetic nervous system
- Pain follows distribution of affected nerve
What is primary vs heterotopic pain?
- Primary: site and source identical
- Heterotopic: site and source different
Why can pain be referred from temporalis muscle to tooth?
Primary afferent of temporalis muscle has collateral branches to neuron of tooth
What structures pass through the infratemporal fossa?
- Temporalis muscle
- Lateral pterygoid muscle
- Medial pterygoid muscle
- Pterygoid venous plexus
- Mandibular nerve
- Posterior superior alveolar nerve
- Chorda tympani
- Otic ganglion
- Lesser petrosal nerve
What LA’s are Amides?
- Lidocaine
- Mepivacaine
- Prilocaine
- Bupivicaine
What LA’s are esters?
- Procaine
- Benzocaine
What is the %, vasoconstrictor, pulpal and soft tissue duration of lidocaine?
- 2% (44mg)
- 1:80 000 adrenaline
- Pulp: 55-90 mins
- Soft tissue: 3-5 hrs
What is the %, vasoconstrictor, pulpal and soft tissue duration of articaine?
- 4% (88mg)
- 1:100 000 adrenaline
- Pulp: 60-120 mins
- Soft tissue: 3-5 hrs
What can retroclination of upper incisors cause?
Stripping of labial gingiva of lower incisors
What is Bolk’s Theory of Terminal Reduction?
As a general rule, that if only one or a few teeth are missing, the missing germ will be the most distal tooth of any given type
What is Bimaxillary Protrusion and how is it treated?
Lips are full and incompetent because of procumbent incisors
Tx: retraction of the incisor segments to allow the lips to move lingually. This is done by extracting first premolars in both arches and retracting the incisor segments into the space made available by the extractions
What is leeway space?
Difference between the combined mesiodistal widths of the deciduous canine, 1st and 2nd molar and the permanent canine and 1st and 2nd premolars.
- Mx: 3mm
- Md: 5mm
What are space gaining strategies?
- S-Stripping (Interproximal)
- P-Proclination
- E-Expansion
- E-E space maintenance
- D-Distalisation (Headgear, Pendulum, Distal Jet, Jones Jig, etc)
- E-Extraction
How can mild crowding be relieved?
Expansion of arch in transverse dimension
What is sunday bite and its relevance?
When class II patients with md retrusion bite forward in order to “mask” their md deficiency. Important to assess this skeletal discrepancy.
Why should maxillary expansion be implemented before other skeletal alterations?
Transverse mx growth end earlier than growth in other directions
Why is early tx of class II div I not recommended?
Issues with relapse, stability and re-treatment. Burnout of pt cooperation can also result.
When should class II correction tx be managed?
Skeletal class II correction is usually attempted during a child’s pubertal growth spurt
- Females: 12
- Males: 14
Wait for eruption of premolars and permanent canines
Why should you assess the transverse plane during protrusion?
Ask pt to bite forward in edge-edge position and observe if there is a posterior crossbite. If there is, a mx expander will need to be used.
What are some appliances that correct class II?
- Twin block
- Bionator (causes md protrusion)
- Herbst (fixed)
- Jasper jumper
What is teuscher activator?
Stimulate growth of md while stopping growth of mx. Combined with headgear
What are options for class II skeletal pattern?
Growth modification
Camoflage
Surgery
How is class II div II managed?
Mx incisors should be proclined to normal position to prevent hindering md growth. Then undergo tx same as class II div I
What is class II camoflage treatment?
Extract upper 1st premolars then retract upper anteriors with fixed appliance. Molars will still be in class II relationship. Just reducing OJ and getting canines into class I relationship.
What does it mean if the patient can guide their mandible to an edge to edge position?
Their eitiology of class III is functional (pseudo class III)
What are negative factors for deciding whether to treat Class III malocclusion?
- Dolichofacial
- No anterior md shift
- Growth complete
- Severe skeletal disharmony
- Poor cooperation expected
- Class III familial pattern established
- Poor facial esthetics
What is the disadvantage of early treatment of class III’s?
Any tx even if successful is still hostage to future md growth and results may relapse and surgery or camouflage tx has to remain as a final tx option.
When is maxillary protraction most effective (class III correction)?
During pre-adolescence (7-10years)
What are examples of headgear for maxillary protraction (treating class III skeletal)
- Delaire Face Mask
- Reverse pull headgear
What is the most appropriate treatment for patients with retrusive maxilla in the late mixed dentition stage?
Protraction headgear to apply orthopaedic forces. To maximise skeletal change, simultaneous rapid mx expansion has been suggested.
When does greatest growth of maxilla occur?
6-8
How many hours of wear is needed to effectively protract the maxilla with headgear?
12-16 hours
What are the effects of chin cup and mandibular restraining on mandibular growth?
- Redirects md growth vertically but doesn’t affect growth velocity significantly.
- Backward md rotation and retroclination of lower incisors
- After using it, there is catch up growth which ultimately leads to relapse and no long term benefit.
Why does a flap need to have a broad base?
In order to ensure a good blood supply to keep tissue alive
What are the 2 basic types of flaps in oral surgery?
Random pattern: from the blood vessels in the area and not from a named anatomical vessel
Axial pattern: Particular artery e.g. palatal flap is based on greater palatine artery
How can bone be removed?
- Drill & bur
- Chisels or osteome
- Rongeurs (end/side cutting)
- Bone file
How does tranexamic acid work?
Antifibrinolytic agent- helps prevent breakdown of the clot.