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Ortho questions Flashcards

1
Q

Name methods to prevent decalcification other than FV?

A
  • Careful case selection
  • fissure sealants
  • fluoride supplements ( tablets , drops)
  • fluoride mouthwash 225ppm
  • High strength fluoride toothpaste
  • OHI - correct toothbrushing and use of interdental brushes beneath wire and around brackets 2x daily
  • Diet advice
  • Regular hygiene appointments
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2
Q

List 8 other potential risks of orthodontics other than decalcification?

A
  • relapse
  • root resorption
  • gingival recession
  • trauma
  • failure to complete treatment
  • ulceration
  • TMJ problems
  • Risk of periodontal disease
  • wear of adjacent teeth
  • loss of periodontal support and vitality
  • mucosal irritation
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3
Q

How would you assess a patient anterior-posterior relationship?

A
  • visually with Frankfort plane parallel to floor
  • Palpate skeletal bases at at two points (upper , lower)
  • By lateral cephalometry - SNA - SNB = ANB
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4
Q

What are the classes of AP relationships?

A
  • Class 1 - maxilla 2-3mm in-front of mandible (ANB 2-4)
  • Class 2 - maxilla more than 2-3mm infront of mandible (ANB more than 4)
  • Class 3 - mandible infront of maxilla (ANB less than 2)
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5
Q

Name 4 special investigations an orthodontist would do?

A
  • Clinical photographs
  • Study models
  • Radiographs - OPT , lateral ceph
  • Sensibility testing
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6
Q

Class 3 incisor relationship definition?

A
  • Lower incisors edge lie anterior to the cingulum plateu of the upper central incisors
  • Overjet is reduced or reversed
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7
Q

Name 8 intra-oral features of a class 3 malocclusion?

A
  • reduced overbite , AOB may be present
  • Posterior buccal or anterior crossbite
  • reverse overjet
  • maxilla often crowded
  • mandible often aligned or spaced
  • proclined upper incisors
  • retroclined lower incisors
  • tendency for displacement upon closing
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8
Q

What systemic disease causes the mandible to grow?

A

Acromegaly

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9
Q

How is a Class III malocclusion managed?

A
  • Accept and monitor - if mild and pt still developing
  • interceptive ortho URA - correct incisor relationship
  • Growth modification ( functional appliance , headgear with RME to reduce and redirect mandibular growth , TAD’s)
  • Camouflage - accept underlying skeletal base and correct incisors to class I
  • Combined orthognathic and orthodontic treatment to correct functional and appearance issues
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10
Q

What functional appliances can be used for class III relationship?

A
  • reverse twinblock
  • frankel III
  • chin up
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11
Q

Pt with anterior cross-bite
When is it best to begin ortho treatment?

A

Intercept as soon as detected with URA

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12
Q

Anterior crossbite involving 21

What featured of the malocclusion makes it suitable for treatment with a URA?

A
  • Tooth in cross-bite is palatally tipped
  • Good overbite (aids stability)
  • Adequate space to move the teeth forward
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13
Q

Design a URA for fixing an anterior crossbite involving 21?

A

A - z spring on UR1 0.5 HSSW
R - adam’s clasp 16,26 0.7 mm HSSW + URd , ULd 0.6mm HSSW
A - only moving one tooth
B - selfcure PMMA with FPBP

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14
Q

URA for posterior cross bite

A

A - midline palatal screw
R - 16 + 26 + 24 + 14 adam’s clasp 0.7mm HSSW
A - reciprocal anchorage
B - self cure PMMA - posterior bite plane

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15
Q

URA for retracting canines

A

A - Palatal finger spring + gaurd ; 0.5mm HSSW
R - 6s adam’s clasp , 11+ 12 south end clasp 0.7mm HSSW
A - only moving 2 teeth
B - self cure PMMA

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16
Q

URA for moving canines palatally

A

A - buccal canine retractor + tubing
R - adam’s and south end clasp
A - y
B - selfcure PMMA

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17
Q

URA for overbite

A

A - robert’s retractor with I.D tubing
R - adam’s clasp 6s
A - y
B - self cure PMMA with anterior bite plane OJ +3mm

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18
Q

What syndromes are associated with hypodontia?

A

Cleft lip and palate
Reiger syndrome
Ectodermal dysplasia
Down’s syndrome

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19
Q

How may hypodontia present to you as a GDP?

A
  • delayed or asymmetrical eruption
  • retained or infra-occluded deciduous teeth
  • Ectopic canines
  • Absence of decidious teeth
  • tooth malformation
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20
Q

Name members of MDT involved in treating hypodontia?

A
  • othodontist
  • restorative dentist
  • paediatric dentist
  • speech and language therapise
  • Clinical psychologist
  • Oral surgeon
  • GDP
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21
Q

What factors can make early loss of primary teeth worse?

A
  • Age of patient - early extraction is worse as will lead to premature eruption of permanent teeth
  • space loss
  • losing the E’s lead to issues with position of 6
  • If it occurs in the maxilla its worse as more space is lost in upper than lower
  • in crowded arches lead to evident space loss
  • If it is in the anterior teeth will lead to psychological consequences affect appearance
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22
Q

When might you consider a balancing extraction of a primary tooth?

A
  • balancing extractions are extraction of the same tooth in the same arch , this is to avoid centrelines shiftor relieve crowding
  • Primary canines for centreline shift
  • First primary molars for crowding
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23
Q

Give 4 reasons for an unerupted 1?

A
  • supranumerary teeth (tuberculate)
  • Trauma to A
  • Crowding
  • Pathology - dentigerous cyst
  • Ankylosis
  • Genetics
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24
Q

What are the treatment options for an impacted 11?

A
  • Accept and monitor
  • Surgical exposure and bonding using gold chain (over age of 9) using orthodontic traction
  • XLA of supernumerary teeth if present
  • Surgical extraction of 11
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25
Q

What is the BSI definition of Class II div 1 ?

A
  • The lower incisor edges lie posterior to the cingulum plateau of the upper incisors
  • Increased Overjet
  • Upper incisors proclined or of average inclination
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26
Q

What dental features are seen in class II div 1 patients?

A
  • proclined upper incisors or of average inclination
  • Increased OJ
  • Class 2 molars and canines
  • overbite varies
  • parted lips may lead to dry gingivae and can exacerbate gingivitis
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27
Q

What soft tissue features are associated with Class II div 1 patients?

A
  • Incompetent lips due to incisor or skeletal relatoinship
  • difficulty to achieve an anterior oral seal
  • May have lip trap or tongue thrust
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28
Q

What are the 6 features of a twin-block appliance?

A
  • consist of two separate bite blocks
  • can have an expansion screw to widen the maxilla
  • Has a anterior bow
  • Adam cribs on teeth
  • removable
  • worn for 9-18 months
  • deterrent rake can be added to prevent NNSH ( non - nutrusive sucking habit)
  • can be adjusted to accommodate any changes
  • have an interlocking mechanism
  • tooth borne
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29
Q

How long should a twin block be worn for?

A

9-16 months

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30
Q

What makes a class II div 1 ammedable to correction with a functional appliance?

A
  • Very mild class II
  • Overjet is due to proclined or spaced incisors
  • There is a favourable overbite
  • only after specialised assessment

Usually URA have a very limited role in the treatment of inc overjet

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31
Q

How is the mandible postured when wearing a functional appliance?

A
  • forward and downward
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32
Q

What are the treatment options for class 2 div 1

A
  • accept and monitor
  • Growth modification :twin block, frankel II , headgear or herbst
  • URA - limited use but can use robert retractor
  • fixed appliances
  • Orthognathic surgery - when growth is complete and in severe cases
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33
Q

What is dentoalveolar compensation?

A
  • A system the maintain normal inter-arch relationship by the mouth anatomical structures
  • normal occlusion can normally be maintained by dento-alveolar compensation
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34
Q

Example of dentoalveolar compensation in class III malocclusion

A

Tongue Procline upper incisor
Lower lip Retrocline lowers

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35
Q

What 4 special investigations are done for class III patients?

A
  • study models
  • clinical photographs
  • radiographs : lateral ceph ; OPT ; CBCT
  • Planning models (Kesling) : setting up teeth to desired occlusion with wax
  • sensibility testing
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36
Q

Define supernumerary teeth

A
  • Tooth or tooth like entity found in the mouth which is additional to the normal series
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37
Q

What is the incidence of supernumerary teeth?

A
  • most common in males
  • found in anterior maxilla mostly
  • 1% in primary and 2% in permanent
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38
Q

What are the types of supernumerary teeth?

A
  • Conical
  • Tuberculate
  • Supplemental
  • Odontome
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39
Q

What is a conical supernumerary?

A
  • small peg shaped tooth
  • close to midline
  • Usually 1 or 2 in number
  • May erupt but tend to prevent eruption
  • May be high, inverted and symptoms free
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40
Q

What is a tuberculate supernumerary?

A
  • Often paired and barrel shaped
  • most common caused of failure of eruption of upper incisors
  • Tend to not erupt
  • need to be extracted
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41
Q

What is supplemental supernumerary?

A
  • extra teeth of normal morphology
  • usually an upper lateral or lower incisor
  • can be 3rd premolar or 4th molar
  • Often extracted due to form and position
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42
Q

What is an Odontome supernumerary tooth?

A
  • Irregular mass of dental hard tissue
  • can be compound which are discreet denticles
  • can be complex as disorganised mass of dentine, pulp and enamel
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43
Q

What are 6 effects of supernumeraries on the permanent dentition?

A
  • Diastemas
  • Impaction (tuberculate cause impaction of 1)
  • Displacement (crowding/spacing)
  • Cyst formation
  • Root resorption of surrounding teeth
  • Crowding
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44
Q

What is mandibular displacement on closing?

A
  • occurs when there is an inter-arch width discrepancy
  • resulting in upper and lower teeth to meet cusp to cusp
  • resulting in the mandible to be deviated to one side upon closing to achieve intercuspal contact position
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45
Q

Why would you correct a mandibular displacement?

A
  • May cause TMD (best to intercept early)
  • Tooth wear can occur
  • May cause facial asymmetry
  • May cause centrelines shift
  • Teeth erupt in displaced ICP position
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46
Q

What would you use to correct a unilateral posterior crossbite?

A
  • maxillary expansion with :
    URA
    Quadhelix
    rapid maxillary expansion
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47
Q

Design a URA for someone with unilateral posterior crossbite

A

A - midline palatal screw 0.5 HSSW
R - Adam’s clasp on 6s and 4s or ds 0.7 HSSW (0.6 for primary)
A - reciprocal anchorage
B - Self cure acrylic + FPBP (must incorporate all posterior teeth to prevent unwanted tooth eruption)

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48
Q

Child present with ulceration , what 8 questions would you ask?

A
  • where is the ulceration?
  • is it getting better or worse?
  • when did it appear?
  • is there any blisters associated ?
  • have these symptoms happened before?
  • Is there any other area affected?
  • Are there any other symptoms?
  • Any other associated skin lesions?
  • Any symptoms on the lips?
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49
Q

Patient present with ulcers on the lips what should you see intraorally ?

A

Herpes simplex primary infection
* Painful Erythmatous Swollen Gingivae
* Ulcers on lips, Gingivae and Extraoral mucosa
* Halitosis
Herpes labialis
* only present Extra-orally

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50
Q

Give uses of URA other than tipping and tilting of teeth

A
  • Reduce overbite, overjet and crossbite
  • Habit breaker
  • Space maintainer
  • Used as a retainer (HAWLEY)
  • Expanding the arch
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51
Q

Write a prescription for URA to reduce a 6mm overjet and reduce overbite

ex question :
Write a prescription for a URA to reduce a 6mm OJ
1st premolar have been extracted and previous URA retracted canines and reduced the overbite , pt has permanent dentition

A

A - Robert’s retractor with I.D tubing 0.5mm HSSW
R - Adam’s clasp on 16,26 - 0.7mm HSSW , Stops mesial of 23,13 0.6mm HSSW
A - ✔
B - self cure acrylic PMMA ; FABP (9mm)

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52
Q

List 6 signs of good wear and compliant patient on a URA on visit

A
  • URA active component passive
  • Signs of wear on URA ( acrylic part)
  • patient can speak well with appliance
  • no excess salivation
  • patient can insert and remove URA easily
  • teeth have moved (1mm per month)
  • patient arrives wearing the URA
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53
Q

What are the difficulties experienced when wearing a URA?

A
  • May have speaking difficulties at first - practice speaking with URA in loudly
  • Excess salivation at first - should resolve within 24h
  • May feel big and bulky but will get used to this
  • Once activated may feel discomfort/pain but this means that the appliance is working
    *
54
Q

What instructions would you give to a patient wearing a URA?

A
  • wear appliance 24/7 inculding meal times
  • Avoid hard or sticky foods
  • Take out and clean with soft brush after every meal
  • Store in a safe container when playing contact sports
  • non compliance will lengthen the treatment time
  • be careful with hot foods and drinks
  • give contact details in case of complications or failure of components
55
Q

Outline the steps for delivering a URA?

A
  • Check correct appliance for correct patient
  • Check it matches prescription
  • Check for any sharp edges and smooth
  • Check wire integrity for areas of damage
  • Try in the patient mouth
  • Check for any signs of blanching, damage or trauma to soft tissue
  • Check occlusion - flyover > arrowhead > anterior retention
  • Adjust active component - 1mm movement per month
  • Demonstrate to patient correct insertion and removal
56
Q

When should you review a pt after giving them a URA?

A

Every 4-6 weeks

57
Q

What factors can resist displacement forces of URA? (5)

A
  • gravity
  • mastication
  • tongue
  • talking/vibrations
  • Active components
58
Q

Patient has a 12mm overjet, well aligned arch and ectopic canines

What are the possible complications for these features?

A
  • poor appearance - psychological effect
  • Risk of trauma
  • Root resorption of adjacent teeth
  • Xerostomia
  • Displacement on opening
  • difficulty with mastication and speaking
59
Q

What are the dental advantages and disadvantages of fixed dental retainer

A

Advantages
* does not need compliance
* good aesthetics
* no occlusal interference
* does not affect speech
*Cheap and easy to make
Disadvantages
* Only retains anteriors
* Oral hygiene issue
* Tooth is prepped with etch
* composite can debond
* high failure rate ( 50% debond in first 6 months)

60
Q

What are the advantages and disadvantages of pressure vacuum formed retainer? (thermoplastic)

A

Advantages
* good aesthetics
* include all teeth
* cheap and easy to make
* good cooperation
* removable
* no prep to teeth
* does not cover palate
Disadvantages
* occlusal interference
* easily lost
* not as strong and resilient
* can be used for wrong purposes

61
Q

What are the advantages and disadvantages of HAWLEY retainer?

A

Advantages
* removable
* incorporated all teeth
* no occlusal interference
* no prep to teeth
Disadvantages
* problem with compliance
* poor aesthetics
* big and bulky
* interfere with speech
* expensive

62
Q

What information to provide to orthodontist regarding if pt needs ortho tx?

A
  • patient details - name, DOB, CHI, address
  • History (all)
  • Orthodontic examination findings :
    CO;HPC; expectations
    Skeletal base A/P , vertical , transverse
    Incisor relationship
    IOTN score
  • radiographs
  • study models
  • photographs
63
Q

During treatment , patient has a debonded bracket and demineralisation around remaining brackets , how would you manage this?

A
  • never rebond the bracket
  • Account for the components and ask how this happened ( refer to A&E) if suspected possible aspiration risk
  • If wire is circular = remove ligature - take bracket off and give to pt
  • Square wire = move bracket to side - clean underneath and show pt how to clean
  • Give OHI regarding Fluoride use and apply FV to areas of demineralisation and explain to pt why it happens and how to prevent
  • Refer back to ortho to replace bracket
64
Q

child with removed ortho appliance due to poor compliance attends and asks about XLA of upper incisors and upper partial denture

What would be the potential long term risks of XLA of upper incisors?

A
  • Spacing
  • drifting of adjacent teeth
  • problems with mastication
  • aesthetic problem
  • resorption of alveolar bone
65
Q

child with removed ortho appliance due to poor compliance attends and asks about XLA of upper incisors and upper partial denture

What would be the potential long term risks of the RPD?

A
  • increased plaque and increase of caries due to poor OH
  • Increased risk of periodontal disease
  • Poor aesthetics - psychological effects
  • Harder to wear than fixed appliances
66
Q

child with removed ortho appliance due to poor compliance attends and asks about XLA of upper incisors and upper partial denture

he does not want to wear a denture and asks for crowns, what would you advise against this option?

A
  • Destructive - healthy tooth tissue will be removed
  • More expensive than RPD
  • Poor OH contraindicate crown placement
  • Periodontal disease or recession will occur around crown due to poor OH resulting in an unaesthetic appearance
67
Q

What are the oral signs of digit suckinig?

A
  • Proclination of upper incisors
  • Retroclination of lower incisors
  • Localised AOB or incomplete OB
  • Unilateral posterior Crossbite
68
Q

What additions can be made to URA to break the habit of thumb sucking?

A
  • Deterrent rake
  • Hawley retainer (thumb appliance)
  • Palatal crib
  • Bluegrass appliance
69
Q

Explain the effect of prolonged sucking habit on posterior dentition?

A
  • thumb held in the mouth causes the mandible to drop open and and the tongue lies in a lower position
  • this means the sucking action on the cheeks lead to narrowing of the maxillary dentition leading to posterior cross-bite (often unilateral)
70
Q

What 4 methods can be used for stopping NNSH?

A
  • Positive reinforcement
  • Habit breaker URA
  • Plaster on finger
  • preventative nail varnish
  • Gloves
  • Fixed appliance with anterior rake habit breaker
71
Q

What is the incidence of cleft lip and palate in the uk?

A

1:700 births
more common in males

72
Q

What are the general health implications of CLP? (6)

A
  • Hearing problems - otitis media with effusion (glue ears)
  • Respiratory problems
  • Higher risk of infection
  • Problems with speech and mastication
  • Poor aesthetics
  • Congenital cardiac problems - atrioventricular canal defect
73
Q

What are the dental features of cleft lip and palate?

A
  • Increased caries risk
  • High and narrow palate
  • Hypodontia
  • Crowding
  • Growth problems - Class III malocclusion
  • Impacted teeth
74
Q

Outline 5 treatment stages of CLP patients?

A

3 months - lip closure
6-12 months - palate closure
8-10 years - alveolar bone graft
12-15 years - definitive orthodontics
18-20 years - orthognathic surgery

75
Q

What causes CLP?

A

combination of
* genetic = syndromes, sex ratio, family history
* environmental = smoking, alcohol, multivitamins, anti-epileptics

76
Q

What 5 members are involved in the management of CLP patients?

A
  • maxillofacial surgery
  • Cleft nurse
  • Speech therapist
  • ENT; respiratory team
  • Geneticist
  • Psychologist
  • Dental team : Paeds, ortho, restorative, oral surgeon
77
Q

What are the common complications of orthodontics?

A
  • relapse
  • gingival recession
  • root resorption
  • decalcification
78
Q

How is relapse managed ?

A
  • patient education and consent that ortho treatment require long term retention through a retainer at the end of treatment or teeth will revert back to previous alignment
  • Explain that retainers should be worn lifelong to maintain orthodontic treatment results
79
Q

How is decalcification managed?

A
  • Patient education about the importance of oral hygiene compliance
  • Use of fluoride toothpaste and supplements
  • Education about Diet - cut out sugars
  • FV can be applied
80
Q

How to manage recession ?

A
  • Patient education on importance of OH and OHI
  • Gingival recession may be exacerbated by poor OH
  • Tooth movement and brackets close to gingiva may cause some slight gingival recession
81
Q

How to manage root resorption ?

A
  • Explain to patient the risk of root resorption due to tooth movements and that it is minimal for about 1mm
  • Excessive forces are limited in ortho
  • Take pre and post tx OPT and PA to assess bone levels
82
Q

Give other linked complications to ortho other than the main risks? (8)

A
  • loss of vitality
  • Trauma
  • Mucosa irritation
  • Periodontitis or gingivitis
  • Failure to complete treatment
  • Wear of adjacent teeth
  • TMJ problems
  • Ulceration
83
Q

What are SnA , SnB and ANB

A

These are angles that measure the following:
* SnA - the anterio-posterior position of maxilla to the anterior cranial base
* SnB - the anterio-posterior position of the mandible to the anterior cranial base
* ANB = SnA-SnB - the anterio-posterior position of the maxilla to the mandible

84
Q

What are the average values of SnA , SnB and ANB?

A

SnA = 81 ± 3
SnB = 78 ± 3
Anb = 3 ± 2

85
Q

What is the average FMPA angle?

A

27 ± 4

86
Q

What is the average incisor inclination

A

Upper = 109 ± 6
Lower = 93 ± 6

87
Q

What is the ANB for Class I , Class II, Class III patients

A

Class I - 2-4
Class II - more than 4
Class III - less than 2

88
Q

What percentage of 6-18 year olds have a diastema?

A

98% - 6 years old
49% - 11 years old
7% - 12- 18 years old

89
Q

Give reasons for a diastema? (6)

A
  • pathological causes
  • proclined upper incisors
  • generalised spacing
  • midline supernumerary ( tuberculate)
  • hypodontia
  • Prominent frenulum
90
Q

How are diastema’s managed?

A
  • Accept and monitor - may correct with growth
  • Treat the underlying cause
91
Q

How to treat a diastema cause by generalised spacing?

A

Orthodontic management with or without restorative input

92
Q

How to treat a diastema caused by hypodontia?

A

Orthodontics ± restorative management

93
Q

How to treat a diastema caused by proclined upper incisors?

A

URA

94
Q

How to treat a diastema caused by prominent frenulum?

A

Oral surgery to remove/reduce frenulum

95
Q

How to treat a diastema caused by pathological causes ?

A

Oral med , oral surgery or maxfax

96
Q

How to treat a diastema caused by a supernumerary tooth?

A

Oral surgery and orthodontics

97
Q

What primary teeth are mostly infra-occluded?

A

lower D’s
more common in mandible
8-14%

98
Q

How infra-occluded teeth appear clinically?

A
  • metallic sound on percussion
  • found lower in the arch compared to adjacent teeth
  • no physiological mobility
99
Q

How does infra-occluded teeth show radiographically?

A
  • blurring or absence of PDL on radiograph
  • external root resorption
100
Q

What factors determine the management of infra- occluded teeth?

A
  • presence or absence of permanent successor
  • degree of infra-occlusion
  • age of development
101
Q

What are the treatment options for infraoccluded teeth?

A
  • if permanent successor is present - monitor for 1 year as it may self fix , if it does not then extract
  • If no permanent successor XLA as condition will worsen
102
Q

Name components of a fixed appliance?

A
  • bracket/tube
  • bands
  • modules - help bracket and wire to connect
  • Auxiliaries - depends on type of movement achieved
  • anchorage components
  • force generating components
103
Q

What are the components of a bracket?

A
  • bracket slot
  • tie wings
  • bracket base
104
Q

What materials can be used for brackets?

A
  • metals ( Cocr, Au , Ti , SS)
  • Polymers
  • Ceramics
105
Q

What is required before placement of bands?

A
  • separator as it requires space
106
Q

What material is used for bands?

A

Stainless steel with pre-welded attachments (tube or cleats)

107
Q

When do we use fixed appliances?

A
  • alignment of teeth
  • correction of mild to moderate skeletal discrepancies
  • corrections of rotations
  • centreline correction
  • overbite and overjet reduction
  • closure and creating of space
  • vertical movements of teeth
108
Q

What materials can be used for the archwire?

A

SS , NiTi , CoCr, TMA (beta-titanium)

109
Q

How does tooth movement work?

A
  • when an external force is applied to a tooth , movements occur due to bone remodelling occur mediated by the PDL
  • Orthodontic appliances transmit forces to PDL and bone resulting in osteoclast and osteoblast activity leading to tooth movement

cementum more reistant to resorption than bone

110
Q

What are the three theories of orthodontic tooth movement?

A
  • differential pressure theory
  • piezo- electric
  • mechano-chemical theory
111
Q

Describe the Piezo electric theory of movement ?

A
  • piezo electric current generated when bone is deformed
  • which cause movement
  • these currents are short lived and very small so unlikely to play a big role in remodelling
112
Q

Briefly describe the differential pressure theory of tooth movement

A
  • when force is applied to a tooth , bone is resorbed on the compression side and deposited on the tension side
    Compression = resorption
    Tension = deposition
113
Q

Briefly Describe the mechanochemical theory

A

Mechanical loading causes stretching and compression of fibres within the PDL such as
* osteoblasts - produce prostaglandins and leukotrienes
* fibroblasts - matrix metalloprotinases ( breakdown extracellular matrix)
* macrophages - increase production of IL-1
causing bone resorption

114
Q

Give an example of a cell interaction within the PDL that may cause tooth movement

A
  • Cytokines activate osteoblasts to produce prostoglangins and leukotrienes
  • This cause osteoblasts to produce an intracellular messenger
  • Which initiates the production of RANKL and colony stimulating factors such IL-1 and CSF
  • This activates osteoclasts and resorb the bone
115
Q

What does RANKL do?

A

*Both RANKL and CSF cause blood monocytes to fuse and form osteoclasts
* RANKL stimulate the osteoclast to become active and resorb bone
* IL-1 increases the production of RANKL

116
Q

How is bone resorption controlled?

A
  • by osteoblasts , they produce RANKL which activate osteoclasts and OPG which suppresses osteoclast activity
  • the balance between OPG and RANKL regulates bone remodelling
117
Q

What is frontal resorption?

A
  • In frontal resorption, bone is removed from the surface directly adjacent to the force applied (remodelling of socket)
  • whereas, in undermining resorption, remodelling occurs from surfaces further away from the applied force
118
Q

Give 4 methods of anchorage?

A
  • Transpalatal arch
  • Temorary anchorage devices that are non-osseointegrating screws
  • Nance palatal arch - utilises palatal vault for anchorage reinforcement
  • Elastomerics
119
Q

What are the types of anchorage (6)

A
  • Simple - using teeth of different sizes so the smaller moves towards the bigger
  • Compound - using more than one tooth to move a smaller tooth
  • Reciprocal - using similar teeth to achieve equal tooth movement
  • Cortical - maintain intermolar width
  • Absolute - TAD’s - forces distribute to cortical bone
  • Inter-maxillary - using elastomerics
120
Q

What is an overjet?

A
  • the extent of horizontal overlap between the maxillary central incisors over the mandibular central incisors - in AP position
  • average 2-4mm
121
Q

How is overjet measured?

A

Using ruler held parallel to occlusal plane when teeth in ICP

122
Q

What is an overbite?

A
  • It is the extent of vertical overlap between the maxillary and mandibular incisors
  • average 1/2 to 1/3
  • can be average, increased or decreased
123
Q

How is the molar relationship measured?

A
  • Using the buccal segment of 6s relationship
  • Class I - mesiobuccal cusp of upper molar occludes with mesiobuccal groove of lower 6
124
Q

How is the canine relationship measured?

A
  • using the buccal segment of the canines
  • Upper canine occludes with embrasure between the lower canine and lower first premolar
125
Q

How is crowding measured?

A
  • space available vs space required
  • using overlap technique
  • mixed dentition analysis
126
Q

What are the types of crowding/spacing ?

A

Mild - less than 4mm
Moderate - 4-8mm
Severe - more than 8mm

127
Q

How is incisor angulation measured?

A
  • using lateral cephalometry
    Upper 109
    lower 93
128
Q

Why might a first molar be impacted in a 7 year old child?

A
  • Eruption angle
  • Ectopic cyst
  • Small maxilla - not enough space
  • Morphology of E crown
129
Q

What problems are associated with impacted first molar that can be related to the E ?

A
  • Pulpitis of E
  • Premature exfoliation of E
  • May cause pain and discomfort
130
Q

Possible treatment options for an impacted first permanent molar?

A
  • Observe for 6 months - usually will Disimpact on its own (66% at age 7)
  • XLA of E - gain space for premolar or treat crowding later
  • Dis-impaction by
    Dicising distal crown of E
    Seperators
    URA with finger spring and attachment to 6 to push it back
    Band the E and bracket the 6 with open coil

bds4 (63 decks)

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