ortho Flashcards
- Distance curve
- Velocity curve
- Distance curve= tracks actual height each year
- Velocity curve= tracks change in height
- Average peak growth for girls
- Average peak growth for boys
- Average peak growth for girls= age 12
- Average peak growth for boys= age 14
Intramembranous
* Growth from the outside/inside?
increase in length/diameter?
Intramembranous
* Growth from the outside
increase in diameter
Endochondral Influenced more by environmental forces/ genetic factors
Influenced more by genetic factors
- Endochondral ossification occurs at
- Endochondral ossification at synchondroses
- Intersphenoid inactive by age
- Spheno-ethmoid inactive by age
- Spheno-occipital inactive
- Intersphenoid inactive by age 3
- Spheno-ethmoid inactive by age 7
- Spheno-occipital inactive later
Maxilla ossification intramembranous/ endochondrol
* Resorption occurs at
* Apposition
Maxilla
* Intramembranous ossification occurs at sutures posterior and superior to maxilla and also to remodel surfaces
* Resorption anterior maxilla
* Apposition palate, alveolar ridges, tuberosity
Mandible (Embryonic)
* Intramembranous ossification to create
* Endochondral ossification to create
* Fuse together at _________months in utero
Mandible (Embryonic)
* Intramembranous ossification to create embryonic corpus/ramus
* Endochondral ossification to create condylar cartilage
* Fuse together at 4 months in utero
Mandible (Adult)
* Endochondral ossification as condylar cartilage proliferates and produces
* Intramembranous ossification to remodel surfaces
-Resorption
-Apposition
Mandible (Adult)
* Endochondral ossification as condylar cartilage proliferates and produces bone
* Intramembranous ossification to remodel surfaces
-Resorption anterior ramus
-Apposition posterior ramus, chin, coronoid, alveolar ridges
Planes of Growth
* Width (transverse)= age
* Length (anteroposterior, sagittal)= age
* Height (vertical)= age
Planes of Growth
* Width (transverse)= age 10-12
* Length (anteroposterior, sagittal)= age 14-16
* Height (vertical)= age 18-20+
Underdeveloped mandible seen in which syndrome
Treacher Collins Syndrome “Aka mandibulofacial dysostosis”
Upslanted palpebral fissures seen in
Downslanted palpebral fissures seen in
Trisomy 21/Down Syndrome
Treacher Collins Syndrome
– Hypertelorism and Proptosis seen in
Crouzon Syndrome
– Acrocephalic seen in
Apert Syndrome: “Aka acrocephalosyndactyly”
– Byzantine arch
* Syndactyly seen in
Apert Syndrome: “Aka acrocephalosyndactyly”
Brachycephalic seen in
Crouzon Syndrome
Ideal overbite is _____%, ___mm.
Ideal overjet is ____ mm.
Ideal overbite is 10-20%, 1-2 mm
* Ideal overjet is 1-3mm
Anterior crowding often gets worse in ________ years
Anterior crowding often gets worse in 20s-40s
Early mesial shift of first molars to close primate space at around age _______
Late mesial shift of second molars to close leeway space at around age
6
12
Ugly Duckling Stage _____ yrs
11-12
Gum Pad Stage
Primary Dentition Stage
Mixed Dentition Stage
Permanent Dentition Stage
birth to 6 months
6 months to 6 years
6 years to 12 years
12 years to death or edentulism
Curve of Spee __________ plane
Curve of Wilson _________ plane
sagittal plane (Curve of Spee) and frontal plane (Curve of Wilson)
Bolton Analysis measures
tooth size discrepancy by comparing upper and lower teeth
- Anterior divergent= usually Class II/Class III?
Class III
Profile Angles
* Nasolabial angle
– Between
– Should be _____˚
* Mentolabial angle
– Between lower lip and chin
– Should be _____˚
* Cervicomental angle
– Between chin and neck
– Should be ______˚
Profile Angles
* Nasolabial angle
– Between nose and upper lip
– Should be 90˚
* Mentolabial angle
– Between lower lip and chin
– Should be 120˚
* Cervicomental angle
– Between chin and neck
– Should be 90-120˚
Lips
incompetent _________mm separation
3-4mm
______mm incisor show is ideal
2-4mm incisor show is ideal
Cephalometric Reference Planes
* S-N
* Po-Or
* ANS-PNS
* L6-L1
* Go-Gn
Cephalometric Reference Planes
* S-N cranial base
* Po-Or Frankfort horizontal
* ANS-PNS palatal plane
* L6-L1 occlusal plane
* Go-Gn mandibular plane
Cephalometric Analysis
* To evaluate the relationship of the ____ and ________ to each other
Cephalometric Analysis
* To evaluate the relationship of the jaws and dental units to each other
Cephalometric Superimposition
* To evaluate the skeletal and dental changes that occur over time due to
Cephalometric Superimposition
* To evaluate the skeletal and dental changes that occur over time due to growth or treatment
ANB= maxilla to mandible
– __˚ or below is Class III
– ___˚ is normal
– ___˚ or above is Class II
ANB= maxilla to mandible
– 0˚ or below is Class III
– 2˚ is normal
– 4˚ or above is Class II
Ackerman-Proffit
1. Facial Proportions and Esthetics
2. Alignment and Symmetry
3. Transverse
4. Anteroposterior
5. Vertical
Ackerman-Proffit
1. Facial Proportions and Esthetics (lip posture, smile arc)
2. Alignment and Symmetry (crowding, spacing, rotations)
3. Transverse (posterior crossbite, midline)
4. Anteroposterior (overjet, Angle Class)
5. Vertical (overbite, Curve of Spee)
Molar Classification
1. Class I Normal Occlusion ____________%
2. Class I Malocclusion _________%
3. Class II Malocclusion ____%
a. Subdivision 1= ____________upper incisors
b. Subdivision 2= _________ upper incisors
4. Class III Malocclusion _____%
Molar Classification
1. Class I Normal Occlusion (30-35%)
2. Class I Malocclusion (50-55%)
3. Class II Malocclusion (15%)
a. Subdivision 1= proclined upper incisors
b. Subdivision 2= retroclined upper incisors
4. Class III Malocclusion (1-5%)
Force / Area =
Force / Area = Pressure
- Light force causes __________ resorption
- Heavy force causes _________ resorption
- Light force causes frontal or direct resorption
- Heavy force causes undermining or indirect resorption
Uncontrolled Tipping
* _______ goes in direction of force and _____ goes opposite direction
Uncontrolled Tipping
* Crown goes in direction of force and root goes opposite direction
Entire PDL area is loaded so there is equal compression all along one side of the root
Bodily Movement
Crown barely moves and the root moves in the direction of force is called
Root torque
Threshold for tooth movement is around ________ hours
Threshold for tooth movement is around 4 to 8 hours
- Interrupted= force slowly/abruptly declines to zero, eg:
- Intermittent= force slowly/abruptly declines to zero, eg:
- Interrupted= force slowly declines to zero, elastic chain
- Intermittent= force abruptly declines to zero, clear aligners
Root resorption= cementum adjacent to _____ PDL can undergo resorption
Root resorption= cementum adjacent to hyalinized PDL can undergo resorption
Center of Resistance
* For tooth, point of greatest resistance to movement typically at the ________
– Periodontal compromise moves it ___________
– Root resorption moves it _________
Center of Resistance
* For tooth, point of greatest resistance to movement typically at the center of its root
– Periodontal compromise moves it apically
– Root resorption moves it occlusally
Center of Rotation
* Fixed point/ unfixed point
Center of Resistance
* Fixed point/ unfixed point
unfixed point
Fixed point
Force
* Linear vector with
Force
* Linear vector with magnitude and direction
Moment =
Moment = Force x distance
- A force couple creates _________
- A force couple requires __________
- A force couple creates pure rotation
- A force couple requires two points of contact
first order-
second order-
third order-
first order- rotation
second order- angulation
third order- inclination
Uncontrolled Tipping
* MC/MF =
* The center of rotation is ___________ to center of resistance
Uncontrolled Tipping
* MC/MF =0
* The center of rotation is slightly apical to center of resistance
Controlled Tipping
* MC/MF is between ________
* The center of rotation is moved _______ from the center of resistance
Controlled Tipping
* MC/MF is between 0 and 1
* The center of rotation is moved apically away from the center of resistance
Bodily Movement
* MC/MF =________
* Tooth moves bodily and the center of rotation is displaced _________ far away from the center of resistance
Bodily Movement
* MC/MF =1
* Tooth moves bodily and the center of rotation is displaced infinitely far away from the center of resistance
Root Torque
* MC/MF ______
* Root apex moves more than the crown and the center of rotation is displaced in the ________
Root Torque
* MC/MF >1
* Root apex moves more than the crown and the center of rotation is displaced in the other direction
Rotation
* MC/MF __________
Rotation
* MC/MF does not exist
Reciprocal Anchorage
* If both units have equal anchorage values then they will both experience ______________ tooth movement
Reciprocal Anchorage
* If both units have equal anchorage values then they will both experience equal and opposite tooth movement
- Adding more teeth to the anchor unit so that the reaction force is distributed over a larger PDL area
example
Reinforced Anchorage
headgear
Skeletal Anchorage
* __________ act like ankylosed teeth
* Earliest is age ______ when bone is mature enough
* Particularly useful for ___________ molars
Skeletal Anchorage
* Temporary anchorage devices (TADs) act like ankylosed teeth
* Earliest is age 11 when bone is mature enough
* Particularly useful for distalizing and/or intruding molars
Orthodontic Materials
* _______ does all the work
* ________ is just a tooth handle
Orthodontic Materials
* Wire does all the work
* Bracket is just a tooth handle
- Activation= loading/unloading,
- Deactivation= loading/unloading
loading
unloading
amount of force wire applies to tooth to get back to its original shape is called
Deactivation
- Edgewise= slot is open________________
- First-order bend=
- Second-order bend=
- Third-order bend=
- Edgewise= slot is open horizontally
- First-order bend= buccolingual position
- Second-order bend= mesiodistal angulation
- Third-order bend= buccolingual inclination
wires Increasing strength and stiffness:
Increasing strength and stiffness: NiTi < TMA < SS
Metal Brackets
* Made of
Ceramic Brackets
* _________ to fracture
* Increased/Decreased friction
Self-Ligating Brackets
* Eliminates need for __________ placement
* Increased/Decreased friction
Metal Brackets
* Made of stainless steel
Ceramic Brackets
* Prone to fracture
* Increased friction
Self-Ligating Brackets
* Built-in door locks archwire into slot
* Eliminates need for ligature placement
* Decreased friction
* More expensive
Posterior Crossbite
* Tx:
Posterior Crossbite
* Tx: palatal expansion (Quad Helix, Haas, Hyrax)
Anterior Crossbite
* One tooth (or a few teeth) -> wear, gingival strain
* Tx:
* Full underbite -> skeletal Class III
* Tx:
Severe Overjet
* Increased ________ risk
* Tx:
Anterior Crossbite
* One tooth (or a few teeth) -> wear, gingival strain
* Tx: 2x4, active retainer
* Full underbite -> skeletal Class III
* Tx: reverse pull headgear
Severe Overjet
* Increased trauma risk
* Psychosocial concern
* Tx: 2x4, headgear
generalized spacing associated with thumb sucking/tongue thrusting
tongue thrusting
thumb sucking and tongue thrusting Tx:
Tx: habit appliance like rake or blue grass
Palatal Impingement Tx:
Tx: maxillary bite plate
Impacted Teeth
– Canine not past midline of lateral—____% of chance of eruption
– Canine past midline of lateral— ______% chance of eruption
Impacted Teeth
* Kurol’s Rule
– Canine not past midline of lateral—91% of chance of eruption
– Canine past midline of lateral— 64% chance of eruption
Moderate Crowding
* ______mm crowding
* Tx:
Severe Crowding
* _______mm crowding
* Tx:
Moderate Crowding
* ≥4mm crowding
* Tx: lip bumper, LLHA
Severe Crowding
* ≥8mm crowding
* Tx: serial extraction (C-D-4)
- Headgear _______ maxillary growth
- Functional appliances ________ mandibular growth
- Reverse headgear _________ maxillary growth
- Chin cup _________ mandibular growth
- Headgear restrains maxillary growth
- Functional appliances stimulate mandibular growth
- Reverse headgear stimulates maxillary growth
- Chin cup restrains mandibular growth
High-Pull Headgear
* _________ and _________ upper molars
* Best for Class __________
High-Pull Headgear
* Intrudes and distalizes upper molars
* Best for Class II open bite
Cervical-Pull Headgear
* ___________ and __________ upper molars
* Best for Class ________________
Cervical-Pull Headgear
* Extrudes and distalizes upper molars
* Best for Class II deep bite
J-Hook Headgear
* For retraction of ___________
J-Hook Headgear
* For retraction of canines (and incisors)
Reverse-Pull Headgear
* Stimulates maxillary ____________ growth
* Other effects include ______________
* Best for Class ___________
Reverse-Pull Headgear
* Stimulates maxillary forward growth
* Other effects include protraction of upper incisors, retraction of lower incisors, and CW rotation of the mandible
* Best for Class III maxillary deficiency
Chin Cup
* Restrains mandibular ___________ growth
* Mostly ineffective in __________
* Best for Class-______________ excess
Chin Cup
* Restrains mandibular forward growth
* Mostly ineffective in humans
* Best for Class III mandibular excess
Functional appliances
provides more positive mandibular changes
Twin block
- Mostly dental tipping
- Only for mild posterior crossbite
Schwarz
Lingual Bonded Retainer uses
If more than 2mm forward repositioning of lower incisors or large diastema closure of upper incisors
Deep Bite Relapse
* Prevent ___________ of incisors
* Tx:
Deep Bite Relapse
* Prevent overeruption of incisors
* Upper modified Hawley with anterior bite plate
Open Bite Relapse
* Prevent _________ of incisors and _______ of upper molars
*Tx:
Open Bite Relapse
* Prevent intrusion of incisors and overeruption of upper molars
* Avoid oral habits
* Upper modified Hawley with posterior bite blocks
* Vacuum-formed retainers with thickened plastic over posterior occlusal surfaces provides several mm of jaw separation
Acute nasolabial angle-Extraction/non-extraction
Extraction
flat retrusive lips-Extraction/non-extraction
Non- extraction
Extraction/non-extraction
* Anterior recession or thin tissue
* Camouflage
Extraction
Supracrestal fiberotomy (SCF) is recommended for teeth that had severe _____________
Supracrestal fiberotomy (SCF) is recommended for teeth that had severe rotations
– PDL fibers reorganize in _________ months
– Gingival fibers reorganize in ___________ months
– Supracrestal fibers reorganize in __________year or more
– PDL fibers reorganize in 3-4 months
– Gingival fibers reorganize in 4-6 months
– Supracrestal fibers reorganize in 1 year or more
Envelope of Growth Modification
* Restricting Class II growth ________mm
* Restricting Class III growth ________mm
Envelope of Growth Modification
* Restricting Class II growth 5mm
* Restricting Class III growth 3mm
Post-Operative Complications
* BSSO
Post-Operative Complications
* BSSO
– Damage to IAN/paresthesia
– Condylar sag
Post-Operative Complications
General anesthesia
General anesthesia
– Alectasis= collapse of portion of lung, fever
– Pneumatosis intestinalis= air in the intestines, fever
Tanaka-Johnson= sum width of ___________ and plug into equation
– Sum/2 +________mm = space required for one maxillary buccal segment
– Sum/2 + ___________mm = space required for one mandibular buccal segment
Tanaka-Johnson= sum width of mandibular incisors and plug into equation
– Sum/2 + 11mm = space required for one maxillary buccal segment
– Sum/2 + 10.5mm = space required for one mandibular buccal segment
The ideal orthodontic wire hasHigh/low stiffness.
low
The ideal orthodontic wire hasHigh/low formability
high
Fusion of the maxillary suturesis completed around ages _____
14-16
Palatal suture fusion age_________
11-17
The use ofnonsteroidal anti-inflammatory drugs, such asibuprofen (Advil®)or acetylsalicylic acid (Aspirin®), can block prostaglandin synthesis and result infaster/slower tooth movement
slower
Cervical pull headgear is used to treat excessive ________ and needs to be worn around ____ hours a day.
Cervical pull headgear is used to treat excessive overjet and needs to be worn around 12 hours a day.
Distalizing the molars increases the ______ dimension of occlusion and _______ overbite.
Distalizing the molars increases the vertical dimension of occlusion and decreases overbite.
- Slow orthodontic extrusion is recommended in some cases for _____ placement, andshould not exceed ____mm per month.
- Slow orthodontic extrusion is recommended in some cases for implant placement, andshould not exceed 2 mm per month.
- _____________ is a material thatexhibits the highest coefficient of friction when compared to nickel titanium, stainless steel, and gold.
Beta-titanium alloy
class ______ malocclusionis associated with aflatorshallow mandibular plane angle
class III malocclusionis associated with aflatorshallow mandibular plane angle.
A _______ mandibular plane angleis associated with an anterior open bite, a long anterior facial height, and a class II malocclusion.
A steep mandibular plane angleis associated with an anterior open bite, a long anterior facial height, and a class II malocclusion.
- If a simple tipping force is applied to the crown of a tooth, the center of rotation will be ________the center of the tooth.
- near
malocclusion associated with mouth breathing
(excess overjet, posterior crossbite,
high palatal vault)
The lower lingual holding arch can be associated with an increased risk of _________molar impaction in some patients, as it can prevent the lower _________ molars from drifting mesially
The lower lingual holding arch can be associated with an increased risk of second molar impaction in some patients, as it can prevent the lower first molars from drifting mesially
The order of most commonly impacted teeth in the mouth is
mandibular third molars > maxillary third molars > maxillary canines.
What type of orthodontic movement is most likely to alter pulpal blood flow?
Intrusion
second molar is tilted backward, will result in an increased ____
open bite
If a simple tipping force is applied to the crown of a tooth, the center of rotation will be near
center of the tooth
Which of the following tooth movements requires the most force?
Torque
