Clinical Cases Flashcards
(146 cards)
1
Q
Kindelan et al., 2008
A
Traumatized teeth may also be at risk of undergoing more apical root resorption during treatment.
The nature and timing of the traumatic injury has a bearing on further treatment
2
Q
Arias and Marquez-Orozco, 2006
A
use of NSAIDs, including aspirin and ibuprofen, for pain control may retard tooth movement Nevertheless, as their analgesic properties are proven, they continue to have application in orthodontic pain control.
3
Q
3rd most disliked feature of an unesthetic smile?
A
Black triangles, Cunliffe 2009
4
Q
Which is better VFR or Hawley retainer?
A
Outhaisavanah, 2020
VFR is better than Hawley
5
Q
The ideal range of maximum insertion torque for TADs
A
McManus 2011
The ideal range of maximum insertion torque 5- 15 Ncm.
Effect of miniscrew placement torque on resistance to miniscrew movement under load.
6
Q
Relationship between
vertical skeletal pattern and success rate of orthodontic mini-implants. Due to relatively thin maxillary cortical plate, increased MMPA patients have higher failure rate
A
Moon et Al 2010
7
Q
Classification of maxillary tooth transpositions
A
Sheldon & Lina Peck 1995
8
Q
international congress of anatomists and physical anthropologists was held in Frankfort, Germany, in 1882,
A
Frankfort plan
9
Q
)mean rate of space closure of 0.81 mm per month with NiTi coils versus 0.58 mm with elastomeric chain and 0.35 with active elastomeric ligatures.
A
Dixon et al. (2002
10
Q
reported no benefit associated with forces in excess of 150 g during space closure.
A
Samuels et al. (1998)
11
Q
0.019 × 0.025-in. stainless steel wire has approx. 8 degrees of geometric play in a 0.022 × 0.028-in. slot
1) the inability to fill the slot because of the size difference of archwires and bracket slot,
(2) irregularities from the manufacturing process of brackets precluding proper engagement, (3) differences in the stiffness of wire alloys engaged to the bracket slot,
(4) variations between actual and reported bracket torque values.
(5) ligation modes, all of which might account for increased third-order clearance or bracket-archwire “play.”
A
Gioka and Eliades 2004)
12
Q
Clinical research has shown relatively little impact of bracket dimensions either on treatment duration, quality of result or potential side effects of treatment
A
Yassir et al. 2018; El-Angbawi et al. 2018).
13
Q
Stainless steel springs close buccal segment spaces as rapidly as NiTi coil springs.
(0.58 mm per 4weeks for NiTi / 0.85 mm per 4 weeks for SS)
A
Norman et Al 2016
14
Q
Canine travels a distance of 21.99mm in the3-dimensions between the age of 5-15 years
A
Coulter and Richardson, 1997.
15
Q
prevalence of
tooth-size disproportion of this order in an orthodontic population is around 24% in the mandibular arch and 28% in the maxillary arch
2mm of tooth size arch length discrepancy is clinically significant
A
(Othman and Harradine, 2007).
16
Q
1- Lateral incisor root resorption by impacted 3 in normal radiographs, prevalence of 12.5%.
2- Conventional CT scanning 48%.
3- cone beam CT scanning 67%.
4- cone beam CT scanning 74%.
A
1-(Ericson and Kurol, 1988b).
2- (Ericson and Kurol, 2000a, b).
3- (Walker et al., 2005).
4- Alemam et Al., 2020.
17
Q
*71% were developmental in origin,
*22% resulted from trauma to the deciduous predecessor
*7% were associated with cysts or supernumerary teeth
A
(Stewart, 1978).etiology of dilaceration
18
Q
If canine not palpable at 9-10 y then investigate
A
Mittal 2017
19
Q
Maxillary lateral incisor hypodontia : factors favoring space closure Vs space opening
A
Savario & McIntyre 2005
Silveria & Mucha 2016
20
Q
Proclination is an effective means of reducing overbite with each five degrees of proclination leading to overbite decrease of the order of 1 mm
A
Eberhart et al. 1990
21
Q
Andrews 1972, 6 keys to the ideal occlusion based on analysis of 120 non-orthodontic normal occlusion
A
– Class I molar relationship
– Correct crown angulation
– Correct crown inclination
– Absence of spacing
– Absence of rotations
-Flat or gentle occlusal curve
7th key- absence of Bolton discrepancy—-MBT
22
Q
Incremental vs one time correction of increased OJ for modified twin block therapy
A
Banks 2004
23
Q
TB is a more effective functional appliance than Dynamax in overjet reduction and many adverse effects from Dynamax
A
Thiruvenkatachari 2010
24
Q
Dynamax made by
A
Nivelle Bass 2003
25
With An overjet more than 9mm up to 45% sustained dental injury
Less than 9mm 23% sustained dental injury
Female sex predilection
Todd & Dodd 1985
26
Risk factors for gingival recession
1-thin gingival bio type
2-presence of recession prior to ttt
3-gingival inflammation
4-poor OH
27
Which circumstances lower incisor proclination is stable?
1- after correction of class II/2(Mills1973)
2-after surgical correction of class III(Artun 1990)
3-after thumb sucking habit cessation
4-pre-existing lip trap
28
Contraindications of fixed appliance after functional appliance therapy
1- poor OH
2-poor compliance
3- mixed dentition
4-well aligned dental arches with no lateral open bites
29
Causes of late incisors crowding
1.tooth size & shape
2.mandibular 3rd molars
3. physiologic mesial drift of teeth
4.lack of interproximal wear
5.Occlusal forces
6.soft tissue changes
7.late mandibular growth. (decrease of inter canine width due to )
8.mandibular growth rotations
30
Mechanics for firing space without TADs
1-Class III elastics
2-adding torque to the incisors
3- post segment can be protracted individually tooth by tooth
4- archwire rounded and reduced in dimension to reduce friction locally
5- light forces
31
Bracket prescription after functional appliance
According to Fleming 2007 MBT
Choose a bracket prescription with increased :
-labial root torque in the lower labial segment
-palatal root torque in upper labial segment
-buccal root torque in maxillary molars if maxillary expansion took place to counteract unwanted buccal flaring .
To counteract excessive Dentoalveolar changes during the functional phase.
32
How to prevent relapse after functional phase? TRANSITIONAL l phase
1- overcorrection
2- deep and steep anterior bite plane
3-night time wear with occlusal trimming to allow lat open bite closure
4-continue functional phase during permanent dentition
5-headgear during early phase of fixed appliance
6-use of early class II elastics
33
of all the statistically significant differences we found, only 5 were deemed to be clinically significant by our definition:
1-ideal smile arc
2-ideal buccal corridor
3-maximum gingival display
4-upper to lower midline
5-cant.
Springer et Al 2011
34
The most significant features of an ideal smile by order of importance?
According to Springer et al 2011:
1- smile arc
2-buccal corridors
3-gingival display
4- upper & lower centerlines
5- cant
35
Ballista loop
Jacoby 1979
36
0.05%= 230 ppm= 500 microgram NaF [daily mouthwash]
0.2%= 900 ppm NaF [ weekly mouthwash]
1.1%= 5000 ppm= 5 mg NaF [high Fl toothpaste]
0.619%= 2800 ppm= 2.8 mg NaF [ medium high toothpaste]
5%= 22600 ppm= 22.6mg NaF [duraphat fluoride varnish]
Fluoride
37
VBA
VBA is a very brief advice from dental professional to a pt smoker not on Medical need basis
[The best way to stop smoking is with a combination of behavioural support and stop smoking aids, which can significantly increase the chance of stopping.]
38
Genes involved in CLP
IRF6
MSX1
FGF (fibroblast growth factor)
BMP4 (bone morphogenic protein)
39
Adult orthodontics differs from adolescent?
1-Medical status
2-psychological status(body dysmorphic syndrome )
3-previous orthodontic treatment (OIIRR)
4-lack of growth
5-TMD
6-Restored dentition
7-Periodontal condition
8-Treatment mechanics
9-motivation
10-esthetic demand
11-impacted canine
12-Retention
40
CAT, material,mm?
Aligners are generally made from poly-vinyl siloxane (PVS)48 and should be worn full- time, except when eating, and replaced every two weeks, with the aim of moving the teeth by 0.25 mm with each align
41
CVM
Lamparski 1972
Hassel & Farman 1991
Baccetti et Al 2005
Baccetti et Al 2008
42
CVM staging differences
McNamara & Baccetti2016, user guide
the shape of C3 and C4 vertebral bodies change in form from trapezoidal to rectangular horizontal to square to rectangular vertical.
C3 and C4: trapezoidal in CS1 to CS3.
C3 and C4: rectangular horizontal in CS 4.
C3 and C4: square in CS 5.
C3 and C4: rectangular vertical in CS 6.
CS 1 and CS 2 prepubertal.
CS 3 and CS 4 circumpubertal
CS 5 and CS 6 postpubertal.
CS1–ideal time to intervene with facial mask therapy combined with rapid maxillary expansion (RME) is at CS 1. Maximum skeletal adaptations.
CS2– “get-ready” stage because the peak interval of mandibular growth should begin within a year after this stage.
CS3– maximum craniofacial growth velocity is anticipated.
CS4–continued accelerated craniofacial growth can be anticipated.
CS5– most substantial craniofacial growth has been achieved.
CS6– a patient can be evaluated for corrective jaw surgery or the placement of endosseous implants in the esthetic region. (most difficult stage to determine)
gold standard for determining the (continuation or cessation) is the evaluation of two lateral headfilms taken 6–12 months apart
43
Types of growth spurts
3types
1-neonatal(1-2y)
2-juvenile(6-8y)
3-adolescent (M12-14-F10-12)
44
Growth prediction methods [enumerate]
1-peak height velocity curve / growth chart.
2-simple questioning
3-CVM.
4- secondary sexual characteristics
5- scammon’s growth curve
6-dental developmental age
7-chronological age.
8-hand wrist R/G.
45
Lip growth
Upper lip female:20-22 mm
Upper lip male:22-24mm (males grow more than females)
Growth plateau at 18y males
At 14 y females
Lower lip growth plateau in both sexes at 16y
46
Age of decline of growth to adult levels?
Dimension. Female. Male.
Transverse. 12 years (maxilla). 12 years (maxilla)
intercanine width 9 years (mandible). 9 years (mandible)
Anteroposterior 2-3 years after first menstruation. 4 years after sexual maturity
14-15 years (maxilla) 17 years (maxilla)
16-17 years (mandible) 19 years(mandible)
Vertical. 17-18 years Early 20s
47
What measure should we take to ensure successful class II/2 Treatment?
1-lower incisors bite anterior to upper incisor root centroid
2-composite build-up of upper incisor cingulae
3-proper torque of U&L incisors
4-increase the interincisal angle
5-retention U&L bonded retainers
6-Begg retainer(wrap around)with anterior flat bite plane.
48
A consonant Smile arc 1st
Average buccal corridors 2nd most important feature for à beautiful smile
Moore et Al 2005
49
Sizes and materials of bonded fixed retainers?
Metal bonded retainer. Esthetic bonded retainer
1-Round. SS. Multistrand. 0.0175”. 1-polyethylene woven ribbon. 1mm
2-Round. SS. Multistrand. 0.0195". 2-fiber reinforced composite resin 0.75mm
3-Round. SS. Multistrand. 0.9mm. 3-glass fiber reinforced
4-Round. SS. Coaxial. 0.0215” 4-silanised glass fibers. 0,5mm
5-Flat. Ti. Tri flex. 5-
6-Round. SS. Dead softTwisted0.0009"
8-
9-
50
Hierarchy of stability
*Vertical change: {AOB}——->Worst prognosis
• Transverse change: ———>Poor prognosis
• Alignment: irregularity and spacing ———Moderate prognosis
• Vertical change: deep overbite ———>Moderate prognosis
• Antero-posterior change: ———>Best prognosis
51
Lower arch expansion and lower incisors proclination are inherently unstable
Ackerman & Proffit 1997
52
No difference between Niti vs multistrand SS in alignment time ,pain,effectiveness
Want et Al 2010
53
1-Four-premolar extraction or nonextraction treatment protocols seem to have no
predictable effect on overall smile esthetics, meaning that if well indicated, extraction in
orthodontics does not necessarily have a deleterious effect on facial esthetics.
2-a small dental midline deviation of 2.2 mm can be acceptable by both orthodontists and laypeople
3- an axial midline angulation of 10' (2 mm measured From the midline papilla and the incisal edges of the incisors) is already very apparent,
4- studies dealing with real smiles, buccal corridor sizes and smile arc alone do not seem To affect smile attractiveness.
Janson 2011 [systematic review]
54
Systematic review of mandibular changes induced by functional appliances are larger if treatment coincides with the pubertal peak in skeletal maturation.
Cozza et Al,2006
55
Deep and steep bite plane dimensions
A bite plane at least 8 mm deep and at an inclination of 70 degrees to the horizontal is recommended.
56
Bacteria in caries and periodontitis
Caries: streptococus mutants/ lactobacili
Periodontitis: porphyromonas gingivalis/ actinobacillus actinomycetemcomitans(juvenile periodontitis)/prevotela intermedia/ fusobacterium.
57
Classification of WSL
Gorelick , 1982
Score 0: no WSL
Score 1: slight
Score2: severe
Score3: cavitated
58
WSL,Treatment?
1-OH improvement/removal of wire/education
2-topical fluoride
3-bleaching
4-CPP-ACP(casein phosphopeptide amorphous calcium phosphate)tooth mousse
5-resin infiltration
6-microabrasion
59
Braun S. 1996 the curve of Spee revisited.
depth of 9mm needs only 2mm space
The arch circumference reduction is considerably less than that found by earlier investigators, implying that the incisor protrusion often associated with leveling the curve of Spee is not primarily due to the aforementioned differential, but rather more directly due to the mechanics used in leveling the curve of Spee.
60
Othman & Harradine 2007
1- 17%of population has more than 2 standard deviation from Bolton analysis.(24%mand-28%max) prevalence of tooth-size disproportion of this order in an orthodontic population
2- up to +\-2mm correction is clinically significant.
3- visual method for crowding assessment has low sensitivity and specificity.
61
Who said?
1-3rd molars do not affect anterior crowding relapse?
2-Preventive removal of 3rd molar to reduce late incisors crowding can’t be endorsed
1- Cotrin et al 2020.
2- Harradine 1998.
62
Surgical indicators for class II correction according to Proffit?
1- 10mm or more OJ
2- total facial height more than 125mm.
3- pogonion behind nation perpendicular more than 18mm
4- small mandibular body less than 70mm (Go-Pog)
63
Upper & lower limits for incisal mov.to compensate for classIII: 120 upper (to S-N)80 lower(md plane)
Burns et al 2010
64
Overall failure rate of mini screws
Alharbi et al 2018 says rev/ meta analysis(Almuzian,D.Bearn)
Overall failure rate of mini screws is 13.5% (11% maxilla- 16.5% mandibule)
Diameter, length, design, pt age and jaw of insertion had minimal effect.
Risk factors:non-keratinized mucosa and smocking had statistically significant effect
65
Mod quality evidence
NiTi coil spring faster space closure(0.2mm/month) than Elastomeric power chain
Mohammed & Almuzian 2017
66
No evidence that active Ortho ttt prevent or relieve TMD.
Luther et al 2010 Cochrane sys rev
67
RBB survival rate
*Cantilever all-ceramic RBFPDs gave a better outcome than metal-ceramic cantilever RBFPDs for the replacement of missing anteriors. (No prep or minimal prep)
*Zirconia-ceramic RBFDPs yielded a 10-year survival rate of 98.2% and a success rate of 92.0%.
*[Phosphate monomer containing resin cement and zirconia.]
*Survival of Cantilever RBB better than fixed fixed RBB. Due to limitation of movement between different abutment teeth.
*Increase bond strength by modifying tooth prep:
-proximal grooves/path of insertion/cingulum rest/ labial wrap
68
Effectiveness of early Ortho ttt with TB app.
O’Brien, et al 2009 RCT AJODO.
10 year multi center RCT.
No difference bet. Early[8-9] or late[adolescent 12.5y]
With respect to skeletal pattern, self esteem or extraction pattern.
69
Class III protraction face mask
Mandall et al (2010, 2012 & 2016)
15month ttt, 70% of pt had +ve OJ(4.4mm) and ANB (2.6)
Patients maintained dental outcomes at 3years & 6 years follow up( 70%-68%)
All skeletal effects lost.
Need for surgery reduced (only 1/3 of pt who had pFM ttt still needed surgery)
70
Conventional vs Active or passive self ligation brackets
Single step etch+ primer vs conventional etch /primer
Fleming et al 2013
No difference in alignment, inclination changes.
Fleming 2010
Decreased working time but higher failure rate
71
Success rate of maxillary canine auto transplantation
Patel et al 2011
Survival rate 83% average duration 14.5 y for grossly malpositioned with little scope for Ortho alignment
72
Part time vs full time wear of VFR retainers
Thickett & power 2010
No difference
73
Fluoride application during Ortho ttt
Benson et al 2018 Cochrane sys rev
Application of Fluoride varnish every 6 weeks effective in reducing WSL by 70%
74
Prevalence of hypodontia
Khalaf et al 2014.
Overall prevalence 6.4%( highest in Africans followed by Europeans)
Most common affected: mandibular 2nd premolars/maxillary lateral incisor and 2nd premolar.
75
Early ttt of prominent upper front teeth Klaus Batista et Al 2018 Cochrane review
Low to mod evidence that early ttt for children with prominent upper front teeth is more effective in reducing incidence of incisal trauma. [By 12% because 31% of late ttt group already had incisal trauma while only 19% of early ttt group had incisal trauma so the reduction of 12% in incidence of incisal trauma to prominent upper incisors].
76
Methods to prevent lingual rolling of a s during space closure after 6s extraction
1-alignment on rectangular NiTi wires
2- full sized SS rectangular wire for space closure
3-widening the wire posteriorly
4-lingual root torque in wire
5-class II elastics from lingual cleats
6-MBT prescription -10
7-light controlled forces
8-double forces( buccal & lingual)
77
Extra oral and cephalometric methods of telling which component is the malocclusion?
E.O.:
1-Virtual ttt objectives.(ant positioning of md, cotton roll in labial sulcus)
2-masking the face.
3-Signs of maxillary deficiency.
4- zero meridian line.
5- NLA
Ceph:
1- Nasion perpendicular
2- SNA- SNB and not ANB.
3- Harvold unit length.
78
Canine protected occlusion is better than group function occlusion, why?
1- canine has better canine/root ratio.
2- canine has more root surface area, better proprioception during lateral excursion.
3- canine root shape is concave, better directed to tolerate occlusal forces.
Doc#10
79
Mandibular rotation
Apparent rotation: -7
Actual rotation: -15
Angular remodeling in the mandible masks the actual rotation by 50%.
Low angle= negative growth rotation = anti clockwise rotation
80
Causes of deep bite
1-skeletal: Class II skeletal base [div1 & div 2].
2-dental: poorly defined cingulum, absent occlusal step.
3- soft tissue: lip trap
4- habits: thumb sucking
81
How to minimize lower incisors proclination?
1- bypass incisors during bonding
2- MBT prescription
3- swapping canine brackets
4- labial root torque
5- cinch back
6- class III elastics
7-power chain (with extraction cases)
8- IPR
Reverse COS
Slot 18
Using full size rectangular archwire
Torquing auxiliaries
82
Prognosis of stability
Cl II div2: Increase interincisal angle & lower incisal edge occluding 2mm anterior to upper central root centroid.
Cl II Div 1: upper incisors should be under the control of the lower lip.
83
Sys rev on different movements causing OIIRR
Weltman et al 2010
84
Headgear accidents percentages
6% of HG patients are injured.
40% of them extra oral injuries
60% of them intraoral injuries
20% of them midfacial injuries
85
Maxillary lateral incisors and mandibular second premolars were the most commonly missing teeth. A trend away from space opening and prosthetic replacement toward orthodontic space closure was observed from 2000 to 2017/2018. This may reflect a change in attitude toward prosthetic replacement options and/or greater optimism with biomechanical strategies since the implementation of temporary anchorage devices to assist in space closure.
Steven Naoum et al 2021
Fleming quoted his paper in Angle orthodontics.
86
Hypodontia classification/ prevalence
Mild: 1-2/moderate:3-5/ severe: 6 or more {Al-Ani2017}
4-4.5% in UK
87
Genes of hypodontia
MSX1/ PAX9/ AXIN2/ EDA/ FGF3/ WNT10A/ BMP4.
OVER 300 DIFFERENT GENES
PAX9 —> lateral incisor
MSX1–> all second premolars and mandibular central incisor
AXIN2–> lower incisor
EDA—>severe hypodontia
88
Indication for Hawley and Begg retainers
Occlusal settling
Maintenance of transverse expansion
Temporary tooth replacement
Begg retainer for mesial space closure and occlusal settling
89
OIIRR, classification, prevelance, causes?
Weltman et Al 2010 —>90% of orthodontic cases undergo OIIRR
Levander& Malmgren Index (1988) of OIIRR:
0 —>no root resorption
1 —>blunting of root tip
2 —>less than 2mm (majority)
3 —>more than 2mm & less than 1/3 root length (15%)
4 —> more than 1/3 root length (<5%) According to Becker 2005 not much harm
Causes:
1-#Pt related factors:
Age/gender/ethnicity(low in Asians)/habits(nail biting-wind inst)/med history(asthma)/genetics.
2-#Tooth related:
Abnormal morphology/ taurodontism/roots in contact with cortical bone/teeth with no occlusal contact/trauma hx.
3-#Ttt related:
Heavy/ continuous/intrusive forces/Amount of tooth movement/ duration of treatment.
Tipping movement/ class II elastics.
90
Hierarchy of stability
Worst prognosis—>AOB
Poor prognosis —>transverse
Moderate prognosis—>deep bite/alignment/spacing
Good prognosis —>AP
91
How do you align an impacted canine?
1- TPA with SS auxiliary (palatal)
2-TPA with TMA fishing rod( buccally directed)
3-URA(twin bloc+ monkey hooks)
4-Magnets(bulky)
5-TADs(in opposing arch)
6-ballista loop(14ss)
7-piggy back(14Niti)
8-elastomeric chain
9-SS archwire auxiliary(simple &effective)
92
Signs of vertical maxillary excess
1-increased lower anterior facial height
2-increased incisal show at rest
3- increased gingival show at smile
4-incompetent lips
93
Factors affecting incisor display
1-type of smile
2- lip elevation(7Mm)
3- lip length
4-vertical dental display (10.5mm)
5-vertical maxillary display
6-age: decrease with age
7-sex:female 3.5mm/male 2mm
8-incisor inclination
94
Supracrestal fibrotomy
Pericision, Edwards 1988
*Def:Surgical procedure involving sectioning supracrestal fibers.
*How:holding scalpel no.12 vertically in gingival sulcus and severing the fibers
*Never done to a mid labial surface of a tooth with narrow gingiva or thin alveolar bony support.
*Alternative: divide interdental papilla
95
Classification of skeletal class II
Steiner
Mild:4-7
Moderate:7-9
Severe:>9
96
When to tell if pt is orthognathic surgery case or not?
*skeletal discrepancy& A-B points [*ANB= -4 / >9]
*vertical proportions: low or average
*Cheif complaint (if pt comlpains from profile)
*age /growth potential.
*achieve edge-to-edge/ displacement
*degree of dental compensation
*soft tissue mask sk. Discrepancy [NLA- E-line]
*space conditions & occlusal parameters
97
How to measure lip length
1- average : 19-22mm.Philtrum height
2-linear: from subnasale to intercommissure line.
3-Ratio: 1/3 of LAFH.
98
NLA, how to tell which component is responsible
NLA is divided by the FMP into upper NLA & lower NLA.
U NLA= 25•
L NLA= 85•
99
Deep bite stability in ttt goals
1-decrease interincisal angle
2-lower incisor edges bite 2 mm anterior to upper incisor root centroid.
3-proper torquing of U&L incisors.
4- composite build up to upper incisor cingulae.
5-fixed retention
6-Begg retainer( wrap around) with flat anterior bite plane.
100
Non carious tooth surface loss
Basic erosive wear examination [BEWE]
Knight & Smith index for tooth surface loss
101
Theories of tooth movement
Osteoblast—>RANKL & Osteoprotegerin.
RANKL binds to RANK receptor on pre-osteoclast—>osteoclast.
—>Osteoprotegerin binds to RANKL—> stops it’s activity—>apoptosis of osteoclast
—>removes osteoid by matrix metalloproteinase.
Osteoclast resort bone.
1-Pressure -tension theory( Oppenheim)
*force—>pressure side—>resorption/tension side—> deposition
*if force greater and exceeds capillary pressure—>hyalinization(glass like appearance) & undermining resorption: slow to mov/pain/discomfort.
2-bone bending and bio-electric signaling
*bone surface bends & become convex and concave-tension.
*electrical & streaming potentials produced by bone deflection
3- cell Shape change/ signal transduction/secondary messengers
*cell shape mechanical deformation —>activation of integrins—>secondary messengers
* secondary messengers:cyclic AMP/ phosphoinositide
4-signaling molecules:
*Arachidonic acid metabolites: Prostaglandins & leukotrienes—>increase to mov.
*Neurotransmitters & cytokines: pain—>nerve release neurotransmitters—>leukocytes migration—>cytokines—>prostaglandins/growth factors—>bone remodeling.
5-Alteration in cellular function(gene expression) & remodeling
*stretching of periodontal ligament cells—>up regulation of genes &differentiation into osteoblastic like activity.
102
Crossbite correction
1-URA+ exoantion screw
2-Quadhelix( slow fixed palatal expander)
3-HYRAX( fast fixed palatal expander) RME
4-Cross elastics
5-Active TPA.
6-Active TPA with extended arms(on premolars)
7- Expanded heavy Auxiliary archwire (in buccal tubes of molars lighted anteriorly to wire bet.incisors)
8- Miniscrew assisted rapid maxillary expansion. MARPE
103
Initial stability of tads
Initial stability can’t be guaranteed/high failure rate in mandible/ dense bone overheating/narrow band of attached gingiva
104
Sizes ànd sites of tads
Buccal alveolus maxilla:8-10mm length/1.5mm width/ short neck
Palatal alveolus: 8-10mm length/1.5mm width/ long neck
Mandibular alveolus: 8-10mm length"oblique"6mm "perpendicular"/1.5mm width/ short neck
Infrazygomatic: 12mm length/2mm width/ long neck
105
Risks for canine alignment
1-root resorption of neighboring teeth
2-
3-pulp obliteration and discoloration
4-ankylosis 1ry or 2ry
5-decalcification
6-generalized root resorption
7-failure of Treatment
8-Crestal bone loss
106
Types of occlusal plane
1-anatomical occlusal plane: molar cusp to incisal edges/Mx-Md
2-functional occlusal plane: from molar cusps to premolars.
3-geometric occlusal plane: line bisecting MMPA.
4-bisected OP
107
Correction of anterior Crossbite
1- 2x4F.A
2- Raymond’s method: upper palatal buttons/lower labial brackets & elastics
3- URA with expansion screw or Z-spring
4-Catalan’s appliance: fixed anterior bite plane
108
MIH definition/ classification/management
**Def:** hypomineralization of sys origin affecting 1-4 molars &/or incisors.
**Prevalence**:≈13%
**types**: hypoplasia/hypomineralised.
**etiology**:
-prenatal:maternal illness.
-perinatal: low birth weight.
-postnatal:fever/ response tract problems.
**mgmt**:
-GIC/Xtn ideal time/Ortho ttt to close space/onlays restorations.
Problems: difficult to anesthetize/pain/sensitivity/Caries/poor prog.
109
Prop of ideal index
1-valid
2-reliable &reproducible
3-simple & cheap
4-accepted by professionals &population.
5-require minimal judgment.
6-sensitive
7-specific
110
How to assess soft tissue
Static & dynamic.
Static:
1-lip competence
2-lip thickness (14-15mm)
3-lip length
4- NLA
5-MLA
Dynamic:
1-smile arc
2- smile line
3- gingival show & gingival esthetics.
4-buccal corridors
111
Inter arch relation ships
1-Incisal
2-OJ
3-OB
4-XB
5-CL
6-Canine
7-Molar
112
What are the cenmentation steps/ materials?
1-clean tooth surface/ dry
2-isolation/ mix prep
3-apply cement to internal surface of the band covering all surfaces esp from gingival direction.
4-insertion using hand pressure then using bite stick & band pusher.
5- until band is flush with the marginal ridge
6- remove excess and wait for setting advice pt to avoid hard food for 24hrs
Types:GIC/ RMCIC(Optiband)/compomer/zinc phosphate cement
Light cured/chemically cured
113
Theoretical / actual slop?
According to Gioka & Eliades 2004
9.6• & 14•
114
Best wire for single canine retraction
20 SS for low asperities and round configuration
115
When to use MBT prescription
1- after twinblock—> regain torque in U & L
2- class II/2—> better stability
3- class III—> more torqued U & L incisors
4- Extraction of poorly prognostic 6s—> less lingual rolling
116
How to tell pt has acceptable OH to begin Ortho ttt?
According to British periodontal society, less than 10% on gingival index & less than 20% on plaque index
117
Effective radiation dose? Yearly and daily background radiation in UK
According to Isacsson 2015
Bite wing/periapical: 0.0003 msv—>1hr background radiation
Pano: 0.0027 msv—> 8hrs background Radiation
Ceph: 0.0022 msv—> 8hrs background radiation
Occlusal: 0.008 msv—> 1day background radiation
Yearly background radiation—>2.7msv
Daily background radiation—>0.0075msv
118
Indications of small field of vision [FOV] CBCT Isacsson 2015
1- unerupted maxillary canine(if not diagnosed by 2 p.a. Or 1p.a. And a pano)
2-unerupted dilacerated maxillary central(dilaceration management)
3-surgical planning of removal of supernumerary.
4- cleft palate assessment: graphing and ectopic teeth localization.
119
Indications of upper occlusal film Isacsson 2015
1-parallax localization (with pano or with p.a.)
2-confirm presence of unerupted teeth
3- identify supernumerary
4- identify developmental anomalies
120
Risk of cancer from radiography
Pano: 1 in a 1.000.000
P.a.: 1 in a 10.000.000
Ceph: 1 in a 5.000.000
121
Curve of Spee
An imaginary line in the sagital plane drawn between mandibular 1st molars and incisors
Measured by the depth of deepest point from a flat p,and connecting incisor tips and last standing molar
122
Andrews six keys of normal occlusion
1. Molar relationship:
*The mesio-buccal cusp of the upper first permanent molar lies in the groove between the mesial and middle cusps of the lower first permanent molar.
*The distal surface of the disto-buccal cusp of the upper first permanent molar makes contact and occludes with the mesial surface of the mesio-buccal cusp of the lower second molar.
*Functional cusps of lower 1st perm molar occludes in central fossa of upper 1st perm molar.
*cusps lie in embrasures.
2. Crown angulation or mesio-distal tip:
The gingival portion of the long axis of each crown is distal to the incisal portion.
3. Crown inclination:
Labio-lingual or bucco-lingual inclination. The upper and lower anterior crown inclination is sufficient to resist over-eruption of the anterior teeth and to allow proper distal positioning of the contact points of the upper teeth in relation to the lower teeth, permitting proper occlusion of the posterior crowns. A lingual crown inclination exists in the upper posterior crowns, is constant and similar from canines through to the second premolars, and slightly more pronounced in the molars. For the lower posterior teeth, the lingual crown inclination progressively increases from canines through to second molars.
4. Rotations: There are no rotations.
5. Spaces: There are no spaces, contact points aretight.
6. Occlusal plane: The plane of occlusion is either flat or there is a slight curve of Spee.
123
What is a lateral ceph?
It’s true lateral view of facial bones, base of the skull , upper cervical spine and the soft tissues.
It’s standardized from the X-ray source and the film with known magnification so it can be used for superimposition and comparison.
124
Positional factors affecting the surgical management of impacted permanent mandibular canines
O
According to Bolooki 2022:
1-Canine angulation: 0°–15° —>exposure/>45°—>Extraction
2-Canine root position(horizontal):. Expected canine position. —>Exposure/Mesial of expected position—>Extraction
3-Canine crown height(vertical): 1/2 root length-CEJ—> exposure/>root length—>extraction
4-Overlap of adjacent tooth: No overlap < ½ root—>exposure /> Midline—>extraction
Labiolingual position had no effect upon the management decision.
125
Björk & Skieller 1983
Stable structures of anterior cranial base
1-anterior wall of sella turcica.
2-ant clinoid process {Walker point}
3-cribriform plate of ethmoid.
4-ethmoid crest.
5-orbital roof of frontal bone(cerebral surface)
126
Long term prognosis of retained 2nd 1ry molar without successor
Bjerklin & Bennet 2000/ Sletten 2003/ dosantos 2022
If the 2nd 1ry molar survived till the 20s most probably will have long term survival
1ry canines last till 4th decade
127
Crossbite correction sys rev
According to Ugolini 2021:
1-children early mixed dentition(7-11): quad helix more effective , shorter duration for posterior Crossbite ttt.
2- For adolescents perm dentition(7-16):HYRAX & Haas have similar effect in correction &increasing inter molar width
128
Factors affecting lip competency
1- Age
2- lip length
3- LAFH
4-AP mandibulaire position
5- incisors position
129
Factors affecting amount of incisor display during rest and smile
1-Age
2-Sex
3-Vertical maxillary excess
4-vertical dental display
5-incisor inclination
6-type of smile
7-lip elevation
8-lip length
130
Advantages of delta clasp over adams cribs
1- excellent retention
2-adaptable to most post teeth
3- doesn’t need frequent adjustments
4- less breakages
5- keeps its shape and doesn’t loose it with frequent wear of appliance
131
NEw R/G rating & ALARP Principle
Diagnostically acceptable (95%)
Diagnostically unacceptable (5%)
"As low as reasonably practicable "
Increase efficiency:
Rectangular collimating/ intensifying screen/aluminum filter/ voltage 60-70kv/fast films(F)/short exposure time.
Done by Public Health England & faculty of general dental practice 2020
132
Theoretical to actual play
According to Dalstra et 2015:
Actual play = 2.4 x theoretical play
Passive Self ligating brackets have least torque control but with conventional brackets the ligature hold the wire at the back of the slot—>expressing torque
133
Activation of coil spring & push coil
NiTi coil spring—> 1/3-1/2 in addition to its original length
StSt coil spring—>1/3-1/2 in addition to its original length
NiTi push coil—> up to twice inter bracket distance
StSt push coil—> inter bracket distance + a bracket width
134
Bacteria around bands
More causing periodontitis than caries
Actinomyces & streptococcus mutants
135
Bands vs tubes failure rate
According to Millet 2011 Cochrane sys rev.
Bonded tubes have higher failure rate than bands and more decalcification
136
Adhesive remnant index [ ARI]
By Arnut & Bergland 1984
0 all adhesive on bracket
1 less than 50% of mesh exposed
2 more than 50% of mesh exposed
3 all remnants on tooth surface
137
Percentage of hypodontia
M3m —>30%
2nd premolars—>3%
Mx lateral—>2%
Mn central—>less than 1%
Mx3–>0.03%
138
How to manage Bolton discrepancies
1-Accept
2-IPR
3-Composite restoration
4-tilting the tooth
5-extraction
139
Failure rate of bonded retainers
30% in the lower arch (Al-Moghrabi et al, 2016)
50% in the upper arch (Katherine et al, 2017).
The failure rate is higher in the upper arch due to occlusion.
This failure rate increases as the upper retainer extends beyond U2s.
due to L3s cusp tip contact with retainer between U2 and U3.
140
Growth theories
The exact mechanism of facial growth control is not fully understood.
Currently the functional matrix theory is supported.
Some genetic control lies within the cranial base synchondrosis and the nasal septal cartilage.
141
Growth theories enumerate
1- cartilaginous
2- remodeling
3- sutural growth theory
4- functional matrix theory
5-servosystem theory
6-part-counterpart theory
142
MIH
Qualitative enamel defects of systemic origin affecting one or more molars w/out incisors
143
GENE RESPONSIBLE FOR VERTICAL MANDIBULAR GROWTH
AMELX- Amelogenin- amelogenesis imperfecta
144
Difference between double teeth and macrodont
A macrodont has:
No-notching
More than 2 SD in size
Same number of teeth
145
Mechanics for closure of large midline diastema
1-using full size SS archwire
2-swapping the brackets
3-V-bend in middle of archwire
4-closure on long crimpable hooks
146
TMJ management
1-patient assurance and education(30% relieved by reassurance)
2- explaining relationship of TMD and stress
3- resolve pain by conservative approach
4- modify ttt by using light forces
5- suspend ttt and refer to specialist
